environment – Terence Eden’s Blog

Can you meaningfully measure how environmentally friendly a website is?

@edent — Mon, 19 May 2025 11:34:26 +0000

Think global; act local. That's the mantra, right? I can't stop coal plants belching out suffocating pollutants, but can I ensure my website is as environmentally friendly as possible?

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.

Electricity That's Too Cheap To Meter

@edent — Mon, 25 Dec 2023 12:34:59 +0000

Nuclear power was sold to the world as a safe, clean, and economically viable source of electricity. We were told that it would be "too cheap to meter"⁰. Even the most ardent proponent of nuclear power will have to admit that hasn't come to pass. Construction costs for nuclear power stations are dwarfed only by their decommissioning costs. Yes, politics and regulation conspire to increase the price - but nuclear hasn't made electricity particularly cheap. Indeed, we mostly seem to be paying more than ever for our power.

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.

There is a lot of contention about that phrase. It was (probably) about the future prospects of nuclear fusion - but it became attached to nuclear fission. You can read more at the United States Nuclear Regulatory Commission ↩︎

Walking Under The Thames

@edent — Wed, 12 Nov 2014 13:05:37 +0000

Earlier this year, I won the BlueLightCamp Hackathon. Usually prizes are a token of appreciation - vouchers, a books, maybe even a new phone if you're lucky. This, however, was a "money can't buy" prize - a trip through the Thames Barrier.

And so, during one of London's delightfully wet summer's days, I made my way to the site in Greenwich.

Here are some of the photos I took during the trip.

The first thing to note is that the site is an active industrial area - it's not a museum. There are people working every day to keep London safe.

I expected the barriers themselves to be solid lumps - ready to repel the advancing tide.

The size and scale of the machinery is immense.

Being under that much water means that there is the occasional ingress of liquid.

The whole area can get quite damp - which means that pipes often rust and need replacing.

Security on the area is very tight. It's impossible to get in without going through a number of locked gates. The last thing they want is some idiot randomly pressing buttons...

The tunnels underneath the Thames have stairwells leading onto each platform.

I had expected that the barriers would be constructed purely of man-made materials. That is not the case.

Each pier is fully equipped with a wide range of machinery.

The tunnels themselves are dark, dank, and a little creepy. They trail off into the distance in a perfectly straight line. They are silent except for the faint drip of water and the buzz of the lights.

At times, when walking through, it feels like the tunnel goes on forever.

Finally, it's worth taking a moment not only to marvel at this engineering wonder - but to remember the devastating forces of nature which lead to its creation.

Many thanks to the Environment Agency for their generous prize and for letting us experience a hidden part of London.

Making Hay While The Sun Shines

@edent — Fri, 29 Jun 2012 11:00:10 +0000

One of the perils of being a reluctant capitalist is the cognitive dissonance. Normally, on a sunny day, I look outside and smile. Blue skies, warmth, chance for an ice cream, people smiling, lovely.

Yesterday, I saw the sun was shining, I rubbed my hands together and let out an Mr Burns-esque chuckle of delight. Last November, we installed solar panels on our roof. The Government ensures that if you generate electricity, you get paid for it. There's also a payment for surplus energy you sell back to the grid. Of course, electricity bills are also reduced.

After 6 months of waiting for E.on to pull their finger out, we finally received our first payment.

£520.90

Five hundred quid! Tax free! That's for the 6 months between November and May - traditionally not the sunniest part of the year!

We used both the Energy Saving Trust Solar Power calculator and the Europa Solar Calculator to estimate a generation capacity of between 2,500 and 2,700 kWh per year.

In the last 6 months, we've generate around 1,120 kW of electricity - almost exactly on target!

Of course, there's a moral component to this. Every kWh of energy generated from the sun means one less kWh generated by burning coal or oil. There's no nuclear waste to clear up after my solar panels reach the end of their life. The people living in the house have more money to spend or save.

I keep having to remind myself that this is an investment. In approximately 10 years the cost of the panels will be repaid. The FIT is guaranteed for 25 years (rising with inflation). So I have a decade to wait before I'm truly extracting cash from cucumbers, but it's a promising start!

Solar Panels and FIT

@edent — Fri, 18 Nov 2011 11:26:58 +0000

As I mentioned in my last post, we've just had solar panels installed!

Because of Greg Barker MP's idiotic decision to scrap the Feed In Tariff with only six weeks' notice - we've had to get this done in rather a rush.

Thanks to Angi and Philip at Sunny Future Solar, we were able to get our system installed before the deadline. Yesterday, we received confirmation that panels were installed and working and had generated their first 15W of electricity!

Total cost of installation: £12,000. Ouch!

How Making Money From Solar Works

Once solar panels are installed, there are three main income streams.

Reduced electricity bills - when the sun is shining, your toaster and computer are powered by Earth's yellow sun.
Any electricity you generate but don't use is sold back to the grid* at 3p / kW.
For every kW the panels generate, you are paid 43.3p.

*Rather than actually measuring this, it's assumed that you only use half the electricity generated.

All the prices are index linked (so they should rise with inflation) and guaranteed for 25 years. Any money generated is tax-free.

The Economic Reality

There are two main sites which will tell you how much energy you are likely to generate over the year. The calculations are based on where the property is, which direction it faces, inclination of the roof, etc. The Energy Saving Trust Solar Power calculator estimated around 2,500 kWh per year The Europa Solar Calculator estimated around 2,700 kWh per year.

Even at the lower estimate, that's ~£1,100 per year from generating the electricity - and a further ~£40 from selling electricity back.

We're in a slightly unusual situation in that we've installed the panels on our rental property. So our tenants will be getting the benefit of reduced electricity bills.

At the moment, that's only around one hundred pounds per year. But if there's another energy crisis, the amount saved would be higher.

So as greedy landlords, could we charge a premium for a property with cheap electricity bills? Say.... ooooh... £50 per month? Well, probably not that much - and we try not to be evil bastard landlords. Especially as we've been on the receiving end of scummy landlords in the past.

The idea is that the property is more attractive and so isn't left vacant for so long between tenants.

Even if we were making a full £1,200 (tax free) from these solar panels, is that an unreasonable subsidy as the government claim? Let's do the maths.

Total earnings (excluding money saved on bills) = £1,140. The solar panels are meant to degrade by a maximum of 1% each year. Assuming they do so, that's a total of £25,000 after 25 years.

So, 25k on an investment of 12k. That's pretty good, right?

No. Not really. That's about a 3% rate of interest. Even if we were really lucky with the weather and the panels didn't degrade, we'd be looking at a return of 30k - which works out as a 4% interest rate.

Hardly the deal of the century! To give you a comparison, the government predicts a 7% interest rate if you stick your money in a pension.

Now, it is guaranteed - assuming the government doesn't renege on its promises and we don't enter a period of nuclear winter - and it is tax free, but is it really a generous subsidy which needs trimming?

And, even if it is; how can giving just 6 weeks' notice be remotely fair?

A Better Way of Subsidising Solar

Barker has announced huge cuts to the solar subsidy. Whereas before the cut, the FIT would have paid off the capital cost of the panels in 10 year, after the cut, it will be more like 20 years. And that's assuming you haven't taken a loan out to pay for the panels.

Personally, I don't understand why the government doesn't just pay for the damned things themselves. It seems bureaucratically perverse to agree to pay a subsidy, via energy providers, to people who have paid installers, who have purchased the panels.

Surely just simpler to buy the panels and give them to anyone willing to pay for installation. That way there would be vastly less paperwork, no worrying about how to keep track of who needs to be paid what, etc.

Even if you ignore the environmental impact, energy security is one of this countries most pressing problems. We cannot depend on volatile foreign sources of energy.

Surely finding a sane and simple way to subsidise should be one of this government's priorities?

Recycling The FreshCase

@edent — Sat, 28 Nov 2009 07:00:24 +0000

Earlier this month, the lovely people at FreshCase sent me some boxes of wine.

Alex Hilton wanted to know how easy it was to recycle. So, for your edification and delight, I present...

Recycling The FreshCase

Disclaimer

These boxes of wine were sent to me for free. Enjoy alcohol responsibly. Do not attempt without adult supervision.