At 16:35 14 May 2013, wrote:

It strikes me the right answer for sailplanes is a front electric
sustainer=
powered by a very small battery and fuel cell.=20

I like your thinking John. Fuel cells also produce water (useful for
hydration) and heat (useful for socks). If you choose a direct ethanol
version you would also have a ready supply of hooch for when you eventually
land out and need a drink!

Jim