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

That being said, it might still be a good signal that investments in renewable electricity infrastructure could be accumulating up to critical mass in some areas. And that is encouraging.

Hilarious, how to lie with statistics 101.

In general fossil fuels have capacity factors around .55, nuclear about .9, hydro about .4, and solar is between .1-.3

So you can imagine a scenario where we have 200MW of natural gas and 200MW of solar, and a grid load of 300MW. The natural gas could produce 400MW, powering the grid alone. Similarly, we could have up to 1 GW of solar, more than enough. But the averages are what is important, and what we use in ratings.

These stories are mostly “feel good” and without meaning imo. We will hit 100% energy from renewables for x minutes, long before we have enough power for the grid. If we were trying to make all the renewables come online at once, you don’t actually need that much capacity to hit 100%. The capacity factor says we only need 1/5 of the grid as solar to hit “100%” renewables. The reason we haven’t is intentional, we want more consistent power from these typically inconsistent renewable sources.

The only critique I’ll say though is nuclear is definitely clean energy.

80% of California and part of Nevada also. Don't confuse the grid operator with the utility. Those are separate entities.

The ISO is the market maker for electricity - ultimately responsible for keeping supply and demand on the grid in balance. They contract with numerous entities to achieve that.

The utility is responsible for some combination of generation, transmission, distribution, and billing, depending on where you are located.

There are many other players in the markets, including spinning reserves, independent generators, demand aggregators, community-choice-aggregators, and some that play multiple roles.

> Rooftop solar advocacy group Save California Solar said although this milestone should be celebrated, California’s renewable energy progress is better measured by conditions on a hot August summer day than a cool April spring day. Renewable peaks typically occur in the spring, due to mild temperatures and the sun angle allowing for an extended window of strong solar production.

Renewables never reach capacity, well your solar might for a peak moment, but then it will drop as the sun drops.

For example - you have a 200 MW wind farm, you might only be able to produce 10MW at that moment. The capacity is 200MW, the generation is 10.

Also the 3rd was a Sunday in spring - no office workers, less demand, not a heating or cooling day in a lot of California, ie a lower energy day than say a week day in summer where the temp is 105 in the Central Valley.

What do you do when it's not sunny, very cold/hot, no wind, and businesses and factories are open?

Somehow we talk a lot about solar, and not enough about nuclear.

Right now, 3PM in California, the CAISO demand shows around 21GW of demand. http://www.caiso.com/TodaysOutlook/Pages/index.html

Note that CAISO's peak, ever, was 50GW. (PDF) http://www.caiso.com/Documents/CaliforniaISOPeakLoadHistory....

The "installed capacity" of 80GW I believe is the number if you add the theoretical max of all hydro, solar, wind, gas peaker plants, etc. But each source will never simultaneously be at max, so we never get close to this 80GW number. https://www.energy.ca.gov/data-reports/energy-almanac/califo....

I'm also confused by the scales here. How are they praising the use of 15,000 MW (15GW) and 8,000 MW (8 GW) in one sentence, in an article about 97% of California's energy being used, and saying they need 100 GW in the next sentence and being sad they can't put it on rooftops. In an article showing a photo of a solar cell field in a vast, desolate, arid region of central valley.

Their full installed generation capacity is 80GW, but there's huge variability in actual load. As I write this, current load is around 21GW, on a range of between 18.7GW and 27GW over the day. It gets into the 40's in the summer.

https://www.caiso.com/TodaysOutlook/Pages/default.aspx

There's a significant need for reserve capacity to deal with this load variability, as well as plant failures, etc.

California de-rates solar by less than, say, the UK since Cali has a lot of air conditioning load which is coincident with insolation whereas summer days are the low-load periods in the UK.

The capacity before de-rating > capacity after de-rating > highest anticipated load > actual load on a normal day.

The income from said tax could then be used to build out the transnational capacity of the grid, to subsidize transformations that save energy or to build out grid-scale battery storage.

Texas does allow consumers to pay market rate for electricity, you may have heard about last winter people getting bills in the several thousands of dollars when prices spiked.

CAISO was 97% renewable for only a moment, not the entire day.

The 3rd was a Sunday, not a peak day.

And the average price for energy for the day was $30.77 (day head) $27.1 (real time) for TH_SP15_GEN-APND (per MWh)

If you want to do solar for the environment, fine - I won't fault you - but if you are doing it to save/make money, there are better places to invest.

I expect it's just probably doable in a really temperate climate like SF, where you can live without running heating or cooling year-round and try to get your other electric usage way down, but anywhere with hot summers or cold winters is going to risk battery depletion.

https://haas.berkeley.edu/wp-content/uploads/WP294.pdf

We know this because until recently, this ‘ideal situation’ that you propose was available by a company called Griddy, that went balls up when their consumers got absolutely slammed during the Texas snowstorms, and the idea of having the wholesale price if you’re a retail consumer became a very very silly idea

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.

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.

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.

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

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

I don’t know but I wonder if (and it seems likely that) the time arbitrage of electrons is better/simpler (and cheaper?) solved by batteries now or in a few years time.

Fixed price = (unit cost + a profit margin) * number of units

The fixed price is set for a period of time based on historical and forecasted costs. Which costs are allowed and the profit margin for regulated utilities serving fixed price load is determined by the public service commissions.

When their costs go down the regulators will say you can’t charge as much during the next period.

Utilities are a natural monopoly and their prices are controlled.

For example, a 10 MW battery can replace a 10 MW gas generator (assuming it has enough capacity to cover the relevant peak, which is usually a fair assumption because that's what they're designed for). If you only know a battery has 20 MWh, that's not enough information to know what equivalent amount of generation or ramp it can replace.

That's usually how setting a "record" (i.e. a high water mark) works. It doesn't mean the trend line isn't moving in the right direction.

IIUC, the vast majority of ecological impact caused by hydro is already done. It is not making things exponentially worse.

Am I missing something?

On there you can dig in and find what sources are counted as renewable.

Tesla has also broken ground on a Megapack manufacturing facility (Lathrop, CA) employing 1000 people to build roughly 50GWh of storage per year.

https://www.montereycountyweekly.com/blogs/news_blog/pg-es-n...

Zero... same as any other technology. ie: Texas lost around 25GW of needed NatGas capacity in Feb 2021, not to mention the failed coal, wind, and nuclear that also occurred during that event. (Texas had similar shortages in 2011 and 1989.)

> That's the number that matters.

You need to take a portfolio view when thinking about energy supply issues... reality is both your number and their number matter.

What 97% does mean, is less consumption of two finite resources, namely the ability of the atmosphere to absorb carbon and the amount of carbon we have available to us to burn.

Of course, it also means there's a need to either scale the rest of the generation in the ISO down to 3% or export the excess to a neighboring market. Larger base load plants, particularly nuclear, are very bad at lowering their output (Which is why sometimes wholesale electricity prices are negative. These are generators willing to pay people to take their power so they don't have to shut down or otherwise reduce output.)

The cherry on top is that all future energy uses no more material and creates no more pollution, with materials mostly all recyclable at end of life. Over a 30 year horizon, fossil fuel infra cannot compete.