Leonardo

Fig. 2. Paul MacCready, GossamerAlbatross, solar-powered aircraft, 1979. This aircraft was developed by Paul MacCready and his team to cross the English Channel from England to France. The 96-ft-wingspan aircraft weighedjust 55 lbs. The use of synthetic, high-strength, lightweight material played a major role in creating this remarkable design. (Photo: Don Monroe. Courtesy Paul MacCready.) Fig. 3. Paul MacCready, Pathfinder, solar-powered aircraft, 1993. Pathfinderwas developed and built at AeroVironment Inc. in Simi Valley, California. Optimized for low-speed, high-altitude flight, the machine is a wing 100 ft long and 8 ft wide. Each propulsion unit weighs only 13 pounds and consists of a propeller, a motor with internal power electronics, a nacelle, cooling fins and a mounting strut. Solar arrays follow the contours of the wing's up­ per part. Pathfinder flew for the first time in October 1993. MacCready's goal is to develop a version that will fly for months at an altitude of 65,000 ft, serving as a stratospheric satellite. (Photo courtesy Paul MacCready) erer-hunters from the preagricultural era, but now we are operating airlines, computers, television and robotic factories ; we have a finger on nuclear energies for benign or destructive purposes; and we are deleting fellow species of flora and fauna at a frightening rate. 6. Our culture, our institutions (religious , economic, political and educational systems and methods) and our individual reward systems are poorly matched to the task of moving toward a comfortable, permanent accommodation between man and the millions of species of flora and fauna with which we share this wonderful globe. Life in general (and human life especially ) is delightful, but we are working our way into an awkward future. The earth is limited, we have more intelligence than wisdom and technology is evolving to be more of a master than a servant. Unfortunately, a "six sentence" document would be too brief to include a discussion of solutions, even if I knew of any. Let me merely note here that I consider the broadening of our perspectives on the global ecosystem—including our views of how it may have arisen and our possible role in it—and die open discussion of diese serious issues prerequisites for concocting solutions. Solar Energy Is the Energy Hermann Scheer Future generations will certainly ask why both politics and economics in the 1970s, 1980s and the beginning of the 1990s acted in such a passive and cowardly way with respect to the far-reaching opportunities offered by renewable energies. The only remaining open questions are (1) whedier the majority of our present decision-makers will be asked these questions in a bitter and accusatory way, due to the fact that an endless decline with innumerable catastrophes will have taken place as a result of ignoring the solar option, and (2) whether they will be asked with an ironic smile, due to the fact that political and economic priorities will have changed in favor of solar energy and a global solar energy system will have been established within the first decades of the twenty-first century, having been started in the present decade. The economic and social advantages of renewable energies are enormous: they offer the way toward saving both the earth's atmosphere and human health; they ensure an independent, safe, long-term energy supply as well as economic development; they will provide newjobs in industry and thus stem a steadily increasing rate of unemployment ; and they make possible the recuperation of polluted soil and water, enabling us to avoid a global water crisis and to economically liberate agriculture . All these potential advantages are being ignored because of a single factor : the current price of energy. Perhaps there are excuses for individual producers or consumers of energy who act according to these narrow interests. But it is incomprehensible that the same way of thinking exists at the political level. Solar energy is the road that leads us away from die energy-consuming house and toward the energy-producing house; thus, the implementation of soHermann Scheer (politician, writer), Eurosolar, Plittcrsdorfer Strasse 103, D-5S173 Bonn, Germany. Received 27 October 1994. Manuscript solicited byJürgen Claus. This text is a modified excerpt...