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Understanding Solar Energy

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261 points chmaynard | 2 comments | 20 Mar 25 12:09 UTC | HN request time: 0.001s | source
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bryanlarsen ◴[20 Mar 25 14:23 UTC] No.43423941[source]▶
Great article. Unfortunately his California duck curve graph only shows 2023. A graph including 2024 shows how batteries are dramatically flattening the duck curve:

https://cdn-ilcjnih.nitrocdn.com/BVTDJPZTUnfCKRkDQJDEvQcUwtA...

https://reneweconomy.com.au/battery-storage-is-dramatically-...

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Calwestjobs ◴[20 Mar 25 17:00 UTC] No.43425755[source]▶
Hot water tank heated by electricity and powering on at noon is flattening curve. You can say hot water tanks are cheapest, simplest and fastest deployed energy storage device.

Solar + hot water tank can provide any house in US with 100% solar hot water (from PV!) for 80% of time, remaining 20 % of time you can have 10-99% solar heated water.

So we should focus on saying to people that if they buy solar and add electric heating element to hot water tank, then PV system will pay itself much sooner and their batteries will last longer. Becasue it is known and predictable load, you need hot water every day. And hot water is order of magnitude more energy then TV, lighting...

By lowering household usage like this we can make energy transition faster, cheaper.

Also proper construction - house heated only 10 days in a year - https://www.youtube.com/watch?v=5KHScgjTJtE

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andbberger ◴[20 Mar 25 18:02 UTC] No.43426692[source]▶
has PV finally overtaken solar hot water?
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Calwestjobs ◴[20 Mar 25 18:17 UTC] No.43426902[source]▶
well just piping for hot water system is more expensive then PV panels.

But biggest expense is instalation costs(humans) so it depends how you calculate. But PV system can be used for hot water, tv, car, charging kids bikes, lawnmower etc. Solar thermal can be used only for hot water (or cooling if you use multistage heat pump but that is viable only in office buildings or hockey stadiums and such).

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kragen ◴[21 Mar 25 10:53 UTC] No.43434118[source]▶
How much does the piping cost?
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1. Calwestjobs ◴[22 Mar 25 00:15 UTC] No.43442082[source]▶
even with tariffs in place, whole PV system will provide you more kWh per year

per $ invested

then solar thermal system.

rated output is not what you get 100% of time. price per performance is crucial. price per imaginary watts is nonsense.

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2. kragen ◴[22 Mar 25 00:37 UTC] No.43442226[source]▶
You're probably right, but do you have some idea how much the piping costs for a solar thermal hot water system? Because that's what I was asking about.
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