3 ms·

Nowhere in either this article or the paper is an estimate given for cost, nonetheless an analysis justifying the estimate. Desalination has a fundamental ener

by jjk166 3y ago

Nowhere in either this article or the paper is an estimate given for cost, nonetheless an analysis justifying the estimate. Desalination has a fundamental energy cost, and solar energy is fundamentally limited by what is received. The real question is whether it is cheaper to set up a solar-thermal desalinator, or set up solar panels that can power more efficient desalination methods. Solar panels are cheap and getting cheaper quickly as there is an incredible economy of scale. While desalination systems could likewise be mass produced, there will never be as large a demand for that one specific application of solar power as for general solar power. Further, photovoltaics are reasonably simple solid state devices which are well suited to mass production. I am highly skeptical a priori that a solar thermal system could compete on economic terms. Perhaps in a space confined situation it makes sense, but it's tough to run out of space in the ocean.

PaulKeeble 3y ago
A Solar thermal system will definitely out perform using solar panels to produce heat. A typical commercial solar panel is only 23% efficient whereas solar heaters are above 95%. With 4x the energy for the same area and a lot less sophisticated technology there is little doubt heating the water directly is better. But like with all desalination its a relatively slow process that leaks a bunch of material behind that damages everything and the costs will be dominated by all those other aspects not just where it gets its energy from.
- jjk166 3y ago
  You get 4 times the energy per unit area, but if it costs more than 4 times more per unit area, the photovoltaics win. The cost per square meter of solar panels is currently around $40. Is a square meter sized solar thermal desalinator currently less than $160? In 10 years when photovoltaics are $15 per square meter, will the solar thermal desalinator be less than $60?

by jjk166 3y ago

PaulKeeble 3y ago

A Solar thermal system will definitely out perform using solar panels to produce heat. A typical commercial solar panel is only 23% efficient whereas solar heaters are above 95%. With 4x the energy for the same area and a lot less sophisticated technology there is little doubt heating the water directly is better. But like with all desalination its a relatively slow process that leaks a bunch of material behind that damages everything and the costs will be dominated by all those other aspects not just where it gets its energy from.

jjk166 3y ago
You get 4 times the energy per unit area, but if it costs more than 4 times more per unit area, the photovoltaics win. The cost per square meter of solar panels is currently around $40. Is a square meter sized solar thermal desalinator currently less than $160? In 10 years when photovoltaics are $15 per square meter, will the solar thermal desalinator be less than $60?