Current 80% full system Round Trip Efficiency (RTE), for FAB larger than 1 MWh the aim is 84% RTE.
The system in modular and is easily scaled for both power and duration:
Power delivered kW [MW] - from 1,000 kW [1 MW] to 100,000 kW [100 MW] and more, controlled by the number and size of turbo expander generators (multiple suppliers worldwide from 20kW to 50 MW).
Energy stored kWh [MWh] - from 1,000 kWh [1 MWh] to 1,000,000kWh [1,000 MWh] and more, controlled by the number of storage cylinders (volume) for longer duration add more cylinders (multiple suppliers worldwide).
If a client is consuming 1 MW per hour and requires a storage system to cover 6 hours use, a 6 MWh system is required (1 MW generator running on 6 hours of air).
For every MWh the footprint is:
2 x 40 ft ISO Container
(or 1 x 40 ft ISO container footprint, double stacked, each container: w = 2.44 x h = 2.59m x I = 12.19m).
Compressed natural gas industry standard 250 bar.
Cost reduces with both increased power and duration.
Considering 6 MWh (1 MW continuous discharge for 6 hours) whole system capital cost is approximately £507 k/MWh considering storage element alone each additional MWh is approximately £240 k/MWh.
The solution has a 30 year plus operational life without end-of-life hazardous disposal, halving costs compared to lithium-ion.
Hours, days, weeks or months - the mass of air does not change unless it is generating electricity, the heat stores is fully insulated, with 300mm of insulation the heat loss from 180 degres Celsius water to the surrounds is 0.029 K/h. Therefore: 0.696 K/day, 4.872 K/week, 19.488 K over 4 weeks (worst case, without factoring in the reducing differential store temperature over time). Part of the inefficiency is expressed as excess heat, long term heat decay can be accommodated in system design.
Any excess energy can be stored, from the grid or onsite it is an electricity in and our system.
Highview Power (HP) are focused on long duration centralised energy storage while valuable to the National Grid Transmission Operator it is supporting a central generation pushing electricity to grid edge model. Sherwood is embedded storage at the grid edge working into the centre - there is space for both, a second distinguishing factor is round trip efficiency as HP are liquifying air it takes 3 to 4 compression and expansion phases, round trip efficiency, power in and out is low 42-50% (Sherwood Power 80%+).
The system is modular, additional generator power can be added by and additional run hours through the addition of more air cylinders.
Yes, the FAB system is containerised, all modules can be moved to alternative locations.
Yes, the system is asymmetric – it can be designed to charge and discharge at different rates and charge and discharge simultaneously
Yes it can be done, either by manipulating the power electronics or varying the discharge mass flow.