In Britain the government has created a market in energy, where the customer has a choice who they purchase electricity & gas from. It is a scam really but still better to play market than ignore it. Basically you will most likely pay less if you switch from existing supplier as well as often getting better level of service. Also you have option to choose to choose a contract that ensures more of money you pay goes to environmentally friendly generation of electricity. But it seems now the amount of renewable energy produced will be determined more by enforced government targets than green consumer demand.
Before changing utility supplier check out what Martin Lewis has to say at Money Saving Expert.
There are various price comparison sites
One can now buy energy from our previous landlord People for Places (Castle Rock Edinvar).
Green Star Energy have large renewable mix.
Cooperative Energy is a coop.
An environmentally friendly company called Good Energy (spotted when it was previously Unit-E) is used by local project I was involved with, which actually saves allot of money as they were on unsuitable tariff with old supplier. But I think for most home users they won't save much over even the expensive previous monopoly supplier.
I actual signed up myself for temp period as they had a 30 quid intro offer via flyer enclosed with my credit card bill. But I had to chase them up over this, which maybe overall with there higher prices made it not worth while.
Another electricity company that is investing in new renewable supply is Ecotricity which I switched to but they made a mistake mixing up night and day readings and did not send me a new bill quick enough before I got fed up and switch to Ebico.
If you use a low amount or use a pre-payment meter then check out EBIco which with pre-payment meters can be cheapest option. It reinvests all it money in lower prices and the saving from those using of direct debit are spread over all customers. Scottish and Southern who own Scottish Hydro brand do billing and customer service for Ebico, and they got bills right first time for me. They probably don't make sense if high usage like mine when then I had just electric heating.
Several years back I have previously signed up with Powergen (now called EON) for their green option which has undergone several reincarnations now over the years, as they had a free light bulb and money back deal when I signed up.
A friend had a long drawn out incorrect billing experience with them.
After Powergen I switched to Scottish Hydro to save money.
They have 'green' options but my budget was so tight that any spare money went elsewhere rather than choosing a green option.
After switching to some other suppliers including some that were greener and some that were cheaper but Scottish Hydro were only ones had a good customer service experience matching the low level complaints they get; they seem to be only company that produced a correct bill by not mixing up readings or getting address wrong. And good customer service is vital if you are not to waste lots of time having to deal with energy company. Looking back over past bills from many companies on some very unclear as to dates reading were from. This has improved in recent years especially with OFGEM new rules on providing more information on bills. But lots of improvements could be had in this area, especially with giving annual day/night split.
Friends Of the Earth did a report on the supply companies: https://www.foe.org.uk/... Another source of info is http://www.greenelectricity.org/
An interesting look at effect of choosing green tariff was produced by ethical consumer.
It took a while for companies to start marketing their green options much. At start they offered them just for show and seems they don't really want people to take them up. The government can wash it's hands of problem and say look it is up to customer to choose. But as time went on an climate change has gone up agenda they are using them in marketing more, but now with harder government targets I think even less reason for customer to choose them. The market does not deliver, but my view is better to play it for best deal while it exists than not.
I have had long history of mis billing with many suppliers, that often took a long time to sort out. Do keep all communications from your energy provider and records to help if you need to complain. Complaints can be made with help of local trading standards. Consumer Focus who provide energy price comparison information.
If you don't have gas and wish to get a quote for a new connection then who you contact depends on area you live in if in the North of England it maybe Northern Gas Networks, for elsewhere see list of Gas Transporters (and Utility Infrastructure Providers) via OFGEM's website
This book is full of interesting figures. I found what it presented about heat pumps of much interest.
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