While December saw Maine’s Public Utilities Commission considering policy proposals aimed at increasing the state’s solar power generation and negotiators at the Paris climate change summit reaching agreement on international goals to limit man-made greenhouse gas emissions by 2030,  researchers, companies and governments are already devising and putting into practice commercially viable solutions which promise to do both.

A recent book, titled “The Burning Answer,” by Keith Barnham (available at the local library) provides fascinating insights into this rapidly developing “solar revolution.”

Barnham, emeritus professor of physics at London’s Imperial College (Britain’s equivalent of MIT and CalTech), spent the first half his career working in experimental particle physics and the last half researching solar power. Along the way, he invented a solar cell with three times the efficiency of today’s roof-top panels.

In Barnham’s view, the scientific, technological and industrial world took an unfortunate detour from the path of solar power generation in the 20th century after Albert Einstein published a series of 1905 research papers which revolutionized physics. It wasn’t until the end of the century that the world began to return to that path.

One of Einstein’s 1905 papers contained the famous E=mc2 equation, which predicted that a small amount of matter could be converted into an enormous amount of energy. The atomic nucleus was the focus of the physics community for much of the 20th century, as scientists worked on splitting and fusing the nuclei of atoms to convert matter into energy for war and peacetime purposes.

Nuclear energy, however, proved a mixed blessing at best. Its frightening destructive power became apparent at Hiroshima and Nagasaki. Its peacetime promise, once bright, has been dimmed by disastrous accidents at Three Mile Island, Chernobyl and Fukushima, as well as by the huge expense of building and maintaining reactors and the seemingly insoluble problem of nuclear waste disposal.

Another equally portentous 1905 paper by Einstein about the photoelectric effect never captured the public’s imagination as E=mc2 did. In it, Einstein suggested that electromagnetic waves, which include visible light, behave as tiny moving particles or billiard balls. These particle-like waves, known as photons, are, in effect, packets of energy. The higher the wave’s frequency, the higher its energy. A high-frequency wave hitting the surface of certain metals dislodges electrons, and the freed electrons can be channeled as electricity to perform work. This effect is described by the formula E=hf. (“E” stands for energy, “f” for frequency and “h” for a fixed number known as “Planck’s constant”).

Until recently, the most important practical application of E=hf has been in semiconductors (mostly purified silicon chips) for communications and computers. Because of their atomic structure, semiconductors can serve as both electrical conductors (like metals) and insulators (like nonmetals). This technology has given rise to the “semiconductor revolution.” Our world of mobile smart phones, computer games, social networks and online shopping would be impossible without it.

However, photons from the sun can also be used to push electrons through a semiconductor to generate power. The earth is bathed each day by trillions upon trillions of photons from the sun’s electromagnetic radiation, so it’s a vast natural source of power for the taking, provided it’s efficiently harnessed. That’s the basis for the solar revolution.

At the end of the 20th century, the governments of Germany and Japan decided to accelerate solar power use by supporting solar research and putting in place incentives to switch to solar. This triggered growing demand, innovation, mass production and falling prices. The fall in prices was temporarily slowed from 2004 to 2009 due to a shortage of purified silicon, but it resumed again in 2010, thanks to a technological breakthrough in the manufacture of thin-film semiconductors made of materials other than silicon. By now, there are third-generation solar cells three times as efficient as their predecessors.

Barnham’s book discusses, in detail, effective technologies in solar production, collection and storage already in use, debunking many myths about solar power;  for instance, that it can’t be generated when the sun isn’t shining, is too intermittent to substantially contribute to the total electricity supply without adequate battery storage capacity, and is expensive in comparison to fossil fuels and nuclear power.

Barnham points out that when the sun isn’t shining, the wind is usually blowing somewhere, and wind is a form of solar energy. That’s because the sun’s photons heat the earth, which, by convection, heats the atmosphere, causing hot air to rise and cold air to be drawn in from colder areas to replace it. This, together with the earth’s rotational motion, causes winds to circulate between hot and cold regions, and wind, of course, can turn turbines to produce electricity. Thus, solar and wind can be used in tandem.

In addition, actual experience with the real-time output of solar, wind, and biogas electricity generation in Germany’s electrical grid has shown that electrical power supply from a combination of such renewables can match demand throughout the year.

Excess solar power that’s generated when the sun shines can be stored for later use without resorting to batteries. For example, it can be returned to the grid, heat water in a tank, or pump water uphill to raise the level of a hydroelectric dam.

Finally, Barnham dispels the most persistent myth, that solar power is not price competitive, by reviewing the successful experience of Germany and other countries.

In a landmark event in June 2011, the wholesale price of electrical power supplied to the German national grid at peak demand time (when the cost of electricity is highest) was lower than any other type of electricity fed into the grid. The price drop was due to the quadrupling of the amount of solar power connected to the German grid more in the four-year period prior to June 2011. This, in turn, was due to the German “feed-in-tariff” policy, which created a guaranteed price paid for solar electric energy fed into the grid and established in advance a gradual phase-out schedule for that guarantee. The policy encouraged corporate and community investment in solar installations to expand at an exponential rate.

Based on its track record to date, Germany has set 2050 as a target for converting to a 100-percent renewable electricity supply. If solar can be so successful in a northern clime, just imagine what it can achieve in sun-rich countries closer to the equator.

The “Burning Answer” is an intelligent manifesto for the solar revolution. Maine, which had 11 megawatts of installed solar capacity as of the end of 2014, the lowest of any New England state, should take it to heart.

Elliott L. Epstein, a local attorney, is the founder of Museum L-A and author of “Lucifer’s Child,” a book about the notorious 1984 child murder of Angela Palmer. He may be reached at [email protected].