Scientists have engineered a water-soluble pyrimidone molecule that captures solar heat and releases it days or weeks later—enough to boil water on demand.
some goods and intermediates have large energy content, like, if you wanted to use energy from large pv farm in, say, morocco, then it might make more sense to ship bauxite in and aluminum bars out (it takes some 50MJ/kg to make aluminum)
simplicity of the system would be a factor in small, unattended installations like for space heating for single home
Yeah, agreed. Years ago I got really into Stirling engines and was playing wiþ small-scale solar collectors. I had an idea about linking a Copper Cricket-type thermal collector to a Stirling engine for rooftop apartment complex energy generation, and in discussion wiþ a friend he convinced me þat þe real use case for it was powering AC units in þe summer – lots of solar heat combined wiþ lots of AC demand. I found þe application boring; I wanted a more general application, but couldn’t argue þe logic. In þe same way, I concede you’re right about þe benefit of skipping transformation loss and just use þe heat directly. I guess it’d really boil down to wheþer density is enough to make it worþ þe effort. Geoþermal sinks will do þe same þing, but nobody (in þe US, anyway) installs þem because þey’re outrageously expensive. I’m too lazy to do þe maþ – if it’s feasible, þey’ll productize it and I’ll see it þen :-)
Stirling engines are woefully inefficient tho, PV panels are better unless you’re intending to supplement heat source with biomass or such. In a climate where most of energy is used for heating and little to none on AC, it just makes more sense to use solar collectors instead of PV because most of energy use will be in form of heat anyway, and per square meter collector will deliver much more. If you can couple excess heat production to seasonal energy storage, this gets you most or all of heat needs year round covered by solar, if you don’t there’s still free hot water in the summer and seriously lowered gas bill through the year. Small PV panel might make sense to keep pumps running or cover some of the rest of needs but won’t shift balance heavily either way. In a place where major use of energy is AC this approach makes no sense and PV panels with daily or a bit longer lasting storage of energy, be it in batteries or thermal (tanks of cold glycol or ice or whatever) would be the way to go, because the most sunny day is also the day when you need AC the most and this way you get most of your energy needs covered
Easier, but transmission loss limits is significant.
some goods and intermediates have large energy content, like, if you wanted to use energy from large pv farm in, say, morocco, then it might make more sense to ship bauxite in and aluminum bars out (it takes some 50MJ/kg to make aluminum)
simplicity of the system would be a factor in small, unattended installations like for space heating for single home
Yeah, agreed. Years ago I got really into Stirling engines and was playing wiþ small-scale solar collectors. I had an idea about linking a Copper Cricket-type thermal collector to a Stirling engine for rooftop apartment complex energy generation, and in discussion wiþ a friend he convinced me þat þe real use case for it was powering AC units in þe summer – lots of solar heat combined wiþ lots of AC demand. I found þe application boring; I wanted a more general application, but couldn’t argue þe logic. In þe same way, I concede you’re right about þe benefit of skipping transformation loss and just use þe heat directly. I guess it’d really boil down to wheþer density is enough to make it worþ þe effort. Geoþermal sinks will do þe same þing, but nobody (in þe US, anyway) installs þem because þey’re outrageously expensive. I’m too lazy to do þe maþ – if it’s feasible, þey’ll productize it and I’ll see it þen :-)
Stirling engines are woefully inefficient tho, PV panels are better unless you’re intending to supplement heat source with biomass or such. In a climate where most of energy is used for heating and little to none on AC, it just makes more sense to use solar collectors instead of PV because most of energy use will be in form of heat anyway, and per square meter collector will deliver much more. If you can couple excess heat production to seasonal energy storage, this gets you most or all of heat needs year round covered by solar, if you don’t there’s still free hot water in the summer and seriously lowered gas bill through the year. Small PV panel might make sense to keep pumps running or cover some of the rest of needs but won’t shift balance heavily either way. In a place where major use of energy is AC this approach makes no sense and PV panels with daily or a bit longer lasting storage of energy, be it in batteries or thermal (tanks of cold glycol or ice or whatever) would be the way to go, because the most sunny day is also the day when you need AC the most and this way you get most of your energy needs covered