[Retric]

PV’s falling prices have also been associated with falling environmental harm. When you’re talking multiple orders of magnitude you just cannot require as much in production.

IE: You can’t burn 500 gallons of gas if the end product costs 500$. That applies not just to transportation but also how much material and thus mining the raw materials you need, including refining them, the amount of chemicals you can use per panel, how much electricity you can use in production of the device including precursors etc.

[slow_typist]

The argument is valid, if energy is not subsidised. However, burning pv for resistance heating is still wasteful and should be avoided. It is only acceptable for peak production that cannot be put to better use.

[Retric]

It’s wasteful of electricity not necessarily resources.

One of the numbers I was looking at compared air sourced heat pump at night when it’s coldest vs this kind of resistive heat battery. Solar panels are far cheaper and better for the environment on a kWh/day basis so even if the COP is 3 (or less it gets colder at night) * 90%(losses from battery) = fewer panels you more than offset it by needing far more batteries.

Obviously solar thermal setups have advantages if you need lots of heat, but they are also wasted most of the year. If 8-10 months a year you’re only using them for hot water then annual efficiency is closer to 25% than 90%.