The world needs a new source of energy, an unspillable source.

few questions on fuel and boilers for a model steam turbine generator?

what would be the best fuel to heat up a boiler?
what would be the best fuel blocks to heat up a boiler?

what could i use to create a boiler?
(all i have at the moment is a tin can-it dosent produce enough power)
how could i maximise the power generated by the tin can? (ive already come up with making the steam outlet very small in diameter)