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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

#91

Post by londons_explore »

ggm wrote: post #50
skybrian wrote: post #21

Earlier quoted context omitted.

Okay, but once there are competing possible uses of "extra" electricity, it's going to have a price, and if the price is high enough, then high energy losses will result in some of the alternatives being uneconomical. I think it's going to be hard to pick winners, even if you do some of the math.

Okay, but once there are competing possible uses of "extra" electricity, it's going to have a price, and if the price is high enough, then high energy losses will result in some of the alternatives being uneconomical. The idea would be (for me at least, I am not neutral in this) to marginalise the coal and oil and gas generation to make it the most expensive form. If you live in Poland, or Victoria (Australia) you ha…

>. The economic costs of killing children, quite apart from the social costs, are huge.

Citation needed. Considering the economic side only, most places I've seen this cited around $3 - $30 Million per person killed, and compared to many emissions reduction tech, killing people is cheap.

Re: Alphabet spinoff Malta raises $26M for technology to store power in molten salt

#92

Post by rklaehn »

iainmerrick wrote: post #79

Similar technology already in production in the UK: https://www.sunamp.com 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 wit…

This is not really the same. Malta seems to use a heat pump to produce reservoirs of both hot and cold material. This allows to produce electricity via a carnot process with very high efficiency (theoretically 100% because while the carnot process that produces electricity has an efficiency 1). In practice they might get to 70% efficiency or so.

Sunamp.com seems to be just ohmic heating for thermal usage of excess electricity.

Re: Alphabet spinoff Malta raises $26M for technology to store power in molten salt

#93

Post by londons_explore »

spqr0a1 wrote: post #48
Pxtl wrote: post #41

Earlier quoted context omitted.

Pneumatic energy storage and pumped water storage both have very low efficiency but also low cost, so there are plenty of techs in this space that are being explored. The question is whether wind and solar can be made cheap-enough to be worth overbuilding them five times over to feed into inefficient energy storage, or if we should just stick to batteries or hydrogen.

Pumped storage has ~80% round-trip efficiency. It's as good as lithium batteries. The biggest limitation is that there's not much room for growth. Most good sites for pumped storage have already been built.

In the developed world, flooding cities to make hydro stations is very unpopular...

Re: Alphabet spinoff Malta raises $26M for technology to store power in molten salt

#94

Post by londons_explore »

proee wrote: post #37
Retric wrote: post #5

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…

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.

An electric heater's efficiency is "100%", but there are known ways to get much more than 100 percent for typical use cases. For example, heating your house with a heat pump can easily be 300% efficient, since you are also cooling down the outdoors.

"Electric heaters are 100% efficient" should really be "Electric heaters are only 33% as good as this other way of doing it".

Re: Alphabet spinoff Malta raises $26M for technology to store power in molten salt

#95

Post by londons_explore »

blurbleblurble wrote: post #43

This is extremely exciting technology! Any energy science aficionado worth their salt knows that molten salt can have very high energy density.

The paper says that at around 600C, nearly all materials have the same energy density.

Molten salt was chosen because it is a liquid, cheap, safe, and stable.

The paper also considers using rocks, but they're tricky to pump...

Re: Alphabet spinoff Malta raises $26M for technology to store power in molten salt

#96

Post by londons_explore »

occamrazor wrote: post #70

My memories of thermodynamics theory are old and full of gaps, but from what I remember both steps, if performed at "normal” temperatures, necessarily produce a waste of energy. The first step, i.e. using electricity to drive a heat pump, is efficient only if the temperature differential between the cold body and the hot one is small. On the other side, conversion of thermal energy into electricity is efficient only…

Your memories are wrong...

An ideal heat pump is fully reversible with no energy loss.

Re: Alphabet spinoff Malta raises $26M for technology to store power in molten salt

#98

Post by londons_explore »

tkahnoski wrote: post #44
hwillis wrote: post #32

Earlier quoted context omitted.

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.…

This is interesting from a sustainability model. Both lower tech to manufacturer and I'd assume less damaging to the environment than a lithium mine.

This design also needs almost double the amount of hexane...

Not so environmentally friendly...

Neither are used up though, and probably won't devalue with time, so the financial cost of them is just interest payments, and the environmental cost is zero.

Re: Alphabet spinoff Malta raises $26M for technology to store power in molten salt

#99

Post by iainmerrick »

dangravell wrote: post #88
ogrisel wrote: post #84

Earlier quoted context omitted.

Are you sure sunamp is molten salt? To me, molten salt is to store energy at a very high temperature in insulated containers. I thought sunamp is some kind of room temperature phase change material that does not require heavy insulation.

Was going to mention Sunamp. It does use a PCM, and that is described as a salt so maybe it's where the confusion comes from. It also has far better insulation than equivalent devices (hot water cylinders). Typically VIPs, although I've read a few reports about the casing being compromised recently and that wouldn't play nicely with the panel.

Yes, I glommed onto the use of “salt” in both cases and figured they were similar.

Re: Alphabet spinoff Malta raises $26M for technology to store power in molten salt

#100

Post by nopinsight »

Bombthecat wrote: post #97

Just a question: why does a sub from Google need to raise money? I would question the confidence if a super big company starts something and is like: uh you know. We collect money from someone else.

For partnerships in an industry with powerful entrenched interests? An analogous example is the Amazon/Buffett/JP Morgan partnership in healthcare.
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