Energy

We have these major sources of energy available to us, in no particular order and not including fossil fuels that we currently rely on for the majority of our energy today:

• Solar: photovoltaic, solar thermal, solar chimney. Prospective: stratospheric solar array and solar power satellite
• Wind: land-based wind turbine, off-shore wind turbine. Prospective: jet-stream sky windmills
• Ocean: wave, tidal, ocean currents
• Hydro-electric
• Nuclear: nuclear fission. Prospective: nuclear fusion and accelerator-driven thorium-fuelled energy amplifier
• Geothermal: shallow geothermal heat pumps, volcanic related geothermal, deep geothermal
• Biomass: vegetable oil, compost methane, fermented crop waste, algae, sustainable wood, and clean burning of organic waste, animal dung and rubbish

Energy availability from solar and geothermal alone far exceed our current and likely future energy requirements and could sustain humanity indefinitely. Also steadily increasing energy efficiency, due to improved machine design and increasing cultural awareness should become a significant factor in our energy use.