Necessity is the mother of invention, they say. Sure enough with the prospect of at least six more years of power cuts, businesses, homes and offices in Nepal are all migrating to solar power in a big way.(..)Across Patan, the World Food Programme (WFP) office recently completed the first phase conversion of its entire office to solar power, even when there is electricity from the mains. "Our annual electricity bill is $20,000, and we spend $12,000 on diesel," explains WFP's Tyler McMahon. "We hope to cut the utility bills by half once the whole system is in place and will completely eliminate the diesel bill for the generator."