California exceeds 100% of energy demand with renewables over a record 30 days | Hacker News Reader

California exceeds 100% of energy demand with renewables over a record 30 days

electrek.co

34 pointshochmartinez29 comments

This is an encouraging milestone. Is it trivial at this point to figure out whether a solar home install is cost effective? ie plug in your address, your last 12 pg&e bills, and get a complete quote with a break down of time to profitability?

Not trivial. Factors: Local labor costs, PV import tariffs, net metering arrangement, roof space and tilt angle, electricity prices, local solar irradiance levels, solar seasonality, and large cost difference between grid tie versus hybrid battery systems.

If you live in a reasonably sunny country, the shorthand you can use is 4.5*(system size in KW), which equals the daily number of kWh your system will produce. Say that number is 30kWh. Then multiply 30 by your per kWh electricity costs. Say $0.2*30. That's your daily savings estimate, $6. Then you can figure out how many years to ROI by comparing it to the system cost. This approach will be more or less accurate if you have a battery or a nice net metering arrangement. It will be less accurate without either of these things.

I've used this and compared to friends who have installed solar, and it's been roughly accurate to +/- $1500 or so.

https://sunroof.withgoogle.com/

Sizing and cost for install seems wildly inaccurate for me in the bay area. Says a 2kw system will cover my needs and cost $8k to buy and install.

Is it assuming I already have a huge battery or net metering?

I've been frequently tempted by that tool but then when I go to try to take the next step I hit a bunch of complexity with installers. The Tesla experience is pretty good but seems to carry a huge markup.

Yeah, I put my contact info into one of the modeling websites thinking I would get a technical estimate, and not only did it not get it, they just sold my info ad now I get 3-5 spam calls a day. They all started as solar companies, but have branched out into general scams.

Discussion at the time (it's now 45 days) [0] (136 points, 1 month ago, 155 comments)

[0]: https://news.ycombinator.com/item?id=40048842

The headline should be electricity demand, not energy demand. Easy to forget that electricity is a fraction of total fossil fuel energy use

and it's also just an excess during mid-day (excess during .25h up to 6h in the day if I understand correctly) which does not cover the reat of the day through batteries.

It also say "it's only the start, it's going to be more in the future" but tbh I expect hydroelectric power to go down in the future...which represent up to 20% of the demand, and is the most practical renewable source.

Also batteries system is "one of the largest in the world" and barely allow to delay +4h of power...that shows how big is the task.

Title is definitly missleading.

https://www.pv-tech.org/caiso-approves-transmission-plan-to-...

https://www.energy.ca.gov/news/2023-10/california-sees-unpre...

https://www.energy.ca.gov/data-reports/energy-almanac/califo...

https://app.electricitymaps.com/zone/US-CAL-CISO

California is the fifth largest world economy. Currently, solar is pushing ~16-19GW sustained during solar hours. For comparison, Germany has 80GW+ of solar generation capacity. It is trivial for California to push the remainder of its fossil generation out of the mix. Based on current trajectories, I would be shocked if California doesn’t meet their mandate far sooner than expected.

(Earth receives enough solar energy in less than half an hour to power humanity for a year; scale collection and storage accordingly)

Are you comparing California power generated to German nameplate capacity? How do they compare apples to apples, or oranges to oranges?

Wikipedia says California has 46 GW nameplate capacity and Germany has 81 GW nameplate.

Germany produced 53 TWh of solar in 2023 (12% of electricity used)

Wikipedia data for California 2023 is incomplete, but it looked to be on track for ~39 TWh in 2023 (same as 2022), and 17% of electricity used.

Following up, Germany has too much solar, and needs more transmission and storage it appears (or load shifting to daylight hours): https://www.bloomberg.com/news/articles/2024-05-22/solar-pan... | https://archive.today/6cDAY

https://research.sebgroup.com/macro-ficc/reports/49776

"German electricity prices are collapsing during the sunniest hours of the day as the country is flooded with solar power, potentially curbing profitability. The price of power during daylight hours over the past 10 days was €9.1 per megawatt-hour compared to €70.6 during the rest of the day as the number of solar installations continues to increase across the country, SEB AB wrote in a note. This means on sunny days, output can outstrip demand leading to negative prices in the market, with the grid unable to handle so much power and insufficient storage capacity. Although many producers are not directly exposed to the spot prices, these trends bring down revenues overall. Total installed solar capacity soared to more than 80 gigawatts at the end of 2023, according to the bank, 30 gigawatts higher than average demand."

> Total installed solar capacity soared to more than 80 gigawatts at the end of 2023, according to the bank, 30 gigawatts higher than average demand."

Solar only has about a 10% capacity factor in Germany so we can conclude that they don't have enough solar yet and this author has no idea what he is talking about.

Exactly.

I am lazily comparing total capacity and current daily generation mix trends from ElectricityMaps. The specifics are not so important, the trend and velocity of change is, and those are clear based on the data.

(ElectricityMaps is in the business of accurately tracking both generation capacity and generation mix for their carbon intensity data consumers)

in terms of trends, the number seem to indicate that California is far ahead of Germany in terms of solar as a % of generation, and saturating summer daytime production. This is where things get tricky, because you your cost for kwh increases radically for storage, or overbuild capacity that is only useful in the winter.

Accurate, the last part will be the hard part, but we must learn how to.

It's not summer yet. There was one day last week that called for the A/C. And with PG&E rates damn near doubling, I just don't know how retirees and others are going to deal with the abundance of heat, available power and double drain on the wallet.

Regardless of the source, people are going to roast, and some will die because of unaffordable cooling.

Solar output scales with sunlight hours

I was thinking of a solar panel direct to heat pump arrangement. (via inverter) More sun, more power to cool.

Yet, the big argument for batteries is that the peak load (so they say) is from 4 pm to 7 (or more) pm, when the sun is lower, and cosines do you in. Anyway, that's when variable rates go up.

Maybe they should move to a climate that is suitable to their needs? Moving somewhere unbearably hot and then relying on technology to make it palatable is not sustainable.

Will you say the same to the old people who move and then subsequently can’t shovel snow in the winter?

In a condo the shoveling is taken care for you. Singe family dwellings are inefficient. That’s a relic from days surplus carbon capacity.

Yeah, elderly people, who are struggling to pay their bills as is, should spend $10k to pay people to pack up their stuff, break their lease, and move to a state with a better climate than, checks notes, California.

"...supply exceeds demand for '0.25-6 h per day,' and that’s an important fact. The continuity lies not in renewables running the grid for the entire day but in the fact that it’s happening on a consistent daily basis, which has never been achieved before.

...

...California will entirely be on renewables and battery storage 24/7 by 2035."

I work for a school. We reached out to So Cal Edison to ask what percent of the power they deliver comes from non-renewable. They said 40%.

I guess this is what paying $0.72/KWh during peak gets you.

Iowa has more renewables than CA but has cheaper electricity prices than the national average. There are a few examples like this that prove that the inference you're attempting to make is symptomatic of stupidity.

I didn’t assert causation.

Does Iowa have the same heavy handed government regulations to strictly build out renewables and take non renewable power plants offline?

I agree with you, Texas has the most renewables, and power is relatively cheap. The problem is the strict regulations prevent utilities from make better economical decisions.

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