> Each operator has an allowance of credits, where each unit gives the owner the right to emit one metric tonne of carbon dioxide or other equivalent greenhouse gas. Operators that have not used up their quotas can sell their unused allowances as carbon credits, while businesses that are about to exceed their quotas can buy the extra allowances as credits, privately or on the open market.
[1] https://en.wikipedia.org/wiki/Guarantee_of_origin#Production...
My understanding is that if you're producing through natural gas and someone else is producing through wind you can buy a certificate from them and then claim that your electricity is renewable.
The UK's energy mix is still 50+% gas, and I believe nuclear is not considered renewable... So there is a serious limit to what suppliers can claim is really coming from renewable sources. Especially at night.
gas is 40%, wind 16.9% solar 4% biomass 6.3% [1]
E-ON is about 13% [2] of the market share, just wind is enough to cover that and more (and 13% is assuming the grid generates energy just for customers, not industries, which it isn't)
Point is, there is enough renewable energy on the grid, it's a matter of how energy suppliers are going to fight to package it to clients. If the fight becomes hard on their end, they will be incentivised to generate more renewable.
[1] http://www.mygridgb.co.uk/last-12-months/
[2] https://www.ofgem.gov.uk/data-portal/electricity-supply-mark...
If the price is the same as the non-renewable suppliers and not all electricity is from renewable sources, then by switching to a renewable supplier all you're doing is bumping someone else onto a non-renewable supplier aren't you?
Presumably if everyone switched to a theoretical renewable-only supplier with no offset certificates now, they would have to stop making the renewable energy promise?
Eon are not the only ones coming up with such tariffs, most suppliers are jumping on the bandwagon.
What I want is the big picture, moving the needle towards more renewable. I don't want all of my electrons to come from a wind turbine, just voting with my wallet such that renewable percentage goes up and up.
With all the challenges it implies in terms of peak management, storage, seasons etc.
Advertising "100% renewable energy" means that there is enough renewable energy produced to meet demand at all times.
That's part of why I am dubious of these claims. It does not seem straightforward to guarantee this to millions of customers.
It's a bit of a flaw with the whole system really - only companies with a public brand to protect will go renewable, which is far from the economically smart way to do it.