In addition to Which?’s  The Big Society initiative https://www.whichbigswitch.co.uk/ , the following is directly related to our work in coalition formation (to buy energy collectively for a group of consumer) in agentswitch. 

http://groundswell.nonprofitsoapbox.com/index.php 
that claims to have already saved $215K by buying electricity for a group of consumers (consisting of companies, organisations and communities) in the US.