It turns out that the particular shade of green provided by your electricity supplier is determined by the fuel mix used to generate their electricity: the relative amounts of fossil fuel, renewable and nuclear energy.
The fuel mix is published for the main UK suppliers on electricityinfo.org, and it also tells you the amount of carbon dioxide emitted when generating each unit of electricity in kilograms of carbon dioxide per kiloWatt-hour (kgCO2/kWh).
We were supplied by Powergen (E.ON), who at 0.575 kgCO2/kWh have slid to the bottom of the table since I started looking at my options. I notice that the proportion of renewable energy used has dwindled to almost nothing in the latest figures.
My baseline was originally 0.377 kgCO2/kWh, and the goal of this exercise was to reduce this further. There are significantly better performing suppliers out there and we decided that a modest increase in the bill was acceptable.
My guiding principles.
There seem to be three main approaches used by suppliers when trying to provide a greener tariff.
- Buying carbon offsetting and environmental investment funds.
- Mixing traditional and renewable power generation to dilute the overall impact.
- Using power entirely from renewable sources: principally wind, hydro and solar.
Now the first option seems pointless to me. I’m perfectly capable of offsetting my own carbon emissions, I decided to do just that this year, and that way I can choose exactly how my offset money is spent.
The point of this exercise is to avoid offsetting and channel my money into fostering the development of renewable energy. Either of the last two options would help to achieve this goal, but clearly the latter is the most effective by excluding fossil fuels entirely.
Finally, I’m a big fan of a diverse approach to just about everything. In my experience these solutions tend to be far more robust: it might be that one type of renewable technology becomes dominant in the future, but at this point there isn’t enough operational experience to tell which one.
Assessing my options.
Most of the mainstream suppliers offer green energy tariffs, but these appear to heavily depend upon the carbon offsetting route to gain these green credentials: failed at the first hurdle.
One company taking the middle route is Ecotricity who still use a diverse range of power generation methods, including renewable and more traditional sources. As you now know, I like diversity, but unfortunately Ecotricity are entirely focused on investment in wind turbines for their renewable power.
Wind power is the focus of renewable attention in the UK, but it’s not the only game in town. I’m not convinced that I want to help fund wind power technology to the deficit of all other renewable sources. I don’t believe wind power is the answer many seem to think it is.
What remains are the top performing green alternatives, both relatively small companies: Good Energy and Green Energy. Both support a range of renewable generation technologies, both have price plans that are entirely based on renewable sources, both are committed to supporting smaller power producers, and both cost about the same.
So why did I settle on Good Energy? Two reasons really: I’d read favourable reviews of the switching process, and more importantly, their close involvement with the supply of grid attached domestic solar systems and the purchase of the subsequent excess electricity.
I suspect that this use of British roof-tops may have valuable contributions to make to meeting our power demand and energy security needs in the future, and it’s something I’m considering for another day.