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California grid set record of 97% renewable power on April 3

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Re: California grid set record of 97% renewable power on April 3

#191

Post by Symbiote »

WalterBright wrote: post #177

If electricity is cheaper to generate when the sun is shining, the retail price of electricity should reflect that. In fact, the retail price should fluctuate minute by minute, so that demand can be shaped to match supply. Trying to match variable supply to a fixed retail electric rate is certain to cause energy gluts and shortages. For example, I'd be happy to charge my electric car during price minima, heat the ele…

Here's the price for my residential electricity in Denmark for the next 24 hours: https://i.imgur.com/EER7bMP.png

The light part of the graph is transport costs and taxes.

I think the price moves within a range -- I'm protected from enormous spikes, but I also won't see the price go negative.

This is a standard tariff, there are other options for people owning electric cars. There's also an app to show this information, and (I assume) a way to tell the car to charge at the cheapest time in next few hours.

Re: California grid set record of 97% renewable power on April 3

#192

Post by WalterBright »

tomp wrote: post #183
WalterBright wrote: post #177

If electricity is cheaper to generate when the sun is shining, the retail price of electricity should reflect that. In fact, the retail price should fluctuate minute by minute, so that demand can be shaped to match supply. Trying to match variable supply to a fixed retail electric rate is certain to cause energy gluts and shortages. For example, I'd be happy to charge my electric car during price minima, heat the ele…

> If electricity is cheaper to generate when the sun is shining, the retail price of electricity should reflect that. This would be amazing. It would quickly turn the population off further investment in solar and other unreliable, unpredictable sources of energy and prove that nuclear is the only viable green power.

We pay variable prices for gasoline every day, mainly due to unpredictable supply. Society hasn't collapsed.

Re: California grid set record of 97% renewable power on April 3

#193

Post by thow-58d4e8b »

WalterBright wrote: post #177

If electricity is cheaper to generate when the sun is shining, the retail price of electricity should reflect that. In fact, the retail price should fluctuate minute by minute, so that demand can be shaped to match supply. Trying to match variable supply to a fixed retail electric rate is certain to cause energy gluts and shortages. For example, I'd be happy to charge my electric car during price minima, heat the ele…

That's close to the way things work in Europe

Pricing for the next day is decided on the spot market, around 2-3 PM. All large consumers and producers place bids on one-hour slots until the market clears. Prices do not fluctuate minute-to-minute, but hour-to-hour. Consumers might opt in to electricity resellers selling spot prices, or get a fixed but usually higher guaranteed price per kWh. All that changes for the end consumer is that your electricity meter readings will be forwarded to a different company

Re: California grid set record of 97% renewable power on April 3

#194

Post by Symbiote »

WalterBright wrote: post #190
wcoenen wrote: post #185

Earlier quoted context omitted.

These are called "time of use tariffs". Here in Belgium this type of tariff is marketed under the name "dynamic tariff". (It's only offered by the biggest player Engie, but other companies are working on it.) The price varies hourly, but it is determined by the day-ahead electricity market so the price schedule for the day is known the evening before.

It's a good approximation. But renewable power generation is affected by the weather, and the weather is not predictable. The price should change minute by minute. Of course, this implies people having internet-connected hot water heaters, car chargers, etc., which are hardly expensive.

The weather across all of Europe (which is relevant for the pricing) is reasonably predictable.

Re: California grid set record of 97% renewable power on April 3

#195

Post by usrn »

rtkwe wrote: post #152
offmycloud wrote: post #148

Their math seems off. I really don't see how you get to 97% renewable when the state was burning natural gas to generate 2.8 GW of non-renewable power and had about 1.1 GW of nuclear at the time. There might be some funny math here where they assign all of the "dirty" power generated in the state to exports and can claim that that California is running on renewable power. Source: https://www.caiso.com/TodaysOutlook/P…

The energy is pretty perfectly fungible so it makes about as much sense credited to the state as it does to the wider grid. If you just look at CA it generated 97% of its energy needs in state from renewable energy at that time. That it was connected to a larger grid so it was generating excess power dirtily doesn't really change that math.

The implication here is that you don't need the non-renewable part. That's not true if you have to have it when the renewable part isn't producing power.

Re: California grid set record of 97% renewable power on April 3

#196

Post by usrn »

WalterBright wrote: post #177

If electricity is cheaper to generate when the sun is shining, the retail price of electricity should reflect that. In fact, the retail price should fluctuate minute by minute, so that demand can be shaped to match supply. Trying to match variable supply to a fixed retail electric rate is certain to cause energy gluts and shortages. For example, I'd be happy to charge my electric car during price minima, heat the ele…

I don't want to live in a place that does that, my power consumption over the course of the day is pretty consistent.

We already do that for industrial power consumers how are most capable of changing the time they put load on the grid.

Re: California grid set record of 97% renewable power on April 3

#197

Post by DocTomoe »

thow-58d4e8b wrote: post #193
WalterBright wrote: post #177

If electricity is cheaper to generate when the sun is shining, the retail price of electricity should reflect that. In fact, the retail price should fluctuate minute by minute, so that demand can be shaped to match supply. Trying to match variable supply to a fixed retail electric rate is certain to cause energy gluts and shortages. For example, I'd be happy to charge my electric car during price minima, heat the ele…

That's close to the way things work in Europe Pricing for the next day is decided on the spot market, around 2-3 PM. All large consumers and producers place bids on one-hour slots until the market clears. Prices do not fluctuate minute-to-minute, but hour-to-hour. Consumers might opt in to electricity resellers selling spot prices, or get a fixed but usually higher guaranteed price per kWh. All that changes for the e…

As an European with a fixed-Euros-per-kWh-contract (with two prices, one for daytime, one for nighttime, the latter being a bit cheaper), I'm curious - which countries allow you to get a contract in which your electricity costs get updated daily?

Re: California grid set record of 97% renewable power on April 3

#198

Post by [deleted] »

dap wrote: post #145
haliskerbas wrote: post #8

Earlier quoted context omitted.

I’ve been trying to do the math for my own home, are solar panels actually cash flow positive, once you account for efficiency decrease overtime etc.? It always seemed like one barely breaks even in 2 decades

I got a quote last fall in the SF Bay Area for a system: - 6.4 kW (16x400W panels), microinverter-based (little to no maintenance expected in 25 years) - estimated to produce 8,500 kWh in year 1 - the panels are warrantied to produce 86% in year 25. Let's use 80% as a more conservative estimate. - up front cost: $16,500 after the federal tax incentive - alternative: paying PG&E $.25/kWh on average (conservative estim…

[deleted]

Re: California grid set record of 97% renewable power on April 3

#199

Post by mrep »

FPGAhacker wrote: post #155
dap wrote: post #145

Earlier quoted context omitted.

I got a quote last fall in the SF Bay Area for a system: - 6.4 kW (16x400W panels), microinverter-based (little to no maintenance expected in 25 years) - estimated to produce 8,500 kWh in year 1 - the panels are warrantied to produce 86% in year 25. Let's use 80% as a more conservative estimate. - up front cost: $16,500 after the federal tax incentive - alternative: paying PG&E $.25/kWh on average (conservative estim…

The fact that the return is not compounding makes a very large difference here. $16,500 returning 10% of the original principle per year isn’t a great investment. 25 years you have $41,000 + 25 yr old solar panels. $16,500 returning 10% compounding over 25 years gets you $162,000 + the $16,500 principle. Considering opportunity cost spread evenly over 25 years, those panels cost over $5000 per year. There are plenty…

You are ignoring investing the savings which if the stock market returns 8% vs the panels at 13%, you would get a 50% higher return with the panels + investing the savings in the stock market vs just the stock market after 30 years. Albeit, it does take 13 years to come out ahead.

  >>> x = 0
  >>> for y in range(0,30):
  ...   x *= 1.08
  ...   x += 2125
  ...   print(y, x)
  ...
  0 2125.0
  1 4420.0
  2 6898.6
  3 9575.488000000001
  4 12466.527040000003
  5 15588.849203200003
  6 18960.957139456004
  7 22602.833710612485
  8 26536.060407461486
  9 30783.945240058405
  10 35371.66085926308
  11 40326.39372800413
  12 45677.50522624446
  13 51456.705644344016
  14 57698.24209589154
  15 64439.10146356287
  16 71719.2295806479
  17 79581.76794709972
  18 88073.30938286771
  19 97244.17413349713
  20 107148.70806417691
  21 117845.60470931107
  22 129398.25308605596
  23 141875.11333294044
  24 155350.1223995757
  25 169903.13219154175
  26 185620.3827668651
  27 202595.01338821434
  28 220927.6144592715
  29 240726.82361601325
  >>> x = 16500
  >>> for y in range(0,30):
  ...   x *= 1.08
  ...   print(y, x)
  ...
  0 17820.0
  1 19245.600000000002
  2 20785.248000000003
  3 22448.067840000003
  4 24243.913267200005
  5 26183.426328576006
  6 28278.100434862088
  7 30540.348469651057
  8 32983.57634722314
  9 35622.26245500099
  10 38472.04345140108
  11 41549.806927513164
  12 44873.79148171422
  13 48463.69480025137
  14 52340.79038427148
  15 56528.0536150132
  16 61050.29790421426
  17 65934.32173655141
  18 71209.06747547553
  19 76905.79287351358
  20 83058.25630339466
  21 89702.91680766625
  22 96879.15015227956
  23 104629.48216446194
  24 112999.8407376189
  25 122039.82799662842
  26 131803.0142363587
  27 142347.25537526738
  28 153735.0358052888
  29 166033.8386697119

Re: California grid set record of 97% renewable power on April 3

#200

Post by DocTomoe »

WalterBright wrote: post #192
tomp wrote: post #183

Earlier quoted context omitted.

> If electricity is cheaper to generate when the sun is shining, the retail price of electricity should reflect that. This would be amazing. It would quickly turn the population off further investment in solar and other unreliable, unpredictable sources of energy and prove that nuclear is the only viable green power.

We pay variable prices for gasoline every day, mainly due to unpredictable supply. Society hasn't collapsed.

And we would happily change to another system if it provided long-term price stability.
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