No: You are not using 100% renewable electricity

Everyone’s favourite energy company EDF recently wrote to tell me…

And by ‘changing’ they meant ‘increasing’. Roughly, the price of electricity is going up by about 10% apparently because “The wholesale cost of energy has gone up more than 50% in the last six months.”

But later in the e-mail they assured me that:

I’ll come to the asterisk in a minute, but it struck me that these two statements didn’t sit well together.

First of all, no electricity source has ‘zero’ carbon emissions: they just mean: ‘low’ carbon emissions.

Secondly, low-carbon electricity comes from either nuclear, wind, solar, biomass or hydroelectric sources, none of which have had cost increases: the increases have been mainly in the price of gas.

So one might think that EDF would be under no-obligation whatsoever to raise their prices.

Could the asterisk hold an explanation? The full asterisk text is at the end of the article but the key part is this:

All our residential tariffs are backed by 100% zero carbon nuclear electricity

Since the costs of nuclear electricity have not risen at all, one might feel further emboldened in the idea that EDF might not be obliged to raise prices after all.


Electricity doesn’t work like that

The way we supply electricity in the UK is complicated, and includes several ‘market’ elements. Here are two ‘explanatory sites’

At its simplest,

  • ‘Wholesale’ suppliers offer to supply electricity and ‘Retail’ companies buy from a variety of suppliers.
  • The ‘Wholesale’ companies try to sell as much electricity as they can, and make money from the difference between what it costs them to produce electricity and the ‘market price’ of electricity – which varies through the day.
  • The ‘Retail’ companies buy on behalf of their customers, and make money from the difference between what they pay and what they charge you.

The market structure is complex but aims to make sure that demand is met, and that there is a contingency against plant failures or surprise demand.

Some contracts are long-term – signed months or years in advance. And others are short-term signed only a few days before the required date of delivery. But if the price of electricity from gas-fired stations goes up – then because that electricity is essential to ‘keep the lights on’ – the market structure results in a general price increase.

But all the electricity which is supplied – from solar or nuclear or gas-fired plants or interconnectors – is ‘pooled’ to meet our collective national needs and supplied over The National Grid.

National Grid

The National Grid infrastructure is owned by a multinational for-profit company called National Grid plc. It’s major shareholders are banks.

Click for a larger version. These are the top 10 shareholders in National Grid plc as of June 2021 (source: StockZoa)

If EDF delivered their low-carbon electricity to you over EDF’s own wires, then it could potentially be low-carbon.

Similarly, if you use electricity generated on your own rooftop without calling on the National Grid at all, it can be genuinely low-carbon.

But if you have your ‘green’ electricity delivered over the grid, then it is pooled with electricity from all other sources and what you draw from the grid can – in my opinion – no longer be considered ‘low-carbon’.

Engineering not Accounting

Now you might think that if you paid for ‘green’ electricity to be ‘poured’ into the grid on your behalf, then using clever accounting you can consider the electricity you ‘withdrew’ from the grid to be ‘green’.

Unfortunately, although National Grid plc is run by accountants, the network itself operates on the principles of basic physics and engineering.

And the plain fact is, the grid doesn’t work without ALL the suppliers contributing. So in order to supply you with ‘your’ ‘green’ electricity, it is necessary to have gas-fired stations operating pretty much all the time.

And if those gas-fired power stations were switched off, the demand on the grid would exceed supply and the grid would shut down, and none of us would get ANY electricity.

So if the delivery of ‘your’ green electricity requires other people to have ‘grey’ electricity, then I don’t think that ‘your’ electricity should really be considered ‘green’.

And there’s more!

Although we can choose to use nominally ‘green electricity’ in our own home, we rely on electricity being used by lots of other people. For example:

  • In shops, and their supply chain, particularly for refrigerated products.
  • In factories that manufacture stuff we need.
  • On roads, to operate street light, traffic lights and speed cameras.
  • In hospitals.
  • In internet service centres.

And much more. This ‘other electricity’ which may be ‘grey’ or ‘green’ in terms of carbon-accounting, is in part ‘ours’ too, even when we personally are not using it.

This is the nature and power of the grid. Just like the electricity that flows in it, it is shared by us all.


When I am working out how much carbon dioxide I am personally responsible for, I don’t assume that my electricity is carbon free, despite being told that it is by my electricity company!

Instead I use figures from web sites such as MyGridGB or Carbon Intensity who add up the actual sources of electricity contributed to the grid and calculate the overall carbon dioxide emissions.

  • For each kWh I draw from the grid emissions are, (in 2021) about 240 gCO2 per kWh in 2021
  • For each kWh I draw from my solar panels, after accounting for their embodied carbon dioxide, 0 grams of CO2 are emitted.

Also for each kWh of solar electricity I export back to the grid, I count the CO2 that was not emitted by a gas station because of my contribution which is about 450 gCO2 per kWh.

When I am trying to convince myself that net-zero living is achievable, I subtract these emissions from my total. But I am not sure even that is fair.


The asterisk text in full

* EDF home customers get energy tariffs backed annually by zero carbon electricity as standard.

All our residential tariffs are backed by 100% zero carbon nuclear electricity, with the exception of our EV tariffs which are backed with 100% zero carbon renewable electricity.

Electricity for our GoElectric tariffs come from renewable sources such as wind, solar, biomass, tidal and hydroelectric. At the end of each fuel mix reporting year we’ll make sure we’ve purchased enough renewable electricity from EDF owned, renewable generation to match the total volume of electricity supplied to all of our customers on the GoElectric tariffs. A fuel mix reporting year begins on 1 April and ends on 31 March the following year. UK fuel mix disclosure information, published by the Government (BEIS), recognises electricity generated from wind, solar and nuclear fuel produces zero carbon dioxide emissions at the point of generation. See our tariff table for more information.

Other environmental benefits:
Other suppliers include the funding of other carbon reducing initiatives such as tree planting in the price of their tariffs. Whilst our GoElectric tariffs don’t directly fund or offer any additional environmental benefits beyond being sourced from renewable generators, EDF is Britain’s biggest generator of zero carbon electricity and as part of the EDF Group (which, in 2017, was the largest generator of renewable electricity in Europe) is committed to going beyond the requirements of 2°C trajectory set by COP21 by drastically reducing our CO2 emissions.

2 Responses to “No: You are not using 100% renewable electricity”

  1. Simon Duane Says:

    At the last moment, I stopped myself from clicking on “Post Comment”, fearing that your blog is not the place to push discussion in this direction. I’ve cut and pasted those words below, instead. Without irony – I hope you’re still keeping well, all the best! Simon

    Not to put too fine a point on it, Michael, at the heart of what is driving global heating is capitalism, with its insatiable demand for growth. Capitalism can foster mechanisms that may tend to reduce the carbon emissions that drive global heating but if, and only if, those mechanisms represent a business opportunity for someone. The trade in “renewable energy guarantees of origin”, decoupled from trade in the energy for which those guarantees are issued, lays this bare. With apologies for the pessimism.

    On Thu, 2 Sept 2021 at 19:56, Protons for Breakfast wrote:

    > protonsforbreakfast posted: “Everyone’s favourite energy company EDF > recently wrote to tell me… And by ‘changing’ they meant ‘increasing’. > Roughly, the price of electricity is going up by about 10% apparently > because “The wholesale cost of energy has gone up more than 50% in” >

    • protonsforbreakfast Says:

      Well obviously one could write a lot about this. But broadly I agree.

      The gigantic growth in coal oil and gas production AFTER it was known that they caused global warming (in say 1980) demonstrates the efficiency with which capitalism can fund profits to the wealthy while leaving the rest of the world to pick up the pieces and pay the cost of their endeavours.

      But I think it is broader than that.

      I think the shift from producing carbon dioxide is epochal for humanity. Basically, burning stuff has just been “what we do”. Wherever humans go – they burn stuff. The trick has worked well for maybe 100,000 years and changing is not going to be easy.

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