With 8 billion people on this planet, and more coming every day, we consume significant energy. Regardless of climate considerations, our current sources of energy must be replaced before current sources are exhausted. This paper analytically examines ramifications for wind, solar and tidal energy sources, each used as the sole source of energy.
Wind is shown to have highly significant local climate implications which may not be acceptable. Air movement, being the essence of climate, is profoundly affected in a local sense. Wind turbine farm energy extraction results in slowing of air velocity in the planetary boundary layer which presents the equivalent of an “air mountain” to air movement. The “air mountains” can result in nearby excessive precipitation and more distant drought conditions.
Solar cells, while probably the best choice, still have significant negatives with respect to atmospheric heating. Solar cells become physically hot, and as thin inclined solar heated planes they transfer quantities of excess solar energy directly to the atmosphere rather than storing it temporarily in the ground.
Analysis based on conservation of Earth and Moon angular momentum shows that tidal energy extraction has long term implications with respect to lunar displacement. Current annual lunar orbit radius increase (due to natural tidal energy dissipation) of about 4 cm/year would increase to about 24 cm/year if tidal energy were our only source. The lunar orbit increase is accompanied by slowing of Earth rotation rate, eventually leading to the Earth virtually stopping albeit over billions of years. Otherwise, tidal would be a good energy source except oceans are so far from almost every place. This requires extensive distribution system investment. Be aware that tidal effects include effects on air movement as well as oceans.
Each of the investigated sources is not steady, so energy must be stored on a daily basis. Significant world-wide energy storage in batteries is probably impractical due to limited materials availability. The most efficient practical storage concept is pumped hydraulic (water tower) storage, but not all locations can provide large lakes. So, it is suggested that large arrays of strategically located thermal storage facilities could be the answer. Excess electrical energy generated during the selected intermittent energy source active times could be used as the thermal storage facility heating. It would seem practical to use subterranean electrically heated high temperature storage of thermal energy with daily conversion back to electrical energy via gas turbine/generator loops (perhaps using CO2 as the working fluid). Use of high temperature in the storage facilities improves Carnot efficiency and making them subterranean minimizes heat loss to the atmosphere and fire hazards.
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