There are several services which claim to be able to detect just how lean, green, and clean your website is. But, in my opinion, they're all a bit inadequate.

WebsiteCarbon

The WebsiteCarbon.com service gives me this very pleasing report

But what does that actually mean? There's an almost content-free description of their rating system. It boils down to how large your web pages are and whether your data centre runs on green energy.

I specifically chose Krystal as my host because of their green energy credentials. So it got that right.

WebsiteCarbon seems to just be an advertising pitch for their paid-for auditing services:

You can get a comprehensive view of a website’s emissions and potential improvements by carrying out a Website Carbon Audit.

Let's try another service.

EcoGrader

EcoGrader gives me a lower score but provides a lot more detail about why.

They also give tips on how I can improve things.

Do you notice anything about those tips? They're basically the same as Core Web Vitals! A set of useful, if generic, tips to optimise your website.

Others

There are several other services which claim to measure your site's eco-credentials. But, as far as I can tell, they're all doing the same thing; reskinning Core Web Vitals or similar products.

Some, like, Blacklight are promoted on the claim that excessive tracking scripts are an environmental disaster. In the end, the message is the same - clean up your website to make it faster more efficient.

What Does This Mean?

The energy efficiency of modern codecs is often asymmetric. It might be energy intensive to encode a movie - but that's paid back a thousand-fold by having to store and stream less data and by the efficiency of the decode process at the user's end.

If you operating at planetary scale then, yes, a small saving affecting a billion users will have a huge impact. If you're optimising a single hero image on your recipe blog, probably not so much.

Much like the discredited idea that by switching off your "standby" devices you can save £££, most of these website changes are marginal at best.

Yes, we should strive for svelte and performant websites - as much for usability as for environmentalism. It makes ecological sense to choose a hosting provider who is at least somewhat responsible in their energy usage - as much for cost as for anything else.

If these websites help convince your boss that you can remove horrific amounts of JS, upgrade images to WebP, and set sensible caching policies - great! Sell them the shiny accreditation badge while you go about making the site better.

Finally, a word of caution to anyone implicitly trusting these services - there's no way to know what's going on in the background of a website. An ultra efficient looking website served from a green data-centre, might be spinning up a dozen LLMs just to churn out the page content. A slow website might be solar powered. All those ultra-compressed images might be adverts for fossil fuels.

And every time you leave a comment on my blog, I shoot a panda.

So our winter electricity bills must be massive, right?

Nope.

The normal cost per kWh is 28.5p (including VAT). We're paying less than half that - 12.4p per kWh.

This is thanks to two things - a smart tariff and a home battery.

The Octopus smart tariff charges us a variable amount throughout the day. Every 30 minutes the prices change to reflect the demands on the grid. During peak times, it can go as high as £1/kWh. That's a good incentive not to run the tumble-dryer at the same time as the rest of the country is cooking dinner!

During quieter times, the price of electricity drops - there isn't much demand at 3AM so prices fall. Sometimes they fall to zero. Other times, they fall into negative territory and we get paid to use electricity.

Now, that's all well and good, but most people don't want to shift their consumption habits. The dishwasher goes on when it is full and dinner is cooked before Coronation Street starts. That's where the battery comes in.

We have a 4.8kWh battery. It is hooked up to the Internet and knows what our energy prices are minute-to-minute. When electricity is cheap, it charges up from the grid. When electricity is expensive, it discharges into our home. If we boil the kettle at 7pm, the sensors on the battery detect that we're using expensive electricity and starts outputting stored electricity.

Essentially, we don't have to alter our lifestyle at all. Here's a typical December day. The graph is quite complicated, so let me step you through it.

The bottom graph shows how expensive it is to buy electricity throughout the day. As you can see, there is a peak in the early evening when electricity becomes expensive.

The top graph has two interesting lines on it. The purple line shows how much electricity we're drawing from the grid, the blue line shows what the battery is doing. Early in the morning electricity is cheap - you can see the purple line rising as the blue line falls. That shows the battery is charging. You will notice that it only charges at the cheapest possible times.

In the evening, you can see the purple line dip to zero and the blue line rise. That shows the battery is discharging into our home and there in no electricity being purchased from the grid. There's a similar dip at about 0830 when there's a little spike in price. Clever battery!

I want to stress that is is all automated. I don't have to do a single thing. The battery speaks directly to my electricity provider to get the half-hourly costs. The battery can predict what our usage will be, but keeps most of the electricity for the expensive times of day. Our smart meter sends our usage back to the energy company automatically.

Savings

Against a normal tariff of 28.5p/kWh, I'm paying 12.4p/kWh. That's a saving of 16.1p/kWh.

The bill above shows 320kWh per month, which means a saving of £51 from the electricity I buy. That's approximately a 55% discount.

We've had that battery since August, so about 5 months. In that time it has saved us approximately 500kWh. We only moved onto the smart tariff a few months ago, so work out the savings there is complex - but I estimate it's about £130.

December is a high use month (lots of lights on and oven cooking). During summer, the battery mostly fills up with free solar power. It is hard to predict exactly what we'll save in a year, but it should easily shave 50% off our electricity bills.

Cost

But, of course, there's no such thing as a free lunch. Our 4.8kWh battery cost about £2,700 to supply and install. That's a large chunk of change. Based on our current projections, its payback period should be about 7 years. Of course, if electricity prices rise significantly, the payback period will shorten.

Solar panels are also expensive to install - between £4,000 and £12,000 depending on your property and how complex your roof is. They mean we pay virtually nothing for electricity in spring and summer. Again, the payback period is under a decade.

We can also sell our excess solar back to the grid. In theory we could also buy cheap electricity in the morning, store it in the battery, and then sell it back at peak times. In practice it isn't worth it; the cost of buying electricity at peak is higher than the price we could sell it for. So it makes sense to use the power rather than selling it.

If you can afford the large up-front capital costs, solar + battery allows you to make massive savings with a dynamic tariff. In times of solar excess, we pay close to nothing per kWh. In winter, we shift our consumption to pay at the cheap rate.

Effectively, it's like pre-purchasing all your electricity for the next decade.

Final thoughts

There's no doubt that the cost makes this prohibitive to many people. Ideally, the state should be mandating that all new homes have solar panels and space for optional batteries. We also need V2G (Vehicle to Grid) to allow electric cars to act as home batteries.

But there's no doubt that these technologies actually work! Yes, solar works in rainy London. And, yes, even fairly small batteries can make a significant difference in winter. We're on the cusp of a domestic energy revolution. When coupled with a smart tariff, it means people don't have to change the way they behave in order to save energy.

Octopus Energy (join and we both get £50!) offered to send an engineer around for free to assess our property for suitability for an Air Source Heat Pump (ASHP).

The engineer was friendly, knowledgeable, professional, thorough, and just full of bad news!

Here's a short summary of the issues they found:

• Siting of the ASHP. It can't be in view of the road, so it needed to be in our back garden.

• Space for the ASHP. We had just about enough space on our back wall - given the existing pipe-work, doors, etc.

• Surface for the ASHP. Needs to be on concrete or similar. We have decking (which, to be fair, could be removed).

• Distance from neighbours. The ASHP makes a bit of noise - about as much as a washing machine. Regulations say that it has to be at least 8m away from a neighbour's window. Not possible in a narrow terrace.

• The ASHP runs on electricity. Quite a lot of electricity. We'd need our main fuse upgraded and new tails. Both are possible - but the space we have in our utility cupboard is already cramped. Fitting in another distribution box would be disruptive. As would laying new cables from the front of the house to the rear.

• ASHP requires a hot water tank. At least 100 litres - but probably closer to 200l. That's at least 200Kg of weight. While I think our loft could take it, their structural engineering calculations differ - and who am I to argue?

• So where would the tank go? We'd either have to lose a bunch of space in a room or remove a cupboard.

• Because ASHP run at a lower temperature than a conventional gas boiler, it was likely that our radiators would need to be upgraded to larger sizes.

• On the plus side, the ASHP would work flawlessly with our Tado smart thermostat. Which is nice.

So, there we have it. For our tall and narrow terraced house, an ASHP just isn't possible without a lot of disruption and a significant change to the installation regulations.

Next steps

We've been experimenting with Far Infrared Heating. Solid panels which directly heat the room. They're less energy efficient than a ASHP - but they provide heating pretty much instantly. They can be individually controlled, which should lower their cost. They're also plug-and-play so don't require any domestic remodelling.

We might move our gas hob to induction. That'll be quite expensive - and we don't use a lot of gas when we cook.

Hot water is the next big thing to tackle. An electric shower would work well. Using solar power to feed into the shower would work. But boiling a huge bathtub's worth of water is another matter. We either need a water tank and something like an iBoost to divert solar into an immersion heater. Or a heated tap. Or a not-yet-invented microwave boiler.

A little bit of a setback to our dreams of a more efficient house - but not the end of the world.

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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The good news is that Sam from Humm is actively working on making the Adobe Air upload application work under Linux. So, how does the process of uploading your data to the service work?

All in one

The Application is a real "one click" experience. It autodetects your SD card, sees which files are there, and sends them straight to the server after you click the button.

Here we go...

So, after waiting a few hours for the data to process - what do the graphs look like.

Monthly Electricity Usage (click for bigger)

Well, they're a little underwhelming and a bit of a mess. Now, in fairness, I've only uploaded a few weeks' of data - no doubt the graphs will be richer when I've uploaded more data. This is a beta service and it's clear that there are a lot of improvements being made.

Weekly Comparison (Click for bigger)

Annoyingly, you can't compare two different Plug Bugs - so I've no way of knowing if my computer is more energy efficient than my laptop.

There doesn't seem to be a way to go into historic data

There's no graph to show my gas usage. I've questioned the wisdom of a gas monitor - it only looks at hot water so doesn't measure cooking or hot air systems.

Overall, this is a pretty good start. I can see my hourly, weekly and monthly usage and compare how I'm doing.  It could do with some spit and polish to make the graphs more intuitive and useful.  I wonder if there's any way to get the data into Pachube or something similar.

In order to visualise the data, I have to manually upload the files to the Green Energy Options MyEnergy site.  Rather than a simple web based uploader - GEO have decided to go with Adobe Air as their platform for uploading and viewing the data.

Here are the steps I had to take to get the service working - as you will see, it wasn't easy and ultimately failed.

The site asks me to install some software in order to upload the files.  My Operating System is Ubuntu Linux - I was afraid this software would be Microsoft Windows only and I'd have to use WINE.

Let's go!

Then the site tells me I'll need to install Adobe Air.  Luckily, this can be done through the browser.

Nice and Easy?

The installation through the browser was fairly swift and painless.

Installation of Air

The installer popped up some fairly scary warning messages.  If you're going to be asking people to install your software, you need to make it as easy as possible to get.  Signing and certifying your software will reduce "error" messages like this and increase confidence in your product.  Without it, I've no way of knowing that your site isn't compromised.

DANGER, WILL ROBINSON

True to the installer's word, I ended up with an icon on my desktop.

Desktop Icon

So, I double click...

This looks hopefull...

The software has a think before popping up this helpful error message.

...DENIED!

I know what you're thinking.  "The silly sod has forgotten to plug the SD card in."  Ummm.... nope!

SD card inserted

The SD card is inserted - using the supplied reader - and my system has identified and mounted it correctly.

At this point, I'm stuck.  So I give up.

What's so frustrating is that it doesn't have to be this way.  I've no idea what the benefits are of Adobe Air - but asking your users to install something new is always problematic.  Plain old Flash - which has its fair share of problems under Linux - allows you to upload multiple files - take a look at the standard WordPress image uploader.

WordPress Multiple Select

As with everything - Keep It Simple and Stupid.  Do your users really want to install extra software for your product? Do they really need to? Is there another, simpler way which gets the same results?

I'm sure - uber-hacker that I am - that I'll figure out a way to make it work. But the point is, I shouldn't have to.

Eon were doing a special offer in their Energy Shop for a free PowerDown Plug worth about £15.  Here's the unboxing.

The Duet offers a secondary display that is attached to the Solo display and provides the monitoring of up to 6 appliances and central heating. It also provides the ability to compare the energy usage of the appliances and heating over time.

In addition to the Solo, the Duet displays:

• Current energy usage (load)
• Overall consumption today
• Environmental impact: CO₂ emissions and cost of energy used today
• Heating & hot water usage
• Energy consumption of up to 6 distinct appliances (in terms of energy, cost and CO₂ emissions)
• Remote on/off control of the 6 distinct appliances with safety and security lock options

As with the Solo device, the Duet is a user installable product and does not require professional installation.

Here are the unboxing videos