One of the fantasies shared by everyone, including those in the nuclear industry, is that it will someday become possible to provide all of our power needs with clean, non-polluting solar power. Standing in the way of this dream are solar energy's inherent thermodynamic limitations which when taken into account suggest we will never achieve energy sufficiency without a mix of tradional as well as alternative sources. Bluntly, solar energy has three problems that cannot be wished away:
1) Solar is a low density energy source. That means there may be a lot of energy packed in natural energy systems, but it is dispersed over large geographical areas, requiring an extensive concrete and steel infrastructure to collect the power.
2) Solar systems are intermittent (the sun sets at night, the wind sometimes fails to blow, the tides are cyclical). This requires massive storage capacity to even-out the fluctuations in power
3) As a consequence of the first two problems, solar energy is resource intensive. Because of their low power density and need for load shifting storage, solar systems require massive amounts of infrastructure in the form of solar collectors, windmills, transmission systems, maintenance facilities, storage reservoirs, etc.
The problems associated with large scale natural energy systems are thus formidable. That does not mean they cannot be overcome, only that solar power must be competitive in the economic arena with other energy systems to justify its use. Solar is already competitive in certain energy niches, but is unlikely to be competitive in all energy domains and this is where a mixed energy economy and nuclear energy come into play.
Of course, a rational energy policy is not what's being debated at Yucca Mountain, but a social and political policy. Solar is often promoted by people like Ken Bossong of Ralph Nader's Public Citizen's Critical Mass Energy Project for reasons other than its efficiency or safety:
It is growing increasingly more apparent that achieving an economy based on solar technologies in no way assures the realization of any political goals. It is now clear that the U.S. can move from a nuclear/fossil fuel economy with little change in the status quo. Without a concerted effort to promote solar technologies in the context of social change, we face continuation of the problems of maldistribution of wealth, of environmental degradation, of energy waste, of health threats to workers and individual citizens, and of continued centralization of power and decisionmaking. [Bossong, Ken; A Solar Critique, Citizen's Energy Project, 1980, p1)
Solar as an energy solution is quite a different animal from solar as a social policy: the former can be judged on technical merits while the later is merely a theory of Washington's environmental policy activists. The keyword from Bossong quote is centralization (supposedly the crime nuclear energy and industrialized solar energy are guilty of) as opposed to decentralization, which we've seen is a codeword for radical political advocacy. American's may not realize that a simple thing like a solar water heater is in some circles considered a revolutionary device.
Criticism of extremist proponents of solar energy representing groups like the SECC should not be confused with criticism of solar energy itself. In fact, the much maligned Department of Energy is one of the main researchers and boosters of solar energy, though at the same time they are accused by the anti-nuclear lobby of being totally inept in their conduct at Yucca Mountain. In an ironic twist, many of the DOE's solar studies have been used as the core of the repository opposition's utopian fantasies in which the world transitions to a solar civilization.
Sandia National Laboratories is conducting research for the Department of Energy on one of the most promising technologies called central receiver solar plants. Early experiments at the ten megawatt Solar One demonstration plant just outside Nevada in Barstow California have led to calls for a second demonstration plant called Solar Two. Solar Two is a more advanced design using elements from the Solar One site but employing molten nitrate salts as an energy storage medium. Unfortunately, even though Solar Two isn't even operating and in any event would generate at most 50 megawatts (compared to the 500 to 1200 megawatts of commercial nuclear plants) many environmentalists already want us to foreclose our nuclear future in favor of this just-emerging technology.
But what does Sandia National Laboratories, which has hands-on experience actually operating solar plants rather than the wishful theorizing of armchair engineers in the Green movement, have to say about the potential of central receivers?
IT'S RELIABLE, CLEAN -- Under development for more than 15 years, solar central receiver power plants can play a large part in supplying the world's increasing needs for electric energy. They can produce electricity more cheaply than can any other utility scaled solar power plant. In addition, they will always meet even the most stringent environmental regulations.
IT'S UNIQUE -- These are the only solar power plants that can be designed with a capacity factor ranging from 25 to more than 60 percent -- meaning a central receiver power plant can operate at capacity for up to 60 percent of the year without using fossil fuel as a back-up, thus delivering power during most peak demands. And central receivers have the ability to store energy very cheaply. Because of this, they can deliver electricity on demand, even at night. This ability is known as load shifting. ["A Solar Electric Power Plant", Sandia National Laboratories SAND960235]
Note first that Sandia claims for its plant only the ability to produce electricity more cheaply than other utility scaled solar plants, a far cry from actually beating the cost of nuclear. Secondly, they only claim a capacity factor of "from 25 to more than 60 percent" compared to nuclear's 65 to 85 percent. Even more importantly, the solar capacity factor comes at the wrong time of the year (summer) to take care of the major home electrical heating load in winter. Nighttime loads, though serviceable, are not guaranteed.
In other words, even as sophisticated as Sandia's solar central receiver is, it still needs back-up fossil fuel plants (or perhaps nuclear!) to make it year round viable. Sandia goes on in their brochure:
It will be economical -- Using the most modern central receiver technology, a 200-megawatt plant could supply electricity at a cost competitive with power from fossil fuel. All the advanced generation technology needed for such a plant is proven. The cost of electricity from this solar plant is only 1 to 2 cents per kilowatt hour higher than from a coal plant of similar size. Many believe this is a small price to pay for such a clean and environmentally sound source of energy.
IF -- The initial investment, however, is several hundred million dollars, and this size plant has never been built before. An investment in such a venture -- in spite of the evidence to the contrary -- seems risky to many. A smaller demonstration plant could be the first step toward commercialization of the technology, thereby assuring a clean, inexhaustible, and secure domestic supply for power plants of the future. ["A Solar Electric Power Plant", Sandia National Laboratories SAND960235]
Note here that 1 to 2 cents higher per kilowatt hour than coal plants of 200 megawatt size may translate into up to three times the cost of nuclear power, hardly a bargain here. This is without allowing for the introduction of next generation nuclear plants which have much higher efficiencies, greater safety and lower costs than present models.
Also, the startup costs of solar are large even compared to the startup costs of nuclear (which are also front end loaded), so any savings from solar technology would not be seen until far into the future even if it were employed today. And if 1 to 2 cents a kilowatt hour is a small price to pay for such a clean and environmentally sound source of energy (which, by the way, nuclear is also) why hasn't anyone in the Green lobby made themselves rich by putting a consortium together to build solar receivers in such anti-nuclear, energy starved states like New York?
This is not to heap abuse on solar, the people at Sandia have made huge strides in solar energy research and should be encouraged to bring these technologies on line whenever and wherever economically feasible. Instead, this strikes at the heart of the political motivations of some in the solar community and in the anti-nuclear opposition at Yucca Mountain. Before Nevada and the United States head down the path of rosy solar scenarios, we should ask whether there is compelling evidence that solar is our best option.
Most disturbing about the Sandia brochure is not its contents, but that Judy Treichel of the Nevada Nuclear Waste Task Force gives out this brochure as evidence that a solar future is just around the corner. While Treichel is quick to accept a solar sales brochure from the DOE (represented by Sandia), she has been unwilling to accept studies from this same agency about the safety of Yucca Mountain and about new developments in the nuclear industry (such as High Temperature Gas Reactors). A dispassionate engineering analysis at best rates solar as a potential large scale element in a mixed energy economy and it is typical of the technological naivete of the state's representatives that they feel solar is a magic bullet for our nation's energy needs.
Another area that Nevada's anti-nuclear/pro-solar activists have sidestepped is the adverse environmental and economic costs of solar energy. The Second Law of Thermodynamics declares that no machine can run without waste or some form of pollution. In the early 1980s, Ken Bossong (now at Public Citizens) worked with Scott Denman (now SECC executive director) as part of the Citizens Energy Project. Bossong was candid about solar energy problems in an article titled Hazards of Solar Energy:
Solar is being touted by its growing cadre of supporters as a technology that is environmentally benign -- one that promises to be a panacea for problems ranging from pollution to social and economic injustice to national security. While dispersed, small-scale solar technologies can offer many advantages over their fossil fuel and nuclear power competitors, they fall short of the qualities they are now being credited with . . . . . Moreover, there could be a backlash against solar technologies from the general public when it realizes solar is not all it stacks up to be now. . . . . projections are that over two million homes by 1985 will be employing one or more solar technologies and that will present an immense pollution control problem. [Bossong, Ken; "Hazards of Solar Energy", Solar Compendium, v2., A Solar Critique, 1980, p65]
So even in solar utopia, there are problems. At least in 1980, the Citizens Energy Project (which becomes the Safe Energy Communications Council) wasn't afraid to reveal solar shortcomings. Bossong goes on:
There is a price to be paid with every energy technology. The only way to lessen the costs associated with an energy-intensive society is to make it less energy intensive. Simplifying lifestyles, developing an ethic of conservation, and being mindful that anything we do has an impact are really the only ways to curb problems of pollution, poverty, etc. Solar is not a total solution; it will help but only if used intelligently. ["Hazards of Solar Energy", p66]
Is a less energy-intensive society in mankind's best interest? Only if there is no alternative and solar is pushed coercively as the only option. But even a nationwide transition to solar energy would not necessarily solve every environmental problem and Bossong is a wealth of information on the possible dangers:
PASSIVE SOLAR ENERGY --
While probably the least environmentally offensive of all the possible solar technologies, there are still a number of drawbacks associated with passive solar systems. A primary environmental concern is potential degradation of interior air quality as measured by temperature, humidity, and air circulation patterns (e.g. stuffiness, high humidity, and mold or fungus accumulations) . . . This problem could be increased if indoor pollutants are retained in the building's interior . . .
The Federation of American Scientists suggested that radon in buildings accounts for 20,000 cases of lung cancer per year; even if this estimate is a gross over-estimate, it can be seen that there is a possibility of increased danger from radon build-up in tightly sealed buildings. . . .
A second problem posed by passive solar systems is the possibility that passively designed homes will incorporate air circulation passages that may compromise the fire integrity of a building structure -- that is, make it easier for a fire to spread through a building. ["Hazards of Solar Energy", p66]
Thus, even with passive solar heating there are dangers. Ironically we might be exposed to more radiation from trapped radon in our passive solar homes than if we lived next door to a nuclear plant. To be fair, Bossong does suggest solutions to these problems, although Bossong et.al. have never accepted the nuclear industry's solutions to their problems. Active solar systems pose similar questions:
ACTIVE SOLAR ENERGY
. . . . A large demand for active systems could also pose a serious resource depletion problem for such materials as copper and aluminum (keep in mind that the U.S. already imports a portion of its copper; an increased demand for copper tubing for collectors could increase imports so that oil imports will decrease while copper imports will rise).
In addition, workers would be exposed to a range of chemical substances used in collector manufacturing such as the materials used in selective coatings for collectors or any plastics employed.
The most immediate problem posed by active systems once installed is that they might adversely impact upon the structural safety of a home; . . . . the glass employed in an active system is subject to breakage due to vandalism or other causes such as hail or hurricane with consequent injury to a building's occupants. . . . Decomposition of the selective coatings of the collectors could likewise release toxic gases; a related hazard is "outgassing" -- i.e. some solar systems use insulation materials that may discharge toxic or corrosive fumes when the collector overheats.
Certain working fluids . . .(which could also include such other commonly used chemicals as nitrates, nitrites, chromates, sulfites and sulfates) degrade over time . . . . If not properly disposed, these working fluids could degrade water supplies and affect aquatic life. . . .
A related problem is potential contamination of potable water by the solar working fluid. ["Hazards of Solar Energy", p67]
Reading Bossong, one feels that the promise of solar utopia is like Icarus crashing from the sky at the hands of one of its own proponents. Moreover, we haven't included every conceivable possible solar disaster as usually done when nuclear systems are critiqued. Still other problems arise:
While posing fewer problems once installed and operating than active solar collector systems, photovoltaics pose potentially more serious problems in the earlier stages of manufacture -- including mining and refining of the materials used and the subsequent production of the (solar) cells themselves.
The manufacturing and refining operations entail a range of environmental pollution problems. In the refining process for silicon, gaseous carbon monoxide and submicron-size particulates of silicon oxide are discharged . . . . silicon oxide can become a respiratory irritant. For every metric ton of silicon processed, 28 kilograms of solid soluble metal chloride and undetermined amounts of gaseous hydrochloric acid can be produced at the workplace. . . . .
Similar and additional problems may be posed by cells that are produced using highly toxic cadmium sulfide or gallium arsenide. Extraction of gallium from zinc and aluminum ores yields mercuric and acidic effluents as well as large volumes of alumina sludge which pose disposal problems. The use of arsenic in the production of gallium arsenide cells poses worker health problems. The cadmium used in the production of cadmium sulfide cells is a highly toxic substance whose dust can be a cause of kidney disease, emphysema, and pulmonary edema and is suspected of being a cause of hypertension.
Further, the Argonne National Laboratory has reported that: "The relative risk of workers involved in cell-related production activities is among the highest occupational risks in the U.S. In addition, environmental effluents emitted during cell production containotentially toxic substances. Large scale development of terrestrial photovoltaic systems could result in significant release of these toxic substances with substantial public health risk.
There is also a possibility of localized climatic changes in areas where large numbers of photovoltaic arrays are located; "heat islands" could be created . . . ." ["Hazards of Solar Energy", p69]
Photovoltaics are obviously not an energy panacea. The pollution problem from photovoltaics is real and Bossong neglects to mention that the energy needed to create solar cells is substantial, meaning it takes a long time before the system breaks even as far as energy consumption. If photovoltaics have problems, what about wind systems?
"SMALL WIND SYSTEMS
A starting concern with small wind systems is the possibility that the blades could pop loose and be thrown resulting in possible injury to persons nearby . Structural collapse of the system is also a possibility.
Possibly a more significant health problem is that of burns, shock and electrocution from improper handling or poorly maintained equipment. . . . Personal injury could also result from falls from towers (not that far-out a possibility when one considers the frequency of serious injuries in cases of falls from roofs by persons repairing them).
A wind machine can result in decreased wind speed, increased soil moisture, temperature changes, increased relative humidity, and other impacts downwind of the structure. Likewise there could be other minor impacts on local ecosystems. . . . There is also the possibility of birdkills . . . And the noise produced by the whirring of the blades may be audible to nearby residents . . . ["Hazards of Solar Energy", p71]
These seem like a lot of concerns, yet we have culled the list presented by Bossong. Another area where many problems will occur in any large scale solar application is energy storage. According to Bossong:
Among the options for solar storage technologies are batteries and rock bed storage. The latter poses potential problems of fungus growth and invites the use of herbicides and fungicides with their incident problems.
The former, i.e. batteries, pose a range of health and environmental concerns. Battery systems include lead/acid batteries now widely used as well as nickel/iron and nickel/zinc types. Among advanced systems under development for longer range applications are sodium/sulfur, lithium/metal sulfide, zinc/chlorine, zinc/air, and iron/air. The production, use and disposal of these batteries will probably entail the use of substantial quantities of lead, nickel, antimony, zinc, and other materials that are persistent, cumulative environmental poisons. Toxic gases can also be released as a result of fires or overheating in the case of accident or failure of battery chargers. ["Hazards of Solar Energy", p72]
Bossong's preoccupation with small-is-beautiful technologies leads him to neglect the fact that large scale industrial storage systems for thousand megawatt utilities will be equally havoc producing. The technologies involved, such as nitrate salt heat storage, reservoir pumping plants, battry storage, etc. are too diverse to fully examine, but their environmental impact is substantial. One final quote from Bossong on alcohol fuels:
Producing alcohol from diseased crops or agricultural wastes is potentially an attractive way way to increase farm income, create new community based businesses . . . There is, however, a danger that agricultural wastes that would otherwise be plowed under to regenerate the soil would instead be used for alcohol production; the result could be a gradual depletion of the soil.
There is further the possibility that farm land now used to produce food could instead be converted into alcohol fuel production lands, thereby removing needed crops from the marketplace.
. . . alcohol for automotive fuel could result in a "mining of the soil if all the stover is removed" according to the U.S. Department of Agriculture. ["Hazards of Solar Energy", p73]
It's a pretty gruesome solar world Ken Bossong has painted. Of course, his remarks are taken somewhat out of context and unfairly overstate the risks of solar technology. There are two points we wish to make: 1) solar energy has its own set of costs and risks (i.e., it is not free), and 2) distorting the risks solar hazards is just as counterproductive as distorting similar levels of risk for nuclear technology.
If perceived risks are reality, as the opponents of nuclear energy and Yucca Mountain contend, then with a little manipulation of the "facts" concerning solar energy the public might be made to believe solar energy is a blight on civilization. This might especially be so if the pro-solar community could be persuaded to cough up fifty million dollars to create a Nevada Solar Project Office, staffed of course by nuclear industry supporters whose only purpose was to undermine the image of solar energy.
Unfortunately, the groups who have radicalized the Yucca Mountain debate and made solar energy the Holy Grail of the politically correct, seem shocked when their own tactics are used against them. Should the nuclear industry have used scaremongering against solar technologies (as well as character assassination and diversion of funds that we've covered before), the Greens would have protested vehemently.
There are many aspects of solar energy technology that are quite encouraging. Our objective is not to diminish the enthusiasm for solar research, but merely to put it into context. Engineers have a concept known as "engineering tradeoffs" which helps them keep a touch on reality. Lawyers, sociologists, political policy activistss and the staffs of most environmental energy think tanks have no such philosophical rule of thumb and no such contact with reality, especially in regard to solar technology. Engineers test their products in the marketplace to see whether they will fly both physically and economically. The environmentalists have no such restraint and conduct solar engineering by law suit and harassment. Whether solar energy becomes the wave of the future, will not be decided in academia, but when investors see a chance for profit in a working technology. Before abandoning nuclear technology for environmental or sociological reasons, it would be nice to see a solar system which actually produces 1000 megawatts reliably.
According to Bossong:
The public should not be cajoled into thinking that solar is a convenient way to encourage or sustain present wasteful and irresponsible lifestyles. Solar is a solution to problems of pollution, national security, unemployment, etc. when used in conjunction with other policies that respect the environment, individual rights, etc. It is not a total panacea. ["Hazards of Solar Energy", p75]
We heartily agree. Perhaps solar plus nuclear might solve many of the problems we face, but of course this in part depends on solving the nuclear waste disposal problem and the construction of Yucca Mountain. In the mean time, we should be aware of the potential paradox that solar energy represents. That is, that the most natural and "free" energy source, the sun, may require numerous hidden environmental tradeoffs for its widespread utilization.