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Understanding Solar Energy

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261 points chmaynard | 4 comments | 20 Mar 25 12:09 UTC | HN request time: 0.894s | 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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1. megaman821 ◴[20 Mar 25 18:49 UTC] No.43427345[source]▶
Using a hot water tank as a battery is an incredibly simple idea. I wonder how much electric hot water heaters on a timer could flatten California's duck curve.
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2. ok_dad ◴[20 Mar 25 18:53 UTC] No.43427392[source]▶
There’s a company doing that in Hawaii, I think it’s called “shift energy”. I interviewed with them, it seemed like a great operation, but a bit hobbled by being a startup in Hawaii. I respect it though, I’d do the same.
3. applied_heat ◴[21 Mar 25 03:56 UTC] No.43431663[source]▶
They have been controlling hot water tanks in New Zealand for decades… probably since the 70s. They use what they call a ripple signal by adding 400 hz on top of the 60 and then relays on your hot water tank detect the 400hz and switch it off
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4. Taniwha ◴[21 Mar 25 06:09 UTC] No.43432295[source]▶
We also control (or used to control) our street lights in AoNZ using ripple control (it was implemented with a tuned reed relay in some towns). Back in the 70s friends built a ripple transmitter and sent morse across Ōtepoti by turning on/off their suburb's street lights (at 2am)