By design, the smart-meter is limited in how much data it can send back. You can choose to have readings sent monthly, weekly, daily, or half-hourly. There's no option for minute-by-minute precision. That's useful from a privacy perspective - and no doubt makes the network engineering simpler - but slightly annoying from a home-monitoring perspective.

The smart-meter has the ability to send real-time information to a local device using the ZigBee network. If you have an in-home display (IHD) then you'll have seen just how accurate it is.

As I've discovered, you can't just pair any-old ZigBee device to your meter. Luckily, Octopus have sent me the "Mini". A little device which connects to the smart-meter and your home WiFi, then reports usage every 10 seconds. Let's put it through its paces.

Size

Mini by name, mini by nature!

It's rare to find a device smaller than its plug. I half-wonder if they could have integrated it and just made it into a smartplug.

Annoyingly, it is micro USB. I am a USB-C maximalist. There's no reason this device shouldn't use the same cable as everything else I own.

Installation

Plug the Mini in - ideally within 5m of your smartmeter - and wait for the blinkenlight. Follow the in-app instructions. Because, like every modern device, it needs an app. You need to install the standard Octopus Android app, and can then add the Mini to your account and to your WiFi.

Like all cheap IoT devices, it will only work on 2.4㎓, so you may need to adjust which network your phone is on.

And then…

That's it. Every 10 seconds it sends an update to Octopus. You can use the app or the website to view your current consumption or to see your last 5 minutes or last 30 minutes usage.

If you're a dab-hand with the API, you can poll that. Or you can connect it to HomeAssistant.

Downside

In theory this is nifty, but there are a few things I'm not keen on.

• Export readings simply don't work for some brands of smart meter. That's an annoyance - my meter can send half-hourly readings for export, but the Mini just shows that I'm using zero Watts.
• No local connection. It sends the data to Octopus, so I have to use their API to get the data. I'd like the ability to stream it directly from the Mini.
• USB-micro. We live in the future. USB-C or GTFO!

Honestly, a bit disappointing. If you don't have solar panels - or your meter works correctly - this could be very useful. Even so, the lack of an local API is a bit of a buzzkill. Sadly, for my purposes, it isn't very useful.

OK, an Internet connected smart plug. What's so interesting about that?

Our Windfall Plug turns on at the optimal times in the middle of the night to charge and power your devices with green energy.

Ah! Now that is interesting.

The proposition is brilliantly simple:

1. Connect the smart-plug to your WiFi.
2. Plug your bike / laptop / space heater into the smart-plug.
3. When electricity is cleanest, the smart-plug automatically switches on.

The first thing to get out of the way is, yes, you could build this yourself. If you're happy re-flashing firmware, mucking about with NodeRED, and integrating carbon intensity APIs with your HomeAssistant running on a Rasbperry Pi - then this isn't for you.

This is a plug-n-play(!) solution for people who don't want to have to manually update their software because of a DST change.

Beta

This is a beta product. It isn't yet available. Some of the things I'm reviewing will change. You can join the waitlist for more information.

Connecting

The same as every other IoT device. Connect to its local WiFi network from your phone. Tell it which network to connect to and a password. Done.

If you run into trouble, there's a handy help page.

Website

Not much too it at the moment - because it is in beta - but it lets you name the plug and control it.

Turning the plug on and off is a single click. Setting it to "Windfall Mode" turns on the magic. You can also fiddle about with a few settings.

The names and icons would be useful if you had a dozen of these. I like the fact that you can change how long the charging cycle is. 30 minutes might be enough for something low power, but something bigger may need longer.

One thing to note, you can control it by pressing a button on the unit or you can toggle its power from the website. If you manually turn it on or off you will need to manually toggle it back to Windfall mode using the website.

There's also a handy - if slightly busy - graph which shows you the upcoming carbon intensity of the UK grid.

You can also monitor the energy draw of devices connected to it. Handy to see just how much electricity and CO2 emissions a device is burning through.

That's it. For a beta product, there's a decent amount of functionality. There's nothing extraneous like Alexa integration. Ideally this is the sort of thing you configure once, and then leave behind a cupboard for years.

Is it worth it?

I think this is an extremely useful device with a few caveats.

Firstly, how much green energy are you going to use? Modern phones have pretty small batteries. Using this to charge your phone overnight is a false economy. Charging an eBike or similar is probably worthwhile. Anything with a decent-sized battery is a good candidate.

Secondly, will your devices work with it? Most things like air-conditioners or kettles don't turn on from the plug alone. Something like a space-heater is perfect for this sort of use - as soon as the switch is flicked, they start working.

Thirdly, what's the risk of only supplying power for a few hours overnight? I wouldn't recommend putting a chest-freezer on this (unless you like melted and then refrozen ice-cream). But for a device with a battery, it is probably fine.

Fourthly, it needs a stable WiFi connection. If its connection to the mothership stops, it loses Windfall mode. It can still be manually controlled - but it will need adequate signal on a reliable connection to be useful.

Finally, as with any Internet connected device, you introduce a small security risk. This doesn't need local network access, so it can sit quite happily on a guest network without spying on your other devices. But you do give up control to a 3rd party. If they got hacked, someone could turn off your plugs or rapidly power-cycle them. That may not be a significant issue, but one to bear in mind.

If you're happy with that (and I am) then I think this is simple way to take advantage of cheaper, greener electricity overnight. Devices like these use barely any electricity while in standby - so if you're on a dynamic pricing tariff, it won't cost you much to run.

Interested?

You can join the waitlist for more information.

Starting with this build, we are introducing the Power Grid Forecast API. This API empowers app developers to optimize app behavior, minimizing environmental impact by shifting background tasks to times when more renewable energy is available in the local electrical grid. Announcing Windows 11 Insider Preview Build 26052

Some computational processes take a lot of electricity. Back in the old days, batch computing meant that programmers could use "spare" CPU cycles at night. Their code ran when no-one else was using the machine. These days, it is common for computational tasks to be outsourced to where-ever electricity is least polluting. For example, shifting overnight processing to countries on the other side of the planet with excess solar power. With Windows' new APIs, they can wait until electricity is too cheap to meter before doing something computationally expensive.

Computing budgets are usually set in terms of FLOPS, Watts, or seconds. I think it is fascinating that we might soon routinely add CO₂ to that equation.

I've written before about domestic appliances being smart about their electricity use. It would be brilliant if your freezer knew to wait 10 minutes for less-polluting power before running its compressor. Similarly, you could tell a clothes dryer to be finished by the time you get home - but let it decide when to actually run.

I also wonder if a games console could drop its FPS, or outsource some of its processing to the cloud, when domestic electricity becomes too expensive.

Of course, the downside is obvious. Can your code refuse to run if it thinks it will cause harm? Is there an interpretation of the laws of robotics which prevents a machine from polluting?

I don't really think that domestic devices will refuse our requests in the near future. But I am curious what incentives - financial or otherwise - there might be to encourage more efficient resource use.

Nukes are clean! They are cheap! They are safe and healthy! They are brilliant! Nuclear power will save us all!

Look, I 100% agree that nuclear power is theoretically better than every renewable power source. Nuclear totally clean⁰! Fewer people die of nuclear radiation poisoning than fall from roofs installing solar. Governments never need to cover-up the true cost of nuclear fall-out and decontamination¹. Why can't people get it through their thick skulls that nuclear power is just so fricking cool?!

I agree! Harnessing the power of spicy rocks is a pretty nifty way of making electrons flow.

But here's my real test for nuclear power. Why can't I have a mini-nuke at home?

I'm quite serious.

On my roof I have 5kWp of solar panels which provide 100% of my electrical needs throughout the year. I also have 4.8kWh of battery storage. This technology exists. It works.

If I wanted, I could install a wind turbine. I don't think I need planning permission for that. It might not be cost effective - but plenty of people will sell me one. Again, totally feasible.

I have an incoming gas supply which I use for heat. I suppose I could buy a mini turbine to turn that into electricity. Or I could use a thermoelectric device to turn gas heat into electricity. Bit of a faff, but doable.

Similarly, I can burn wood (or coal) at home and use that for energy. I can go into the woods right now and pick up some sticks which will turn into lovely heat.

I could even buy a petrol / diesel generator and - although the fumes would be disgusting - I could make electricity that way.

Finally, if there were a river running through my property, I could install a hydroelectric generator. There isn't, so I can't. And I don't think my domestic water pressure could do more than power a few LEDs.

So where's my home-nuke kit?

Every other form of electricity generation has a version which can be reasonably installed in the home. Some of them have to be installed by a competent and qualified person. Some of them need yearly check ups. Some of them require planning permission or emissions controls. But they all provably work.

Except nuclear.

Is it because it isn't cheap enough at a smaller scale?

Would the risk of a small nuclear explosion be that much worse than the occasional gas explosions we have?

If my solar panels fell from the roof, they're fairly light but would still give you a nasty bump on the head. A fly-away wind turbine could probably kill someone nearby.

Burning wood, coal, oil, and other combustibles can create some pretty noxious pollution. Would a micro-nuclear reactor be better?

Perhaps there's an alternate future where Chernobyl and Windscale and Three-Mile Island never happened and we're all driving around with Mr Fusion reactors on our cars².

I would be perfectly comfortable living next door to a large, well-managed nuclear power station. But would you sleep soundly knowing your neighbour had a small Generation IV reactor in their basement?

In 1954, the first grid-tied nuclear power station went online. It's 70 years later and nuclear power is no closer to a domestic version. Perhaps the pro-nuclear dudes have an answer for that?

Well, not quite.

On Christmas Eve, my electricity company emailed me to say that I would have several hours of free electricity. They would charge me £0.00 per kWh. More than that, at a few specific times they would pay me for my electricity use!

Here's the graph of my half-hourly prices:

Most factories and heavy industrial plants weren't running the day before Christmas. UK power usage spikes when everyone boils a kettle at the end of a football match or other similar event - but there was nothing so momentous happening at 3AM. So supply outstripped demand.

Anyone with a smart-meter could have been paid to charge their car, run their tumble dryer, or stay up until the wee hours playing on their console.

And was it nuclear power which did this? No.

As shown on the live grid tracker about two-thirds of the day's electricity came from renewables. It was pretty overcast, and our solar panels barely made 1kWh.

It wasn't mined uranium which gave us power which literally had to be given away; about 62% of the electricity came from wind.

At this point, the nuclear lobby will start whinging about subsidies (both nukes and renewables are generously subsidised) and how wind can't provide a base load (which is fair). But although sticking a bunch of turbines in costal waters is an engineering marvel - it's pretty cheap compared to building and maintaining a nuclear power station.

Wind - and other renewables - have done what nuclear couldn't. They have provided such an abundance of electricity that consumers are paid to use it.

History and the Future

It's worth looking at the original quote from 1954 about electricity becoming too cheap to meter:

As well as nuclear, he talks about "photosynthesis". Well, the UK now has 15.6 GW of solar capacity across 1,430,994 installations. A small part of that is my solar panels!

The UK also has around 27GW of wind capcity installed.

It is entirely possible that the UK will have generated the majority of 2023's electricity from renewables.

Because home appliances are increasingly efficient, domestic energy use is falling - it's down 19% since 2010. Electricity use by domestic properties was about 96.2 TWh in 2022 and 135 TWh was generated by renewables.

Yes, electricity is fungible, but you can convincingly make the case that every home in the UK was powered by renewables.

Solar panels don't work at night, and wind-turbines don't work when there's no wind. We'll always need something to be able to provide a base-load of electricity. That might be nuclear, or fossil fuels, or it might be storage from the excess power from renewables.

Sadly, the world is still filled with war, famine, and disease. But, for a few moments on a winter's evening, wind power genuinely became too cheap to meter.

Shameless Plug

If you want to move to a time-of-day electricity tariff, you can join Octopus Energy - if you use that link, we both get £50 bill credit.

That means... GRAPHS AND STATISTICS!

Our battery was commissioned just after midday. This graph shows:

• 1630 - it was fully charged.
• 2000 - the sun had set and the battery started discharging into our home.
• 0700 the next day - the sun rose and started generating electricity, so the battery stopped discharging.
• 0900 - solar was generating more power than the house needed, so the battery started charging.
• 1400 - the battery was fully charged.
• 1830 - we started cooking dinner in the oven and the battery started discharging.

Let's see how that maps on to our energy usage. This is what a typical WFH day looks like:

To be clear, this is how much electricity I used during the 24 hour period. This graph doesn't care if the electricity came from solar, the battery, or the grid.

Our total energy mix for the day was:

The majority of our electricity use today came from yesterday's solar!

And what does that do for our electricity bills? We use Octopus Energy (join and we both get £50) who take smart-meter readings every 30 minutes. Here's the graph they provide for the electricity we bought:

It is hard to perfectly calibrate a battery to monitor the precise energy flow - but that's pretty bloody close! Ideally that would be reading 0 Watts overnight as the battery supplies the house. But I can live with that tiny trickle!

In total, we drew 433 Watts from the grid over 24 hours. That cost us £0.09! The battery saved us about £0.75 that day.

We're lucky to be on a fixed-rate tariff where the energy prices are low. If we were on a modern tariff, the UK's price cap is 30p/kWh. So we'd have paid £0.13 for the grid electricity, and saved £1.01 using the battery.

Big Graph Showing Everything

This is the view of our electricity use as seen by the battery's sensors:

The red shows what we actually used - and you can see the battery in blue discharging to match demand. The purple line shows what the grid was doing - we exported about 5.8kWh of electricity.

Finally, the yellow shows the solar being generated. As described above, the battery has a sensor to detect the current flowing through the wires. How does that match with what our inverter is reading?

They're almost an exact match!

Conclusion

Solar batteries have a large up-front cost. But they work. On a fairly wet and dreary summer day, they performed perfectly. As we move into winter, we'll switch to a dynamic electricity tariff. That will allow us to charge the battery when power is cheap and then use it when prices are high. So expect another blog post in 4 months' time describing if that has worked as expected!

But the same thing happened the next day. And our alarm system app started complaining that it couldn't reach our home network. Nor could our security camera app, heating app, and lighting app.

Bother.

At first, I thought the Internet had temporarily gone out. Our ISP's fault page showed no disruption in the area and no problems with the line.

Arse.

I checked with the local power company - and there were no cuts reported in the area. So I checked our smart meter data. Our energy company gets reports every 30 minutes from the meter. That let me see that, at some point after 0930 one morning, the power had gone out and hadn't come back.

FUCK!

The smart meter was sending back 0kWh every 30 minutes. So I was reasonably sure that the house hadn't burned down. And, after a moment of panic, felt sure that if there had been a gas explosion, ram-raid, or meteor strike, someone would have found a way to contact me. So it was probably a fuse tripping which had knocked everything out.

Wait! What about our UPS?!!?

Last year we got a small Uninterruptible Power Supply. In an act of hubris sure to tempt the wrath of Jupiter, I said "I never get power cuts". Lord, what fools these mortals be! Checking on a few of my cron jobs from a home server, the UPS kept the WiFi, Internet, and a few other bits and bobs running for a couple of hours before starving to death.

We decided not to cut our holiday short by a few days or ask a friend to pop in and, instead, waited until we got home to flip the circuit breaker. The only calamity to have befallen us was a bunch of spoiled freezer-food.

But it got me thinking about all the things which went wrong, and how I could have prevented them.

No Alerting

I have a UPS. It has a USB port. It is connected to my server. My server can communicate with my UPS. Do I make use of any of this? NO!

Conceptually, it is pretty simple.

apcaccess -p BCHARGE -u will retrieve the battery level. Run that every few minutes in cron. If it dips below 100% then send an email with the full apcaccess status output.

No alternative ISP

When I thought it was an Internet outage, I cursed myself for not adding a 4G USB dongle to my router. That would have allowed me to see whether it was the ISP or the electricity which was the issue. It would also have helped with:

No Cloud Storage for Security

As a paranoid little geek, I made sure that all my security cameras only store data on the LAN. But that means that if they had caught images of a burglar breaking in and cutting the power, I'd have no means of retrieving them.

Perhaps I need to rethink my strategy? Do I trust myself - or someone else - to configure AWS properly so that I can access images but ne'er-do-wells cannot?

WiFi Circuit Breakers?!?!!?

My house is stuffed full of dangerous IoT equipment. Why not add WiFi to the fuse board? Yup, someone makes a Wi-Fi MCB which features "Intelligent Reclosing".

If I'd had that installed, I could have been alerted that something was a problem and then tried to flip the switch.

I've no idea if they're legal to install in the UK - but Amazon sells them for about £40.

What else?

I can't stop lighting from striking our house. I have off-site backups of all our important digital stuff. But what more can I do?

I suppose I could have hired a house-sitter - but that seems more geared to watering plants than dealing with complex maintenance.

The electrics were checked a couple of years ago - I could schedule a more regular assessment.

We have solar panels and a battery - but they don't work in a powercut to prevent domestic brownouts and the risk of feeding back into the grid. It might be time to look at re-doing all our electrics so that critical components can run directly from solar?

Perhaps I should abandon all ideas of leaving the house ever again - but that doesn't seem healthy.

Electricity is such a fundamental part of life but, in the end, our house survived without it. The UK's weather is rarely extreme, and our property is well insulated. Maybe I should just learn to let go and accept living by candlelight?

WWYD?

But it doesn't need to be this way. Exposing users to the immense variability in pricing is probably too dangerous - as seen in Texas recently. Imagine if your electricity provider could say "hey, prices are going to be high tonight. We'll pay you to use less electricity!"

Well, that's what my energy provider are doing! Here's an email I received from them:

Join Octopus and we both get £50!

The UK is experimenting with flexible energy pricing. This is made possible by the large-scale rollout of smart meters. They measure electricity consumption and report it back at up-to half-hourly intervals⁰.

My solar panels already take advantage of this capability. I get paid the half-houly market-price for every kWh of sunshine I export. Octopus publish their price so, in theory, I could tell my battery to store energy at midday when it is cheaper and then sell back to the grid when it is more expensive.

Now, there's just one catch with this offer. The reduction is based on your average usage at that time. If you usually have your electric oven on between 1700-1800 then you'll be able to make some big savings. But if you're already fairly efficient, it is less likely you'll be able to take advantage of this.

The day before the experiment, this was our half-hourly usage:

So, if we were to turn off all our electricity we might be given about £1.95 as a reward. Not nothing, but perhaps not worth sitting in the dark for an hour?

But, in the spirit of experimentation, we tried it! Lights off, TV & games consoles off, chargers unplugged, no cooking or cups of tea. We made our own entertainment¹.

What we earned & what we learned

Using our home monitoring software, here's what happened to our electricity use for that hour:

As you can see, at 1700 we dropped our usage significantly. The hours before and after, we were using about 900Wh. But from 1700-1800 we were down to about 184Wh.

That's about 20% of our usual use for that hour. Our usual cost at that time of day would have been around £0.20 for the hour. Instead, we only used about 4 pence-worth of electricity.

A few days later, we got this message from our electricity provider:

OK! They base the average over the last few weeks, so it isn't surprising that their numbers differ slightly from mine.

So, how much of a reward do they pay us?

I have no idea why they do this in points. Presumably I might be able to exchange the points for a chance to win a prize? Seems silly to me; just use money.

And then, of course, the inevitable "nudge":

I'm not sure how I feel about that sort of nudge. I think we did everything we reasonably could. I'm not a big fan of that sort of competition.

Was it a hardship for us to turn out the lights for an hour? No. But there is a slightly worrying idea that people might feel pressure to turn off vital things like life-saving equipment, freezers, or alarms.

Will people change their behaviour for a couple of quid? That remains to be seen. Should people have to change their behaviour? That's a more complex question. Janet Gunter has a blog post which explores the limitations of this approach.

The idea of a personal carbon footprint has despicable origins - but when scaled up to a population level, it can be a useful way to phrase a problem.

If people merely shift their electricity consumption to an hour before or after the load shedding period, does it have a meaningful impact?

Anyway, I think it is useful to do experiments like this. Perhaps thousands of people will find it useful and it'll scale up to millions of people. Perhaps it won't make a difference at all. But the only way we can find out is by experimenting. And I'm eager to see what happens!

If you're interested in trying this, join Octopus and we both get £50!

How did the rest of you do?

WNJ85

@Will L-J

The figures are in for #OctopusEnergy #SavingSessions and am pretty happy with the outcome considering didn’t go to extremes like some! Popped the #ASHP into ‘Holiday Mode’ for the hour, delayed dinner prep till after 18:00 and didn’t plug the #BEV in to charge straight after getting home as one would normally if needed charge!

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wishy

@Steve Scott

@Edent 48% cut aparrently. Not bad for a test run without changing much

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hd

@Hermit Dave

Took part in 1st #SavingSessions by #NationalGrid & #OctopusEnergy. 83% reduction in electricity usage over an hour compared to average of previous 10 days.

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mttkng

@Matt King 🍔

Got the results of my #OctopusEnergy #savingSessions from earlier this week. I cut down usage in that hour by 89% earning a bonus of £1.43. Apparently I saved 59% more than my neighbours. Useless bunch.

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sfscotland

@S Fraser

@Edent I'd completely forgotten to check until I saw your results. I saved the equivalent of £4.61 with a 91% reduction in use during that hour.

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Energy Saving Trust

@EnergySvgTrust

A quick way to #saveenergy at home is to turn off tablets, laptops and consoles as soon as you stop using them, and ideally unplug them.

This is a big potential #energy saver and could save you up to £30 a year.

Find out more here:
ensvgtr.uk/pS1ut

#EnergyEfficiency pic.x.com/q2CWdlkaBH

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This is known as "Vampire Energy" and, amusingly, is a bit of a Zombie statistic. Being the party-pooper that I am, I emailed the Energy Saving Trust to ask how they calculated the stat. They replied quickly with:

The calculation for £35 savings from turning off stand-by devices per year per household comes from average 201KWh for stand-by power times GB average standard electricity price 16.471 £p/KWh, then rounded to nearest £5.

201KWh comes from “Further Analysis of the Household Electricity Survey Early Findings: Demand side management”.

Please note that the term “stand-by” used in this situation also include device on idle mode.

Please refer to the report in more detail about the assumptions used in the analysis. Here is the link for this report: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/275483/early_findings_revised.pdf

OK, let's take a look at the 2013 report.

First up, what disclaimers do they have?

Straight away they say that it's hard to measure low power devices - so they've been rounded up. But at least they're honest about their methodology.

So, what devices did they monitor?

I'm not sure how many people were still using VCRs back in 2013 - Dixons stopped selling them in 2004. I'd bet hardly anyone uses them now. If you still use one - please switch it off at the wall when not in use!

Set top boxes still exist - but most TVs now have digital decoders built into them. When the TV is on standby, the "STB" is also on standby. Drawing a tiny amount of electricity. But, OK, not everyone has a new TV.

What about things like Sky boxes? Well, the report mentions two issues:

Yes, you can switch these boxes off at the wall - but then they won't record the programmes that you want.

As the report was being published, Sky updated their boxes so they'd be eco-friendly. I'm told that this mode is now the default - but it may be worth checking to see if your devices have an "eco" setting. That will do more good than unplugging things.

It's not just AV equipment contributing to this "vampire" power. Computer equipment is also included:

Again, the report acknowledges that things like modems and routers don't really count as "standby" because they can be in constant use. If you want to check your TikTok in bed, you don't want to have turned off the WiFi.

Laptops have a high average "standby" because they use the first few hours charging their batteries. So, again, legitimate use rather than "vampire" use.

The report also looks at things like microwave oven clocks, tumble-dryers, dishwashers. Some of these do use a considerable amount of standby power. Although resetting the clock on the microwave every morning may not be the best start to your day.

That all feeds in to the 201kWh per year figure.

There's also some discussion about the idle power for things like doorbells, smoke alarms, burglar alarms. They have a significant power draw - but I don't think anyone would suggest that it is sensible to switch off your alarms overnight.

Remember that original Tweet?

Energy Saving Trust

@EnergySvgTrust

A quick way to #saveenergy at home is to turn off tablets, laptops and consoles as soon as you stop using them, and ideally unplug them.

This is a big potential #energy saver and could save you up to £30 a year.

Find out more here:
ensvgtr.uk/pS1ut

#EnergyEfficiency pic.x.com/q2CWdlkaBH

---

It suggests turning off tablets - which are not included in this report. Go buy a cheap Watt-meter and see how much "vampire" energy it is using. Once the battery is fully charged, it will use very little.

Similarly, laptops - even older ones - won't draw too much electricity once they've gone to sleep.

Consoles? Sony publishes stats for the PlayStation. Some of the older ones will use up to 4W in "rest" mode. That allows the device to check for updates and to power on quickly. If you switch it to low-power mode, it'll use less than a Watt.

This "advice" is bunkum.

Should you switch your devices to "eco" mode? Absolutely! Will it save you £30? Not even close.

Update - 27th April 2022

This zombie stat is doing the rounds again today. Here's a Twitter thread where I go into a bit more detail about it.

Terence Eden is on Mastodon

@edent

I looked into these claims when they were made last year.

It is mostly nonsense.

Here's what I found shkspr.mobi/blog/2021/10/n…

Sadly, the BBC don't link to the original British Gas research.
Pushing responsibility onto the consumer is, ironically, gaslighting.None

BBC News (UK)

@BBCNews

‘Vampire devices’ cost UK households £147 a year bbc.in/3xX0yOY

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My friend Paul Curry recommended the APC SMT1500i. It usually retails for around £700, but I found a refurbished one for £200

Let's put it through its paces!

It's a chunky monkey! And weighs about 25Kg. So best set it on the floor, or a really sturdy shelf. It's about the same size and shape as a PC tower - with an array of blinkenlights and buttons on the front.

It's pretty simple to use. Plug it in to the mains using the supplied kettle leads. It'll make some beeping noises and the batteries will start to charge. This causes the fans to spin. They're not overly noisy - but they turn off after 3 hours when the unit is fully charged. The unit sits passively quiet until there's a power cut.

You'll notice that on the back are eight IEC sockets. You'll need an IEC to UK plug adapter in order to connect your electronics.

And... that's it. I charged the UPS, plugged my kit in, then unplugged the UPS from the wall to simulate a power cut. It immediately started beeping, to let me know it had lost power, and its little lights started flashing. And, most importantly, all of my gadgets stayed on!

It can output 1kW for about 6 minutes - for a more modest 400W, it'll run for half an hour. So should be able to keep most gadgets going but it isn't going to run your gaming rig for several hours.

Importantly, it has serial control, so you can tell your servers to gracefully shutdown when the power goes out. Let's take a look!

Linux Usage

The RJ45 port is not, sadly, Ethernet. It's a serial port. Kinda redundant as there's a USB-B port as well. Plugging it in to a Linux machine gets you this on lsusb: 051d:0003

Although APC provide their own software, it seems a bit outdated and doesn't fully support Linux.

There's a good tutorial to get the UPS talking to Ubuntu.

Once that's done, you can monitor the battery from the command line. I wasn't able to find a way to upgrade the firmware, or do anything fancy like that. But it seems to show all the basics.

Overall, it's a great little UPS.

We installed 5kW of solar panels on our roof in 2020. Half are East-facing, half West-facing.

Over a full year, they've generated 4,165kWh.

By comparison, the average UK household uses about 3,800kWh of electricity per year.

But working out exactly how much we've used is slightly trickier. We have a smart meter which reads our import and export. And a generation meter which shows how much we've generated.

MATHS!

Our Import - that's the electricity we buy from the grid - was recorded on our smart meter:

Meter Reading on 2020-03-21 was 1,904kWh
Meter Reading on 2021-03-21 was 4,665kWh
Total Import = 2,761kWh

Our export - when we sell electricity back to the grid - was also recorded on the smart meter: 2,768kWh.

We exported exactly the same amount as we imported! We are net energy neutral!

How much did we use directly from our panels?

Generated: 4,165 kWh
Exported:  2,768 kWh

Generated - Exported = Domestic Solar Use

4,165 - 2,768 = 1,397

1.4MWh went directly from our panels into our gadgets. That's about a third of what we generate.

So, our total consumption is:

Import + Domestic = Total consumption.
2,761+1,397=4,158

Roughly, our annual electricity use is 4.1MWh. That's the same as we've generated from our roof.

Offsetting Usage

We got a 2kWh battery a few months ago. It has enough storage to charge up during a summer's day and discharge over night. Ideally, we'd have a couple of MegaWatt hours of storage to charge in summer and discharge all the way through winter. But that tech is a long way off.

We try to run things like the tumble-dryer and dishwasher during the day to make use of the green energy. The big electricity cost is our oven - it's hard to run that during the day if we want a hot meal in the evening.

Our overnight use is a fairly constant 100W - a bunch of smarthome devices and fridge/freezers doesn't take too much. Not many efficiencies to be found there. Some things just need to run continually.

Having spent a year working from home (thanks COVID!!!!) our domestic usage is significantly higher than previous years. WFH means that our computers consume lots of electricity in the day, and our TV & games consoles are powered all through the evening.

Money

In an ideal world, we'd sell electricity for the same price that we pay to import it. Sadly, that's not the case. See "Some thoughts on selling electricity back to the grid" for the details. Basically, we pay 15p/kWh to buy electricity, and we sell it back for 5.5p/kWh. When we sell electricity, the money is taken off our monthly bill.

Over the full year, we've saved about £365. Basically a quid a day. Or, to look at it another way, we've reduced our electricity bills by 60%.

It isn't the most profitable investment - but it makes me extraordinarily happy. And, if energy prices rise, we'll save even more.

What's Next?

We're currently with Octopus Energy (get £50 if you join using that link). They offer a time-of-day tariff. Prices fluctuate based on electricity demand. If we can hook our batteries up to their API, we can discharge the battery when prices are high - and potentially sell back to the grid at a more profitable time.

I blog about our solar panels a lot. But they are pretty boring. They just sit there working. The cost of installation varies depending on where you are in the world and how complicated your roof is. But our small roof generates all the electricity that we use in a year.

This isn't the future - it is now.

Sadly, last year, it died. It was prototype hardware, and these things happen. Moixa offered to replace it with an updated model - which was generous of them. While we were waiting for the new model to come in to stock, we moved house. Then COVID happened...

Anyway, long-story-short, we now have a shiny new 2kWh battery installed!

The batteries came delivered like this:

And were installed in this:

And then wired in like this:

Then given a slightly less industrial look like this:

It has many blinking lights to tell us how it is doing.

It was a bit of a chore to get installed. We had holes drilled in walls. Then we needed to get our electrics checked. Then it needed to be commissioned. Not helped by various lockdown restrictions. But we got there in the end. Moixa were superb at keeping us informed all the way through the process.

How it works

It's slightly more complex than you may think.

• Solar power is generated on our roof as DC.
• An inverter in our loft converts this to AC and pumps it into our consumer unit.
• If we are using electricity, the solar power flows into our house.
• If there is surplus solar power, it goes back to the grid. Our SMETS2 smart meter records how much we have exported.
• A clamp on the tails under the meter records the flow of electricity.
• If we are exporting, the battery sucks up the energy to store later.
• If we are importing, the battery pumps out the energy to use immediately.

Phew! Got that?

CONNECT IT TO THE INTERNET!!!!

Every single thing in my home connects to the Internet. EVERY. THING. The battery is no different. This allows for two useful things:

1. Monitoring of the battery - by myself and Moixa.
2. Adaptive charging
3. Being hacked

The monitoring function is available via a website. It shows simple diagrams like this:

You can also see more complex minute-by-minute graphs.

I'll write a later blog post about the API and how it can be used.

The adaptive charging is interesting. It can, theoretically, look up the weather forecast to work out when it is optimal to charge and discharge. Similarly, it could work with your energy provider to see when their spot rates for electricity make it worth selling.

I'm with Octopus Energy who do some interesting things with adaptive pricing.

Power Cuts

One important thing to note - home batteries do not help you if your area has a power-cut. If there was a cut, the battery might pump power back into the grid - this would be a risk for any electrician working on the grid.

Cost

The cost of battery storage is high.

• Initial install: £500
• Removal of old battery: £175
• Fitting of new battery: £450
• Compensation for original battery not working: -£200
• Cost savings from original battery: -£125

Total: £800

By comparison:

• Tesla PowerWall costs around £6,000 for 13.5 kWh
• Duracell costs around £4,500 for 3kWh

More comparisons are on the Which Guide to Solar Batteries.

Is it worth it?

In monetary terms - no. Probably not. Electricity prices are about £0.14 per kWh when purchased from the grid. So the maximum it can store is about £0.28 worth of electricity.

I can sell my surplus solar electricity at about £0.055 per kWh. So the energy I store for later use, I could have sold.

So I "lose" 5p by not selling it, but "gain" 14p by not buying it in. Call it 9p per kWh.

If the battery charged to full every day of the year, it would save us around £100 per year. So a payback period of around a decade. That improves if electricity prices rise.

But it's not (just) about the money. This is an investment in the future. I believe that distributed local energy storage will play a huge part in our future energy mix. I want to make sure that companies like Moixa have customers and that people will see the benefits of home storage.

Our solar panels produce all of the electricity that we use in a typical year. But we can't make use of all of it. Ideally, we'd have a MegaWatt battery which charged all summer long. But, for now, I'm quite happy with this little box whirring away in the corner.

Discounts!

If you buy a Moixa solar battery and mention my name, you'll get a £200 discount - and I'll receive a £200 incentive.

Score!

If you switch to Octopus Energy we both get £50!

The AS302P SMETS2 has two buttons. I've labelled the top button A and the bottom button B.

Press the A button once to bring up the menu. The display should light up. It should show "General".

Press the B button. This scrolls down the display. Press it a couple of times until it says "Registers". If you go past it, press it again and again until Registers scrolls back into view.

Press the A button to enter the Registers menu. It should show the word "Cumulative".

Press the A button to enter the Cumulative menu. It should show your "Import".

Press the B button to scroll down. This should eventually show you your "Export" in kWh.

This "Cum. Exp." figure is what you give to your energy provider when they ask for your solar export readings.

If that doesn't help, you can read the AS302P manual.

(And, yes, your energy provider should really be able to read these automatically. That's the whole frickin' point of a smart meter!)

It's a SMETS2 meter, which means it has a number of interesting features.

• ALCS (Auxiliary Load Control Switch) - this means that a car charger can be remotely started and stopped based on network demand.
• DCC connection - this means it can report back to my energy supplier every 30 minutes, and I can swap between providers quickly.
• High resolution usage - this means I can be charged on multiple time of day tariffs.

But, most importantly to me, it is Zigbee certified.

The meter offers ZigBee Communications for tunnelling information to the Comms Hub and to provide Customer Information for use with Type 1 or Type 2 Devices.

This means it can connect to a HAN (Home Area Network) using the ZigBee Smart Energy Profile (SEP) Version 1.2. This is the thing which sends data to your in-home display hub.

So, can we connect anything to the Smart Meter?

Our first stop is the Honeywell AS302P Manual. The UI of the meter is dreadful. There are two buttons:

1. A - the select button
2. B - the scroll down button

In order to go "back" in the menu, you need to scroll down to the menu item which says back and then hit A.

There's lots of info in there. I've redacted the PAN, XPAN, Network Info, and EUID for privacy:

But here's the interesting one - the ability to leave the existing network! I'm not yet brave enough to press it. First, I need to buy a Zigbee receiver and learn how the software works. Wish me luck!

My supplier - Bulb - pay me 5.38p for every kWh I export. I pay them about 13p for every kWh I import.

You notice the discrepancy? When I tweeted about this, some people got angry on my behalf. How could I stand being ripped off like this? Why couldn't I sell electricity to my neighbours at full price?

Personally, I'm quite happy with the deal. I sell the electricity at "wholesale" prices - and Bulb resell it at "retail" prices. I'm down 8p/kWh - but look at what I get in return:

• Single point of contact. I don't have to negotiate with each of my neighbours.
• Predictable prices. If another neighbour gets panels, will I have to lower my prices?
• Reduced cost. How expensive is it to buy a monitoring device, or segregate my electrical network?
• Lower chance of default. Is a large energy company more credit-worthy than a local community?
• A regulated environment. What if a neighbour disputes how much energy I've supplied?

Basically, this is the calculation that every seller makes. Trade risk for lower returns.

Would it be lovely if I could sell my organic, small batch, locally-sourced electricity directly to my neighbourhood? Sure! But the reality of me having to set up agreements with multiple parties makes it impractical.

Well, that didn't exactly turn out that way! But as our electronics have become more efficient, the cost of processing payments begins to outweigh the cost of providing electricity. How much would you pay to fully charge your smartphone? A quid? 50p? If you're desperate, a fiver?

A modern phone battery can hold about 22Wh (Watt-hours) of electricity. My domestic power provider charges about 13p per kWh (kilowatt-hour). So the energy in your phone costs less than half a penny.

If you have the latest Tesla, with the biggest battery - 100kWh I think - the total cost of electricity will be around £13. My car, the slightly more modest Soul EV, has a 30 kWh pack - less than £4 to fill from empty.

Given that most people won't be charging from 0% to 100% - and most merchants won't let you use a credit card for anything under a fiver - we can safely say that electric cars are too efficient to meter :-)

Except, that's not how the real world works. Use a litre of water at home and it'll cost you less than a penny - but buy a litre of water from a supermarket and you'll pay considerably more.

Why? Partly the infrastructure to supply you, partly the plastic bottle. Add in the advertising costs, staffing costs, insurance, and goodness knows what else - and you can see how expensive shop-bought water can be.

The same applies to supplying electricity for someone to consume. Even if you're just fitting a domestic plug socket, there's a labour cost involved, and the cost of periodic checks, and the cost of advertising that it is available. If you're supplying a rapid charger - 50kW as opposed to a domestic 7kW - there are some huge costs for equipment and supply.

For example, Electric Highway charges 30p per kWh to use their rapid chargers. But, even so, filling up from 20% to 80% is only going to cost a fiver. Once you factor in credit card fees, it's hardly worth collecting the cash. (And anyone who mentions a dodgy cryptocurrency being able to transfer funds instantly and for zero cost gets permabanned from this blog!)

So what are companies supposed to do? Broadly speaking, public car charging schemes fall into four categories.

1. Pay-as-you-go - with an inflated cost per kWh.
2. Pay-per-minute - sort-of makes sense if you're also paying for parking.
3. Pre-pay - top up your account by £X and pay per kWh from there.
4. Membership - pay £Y per month for unlimited charging.

For me, PAYG using a credit card makes the most sense. I mostly charge at home and don't regularly stop at the same charging station. I've used dozens of different charging schemes - here's a quick comparison.

Free! (ish)

I already had a standard 220V socket in my garage. My car came with a domestic charger. I plug it in when our solar panels are generating delicious free-range electricity from the sky gods.

Some public chargers are set to free vend. Usually in supermarket car parks. Electricity is a loss-leader; like cheap baked beans.

PAYG

This is the simplest method. Unfortunately, some schemes require you to pay using their app rather than just having a contactless credit card reader.

• 30p (15p if you're an Ecotricity customer) - Electric Highway
  • Uses a pretty rubbish app, but works fairly well.
• 33p - On street lamppost charging from Chargy
• 39p - Shell Recharge / Smoov
  • Tap to pay with credit card. Nothing could be easier! Read my review
• 30p + £1.80 connection fee - GeniePoint
  • prices vary depending on location and speed of charger

Pay by time.

I think this is a hangover from the cost to park usually being in time-based increments.

Pod Point have an excellent app, but a weird charging structure. Some are free, some cost 25p/kWh, some are £1 for 3 hours, and some change their cost throughout the day.

Pre-pay

A fairly annoying option - unless you always use the same charging network. I have a bunch of credit with various apps which I doubt I'll ever use again - and there's no way to reclaim.

• Polar Instant. £10 minimum top up, £1.20 connection charge. Some chargers are free, some cost £1.00 per hour, others are £6.00 for 30 minutes.
  • Verdict? Confusing, complicated, expensive. And the app is crap.

Membership

Are you a member of your local petrol station? No! The idea is ridiculous. You might collect bonus points from them, but why would you ever subscribe to them?

• £39 / month for up to 200kWh - On street lamppost charging from Chargy
• £68 / month for unlimited - On street lamppost charging from Chargy

If you have no charging at home, and can reliably use a lamppost near your home, this could be a decent service.

Worst of both worlds

Source London have a truly user hostile scheme. £4 per month, and then charging per-minute between 3.6p - 9.5p per minute - plus a surcharge in certain parts of London. Or you can pay a one off fee and the pay more per minute. Or PAYG.

Given the PAYG rates are only about 5p a minute more, you'd have to spend 80 minutes a month on charge to make it worth paying the monthly fee.

Confused? I think that's the idea!

What a mess!

Customers, mostly, don't want to interact with competitive capitalism. We aren't Homo Economicus constantly adjusting our behaviour to find the cheapest deal. We just want reasonable service at a reasonable price.

The infrastructure for charging electric cars is mostly here - but the infrastructure for charging money has a long way to go.

My car has more than enough range for me, but on a recent journey I decided it would be prudent to do a splash-and-dash - shove a few kWh in the battery just in case. I fired up Zap Map and was pleasantly surprised to see that Shell had a rapid charger near me. So, here's my review. Can a station forecourt deliver the power I need?

Location

The charger was clearly signposted and in a prominent location - no hunting around the back of the building. There was a dedicated parking space marked out as EV only, so hopefully it won't get ICE'd

The Recharge unit isn't under cover, but the petrol pumps are. Could be a bit grim in the rain.

Payment

This was perfect! I tapped my American Express card on the unit and the charge started. Proper pay-as-you-go. This is so welcome. Lots of EV chargers require an app, or a special card, or for you to prepay, or to subscribe to paid membership. Shell Recharge is EV charging as it should be - tap to pay, and pay for what you use, not the time you spend charging.

Cost

This is where things get a little tricky. The sign on the charger says 39p per kWh.

That's about 3 times what I pay at home for electricity. But, like bottled water, you're paying for convenience. According to my maths, the real fuel efficiency of an electric car is about 165MPG - so 3x electricity costs about the same as unleaded petrol.

But, there's also an app you can use. The weirdly named "Smoov" - that says the price is 25p/kWh.

I couldn't be bothered setting up the app, so I tapped with contactless.

£20 was reserved on my contactless card. It took 2 days for the final charge to come through: £1.85.

That's the 25p/kWh promised in the app. Obviously the sign is outdated.

Update! The 25p price was a promotion. The regular price is now 39p.

Interface

The interface is basically fine. A colour screen with fairly clear instructions, and push buttons to control it.

It took me a few seconds to figure it out - I doubt I would have enjoyed doing it in the rain.

Stopping the charge wasn't obvious. None of the buttons worked, and I didn't want to hit the prominent "Emergency Stop". Eventually I realised that I had to use the same payment card as I'd used to start. I waved my credit card, and the charge ended. Then I got this message:

This screen hasn't localised this for the UK; we don't use the comma as a decimal separator. I have no idea what "DTC:" means. The 78 at the bottom is current battery percentage - that's not explained anywhere. It also doesn't show the total cost.

Not a very helpful screen, it has to be said. But improvements are on the way.

Terence Eden is on Mastodon

@edent

When you end a charge there's a summary screen. @AllegoCharging haven't localised this for the UK. We don't use the comma as a decimal separator.
I have no idea what "DTC:" means.
The 78 at the bottom is current battery % - that's not explained anywhere.
It also doesn't show £. pic.x.com/esnhotBGdM

---

Allego

@AllegoCharging

@edent Hi Terence, thank you for your feedback, I will forward this to the correct department! DTC stands for Diagnostic Trouble Codes, codes that report malfunctions to the vehicle. We hope to see you back soon! 😊

---

Speed

I wanted a quick charge. Batteries usually charge fastest from empty. I got 7.5kWh in 10 minutes - that's about 45kW. Given the unit is rated at 50kW, I'm happy with that speed. Typically, a half-hour charge will take a battery from empty to 80% full, after which charging rates can slow significantly.

There wasn't much to do at the station - it's a fuel stop, not a motorway services. So we bought some sandwiches and ate them in the car. Glamorous!

Verdict

I'm impressed! Shell are still, no doubt, a morally reprehensible oil company - but they can see that the future is electric.

The price for charging is fair, if a little confusing. And the user interface needs to be localised and properly tested with users.

That said, being able to tap to pay - without any intermediary apps or subscriptions - is a welcome addition to the UK charging market.

I've switched to energy provider Bulb (£50 off if you join using that link). They offer a "peak time" electricity charge which looks like this:

• 23:00 to 07:00 = £0.0815/kWh
• 07:00 to 16:00 = £0.1235/kWh
• 16:00 to 19:00 = £0.3263/kWh
• 19:00 to 23:00 = £0.1235/kWh

By contrast, the standard tariff is £0.1359 per kWh. That means my electricity is 2.4x more expensive for 4 hours per day, during peak time. But cheaper the rest of the time.

Let's look at a typical(ish) day's usage. This is what our home monitoring says we consumed on February 28th. If we ignore the solar power and battery storage, this is the result:

• Normal tariff = £0.95/day
• Smart tariff = £1.06/day

Ooof! Considerably more expensive. We come home in the evening and start cooking and watching TV right on the peak schedule.

Solar

We have solar panels. When the sun is shining, it reduces consumption from the grid. If the amount of power generated by the panels is greater than or equal to our home's energy usage, the meter stands still and we don't get charged.

This is what happens when we sum in the solar power:

• Normal tariff = £0.68/day
• Smart tariff = £0.91/day

Yikes! Dramatically more! During the daytime, we import virtually no electricity. Even when I'm working from home, the sun provides most of our needs - so we wouldn't benefit from the cheaper day rate.

Batteries

We also have a 2kWh solar battery. When the solar panels generate more power than the house can use, the battery is charged. When we're importing electricity, the battery slowly discharges. Let's sum in that as well.

• Normal tariff = £0.60/day
• Smart tariff = £0.76/day

Quite an impressive drop. The battery tends to discharge in the early evening, after the sun has set. So usually peak time for the Bulb tariff. With a bigger battery, we'd save even more in the evening.

Based on this average(ish) day in February, you might think that the smart tariff isn't right for our set up. But that's not the whole story. Let's take a look at a few more interesting days.

Car Charging

We have an electric car. I'm using a regular 13 amp charger (3kW) - rather than the fast (7kW) charger. Here you see the car being charged to full over the weekend - right at peak time:

Solar power was also pretty pathetic those two days, and there wasn't much in the home battery.

• Normal tariff = £3.15 for two days
• Smart tariff = £2.97 for two days

Aha! Even without shifting my car charging time to be after 19:00, the smart tariff could save us money.

Very roughly, if we'd deliberately not plugged the car in until after 19:00, the cost for two days would have been £2.26!

A whopping saving of 45p per day compared to the regular tariff.

Changing behaviours

And that's kind of the point, isn't it? If we shift our energy usage a bit, we get a significant saving. Can our lifestyle cope with waiting until 19:00 to start cooking? That sounds doable.

Can we set our battery to prioritise those peak times? Moixa - the manufacturer - have said they can set the battery to be aware of tariff rates.

Do we need the car to be fully charged? Nope - telling it only to charge in the cheap hours works for us.

If we're willing to change, our power bills drop.

Big Exhaustive Data Crunching

Over 2017-2018 I recorded all of our energy usage. I used it for graphs like this:

@Edent's Home

@edent_home

pic.x.com/FLPfIpv5g0

---

Here's what happens if we compare the Bulb standard tariff with a year of data.

There are a couple of caveats. Previously we charged our car with a 7kW charger. We've purchased new electronics and appliances which are more efficient. We also have a part-time lodger. So the energy profile isn't identical - but hopefully illustrative.

• Normal tariff = £386.93
• Smart tariff = £321.83

Assuming my calculations are correct - and I've got my daylight savings time the right way round - we could save a fairly hefty sixty quid per year!

With some lifestyle tweaks the savings could be even greater.

If you'd like to take advantage of this smart tariff, switch to Bulb (we each get £50 if you join using that link).

Here's a fairly recent trip in my Renault Zoe: That's a mixture of motorways in the cold, and gentle country paths in the summer. Hopefully typical of a mixed driving style.

It takes 971kWh of electricity to move 3,500 miles. So, what's that in MPG? Let's work it out the long way.

I pay 13p/kWh for my domestic electricity.

£0.13 * 971 = £126

So the cost per mile is...

£126 / 3,500 = 3.6p/mile

Currently, UK petrol prices are about £1.30 per litre. There are 4.55 litres to the UK gallon.

(4.55 litres * £1.30) / 3.6p/mile = 165 MPG

That's a pretty good fuel efficiency!

You can calculate it another way:

Eugene Zaikonnikov🌻💛 ✊✌️

@varjag

Replying to @edent@edent You can take it from the other end. A litre of gasoline has energy density energy of 8-9KWh, then 971KWh translates to 107L. That gives abour 1.99L per 100km, or 141.95 British MPG.

---

Eugene Zaikonnikov🌻💛 ✊✌️

@varjag

Replying to @varjag@edent The 23MPG difference is then the market arbitrage between electricity and fossil fuel costs.

---

Now, this is just my car and my driving style. But the evidence is clear; electric driving is ridiculously cheap!

At the moment, if you're getting 50MPG in a petrol car, fuel costs 12p/mile.

(4.55 * £1.30) / 50 = £0.118

The best fossil-fuel cars get under 100MPG - that's still double the cost per mile of an electric car.

If you can supplement your home charging with solar, like I do, the cost per mile falls even further.

edent's Car

@edent_car

🔋 100%
🚗 76 miles
🔌 Plugged in
⚡ Not charging
⚠ Secured and Locked
#RenaultZOE

---

All these API calls can be found by using the Renault ZE Services website. I am indebted to this German blog post for kicking off this work. I'd also like to thank Renault for their "esoteric" use of JavaScript!

What's Available?

This API is fairly limited, here's what you can do with it:

• See battery status, range, charging status.
• Start preconditioning
• See preconditioning history
• See and set charging schedule.
• See charging history

Getting started

First, register with Renault ZE Services. This will give you a username and password.

Secondly, you'll need to get your VIN and API token. This can be obtained by posting the username and password to Renault. For example:

curl \
   -H "Content-Type: application/json" \
   -X POST \
   -d '{"username":"you@example.com","password":"P4ssw0rd"}' \
   https://www.services.renault-ze.com/api/user/login`

This will get you back some JSON with your API tokens. Here's an example:

{
    "token": "AAAA",
    "refresh_token": "BBBB",
    "user": {
        "id": "CCCC",
        "locale": "en_GB",
        "country": "GB",
        "timezone": "Europe/London",
        "email": "you@example.com",
        "first_name": "Terence",
        "last_name": "Eden",
        "phone_number": "+447700900123",
        "vehicle_details": {
            "timezone": "Europe/London",
            "VIN": "VVVV",
            "activation_code": "GGGG",
            "phone_number": "+447700900123"
        },
        "scopes": ["BATTERY_CHARGE_STATUS",
                   "BATTERY_CHARGE_HISTORY",
                   "BATTERY_CHARGE_REMOTE_ACTIVATION",
                   "BATTERY_CHARGE_SCHEDULING",
                   "AC_REMOTE_CONTROL",
                   "BATTERY_CHARGE_LOWALERT"],
        "active_account": "DDDD",
        "associated_vehicles": [{
            "VIN": "VVVV",
            "activation_code": "GGGG",
            "user_id": "XXXX"
        }],
        "gdc_uid": "YYYY"
    }
}

Battery Status

Let's start with the battery. We need to use your token and VIN from above.

curl \
   -H "Authorization: Bearer AAAA" \
   "https://www.services.renault-ze.com/api/vehicle/VVVV/battery"

This gets us:

{
    "charging": false,
    "plugged": true,
    "charge_level": 100,
    "remaining_range": 124.0,
    "last_update": 1476472742000,
    "charging_point": "INVALID"
}

A few point to note. The remaining_range is in Kilometres. The last_update is a Unix timestamp.

Preconditioning

The Zoe can be set to warm-up or cool down depending on the last temperate you set in the car. It will also blast the front window de-mister. The process takes five minutes, so you can set it shortly before you need to set off. Preconditioning will only work when the car's battery is above 45%.

Precondition Now

curl \
   -H "Authorization: Bearer AAAA" \
   "https://www.services.renault-ze.com/api/vehicle/VVVV/air-conditioning"

This command does not return any value. There is also no way to cancel the command remotely - you have to physically enter the car and turn it off.

Precondition Later

If you know that you want to leave at a specific time, you can set the car to precondition at a set time.

curl \
   -H "Authorization: Bearer AAAA" \
   -H 'Content-Type: application/json;charset=UTF-8' \
   --data-binary '{"start":"1753"}' \
   'https://www.services.renault-ze.com/api/vehicle/VVVV/air-conditioning/scheduler'

As far as I can tell, the start time is when you want the conditioning to start - not when you want it to be finished.

There is no way to cancel a precondition.

Preconditioning Last Status

Want to see if the preconditioning message was received by the car correctly?

curl \
   -H "Authorization: Bearer AAAA" \
   "https://www.services.renault-ze.com/api/vehicle/VVVV/air-conditioning/last"

This returns information about who or what sent the request:

{
    "date": 1476538293000,
    "type": "USER_REQUEST",
    "result": "SUCCESS"
}

Preconditioning History

You can also see how often your car has been preconditioned.

curl \
   -H "Authorization: Bearer AAAA" \
   https://www.services.renault-ze.com/api/vehicle/VVVV/air-conditioning?begin=1016&end=1016

[{
    "date": 1476165377000,
    "type": "USER_REQUEST",
    "result": "ERROR"
}, {
    "date": 1476079325000,
    "type": "CAR_NOTIFICATION",
    "result": "ERROR"
}, {
    "date": 1476079270000,
    "type": "USER_REQUEST",
    "result": "SUCCESS"
}, {
    "date": 1476079266000,
    "type": "CAR_NOTIFICATION",
    "result": "SUCCESS"
}]

Start Charging

You may have set your Zoe only to charge at specific times - perhaps to take advantage of cheap rate electricity. You can override this by issuing the charge command.

curl \
   -H "Authorization: Bearer AAAA" \
   https://www.services.renault-ze.com/api/vehicle/VVVV/charge

Again, this won't return a response. If your battery cannot be charged, you'll be notified via email or SMS depending on the preference you set up when you registered.

Charging History

curl \
   -H "Authorization: Bearer AAAA" \
   https://www.services.renault-ze.com/api/vehicle/VVVV/charge/history?begin=1016&end=1016

The begin and end take MMYY as their arguments. That is, if you want October 2016 you need to use 1016.

This returns an array, the most recent charging session at the top.

[{
    "date": 1476538527000,
    "type": "START_NOTIFICATION",
    "charging_point": "SLOW",
    "charge_level": 99,
    "remaining_autonomy": 119
}, {
    "date": 1476472727000,
    "type": "END_NOTIFICATION",
    "charging_point": "INVALID",
    "charge_level": 100,
    "remaining_autonomy": 124
}, {
    "date": 1476462129000,
    "type": "START_NOTIFICATION",
    "charging_point": "ACCELERATED",
    "charge_level": 34,
    "remaining_autonomy": 42,
    "remaining_time": 10500000
}]

The remaining_autonomy is, again, the range in Km. The remaining time is expressed in milliseconds. So 10500000 is the equivalent of 2 hours and 55 minutes.

Notifications

You can use the website to set up notifications. For example, if there is a problem with your charge, Renault will send you an SMS. This API call lets you see what notifications you have set up.

Set Notifications

curl \
   -H "Authorization: Bearer AAAA" \
   -X PUT \
   -H 'Content-Type: application/json;charset=UTF-8' \
   --data-binary '{"battery_status":"EMAIL","charge_start":"SMS","charge_end":"SMS","charge_problem":"SMS","low_battery":"SMS","low_battery_reminder":"SMS","do_not_disturb":null}' \
   'https://www.services.renault-ze.com/api/vehicle/VVVV/settings/notification'

You can change any of the options with EMAIL or SMS.

You can set a "do not disturb" option. This will suppress all notifications during specific times. Sadly, this is a fairly blunt instrument - you can only set one time which then is enforced every day.

In the above example, change "do_not_disturb":null to

"do_not_disturb":{"start":"1710","end":"1811"}}'

This will give you peace between 5:10pm and 6:11pm.

See Notifications

You can use the website to set up notifications. For example, if there is a problem with your charge, Renault will send you an SMS. This API call lets you see what notifications you have set up.

curl \
   -H "Authorization: Bearer AAAA" \
   https://www.services.renault-ze.com/api/vehicle/VVVV/settings/notification

This returns:

{
    "battery_status": "EMAIL",
    "charge_start": "NONE",
    "charge_end": "SMS",
    "charge_problem": "SMS",
    "low_battery": "SMS",
    "low_battery_reminder": "SMS",
    "do_not_disturb": null
}

Charging Times

The Zoe's charging calendar is, sadly, crap. You can say "charge between these times" but you can only have one schedule per day. So if you only want the car to charge between 0300-0700 and 1800-2200 on Mondays - you're out of luck.

It also seemed to force me to set a schedule for every day.

This is a multi-stage process.

Create a schedule

In this example, I'm setting the charging to be active on Monday from 0100 for 1 hour and 15 minutes. All other days start at different times, but last only for 15 minutes. All start times must be at 00, 15, 30, 45 minutes. All durations must be in increments of 15 minutes.

curl \
   -H 'Authorization: Bearer AAAA' \
   -X PUT \
   --data-binary '{"optimized_charge":false,"mon":{"start":"0100","duration":"0115"},"tue":{"start":"0200","duration":"0015"},"wed":{"start":"0300","duration":"0015"},"thu":{"start":"1600","duration":"0015"},"fri":{"start":"1900","duration":"0015"},"sat":{"start":"1400","duration":"0015"},"sun":{"start":"1200","duration":"0015"}}' \
   'https://www.services.renault-ze.com/api/vehicle/VVVV/charge/scheduler/offboard'

View the schedule

Let's make sure the schedule has been sent correctly

curl \
   -H 'Authorization: Bearer AAAA' \
   'https://www.services.renault-ze.com/api/vehicle/VVVV/charge/scheduler/onboard'

Returned - hopefully! - is the schedule:

{
    "enabled": false,
    "schedule": {
        "mon": {
            "start": "0100",
            "duration": "0115"
        },
        "tue": {
            "start": "0200",
            "duration": "0015"
        },
        "wed": {
            "start": "0300",
            "duration": "0015"
        },
        "thu": {
            "start": "1600",
            "duration": "0015"
        },
        "fri": {
            "start": "1900",
            "duration": "0015"
        },
        "sat": {
            "start": "1400",
            "duration": "0015"
        },
        "sun": {
            "start": "1200",
            "duration": "0015"
        }
    }
}

Deploy the schedule

Be default, the schedule isn't activated. It needs to be "deployed" in order to send it to the car.

curl \
   -H 'Authorization: Bearer AAAA' \
   -X POST \
   'https://www.services.renault-ze.com/api/vehicle/VVVV/charge/scheduler/offboard/deploy'

Deactivate the schedule

If you deactivate the schedule then the car will charge whenever it is plugged in.

curl \
   -H 'Authorization: Bearer AAAA' \
   -X PUT \
   --data-binary '{"enabled":false}' \
   'https://www.services.renault-ze.com/api/vehicle/VVVV/charge/scheduler/onboard'

That's all folks?

There are a few other API calls - mostly around registering and removing vehicles, and updating personal details. I've not detailed these because I didn't want to test them with my live account.

What's Missing?

Sadly, the Renault API is quite poor compared to BMW's API. Here's what I'd love to see:

• Vehicle status - doors locked, headlights on.
• Efficiency - last journey, total.
• Mileage.
• Physical location.

The End Result

edent's Car

@edent_car

🔋 100%
🚗 76 miles
🔌 Plugged in
⚡ Not charging
⚠ Secured and Locked
#RenaultZOE

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Further Reading

A living copy of this documentation is available on my GitHub account.