premise: The giant wind turbines on the nearby hill supply the community with 8 million kilowatt hours of electricity each year. Several hundred homeowners have erected solar panels on their roofs to provide most of their summer-time hot water needs. Bio-waste is collected for fermentation to produce methane gas which drives a local generator to augment the towns electricity needs when there is insufficient wind to fully power the turbines. Better insulation has cut the fuel requirements of many homes. Local generation in this isolated, rural community has led to saving on the investment cost of additional transmission lines in the national network. Further efficiencies are gained because the local production of power avoids losses to electrical resistance in the long-distance transmission of power.
hypothesis: When the wind is blowing and the sun is shining, locally generated power accounts for most of this community's energy needs.