Checkout JSEcoin from their website...
"It is mined using surplus CPU resources which would be otherwise wasted. Browser mining has a huge environmental and cost advantage over existing cryptocurrency networks. There is an opportunity to make a real difference with web based cryptocurrency mining. "
Referred link
https://jsecoin.com/?utm_source=referral&utm_campaign=aff270&utm_content=
RE: Bitcoin Mining is Gobbling Up the World's Power