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points by HDThoreaun 3 days ago | 0 comments

It doesnt make economic sense to serve the entirety of daytime electricity demand from solar without batteries. Youd have to tons of fossil fuel plants that turn off during the day and then back on every night. For solar to take the next step batteries are a requirement

[–] Panzer04 3 days ago

It's not quite as bad as that, since you don't consume fossil fuel resources when plants aren't running, but this is mostly a benefit for oil/gas plants, not coal (since the coal is likely useless without the power plant consumer anyway)

[–] shagie 3 days ago

Depending on the type of power plant, it can take quite a while to spin up (or down) one of them and get them to optimal power production.

https://www.eia.gov/todayinenergy/detail.php?id=45956

If you shut down by day, it can take multiple hours for it to be able to provide full load... and multiple hours for it to shut down cleanly. During this time it is producing power at less than optimal rates and/or using the fossil fuels to keep the wheels spinning and in sync with the grid so that they don't have to go through a phase matching period.

(aside for coal - note that it takes more than 12 hours for a coal plant to get running from a cold start)

[–] adgjlsfhk1 3 days ago

That's not really a problem. A spin up over a couple hours matches nicely with the slow sunset over a continent. The sun takes ~4 hours to go from a bit above the horizon in the east coast to a bit below the horizon on the west coast (solar panels make some power in twilight).

Wind also helps since wind makes more power at night, as does demand which is dramatically lower at night.

For coal, Great. Making coal economical is excellent. We should have banned it worldwide 20 years ago.

[–] adrianN 3 days ago

Solar+A couple of hours of batteries is already economically viable. The storage problem that is still expensive is bridging days/weeks of insufficient sun and wind.

[–] traceroute66 2 days ago

> The storage problem that is still expensive is bridging days/weeks of insufficient sun and wind.

It might help if the US wasn't so anti off-shore wind at the moment.

[–] shagie 2 days ago

I live 900 miles from the coast. While the Great Plains are a good source of wind power ( https://www.eia.gov/energyexplained/wind/where-wind-power-is... - Iowa is 43 billion kWh of production - https://iuc.iowa.gov/regulated-industries/electric/iowas-ele... ), I believe it is generally a mistake to assume that power solutions that work for the Atlantic coast can provide power solutions half a continent away.

[–] HDThoreaun 3 days ago

The US uses around 4TWh of electricity a night. A battery with that capacity, to get through the night with no generation, would cost over a trillion dollars. Of course thered still be some generation at night, but still, using a battery just to get through the night is not even close to viable

[–] pinkgolem 3 days ago

You might want to update your numbers, 1 kwh is somewhere between 50€/kwh to 75 including electronics... No economics of scale, shipping included..

That makes 300B

Eu pricing

[–] GlibMonkeyDeath 2 days ago

That sounds like a lot right? But it isn't large compared to US wars to protect energy resources (>$4T just for post-9/11 wars), and the payback it would generate over decades to come. In fact, this level of investment is a total no-brainer, compared to the benefits it will generate (forget about even the climate benefits - just the other economic and defense benefits.)

And we can sure find those trillions when we want to: https://defensecommunities.org/2026/04/trump-requests-1-5-tr.... Or https://www.budget.senate.gov/chairman/newsroom/press/extend.... Or...

[–] adrianN 3 days ago

The war in Iraq cost a trillion dollars.

[–] GlibMonkeyDeath 2 days ago

More like $2 T (combined Iraq-Afganistan $4.3T) https://www.warcosts.org/compare/iraq-vs-afghanistan-cost

[–] Saline9515 3 days ago

Do you imply that it was really cheap, just like solar+batteries?

[–] adrianN 3 days ago

You generally get more return on investment if you invest in building infrastructure in your own country rather than investing in blowing up infrastructure in a different country. So I’m implying that solar and batteries are a lot cheaper than the war in Iraq.

[–] eptcyka 3 days ago

So far.

[–] shagie 2 days ago

That's referring to the Iraq and Afghanistan war with appropriations from 2003 to 2010. https://en.wikipedia.org/wiki/Financial_cost_of_the_Iraq_War

The Iran war that we're currently in is officially at 43B and estimated at 48B. https://iran-cost-ticker.com

[–] banktops 3 days ago

1 week national battery storage is totally doable. All we need to do is convince the rest of the planet to stop making GPUs, phones, computers, and EVs for the next decade, and then give us all their rocks. 78.4TWh is about $19T (all in costs) for a national battery grid for 1 week storage, could be built over ten years but would need the US to build and own double the current global output, not even considering where all the raw materials and labor comes from.

[–] traceroute66 2 days ago

> The US uses around 4TWh of electricity a night.

And if we subtract all those datacentres crammed with Nvidia GPUs ? ;)

If we're being honest here, the problem with the US is that it has always treated any sort of energy source as being infinite and has always been quite extravagant in its use of energy.

Whether a preponderance for gas-guzzling SUVs or datacentres the story is always the same. The US mentality is there will always be infinite oil in the pump and infinite electrons in the cable.

[–] jerven 2 days ago

Is that actually that much more than building 400GW worth of nuclear generation capacity (assuming 10 hours of nighttime)? I think that, that simple calculation shows that it is viable. Even a trillion is 1/32th of the US GDP. Construction over a decade should not stress the US economy at all.

I also think your trillion number is at least double the raw cell cost today.

[–] pinkgolem 2 days ago

A night goes 8 hours or so, so you need 50gw of nuclear

[–] jerven 2 days ago

500gw (Terra is 1000 Giga), which would make the nuclear story even worse.

[–] loomy7 2 days ago

Current li-ion pricing is $19 per kwh (BYD's latest cell's pricing), so a single battery that covers all 4TWh would come in at 76 billion dollars. Still a shit ton but reasonable.

[–] fpoling 3 days ago

Just by scaling up the existing technologies the full cost including installation and maintenance of a grid-scale battery in 5 years will be below 100 usd/kwh. So the price is max 400 billions or 1% of US GDP.

[–] thelastgallon 2 days ago

US has ~250 million cars. If they are all EVs (100KWh), it is 25TWh capacity.

Reserving 20% of that capacity to supply power back to the grid is 5TWh.

EVs can be charged for free during the day, ~20% of solar is lost due to curtailment. Even if a significant percentage (10 - 20%) of the people decide they are going on long drives from Florida to Vancouver and turn off supply-power-to-grid-for-money in the app, its fine, there are plenty of cars. It is the cheapest, most resilient, distributed and self-healing energy ecosystem. Only one problem, it won't make the super billionaires money. Unless it can be packaged in a way to make the super billionaires money, its a no go in US.

This infrastructure buildout costs nothing, people buy new cars all the time (~20M/year), just buy EVs instead. Because people are providing the capital and the storage infrastructure, they should be paid for it.

[–] HDThoreaun 2 days ago

I think this is a pretty decent idea and hopefully within a decade at least california will be doing it. The problem though is that the biggest advantage of an EV is that you charge it overnight and never need to worry about going to the gas station or running low on power. I think a pretty significant number of people would want 100% charge every morning which makes the total addressable battery size a good bit smaller.

[–] AnthonyMouse 1 day ago

EVs with 300 miles of range are pretty common. The average round trip commute is 42 miles, i.e. you have on average more than 7 days before you run out from a full charge. Turning that into ~5.5 days in exchange for chopping tens of dollars a month off of your own electric bill because you're paying the daytime solar price instead of the nighttime something more expensive price is going to be very popular.

And when you know you're taking a long trip you can still do a full charge without needing to do that the other 99% of the time.

[–] bijowo1676 3 days ago

USA should explore Pumped Storage Hydropower more, it has same or better efficiency than battery storage and can use existing facilities like hydroelectric dams

[–] buckle8017 2 days ago

The largest pumped storage facility in the world is in the us.

It's also pretty old.

"USA should look into thing it practically invented" good meme

[–] bijowo1676 1 day ago

then why are we bothering with importing batteries from China if USA has solved the problem with pumped storage ???

dont you see the problem with USA solving the problem and USA still having a lack of energy storage issue ???

[–] shagie 1 day ago

Dispatch time, total installed capacity, and regional power grids.

Batteries have a much faster dispatch time than pumped storage. Pumped storage is good for offsetting reduction in other production capacity, and its dispatch time is faster than peaker plants, but its not as fast as a battery.

https://en.wikipedia.org/wiki/Hydroelectric_power_in_the_Uni...

https://www.eia.gov/todayinenergy/detail.php?id=41833

2020 numbers had 22,894 MW of capacity. More storage capacity for power is needed.

The "where are things located" is in the mountains where there's a significant elevation change. Most of the country is too flat to have pumped storage be practical. Installed pumped storage in Michigan (about 2GW of capacity there) does little for the power demands of North Dakota.

And then... there's also building new ones.

    Even though FERC has issued licenses for three proposed pumped storage projects since 2014, no new pumped storage projects have come online in the United States since 2012. EIA’s most recent survey of planned power plant additions shows no pumped storage projects under development.

That may be in part from the 2005 failure at Taum Sauk. https://en.wikipedia.org/wiki/Taum_Sauk_Hydroelectric_Power_...

    At 5:12 a.m. on December 14, 2005, the northwest side of the upper reservoir was overtopped when water continued to be pumped from the lower reservoir after the upper was full. This led to the catastrophic failure of a triangular section of the reservoir wall and the release of 1 billion US gallons (3,800,000 m3) of water in 12 minutes. 

   ...

   As of 2011, Ameren was reported to have paid a total of close to US$200 million in settlements related to the 2005 breach.

[–] shagie 3 days ago

Part of the pumped storage problem is "where can you do it?"

There's a good number of 'em: https://en.wikipedia.org/wiki/Category:Pumped-storage_hydroe...

https://www.ferc.gov/media/licensed-pumped-storage-projects-...

You'll see that most of them are in the Appalachian mountains and in the Sierra mountain range.

The one in Missouri is one of the interesting ones that isn't in either.

https://en.wikipedia.org/wiki/Taum_Sauk_Hydroelectric_Power_...

> The Taum Sauk pumped storage plant is a power station in the St. Francois mountain region of Missouri, United States about 90 miles (140 km) south of St. Louis near Lesterville, Missouri, in Reynolds County.

It has a hydraulic head of 860 feet and that represents the challenge - you need to find places in the US where you can get several hundred feet of elevation in a short distance.

Hypothetically, lets build one in Minnesota... Taum Sauk Mountain is the highest point in Missouri. The highest point in Minnesota is Eagle Mountain (in the boundary waters - you can't build there, pretend we can) ... the elevation to the top os 550 feet (about half what Taum Sauk provides) over 3.5 miles (Taum Sauk is just over 1 mile). ( https://maps.app.goo.gl/vHfWarwubaLvsf5z7 )

Much of the US is too flat for it to be useful.

[–] justincormack 3 days ago

Coal is a dead end anyway.

[–] rr808 3 days ago

That might work in The SouthWest of the USA, but the Northern bits dont get enough sun to get through the day, so you'll need fossil fuel plants all day night for the Winter. If they're there already its cheaper to use all day in the summer as well.

[–] acdha 2 days ago

It’s more expensive to use them all day: that’s the problem facing power plant owners where renewables are so much cheaper that they break the economics for power plants which were designed to run continuously but are more expensive when wind and solar supply is limited.

(That’s the answer for the northeast, too: New England has no shortage of wind all winter long and batteries don’t care where the electricity comes from)