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Understanding Solar Energy

(www.construction-physics.com)
261 points chmaynard | 4 comments | | HN request time: 0.002s | source
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bryanlarsen ◴[] 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 ◴[] 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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epistasis ◴[] No.43426144[source]
Converting a gas water heater to electric and/or solar is one of the best bang for the buck on decarbonization too. Something that should be done before buying an electric car or swapping out your gas furnace for a heat pump. Though I'm terrible at following my own advice, I still have a gas water heater, just because I needed to replace my car and furnace before I needed to replace my water heater. That said, the sunk cost fallacy applies to carbon emissions just as hard as it does to dollars so I have little excuse for not replacing it except laziness (and space on the breaker panel...)
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ipdashc ◴[] No.43427222[source]
Is it a fallacy though? It doesn't make sense to buy a new EV if you still have a gas car that's working fine. In the same vein, I wouldn't want to throw out my gas furnace or water heater to replace with electric, creating waste and requiring the manufacturing of a new unit
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epistasis ◴[] No.43427793[source]
Can you explain how it's not a fallacy? Compare your lifetime emissions of replacing a gas car with an EV now versus at the "end of life" of the gas car. Emissions will always be lower if you replace now rather than later.

Imagine if everybody switched to EVs right now, en masse. Emissions over the next decade, and every subsequent decade, would be massively lower. Waiting for every gas car to reach end of life before switching is always going to be higher emissions, always.

Similarly, the "waste" already happened when the gas heater was manufactured. There's no additional waste when it's decommissioned. It's a sunk cost, there's no getting that back. The only question is if you switch to lower emissions now, or you switch to lower emissions later.

Now, if you bring money into it, sure, there could be a financial motivation to keep emitting higher amounts of emissions. But if you take monetary considerations out of it, it's always better to stop emitting sooner rather than later.

I'd love to have some serious push back against this. The best I've ever got is "that doesn't sound right..." without any engagement with the quantitation or the ideas. Which is exactly what I would expect if it was a fallacy.

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relaxing ◴[] No.43431648{3}[source]
I think you’re assuming when you switch to EV the ICE car disappears. But more likely it got traded to someone else who has less money, eventually making it possible for someone to own a car who otherwise wouldn’t have.

So the emissions stayed the same and you added the carbon embedded in the new EV.

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robertlagrant ◴[] No.43434777{4}[source]
> So the emissions stayed the same and you added the carbon embedded in the new EV.

Well no, there will be a chain of people all upgrading their cars to better ones. The final car will drop off the bottom of the chain, so you trade an EV for what is likely to be the worst performing car environmentally.

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1. relaxing ◴[] No.43435402{5}[source]
> The final car will drop off the bottom of the chain

Maybe not. The $500 used car lot will take them, and some will get shipped off to third world countries.

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2. epistasis ◴[] No.43437632[source]
But now you're dealing with probabilities, weighed against the certainty of the original EV purchaser emitting less.

Try this: if everyone in the US suddenly purchased EVs, and ditched their ICE cars, flooding the market with old ICE vehicles, would emissions decrease in the world or increase? I think it's pretty clear that the vast majority of the old ICE vehicles would be junked, and there'd be marginally more vehicle-miles-travelled, so the huge wins of everyone using EVs would counteract any increase in vehicle miles from suddenly having cheaper ICE available around the world.

So I would argue that the single person doing that action would have the general same trend as if everyone did it.

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3. relaxing ◴[] No.43439628[source]
> But now you're dealing with probabilities, weighed against the certainty of the original EV purchaser emitting less.

Welcome to public policy.

> Try this:

No, I’ll stay in the real world. Your thought experiment isn’t possible, and extrapolating from it isn’t useful.

4. robertlagrant ◴[] No.43459639[source]
> Maybe not. The $500 used car lot will take them, and some will get shipped off to third world countries.

If you're saying electric cars are pointless, and we should keep making ICE cars, because for a period of transition from ICE to EV some older ICE cars will go overseas, then I'm not sure there's much else to say. I disagree that that's good logic, I suppose.