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Publisher Summary This chapter discusses the environmental impacts of the photovoltaic (PV) system. It is generally believed that PV systems are relatively benign environmentally. It is instructive to compare technologies in three categories of impact: land use, thermal and climatic effects, and emissions. In the case of stand-alone photovoltaic installations, land may also be required for storage of solar-generated electricity. Presumably, battery or mechanical storage could be co-located with generation, with little net increase in land use but perhaps with more severe impact. However, pumped hydro or some other storage systems for central station solar electricity involve more significant use of land. In the case of the PV system, it is difficult to predict how emitted materials will enter the environment and what roles they will play there. Therefore, a simple worst-case model is constructed to give average additions to cadmium and arsenic background levels because of PV and to compare these additions with recently measured urban and suburban background levels. Depending on release rates, PV array manufacturing facilities may also significantly affect concentrations and deposition rates nearby. An estimate of the possible magnitude can be obtained by assuming that emissions from array manufacturing facilities are distributed uniformly throughout an area whose electrical service is obtained from PV.

The use of a new energy technology—whether for conversion of coal to gaseous and liquid fuels or for the photovoltaic (PV) generation of electricity from sunlight—will entail a reallocation of societal resources and a reassignment of the costs of these resources. An important resource in all industrial activity is labor, and among the costs of labor are the effects of that activity on the health and safety of workers. In evaluating photovoltaics on a social-costs basis, it is necessary to consider how the manufacture and use of these technologies would affect the overall role of labor in society and also how the technologies would affect the spectrum of health and safety risks experienced by workers. The worker health and safety issues include not only the social cost picture presented by emerging PV technologies, as compared to conventional options, but also the interaction of technological evolution with accumulating health effects data and changing regulatory standards.

Public health risks arising from photovoltaics (PV) may be direct or indirect. Direct impacts include routine or accidental releases of toxic or carcinogenic materials during manufacturing and utilization of PV systems. This chapter reviews the nature and approximate magnitude of direct public health hazards that might arise in connection with the processing and use of the materials essential to PV systems: silicon, cadmium, and arsenic compounds. While a complete assessment also requires evaluation of the longer-term environmental roles played by these compounds and inclusion of the indirect health and environmental impacts that result from the use of other materials—such as aluminum or copper—and energy in making PV systems, it is necessary to take into account the relative importance of direct impacts. The direct public health impacts of PV appear to be smaller than those of coal.

There are indirect costs and benefits associated with changes in energy technologies. The assessment and valuation of these effects is a subtle and difficult problem, which requires important social judgments as well as major efforts to define the boundaries of analysis. While social judgments must ultimately be made by society through individual and collective choices, it will be useful to provide some rough measures of how substitution of photovoltaic (PV) systems for conventional sources of electricity would alter the allocation of productive resources and the distribution of particular indirect costs and benefits. The bookkeeping may be done along several major axes: labor, materials, and energy. It appears, from virtually all estimates, that the manufacture and use of PV systems would bring about major changes in the number and types of jobs directly involved in supplying energy. PV is now an extremely labor-intensive technology because of the involvement of human labor in virtually all aspects of cell and array manufacture. As the technology matures, with continuous-process automation replacing handwork, there undoubtedly will be a reduction in this intensity. The nature and quantities of materials required for PV systems are still very uncertain. It is not yet known, for example, whether arrays will consist primarily of vinyl shingles, aluminum and glass sandwiches, or some other physical configuration. However, it is likely that relatively large amounts of common materials will be required for arrays producing a given amount of electricity because of the need to cover large areas with durable assemblies.

Publisher Summary In assessing the relative health and environmental impacts of photovoltaic and alternative technologies, several methodological problems arise. These include establishing the basis for proper allocation of social costs, the incomparabilities of different types of social costs and the impossibility of making value-free overall comparisons, the constraints on the displacement of social costs associated with one energy technology by those of another, and the difficulty of accounting for social costs indirectly related to the use of a given energy technology. This chapter discusses these methodological problems. The first methodological issue is a normalization problem stemming from the fact that sunlight is an inconstant source of energy. While fossil and nuclear facilities may be operated as continuously as is technically feasible, solar power installations are limited by variations in insolation, including diurnal, seasonal, and weather-induced var0iations. Because of this, social costs cannot be assessed on the basis of installed peak-generating capacity. Instead, it is useful to prorate effects over the electrical energy produced. The second methodological problem in comparing energy technologies is that different technologies have qualitatively different impacts and thus may not be directly comparable. The third methodological problem is that deployment of one energy technology must be seen as displacing use of another. Accounting for this raises the allocation and commonality issues above, and incomplete consideration may give misleading results. The fourth problem that arises in the assessment of any energy technology is that there are important underlying and antecedent social costs that may be less evident than the direct effects of the technology.

Publisher Summary This chapter discusses the potentially significant hazards—as well as benefits—associated with the manufacture and use of photovoltaic (PV) technologies. Occupational safety issues in PV technologies are likely to be qualitatively similar to those in existing industries. Inordinate safety hazards are usually relatively easy to identify; industries are accustomed to internalizing the economic costs of alleviating them. Rates of worker injury for PV are unlikely to be higher than those currently prevailing elsewhere and generally considered acceptable. The major direct impacts of PV on public health result from atmospheric releases of potentially hazardous materials. As with occupational exposures, the only significant risk in silicon technology appears to come from the release of particulates during the refining of silicon. However, the thermal and climatic effects associated with PV are likely to be minimal. Solar panels may reduce reflectivity and raise local temperatures slightly, but this effect will be partly offset by the conversion to electricity of sunlight that would otherwise produce heat.