Azelio: Energy Storage with Alu PCM + Stirling Engine

[SageBrush]

This is pretty neat
Stirling Engine ‹ Azelio

I imagine up to 40% of solar radiation to electricity efficiency

I still love PV, wind and battery technology but phase change devices are the key tech that brings us to the promised land. Amazing how versatile and useful they are. And to think I learned about phase change as a kid and never realized the potential.

I also suspect that stirling engines have a bright future as materials technology continues to advance.

 

[ItsNotAboutTheMoney]

This is pretty neat
Stirling Engine ‹ Azelio

I imagine up to 40% of solar radiation to electricity efficiency

I still love PV, wind and battery technology but phase change devices are the key tech that brings us to the promised land. Amazing how versatile and useful they are. And to think I learned about phase change as a kid and never realized the potential.

I also suspect that Stirling engines have a bright future as materials technology continues to advance.

40% efficiency would mean you get 40% of the shifted value of the original output.
Batteries give you 80% to 90% of value.

So the trillion dollar questions are, as always, how much per MW and how much per MWh?

 

[SageBrush]

40% efficiency would mean you get 40% of the shifted value of the original output.
Batteries give you 80% to 90% of value.

I mean that 40% of solar radiation is stored and then released as electricity.

Batteries typically store electricity collected from PV panels that are ~ 20% efficient (meaning they collect ~ 20% of the solar radiation.)
So the correct comparison would be 40% Vs (20*0.85)%. Or perhaps (0.9*25)% in the next couple of years for PV+battery.
Battery storage becomes *very* expensive past 2 -4 hours per day at today's prices; this invention is rated by the manufacturers for 13 hours of storage (at an unknown fractional heat loss.)

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As for cost, I imagine a fair starting point is comparison to garden variety CSP hooked up to combined cycle turbines + storage with molten salts. My guess is that this invention scales down much better than typical CSP. A couple per neighborhood perhaps ? I also am encouraged by the use of recycled Alu as the heat storage device. As an aside, while I am fairly skeptical of recycling in general, metals recycling is a different matter entirely and is a REAL THING (tm)

 

[ItsNotAboutTheMoney]

I mean that 40% of solar radiation is stored and then released as electricity.

Batteries typically store electricity collected from PV panels that are ~ 20% efficient (meaning they collect ~ 20% of the solar radiation.)
So the correct comparison would be 40% Vs (20*0.85)%

The fact that it's marketed mainly as a PV and wind add-on, with concentrating solar being a grid alternative, suggests to me that the costs aren't competitive on the thermal side.

 

[SageBrush]

The fact that it's marketed mainly as a PV and wind add-on, with concentrating solar being a grid alternative, suggests to me that the costs aren't competitive on the thermal side.

That is just saying that it is a storage alternative to PV+ battery.

It is not going to compete with 2 hour battery storage.
4 hour ? I'm not sure
12 hours ? Battery is not even in the conversation, and we *do* need some quantity of 12 hour storage

 

[SageBrush]

Supplemental information on Alu
Aluminum and silicon based phase change materials for high capacity thermal energy storage - ScienceDirect

The latent heat per kg of Alu phase change between liquid and solid is similar to water phase change between liquid and gas. The key advantage is 1/10 the volume change as the phase changes. So both are ~ 0.6 kWh per kg

 

[iPlug]

Would be a welcome renewable energy storage addition if it can find a cost competitive place in the market.

Azelio’s claimed 13 hours of dispatchable electricity production is alluring. Standard CSP with storage has not seemed to find its place in the current market.

Azelio markets their tech as pairing with solar PV, wind, or concentrated solar. Among several selling points, no water use is a plus as areas that are typically high solar irradiance are quite often also water stressed.

Hopefully the efficiencies of an Azelio type thermal energy storage system can drive down costs to become a competitive market player. The need is certainly there.

 

[SageBrush]

Would be a welcome renewable energy storage addition if it can find a cost competitive place in the market.

Google says scrap Alu is ~ 30 cents a pound, so 66 cents a Kg. A Kg is about 0.2 kWh of latent heat so figure $3.3 a kWh of heat. Then consider efficiency of 0.3 - 0.4. Sounds like $10 a kWh (electric) for the scrap Alu part of the story.

This is the anti-capacitor: slow and cheap