Ken Bossong makes us aware ofsome problems in the movement towards more benign and appropriate technologies. Even though some of these problems have been dealt with and are resolved, it is important to be familiar with them to maintain credibility. For a copy of this report in its entirety, send 75( to Citizens Energy Project, 1413 K St. N. W, Was/?ington, DC 20005. Reprinted by permission. - LS Solar energy, frequently touted as being an environmentally benign technology by its advocates, may not be all that it is promised to. be. Small-scale, dispersed applications of solar technologies are unquestionably superior to their fossil fuel _and nuclear competitors ; they produce more jobs, stimulate more new businesses, yield fewer pollutants, and offer a range of social benefits. Nonetheless, solar collectors, passive designs, wind generators, photovoltaic cells, wood stoves and other solar technologies do have their shortcomings. The long-run prognosis for evolving a solar economy may well depend, at least in part, upon a realization now of the technology's problems. This is necessary in order to address trouble spots while the industry is still young and flexible; it is necessary to avoid possible injury to 'would-be solar purchasers; it is necessary to lessen the chance of a negative backlash against solar when the general public realizes that it is not a perfect technology; and it is necessary if current solar •advocates are to retain their credibility. Of most immediate concern are active solar collector systems used to provide hot water and space heating; more than 50,000 units have already been installed on homes and other buildings in·the U.S. Many collectors use working fluids such as ethylene glycol to prevent freezing in the winter months; these working fluids frequently contain other additives such as rust inhibitors and biocides as well. Since the fluids degrade after four or five years, they must be flushed out and replaced. Presently no program exists to prevent the waste fluids being flushed into waterways and onto landfills where they will pose certain environmental hazards. A related problem is the emission of toxic gases from solar collectors (i.e. "outgassing") particularly in instances when a collector might be overheated; the released fumes could include fluorinated and chlorinated hydrocarbons and acids. Other potentially significant problems include exposure of workers in.collector manufacturing plants to potentially toxic substances such as those used in selective coatings. A large market demand for the hardware could result in significant depletion of some res~urces such as copper or could increase emissions by industries that produce the raw materials for colle<;:tors (e.g. aluminuin smelting). Lesser problems might include ~tructural collapse of a building unable to support the weight of a collector on its roof or injury due to broken glass. by Ken Bossong Though generally acknowledgeq as_the safest of potential space-heating technologie-s, passive solar systems also have potential drawbacks. Perhaps greatest among these is the possibility of d~gradation of interior air quality in a wellsealed passive building; concentrations of indoor chemical . pollutants, accumulation of molds or fungus, high humidity and stuffiness are all apt to result. A second problem is that passively designed structures may compromise the fire integrity of a building by allowing for easier circulation of interior air; a related problem is that decreased window area (or windows that are more tightly sealed) may make escape from a building on fire more difficult. While posing fewer problems once installed and operating than active systems, photovoltaic solar cells may pose more serious pro):>Jems in the earlier stages of manufacture.' Given that most cells now produced are primarily silicon, one must note the hazards ·associated with an expanded silicon mining (pit mining) industry. These include a higher-than-average level of worker injuries and chronic respiratory problems induced by breathing in silicon quartz dust (i.e. silicosis). The digging of silicon mining pits will disrupt the surrounding e~osystem in much the same way any mining operation will· and there is a problem of ultimate disposal of mining wastes. • Damage to nearby homes frbm mine blasting (similar_to that found widespread in coal mining areas) as well as destruction of roads and problems of fugitive dust can be expected. In the manufacture and rdining processes for si'licon, gaseous carbon monoxide and submicron-sized particulates-of silicon oxide are discharged; the latter is a potentially serious respiratory irritant. Further, for every metric ton of silicon • processed, 28 kilograms of solid metal chloride and undeterm.ined amounts of gaseous hydrochloric acid can be produced at the workplace. During the fabricati_on of the cells themselves, various toxic gases such as boron trichloride and phosphine are released into the·atmosphere; in addition to being a noxious substan~e, low-level chronic exposure to phosphine has been traced to anemia and nervoµs system disorders; standards d·o not yet exist for.the substance. • Similar problems may be posed by cells that are produced usin_g cadmium sulfide or gallium arsenide. Extractjon of gallium from zinc and aluminum ores yields mercuric and acidic effluents as well as large volumes of alumina sludge which poses disposal problems. The arsenic used in the production of gallium arsenide cells is a worker hazara and highly toxic cadmium can cause kidney disease, emphysema, pulmonary edema and hypertension. • Lesser problems posed by photovoltaic cells include minor changes in local climate (e.g. "heat islands" could reduce wind speed and relative humidity while increasing temperatures and cloudiness slightly). There is also an ultimate problem of disposal of used cells.
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