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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

#21

Post by skybrian »

ggm wrote: post #14
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…

Compare the economics of loss here, to the economics of not storing the electricity, and so wasting it in other ways. Yes, there is a round-trip loss through the system. No, this is not always in economics, an insurmountable problem. For instance, "the hump" which was the US air shipment of materiel to China, in order to bomb Japanese forces was obviously a major loss maker in energy terms. Some huge multiplier of fu…

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.

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

#23

Post by empath75 »

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…

If energy is free or nearly free and it’s being wasted currently, then how much does the efficiency really matter?

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

#24

Post by kortilla »

ggm wrote: post #14
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…

Compare the economics of loss here, to the economics of not storing the electricity, and so wasting it in other ways. Yes, there is a round-trip loss through the system. No, this is not always in economics, an insurmountable problem. For instance, "the hump" which was the US air shipment of materiel to China, in order to bomb Japanese forces was obviously a major loss maker in energy terms. Some huge multiplier of fu…

>Energy in the form of electricity is fleeting. If you don't convert it to a persisting potential energy form, it isn't there when you want it. Loss in the system is well understood by the engineers, financiers, planners.

This is true, but it only makes sense if you are talking about generation sources that can’t be controlled (e.g. solar, wind). It’s a complete waste if you’re just storing energy from something like natural gas plants, coal, etc. In the latter cases you are better off deferring generation of electricity you don’t need.

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

#25

Post by Retric »

empath75 wrote: post #23
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…

If energy is free or nearly free and it’s being wasted currently, then how much does the efficiency really matter?

First if you can’t charge every day then your capital costs are effectively much higher.

It’s only ‘free’ before you have a battery in place that can use it. With this buying at 3c/kWh and selling at 6c/kWh is losing money. If anything else can profit and scale by buying at 3.01c/kWh and selling at 6c/kWh then that’s going to win.

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

#26

Post by ddp26 »

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…

Solar can generate heat directly, using Concentrated Solar Power plants: https://en.wikipedia.org/wiki/Concentrated_solar_power

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

#27

Post by Retric »

ddp26 wrote: post #26
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…

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.

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

#28

Post by hwillis »

pytester wrote: post #11
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…

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 insulated tanks. It's expensive to build large turbines, pumps and heaters, the things you need for fast response. Thermal batteries are already kind of iffy compared to batteries (or rather, where batteries will be in 5+ years), so if you skew that price by several factors by going for high power, chemical batteries are definitely cheaper.

In a fully renewable grid, you'd need longer term storage like thermal batteries. 3 days is the most common figure. The electricity price would never go negative, even without batteries- renewables just turn off too quickly. You can just unplug solar panels if they're generating too much power.

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

#29

Post by jkravitz61 »

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…

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 density and cools over time"... energy density is not relevant at all when you have practically unlimited space to store power (GIANT) fields next to your solar/wind farms.

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

#30

Post by starbeast »

ams6110 wrote: post #16
bch wrote: post #9

Earlier quoted context omitted.

From the blog post: > Malta’s solution is to store electricity as heat in high temperature molten salt and cold in a low temperature liquid for days, or even weeks, until it’s needed. The key insight behind Malta is that electricity can be stored as heat in high temperature molten salt and cold in a low temperature liquid for days, or even weeks, until it’s needed. The key insight is an oft forgotten energy storage f…

How can energy be stored as cold? Cold is by definition the absence of energy.

0 - you must play the game

1 - you can never win

2 - you can only break even on a very cold day 3 - it never ever gets that cold

----

f.n. >> the maximum efficiency of the work that can be extracted from a heat cycle is dependent on the relative difference between the hot end and the cold end and absolute zero. The closer you can get the cold end to zero relative to the hot, the higher the efficiency. The energy of a heat engine comes from the potential. If everything is equally hot there is no potential energy just as much as if everything is equally cold. If there is a gradient, you can do work.

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