Bonsoir,
Vous imaginez bien que n'étant pas un spécialiste, juste un inquiet des conséquences du réchauffement climatique, je ne fais qu'essayer de répondre à vos critiques en lisant la documentation disponible au sujet des centrales solaires orbitales, qui a mes yeux semble un concept viable, qui mérite qu'on en parle, étant donné le sujet de la discussion.
Comme vous avez la critique facile, et ce n'est pas du tout un reproche, cela me permet de tester le concept en profondeur, afin, pourquoi pas, de poser les questions difficiles à de véritables spécialistes lorsque nous les aurons identifiés.
À ce propos, la question de la précision du calibrage émetteur-récepteur est intéressante, ainsi que celle du mouvement orbital complet pour arrivé au 98% de disponibilité (en base annuelle) que j'ai pu lire dans la documentation.
Il est vrai que pendant quelques heures par jour, le flux est quasi équivalent dans l'espace et à la surface de la Terre. C'est encore une fois sans tenir compte des cycles jour/nuit, des saisons, de la poussières sur les panneaux photovoltaïques, etc...
Le spatial orbital 261 Watts par mètre carré 98 % du temps (en moyenne annuelle), même la nuit. Autrement dit, la nuit on a pas besoin de laisser d'autres centrales polluantes produire l'énergie que des panneaux solaires classiques ne pourraient pas fournir.
Le rapport complet du National Security Space Office américain relativise quelque peu cet argument :
CordialementUnlike terrestrial solar facilities, microwave receiving rectennas allow greater than 90% of ambient light to pass through, but absorb almost all of the beamed energy,generating less waste heat than terrestrial solar systems because of greater coupling efficiency. This means that the area underneath the rectenna can continue to be used for agricultural or pastoral purposes. To deliver any reasonably significant amount of base‐load power, ground solar would need to cover huge regions of land with solar cells, which are major sources of waste heat. As a result, these ground solar farms would produce significant environmental impacts to their regions. The simultaneous major increases to the regional temperature, plus the blockage of sunlight from the ground, will likely kill off local plants, animals and insects that might inhabit the ground below or around these ground solar farms. This means that that a SBSP rectenna has less impact on the albedo or reflectivity of the Earth than a terrestrial solar plant of equivalent generating capacity. Moreover, the energy provided could facilitate water purification and irrigation, prevent frosts, extend growing seasons (if a little of the energy were used locally) etc. In the plains of the U.S. (e.g., South Dakota, etc), in sub-Saharan Africa, etc. etc. there are vast areas of arable land that could be both productive farm land and sites for SBSP rectennas.
The final global effect is not obvious, but also important. While it may seem intuitively obvious that SBSP introduces heat into the biosphere by beaming more energy in, the net effect is quite the opposite. All energy put into the electrical grid will eventually be spent as heat, but the methods of generating electricity are of significant impact for determining which approach produces the least total global warming effect. Fossil fuel burning emits large amounts of waste heat and greenhouse gases, while terrestrial solar and wind power also emit significant amounts of waste heat via inefficient conversion. Likewise, SBSP also has solar conversion inefficiencies that produce waste heat, but the key difference is that the most of this waste heat creation occurs outside the biosphere to be radiated into space. The losses in the atmosphere are very small, on the order of a couple percent for the wavelengths considered. Because SBSP is not a greenhouse gas emitter (with the exception of initial manufacturing and launch fuel emissions), it does not contribute to the trapping action and retention of heat in the biosphere.
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