Among the renewable forms of energy solar is the most universal. Wind and geothermal forms of energy generation can quite usefulbut nit in all locations whereas the Sun is everywhere. Hydrogen is clean, but a chemical fuel and expensive to generate. Yet hydrogen production can be generated more cheaply when we have less expensive solar power generation, and when the price is right hydrogen may be useful in automobiles and in fuel cells which also will need to be improved and made more cost efficient even when the cost of solar energy generation declines.
The costs of solar energy generation have been improving and that will continue as we go forward. Indeed it has been suggested that we move forward with solar with the idea of making key improvements as we move along. Even with only modest improvements we may still be able to have a major national solar grid and distribution system within 20 years at a cost that would be near that of about 10 percent of the current farm subsidy over that time. Thus, by 2035-2040 the electrical grid could likely progress until it is 90-95 percent based on solar energy.
We have several options. We can build the entire system based on solar-thermal and photovoltaic arrays in about 10 percent of the available government land in the desert southwest and simultaneously build a new nationwide distribution system to distribute the energy generated across the country or we can continue to change the way we build homes and larger buildings to facilitate the integration of solar power generating systems within them. That is, we will generate the power where it is needed. That simplifies the power distribution problems to an extent.
Power generated where it is needed at least for some of the system makes a lot of sense. When in excess the power can be sold back to the power company which may then redistribute it where needed. Eventually we can generate all the power we need in many areas and we can begin taking both coal plants and nuclear plants off line. Coal ash and by-products from nuclear power generation will destroy the environment completely and kill many of us in an untimely way unless we begin a clean up no and stop generation of the toxic by-products of these forms of energy generation. Indeed, if the enormous cost of cleaning up an environment vastly more polluted by radioactive nuclear by-products and toxic coal ash than most people realize then the costs of solar become more competitive than they are presently counted.
In the long run we can mount solar arrays in space where the sun is available 24/7 and guide arrays directly toward the sun on a continuous basis. These space systems would convert the sun’s power into electrical energy that could be sent back to Earth or the Moon on microwave beams. The energy sent to the Moon would be helpful in its colonization. We’ve been working on this strategy since the early 1970s and while many more improvements remain to be made, this form of solar energy generation is perhaps the most important in the long run. The problem with space based systems is that they will be susceptible to both solar radiation and micrometeorite damage. These issues remains to be solved.