3 ms·

While you're not wrong to imply PV doesn't work at night, concentrated solar power (CSP) actually does. It achieves this by heating salt into a molten state whi

by hkt 5y ago

While you're not wrong to imply PV doesn't work at night, concentrated solar power (CSP) actually does. It achieves this by heating salt into a molten state which can then discharge heat (and drive turbines) overnight. CSP is very promising for helping manage peak loads in place of gas, too. There's also batteries: virtual power plants that give us the ability to arbitrage between when power is cheap and when power is needed. These can be rolled out in conjunction with residential PV systems and eventually pay for themselves. A similar approach can be used to store hot water produced during the day by PVT (photovoltaic-thermal) cells. See: https://en.m.wikipedia.org/wiki/Thermal_energy_storage https://en.m.wikipedia.org/wiki/Thermal_energy_storage https://www.energy.gov/sites/prod/files/2014/01/f7/csp_review_meeting_042413_reddy.pdf https://www.energy.gov/sites/prod/files/2014/01/f7/csp_revie... https://en.m.wikipedia.org/wiki/Virtual_power_plant https://en.m.wikipedia.org/wiki/Virtual_power_plant

EricE 5y ago
CSP plants have never gotten beyond the prototype phase because no one has figured out how to make them economically viable. One near me in California just shut down because maintenance costs were skyrocketing. Batteries, in their current form, have all sorts of issues that haven't made them economically viable either. Liquid electrolytes (liquid batteries) do show promise for grid level storage, and I am pleased to see lots of activity around them but we are still probably 5-10 years away from anything worth scaling up around. Hot water is fine for extreme micro uses - individual buildings - but again not even remotely viable for something at scale, let alone replacing base load generation for the grid. Base load is the real nut to crack - and so far solar is no where near being anything but a nice supplement for base load.
- hkt 5y ago
  I'll not argue with anything in your post and accept the issues with CSP as per the status quo, but hot water needn't be a micro, single household scale. I've benefited from a CHP plant powered district heating system and it more than halved my energy use. There's definitely nothing wrong with big centralised heat generation and storage schemes. It also helps address baseload.
tsimionescu 5y ago
The only good battery technology we have today - LiIon - relies on metal of which there just isn't enough on Earth for anywhere close to the required capacity.
ncmncm 5y ago
Indeed, costs for storage are falling even faster now than solar or wind ever did. Solar thermal, already cheaper than nukes, is far from the best.

by hkt 5y ago

EricE 5y ago

CSP plants have never gotten beyond the prototype phase because no one has figured out how to make them economically viable. One near me in California just shut down because maintenance costs were skyrocketing. Batteries, in their current form, have all sorts of issues that haven't made them economically viable either. Liquid electrolytes (liquid batteries) do show promise for grid level storage, and I am pleased to see lots of activity around them but we are still probably 5-10 years away from anything worth scaling up around. Hot water is fine for extreme micro uses - individual buildings - but again not even remotely viable for something at scale, let alone replacing base load generation for the grid. Base load is the real nut to crack - and so far solar is no where near being anything but a nice supplement for base load.

hkt 5y ago
I'll not argue with anything in your post and accept the issues with CSP as per the status quo, but hot water needn't be a micro, single household scale. I've benefited from a CHP plant powered district heating system and it more than halved my energy use. There's definitely nothing wrong with big centralised heat generation and storage schemes. It also helps address baseload.

tsimionescu 5y ago

The only good battery technology we have today - LiIon - relies on metal of which there just isn't enough on Earth for anywhere close to the required capacity.

ncmncm 5y ago

Indeed, costs for storage are falling even faster now than solar or wind ever did. Solar thermal, already cheaper than nukes, is far from the best.