Just about anything that burns or will turn a wheel is the answer to that question.
Around the early '90s there was a brief surge of newspaper interest in generating power from chicken manure but public interest soon waned. But here it is, and owned by an Australian company that is focussing on transforming animal waste derived fuels (AWDF), as well as straw. The ideas have been around a long time, so one can't call it innovative but they made it work and hopefully at a profit. Good one.
The only other innovative one is the burning of part of London's waste at a power station owned by a joint UK and French company.
The rest of the power sources are conventional: nuclear, coal, gas, hydro and wind.
As one would expect, the two big electricity producers FRG (20,510 MW) and France 19259 MW) are obtaining the bulk of their supply from nuclear (France) and hydrocarbons (FRG). The UK (18,262) has a very mixed bag of supply from gas, coal, wind and hydro.
[Sorry about the fuzzy table outline. I used jpeg, because I haven't yet learnt how to create a nice table in HTML].
Coming up: How much power is generated from each energy source?