Ceramic Energy Storage
Wind and Energy Cannot be Stored
Producers are only paid when they sell power.
The more capacity is installed, the less operators are paid as all must sell at the same time.
So today wholesale solar electricity prices in California drop to zero from 1030 am to 1630pm.
German Whole Sale Prices
EU wholesale electricity prices also fluctuate predictably
Here prices range from 15-250 euro MWh within a 36 hour range.
Storing energy for 36 hours will be very profitable.
Whoever manages to store at scale could own this market.
Ceramic Energy Storage uses ordinary bricks heated by electric coils .
like traditional stoves popular in northern countries.
This storage has been used for centuries because it is so efficient.
Heavy industry uses it now to balance energy cycles.
Heavy industry uses high temperature Cowper regenerators to achieve:
* heat cycling rates up to 300 MW
* hourly cycling
* near-continuous operation
* 20-30 year lifetime
Regenerators are cheap and can be adapted to create GWh scale storage right now.
Renewable electricity is fed into a brickwork furnace via electrodes. Energy is stored until it is needed (3-96 hours).
To extract energy, hot air, gas or steam is blown through the brickwork, then piped into a steam turbine combustor via a recuperator.
This schematic shows an example of the last part of the cycle.
Batteries store electricity as charge, then discharge it. Super simple. Calix has chosen a different path, storing electricity as heat, and turning it into steam to drive a steam turbine. An apparently more complex system that is likely to be less efficient.
But steam turbines are already an key part of the power generation loop. All power stations employ steam turbines to actually create electricity. By using this system there’s little efficiency drop.
The key takeaway is that rather than being less efficient, this form of energy storage can be nearly as efficient as battery storage. We are aiming to achieve energy recovery near 60% in the short term, and closer to 80% in the medium term.
Calix’s key technology innovation relates to the transfer of heat into steam turbines. We use a closed loop inert gas system and transfer energy to the turbine by interfacing directly into the compression chamber.
Typically this will require modifications to existing combined cycle gas turbine plants. New builds will be built with the modifications installed.
Our R&D program includes Computational Fluid Dynamic simulations which will produce data on aspects of the closed loop, energy flow and insulation design.
Technical R&D issues relate to the ultimate degree of thermal efficiency the system can produce.
Li-Ion is not a realistic competitor. Salt is. Battery maker CATL is now selling a Sodium-Ion battery for the transport market .
Salt is cheap and abundant so can in theory compete directly with ceramics.
If CATL decides on a research program using Sodium-Ion, the R&D ramp might be in the 4-5 year range. The main hold up will be supply chain issues (10 year horizon?).
If ceramics reach 60% efficiency they will still be the obvious choice for GW power plants.
Prototype Development Timeline
Sketch of Nova One Demonstrator
Six hexagonal brickworks heated by electrodes
Air gas or steam is blown through passages and fed into a central steam turbine for conversion into electricity
800-1500c working temperature
500KWh+ energy density per cubic meter
Suitable for Wind and Solar up to 4GWh
Potential for a 6 hour discharge cycle
Schematic of Brickwork with Fluid Shafts
There are many benefits of ceramic energy storage and reasons to invest in the development of our technology including: