Where are the molten salts coming from?
I believe they're sourced from John McAfee
Alphabet spinoff Malta raises $26M for technology to store power in molten salt
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Re: Alphabet spinoff Malta raises $26M for technology to store power in molten salt
#32Where are the molten salts coming from?
Typical mixtures use eg potassium nitrate, sodium nitrate, and calcium nitrate. Salts are one of the most produced substances on earth. For instance, potassium nitrate is in virtually every fertilizer. I couldn't find how much is used annually, but it's made from potash, and US reserves of that are ~270 million tons[1]. At 40 to 110 kWh/ton[2] that's a minimum of 10.8 billion kWh (10.8 TWh), or a full day of storage.
[1]: https://minerals.usgs.gov/minerals/pubs/commodity/potash/mcs...
[2]: https://www.solarthermalworld.org/content/molten-salt-storag...
Re: Alphabet spinoff Malta raises $26M for technology to store power in molten salt
#33Earlier quoted context omitted.
Germany and California have both experienced negative electricity prices. The economics of this kind of battery could very well work with a low efficiency if it's cheap to build.
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.
Re: Alphabet spinoff Malta raises $26M for technology to store power in molten salt
#34The 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…
A lot of the fundamentals have actually already been researched and at least in academia, the various ideas have all been out there for quite a few decades now. The main impetus has been in getting the funding to kickstart everything, and backing from Alphabet with strong financial support plus an intellectual talent from subsidiaries (Google, X, etc.) to pool from is the killer combination here in my opinion.
Have any links to share?
Re: Alphabet spinoff Malta raises $26M for technology to store power in molten salt
#35Re: Alphabet spinoff Malta raises $26M for technology to store power in molten salt
#36The 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…
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.
Re: Alphabet spinoff Malta raises $26M for technology to store power in molten salt
#37The 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…
Generating heat from electricity is nearly 100% efficient, so the round trip is probably a lot higher than you think. Plus, we're dealt with some pretty competent engineers here. I'm pretty sure they ran through the napkin calculations more than once on the targets they need to hit.
Re: Alphabet spinoff Malta raises $26M for technology to store power in molten salt
#38Re: Alphabet spinoff Malta raises $26M for technology to store power in molten salt
#39Earlier quoted context omitted.
Solar can generate heat directly, using Concentrated Solar Power plants: https://en.wikipedia.org/wiki/Concentrated_solar_power
Those are horrifically expensive relative to PV and largely abandoned tech. A core issue is you can’t concentrate sunlight on a cloudy day making them even less dependable than PV. The Ivanpah Solar Power Facility even reverts to natural gas, this is while costing 4x what PV does. PS: By abandoned the worldwide concentrating solar power installed over the last 20 years is ~1/2 the amount of PV added every month.
Spot on. I made a whole bunch of Solar Concentrator models and did a number of calculations on them. The work was probably flawed for very precise budgeting but order of magnitude should have been correct and even then it would not work, not even close.
The best I found was a moveable array of mirrors and stationary collectors but this too is fragile and a maintenance headache. Leaks of working fluid and mechanical problems would ruin the economics even if you could get the basics to work out in your favor.
Re: Alphabet spinoff Malta raises $26M for technology to store power in molten salt
#40Earlier quoted context omitted.
A lot of the fundamentals have actually already been researched and at least in academia, the various ideas have all been out there for quite a few decades now. The main impetus has been in getting the funding to kickstart everything, and backing from Alphabet with strong financial support plus an intellectual talent from subsidiaries (Google, X, etc.) to pool from is the killer combination here in my opinion.
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.