Warenkorb

Sunpower

by Denis Hayes
Heart of Winter 2005

In 1952 the Truman administration issued Resources for Freedom, ii an assessment of America’s fuel and material needs. Noting that “efforts made to date to harness solar energy [have been] infinitesimal,” the report found that an aggressive solar program “could make an immense contribution to the welfare of the free world.” Resources for Freedom urged that the United States build 13 million solar-heated homes by the mid-1970s.

In 1980 the Carter administration produced A New Prosperityiii, a collaborative effort by several national laboratories and leading universities. In elaborate detail, this volume described technologies and policies that would dramatically increase America’s overall energy efficiency and permit the nation to obtain 28 percent of its total energy needs from renewable sources by 2000.

Over the past half-century, dozens of such reports by disinterested experts have described the potential of solar technologies to meet a large fraction of the nation’s, and the world’s, energy needs within a relatively short time frame. iv None of their goals—often mistakenly characterized as forecasts or predictions—have been realized.

Fifty years after the issuance of Resources for Freedom, efforts to harness solar energy remain insignificant in terms of global energy markets. Thus a skeptic might reasonably ask: If solar energy is so attractive and sensible, why has it always been ignored? Were all those reports just plain wrong?

Actually, most of the enthusiastic reports and studies were right on the money. v The efficiency and reliability of solar energy technology improved as projected. Prices fell sharply, as expected, as production levels climbed and began to achieve efficiencies of mass production. Hydrogen and fuel cells have emerged as an attractive solution to the problem of storing sunlight for times (night, for example) when the sun isn’t shining or for applications (powering an automobile, for example) for which incident sunlight is inappropriate. The resource base is enormous, and at least in comparison with other energy sources, sunlight is rather equitably distributed around the world.

In a nutshell, the problems have been rooted in: (1) bad politics; (2) bad pricing; (3) the Japanese economic downturn; (4) applied technology’s “valley of death”; and (5) the failure of solar advocates to capitalize on their strongest asset—nearly universal public support.


Direct from the Sun to Everyone

Our sun is one of a family of stars that astronomers call yellow dwarfs. Powering it are several kinds of fusion reactions that “burn” 11 billion pounds of hydrogen a second. This fusion has been continuing reliably for the past 4 or 5 billion years vi and is expected to continue for another 4 or 5 billion. vii

The earth’s surface receives, on average, 160 watts per square meter of energy from the sun. Human energy use equals about one ten-thousandth of the solar influx. No country uses as much energy as is contained in the sunlight that strikes its buildings. The sunlight that fell on roads in the United States last year contained roughly as much energy as in all the fossil fuel consumed last year in the world.

The awesome flow of sunlight to the earth powers the hydrological cycle and creates the wind and the weather. Sunlight provides the foundation of the biosphere; green plants bottle up sunlight in energy-rich bonds, using hydrogen from water and carbon extracted from carbon dioxide. That bottled-up energy is the currency of all life. viii

Photovoltaic cells, commonly called solar cells, are an extremely attractive energy option. ix Inherently modular, they gain no important advantages (other than ease of maintenance) from being clustered in large concentrations. Easily integrated into roofs, walls, and windows, they have no moving parts to break. Solar cells produce no acid rain, no greenhouse gases, no radioactive waste, no bomb-grade materials. They simply lie there and produce electricity when the sun shines, the amount of electricity varying with the duration and intensity of the sunlight. x

Solar electricity can be used on-site, stored in a battery, fed into an electrical grid, or used to split water into hydrogen and oxygen. In recent years, solar-hydrogen strategies have attracted increasing attention because hydrogen can easily be stored and transported, and it offers the promise of abundant, convenient power in a world otherwise constrained by threats of climate change. xi Hydrogen fuel cells generate electricity at very high conversion efficiencies and emit zero pollution. xii

Whereas many nations have no oil, coal, natural gas, or uranium, all nations have at least some sunshine, and most have quite a bit. Hence, low-cost solar energy could be a powerful force for abating global tensions and reducing balance-of-trade deficits. Moreover, some nations with intense year-round insolation (solar radiation) are sparsely populated. Those areas, including deserts in North Africa, the Middle East, and the American Southwest, could become net solar-hydrogen producers, exporting clean fuel to regions less richly blessed with sunshine.

That, in any event, has long been the idea.xiii However,

Between the idea
And the reality
Between the motion
And the act
Falls the shadow xiv

The shadow, in this case, has been a national political culture that, from Teapot Dome to the Price-Anderson Act, from “depletion allowances” for the world’s wealthiest industry to exemptions from air pollution regulations for old coal power plants, has consistently fed the fat cats and stacked the deck against solar energy.

Über den Verfasser
Denis Hayes was director of the National Renewable Energy Laboratory during the Carter Administration, and advised the Kerry campaign on energy issues. A lawyer and former professor of engineering at Stanford University, he is a fellow of the American Solar Energy Society. Now president of the Bullitt Foundation in Seattle, Hayes is perhaps best-known as the national coordinator of the first Earth Day in 1970. The views expressed in this article represent only his personal opinions.