In “Solving the World’s Energy Problem, Part 1,” I have argued that fossil fuels are essentially fossilized energy from the sun. Since fossil fuels take millions of years to create and their supply is finite, at some future time our fossil fuels resources will be exhausted (or the limited supply of fossil fuel that remains will become so hard to find and so expensive to recover that its use will become prohibitively costly). I further proposed that biofuels are a suitable substitute for fossil fuels, but our ability to produce biofuels will never be sufficient to replace the enormous amount of fossil fuels that the world is consuming.
Therefore, the world will need alternative renewable energy technologies. Without prejudging exactly what those new energy technologies will be, I believe the best types of alternative energy technologies will be those that allow us to capture and use more energy from the sun. In this way the world would have a sustainable energy supply for as long as the sun is shining.
What might some of those renewable energy technologies be? Based on what can be envisioned now, I can think of three technologies that are nearing the stage where wide commercialization will be possible, and a fourth technology that, with appropriate scientific advances, offers potential in the next decade.
The first is capturing and concentrating sunlight to produce energy in the form of heat. A large project has already been proposed for the California desert to produce electricity by concentrating sunlight using mirrors to heat water to produce steam, which can turn turbines to produce electricity. For regions in the world with plentiful and relatively predictable sunshine, this is a viable way to produce energy.
The second technology is capturing energy from sunlight as photovoltaic energy. Photovoltaic solar energy is currently in use, but only in a small way due to its higher cost relative to electricity produced from fossil fuels. But I do not expect this unfavorable cost to always exist. Research and development into improved photovoltaic materials and methods are ongoing all over the world, and improvements over the current technology are inevitable. The cost of electricity generated from photovoltaic systems will come down and solar panel arrays to produce electricity will become more widespread.
The third technology is wind energy. The energy in wind is a form of solar energy, since the sun heats air, causing it to rise, thus changing air pressure, which is what makes the air move, creating wind. Many parts of the world are able to create useful amounts of electricity from the turning of turbines by wind. In the USA, regions as different as the plains of Texas, the coastal regions of New England, and mountains and coastlines of Alaska are already putting farms of wind turbines in place to generate electricity. Once integrated with the electrical grid, wind energy can become an important part of the solution to the coming energy problem.
The fourth technology is not yet at a point that can be exploited, but in time I believe this will change. This technology is storage of solar energy in what I will call “batteries.” The biggest problem faced in using energy from the sun in real time is that the world undergoes periods of darkness. At night, there is no supply of energy from the sun. But if efficient, cost-effective storage technologies could be developed, energy could be captured and stored during the daylight hours for use at night. Intensive research on suitable storage devices is ongoing, and the world needs a scientific breakthrough to enable efficient storage of energy from the sun to become a reality. But I have confidence those breakthroughs will occur.
In Part 3, I will discuss a couple of other energy sources that are relatively untapped today but could help make up the energy gap in the future.