Solar Is Cheapest Electricity in History, U.S. DOE Aims to Cut Costs 60% by 2030

(cleantechnica.com)

131 points mg | 5 comments | 26 Mar 21 20:07 UTC | HN request time: 0.608s | source

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zizee ◴[26 Mar 21 23:02 UTC] No.26598033[source]▶

I think the future will be robust national/international grids, with a mixture of storage options (batteries/pumped hydro) to smooth out the intermittent nature of wind and solar.

Cynics always talk about the amount of energy storage required for solar as if you need to store 24 hours of energy for solar/wind to be viable.

I'd like to see numbers on having 1 hour of storage for peak demand, a robust national grid, and appropriately provisioned and placed solar and wind, taking the duck curve into consideration.

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1. dukeofdoom ◴[27 Mar 21 00:49 UTC] No.26598746[source]▶

>>26598033 #

So I've been watching these Van build outs into full time living vans for travel. Most of them have solor panels on the roof, and 3 two hundred watt batteries. One guy said it would take him 23 days to fully charge these batteries off of solar vs just a few hours to charged them from the alternator when he is driving. It just doesn't seem very practical at this point. They all seem to have 2 or 3 thousand watt panels on the roof. Is he correct? How does the math work here? How long should it take for a 1000 Watt panel to charge a two hundred watt battery?

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2. philipkglass ◴[27 Mar 21 01:47 UTC] No.26599105[source]▶

>>26598746 (TP) #

I think that your recollection is incomplete or garbled. Modern solar panels are about 20% efficient. They can generate about 200 watts per square meter in midday sun with clear skies. 2000 to 3000 watts of panels would be about 10-15 square meters (107-161 square feet). Do these vans actually have roofs that large, completely covered with panels?

You might expect roof top panels with sub-optimal orientation to generate about 12.5% of their peak rating when averaged over a year. That would be 375 watts, annualized, from a system with a peak capacity of 3000 watts. There is no van-portable battery system currently on the market that can store 375 * 24 * 23 = 207,000 watt-hours. (For comparison, the Tesla Model S battery stores 100,000 watt-hours.)

My guess is that you are not correctly recalling how much solar capacity these vans have installed. When I Google for van life solar I get guides and kits referencing much less power.

For example, this guide:

https://www.genericvan.life/2018/04/30/complete-vanlife-sola...

uses a single 150 watt panel. Based on the photo the article includes, I don't think that the van rooftop has room for more than 3 panels of this type.

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3. dukeofdoom ◴[27 Mar 21 02:20 UTC] No.26599289[source]▶

>>26599105 #

Yes, sorry, I think I got the numbers wrong by a factor of ten. Most seem to use two or three 100 watt panels. So 300 watts is what they are getting in total for most of these build outs. But they usually leave space for fans. So I think absolute max might be something closer to double that. So can you answer with this correction?

4. imtringued ◴[28 Mar 21 10:49 UTC] No.26609296[source]▶

>>26598746 (TP) #

I saw an EV van that had solar panels that generated enough power to drive 50km per day. It was fully decked out to a comical level though.