Ask HN: What can be done to prevent a climate catastrophe?

Re:Ask HN: What can be done to prevent a climate catastrophe? by anonuser123456 on Wednesday October 10, 2018 @11:05AM (#18185541)

Solar water heaters are not cheap. 1 square meter of evacuated solar tubing with a storage tank is > 4k, before installation. That 1 m^2 will give you at most 500w of solar gain for 2-3 hours... in total maybe 5k BTU. That's a factor of 20 off relative to existing systems.

[ Parent | on HN ]

Re:Ask HN: What can be done to prevent a climate catastrophe? by Retric on Wednesday October 10, 2018 @11:25AM (#18185739)

That's not what I am talking about. Bulk collectors for a single home are ~500$. Flat plates run $1,000 - $2,500 per home. Evacuated tubes cost more and collect less energy, but produce hotter water. https://modernize.com/home-ideas/34541/solar-water-heater-co...

1 square meter evacuated solar tubing is used for hot water systems not home heating. It's a question of output temperature, the warmer the water the less cost efficient and more costly the system. High end systems include a backup water heater which means you directly save 1k on a hot water heater.

Anyway, for home heating you don't need 'hot' water, a heat pump operating on even 60f water vs 0f or below air is very efficient. You can also pre heat cold water with a flat plate feed that into your normal water heater and again save a lot of energy.

PS: Also, many people pay 1,000-2000$ / year on home heating even with a well insulated house. These systems generally have payback period under 10 years, assuming you actually need significant amounts of heat.

[ Parent | on HN ]