71–80 of 136 posts
Oh lord, can't you pick less conflicting names? Why don't I just name my company Jeff Bezos LLC?
Actually Google seems to be one of the worst at choosing googlable names ('Alphabet').
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Think of it like this: You produce energy at an amortized cost of $X /MW. You store energy efficiently (lithium batteries) at an amortized cost of $Y /MW back into the grid. You store energy inefficiently (Malta?) at an amortized cost of $Z /MW back into the grid. If Z<< Y, then simply ramp up your input production and you are likely in the money. Also, I'm not sure what you mean by "Worse heat has fairly low energy…
Solar farms are ~0.8 MW / acre that adds up fast. Many current nuclear powerplants are similar energy density when you consider all the space inside the fencing. Energy density is more a problem of materials. If you start talking GW hours it’s ~1GW from a ~38 ft tall and 48 meter diameter tank, even at $1,000 per ton it adds up. On top of that you need steam turbines etc.
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Have any links to share?
https://aip.scitation.org/doi/10.1063/1.4994054 This is the paper the Malta team uses in their blog ( https://blog.x.company/introducing-malta-81bceb559061 ) on explaining how the system works at large. It’s a pretty good summary.
The neat little graph showing the rise in global yearly investments up to 2040 is amusing. Nassim Taleb has made me very wary of these things. what's even the calculation behind a projection like that, it even has a little spike in 2035!
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The cost moment to stop and start spinning metal is huge. These devices can't bid at 5min intervals let alone 30sec. They are precisely the ones which benefit from a method to store electricity, because making steam not exist means then spending time making it exist again, to spin the turbine. They bid into 30 minute supply price moments and then try to run at the highest contract bid price for as long as possible. G…
Thanks - funny how diesel locomotives stay iddling for hours, yet our diesel cars now turn off when stopped for just a few seconds - due to idiotic CO2 related testing and legislation. Result, a horrible experience of noise and lurching, often every few minutes in traffic, less responsive so less safe, more engine ware, all for zero fuel actually saved.
The additional wear is not on the engine itself but on the starter components and those are simply designed for the additional load so that they can deal with the starts and stops.
The rather extreme losses associated with electricity > heat > heat engine > electricity seem like an absolute deal killer. Assuming they are at an extreme 50% round trip efficiency you need to be extremely cheap to have a hope of breaking even. Worse heat has fairly low energy density and cools over time so they can’t really scale the up or down that much. It might be possible if they where starting with heat, but f…
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Solar farms are ~0.8 MW / acre that adds up fast. Many current nuclear powerplants are similar energy density when you consider all the space inside the fencing. Energy density is more a problem of materials. If you start talking GW hours it’s ~1GW from a ~38 ft tall and 48 meter diameter tank, even at $1,000 per ton it adds up. On top of that you need steam turbines etc.
From the description, it sounds like a giant Peltier device, not a steam turbine (otherwise why would they care about having a cold tank?). Solar farms also have a ton of space in between turbines so I’m not sure that metric is relevant. Additionally, since this device uses very safe materials (salt and coolant), there’s no reason you couldn’t dig a really big hole and shove the device inside...it would also provide…
Think of it like a scaled up, reversible refrigerator.
I'd like to know if they also have a 'medium temp' tank, since if they do, they can keep the temperatures of the hot and cold tanks constant, and just change the amount of molten salt in them. That in turn means the compressors can be fixed compression ratios, which will dramatically increase efficiency.
They make a molten salt heat battery for homes and businesses. You store excess heat or electricity in the battery, and use it for central heating and hot water. Since you’re not trying to convert it back to electricity it’s very efficient. It basically replaces a large expensive water cylinder with a smallish box.
PS: I have no connection with or investment in Sunamp, I just think it’s a terrific idea. I am a potential customer, though!
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No, not really- negative prices are very short spikes. They aren't driven by fundamental oversupply, they're caused by fossil plants that are unable to ramp down their power output quickly enough to keep the grid in spec. The amount of storage required is very small, but the required power and speed are high. The whole price advantage of thermal storage is in the amount of stored power. It's very cheap to build insul…
Negative electricity prices are also driven by wind subsidies. Wind producers get 2.3 cents per kilowatt hour in tax credits. This means they make money even when the price of electricity is negative—-up to 2.3 cents a kilowatt hour.
It also isn't true that turning off any power station can't be done instantly. The station has to be able to cope with all its transmission lines suddenly being cut, which is a forced instant turnoff. It's more that the startup time is large, and they think that by losing money now, they'll still be running later when the power price is positive again.