This site lists green tariffs that are specified by the supplier as being 100% renewables. In some cases the supplier’s fuel mix is entirely renewables, in others their fuel mix includes other sources but they guarantee to match the supply to customers on a 100% renewables tariff with electricity sourced from renewables.
You can check suppliers’ overall fuelmix in our fuel mix chart.
Because most electricity supply goes through the National Grid there is no direct linkage between the electricity customers receive and the electricity that is generated or purchased by their supplier. Unless you generate your own electricity, then you are getting electricity from the general mix of supply.
To offer a 100% renewables green tariff, suppliers need to ensure they either supply to the grid at least as much renewable electricity as their customers on these tariffs consume (either through their own generation or by way of contracts with renewable generators) or they need to purchase REGO (Renewable Energy Guarantees of Origin) certificates to an equivalent amount. REGO certificates are sold by renewable energy generators who have supplied electricity to the National Grid rather than to individual suppliers. The certificate scheme is designed to avoid double counting of electricity from renewables.
There has been increasing discussion over the use of REGO trading by suppliers in order to meet their renewables commitment, with some going as far as calling it greenwashing.
At least one electricity supplier argues that their tariff is superior to those that involve the purchase of REGO certificates. Their main argument seems to be that REGO certificates can, at least for now, be purchased very cheaply meaning that the required REGOs to cover supplying a domestic property can be under 50p a year.
This suggests to us not that the concept of matching renewable output to renewable supply through a certificate scheme is invalid but rather that the market may be flawed; the result of supply and demand where renewables generation has increased from 11% in 2012-13 to 29% in 2017-18.
Whether generation and supply is matched up through ‘vertical integration’ (where the generator and supplier are the same company), through contracts between generator and supplier, or through a certificate trading scheme, they all involve generators supplying their electricity into the general pot that is the National Grid, and renewables customers receiving electricity from that pot.
The link between generation from specific sources and supply to individual customers is inherently indirect. But it goes further than that, the quantities of Renewables electricity generated vary with time, and those variations are not matched to when a supplier’s customers use electricity.
So whatever type of 100% renewables tariff you are on you are supplied with electricity from the Brown and Green mix that’s in the grid at the time you use it. REGO certificates (be they from the supplier’s own generation, direct contracts or trading) ensure that for every unit of electricity you use a unit of renewables electricity has gone into the grid, but in none of these cases is it anything other than an accounting exercise.
To portray suppliers who have their own Renewables generation or direct contracts as truly green while those who purchase REGOs as merely greenwashing is, in our view, not looking at the whole picture.
However, with such a low price for REGOs, it can be deduced that REGO trading is providing little financial support to renewables generators. And for that reason, and in the interests of transparency, we have been looking at whether we can include information on this in our listings.
Ideally, Ofgem would be setting down requirements on suppliers to provide this sort of information to their customers and in sales material. But given that Ofgem lets suppliers away with not even meeting their existing licence requirements on publishing basic Fuel Mix information, hoping for that would be wishful thinking.
A further consideration in assessing the Green-ness of a 100% renewables tariff is where suppliers offer 100% renewables tariffs but their overall fuel mix is not 100% renewables. In some cases this can be that they are actively growing their renewables business, but in others it is simply robbing Peter to pay Paul. For every new 100% renewables customer they get, they just give less renewables to their other customers. You can see suppliers’ fuel mix trends on our sister site Electricity Info.