Maximising battery storage by charging at cheap rates from the grid
Energy prices are at an all time high and are likely to continue to increase. With the right battery storage system, it's possible for a household to store enough electricity to supply the full demand of the property. A typical low voltage battery storage system such as Givenergy will charge from the grid or solar at 2.5kWh, meaning 10kWh can be stored during the 4 hrs of Octopus Go’s low rate. And/or will charge at 2.5kWh from your pv array. It can also discharge at 2.5kWh to the property which may meet the demand of an average/low demand property most of the time.
With a higher charge/discharge system such as GSL All In One Or Turbo, it’s possible to charge and discharge at a rate of 5kWh, translating to 20kWh can be stored during the 4 hrs with Octopus Go. And will meet the demand of a property up to 5kwh potentailly resulting in far greater savings if your demand is often more than 2.5kWh. With Turbo, Sunsynk & SolaX it is also possible to have multiple systems to potentially meet even the highest demand properties.
Sizing & selecting which battery storage system is right for you
Two key factors to take into consideration when selecting the battery storage system are the storage capacity and your peak demand.
The advisable storage capacity can be calculated by looking at your average usage over a 24hr period, and determining how much of this amount you wish to be able store. If you don't have a smart meter this can be found on your electric bills or by contacting your supplier. Over-sizing will mean that more capital will be invested than required, but can allow for increased usage in the future. Under-sizing usually results in lost potential savings, but maximises the capital invested.
If you have solar pv then you need to look at how much spare electricity you are generating during the day time that can be stored and how much of this is worthwhile storing to for after daylight hours. This can also be combined with how much you want to charge at night time from the grid to top up the batteries.
Peak demand is the maximum electricity demand at any given time of the day. It is important to know your peak demand to ensure the system you go with will meet either all or most of your demand. A system that cannot supply this demand may mean you still need to draw significant amounts of electricity from the grid during costly peak-rate hours. For example, if you regularly have 5kW of high demand appliances running, and you only have a battery system that can discharge at 2.5kWh, you will still require 2.5kWh from the grid. Whereas If you have a system that can discharge at 5kWh then you will meet your peak demand without needing to draw from the grid.
Battery storage key comparison
All prices for illustrative purposes only based on typical system sizes and accurate at the time of publishing. Please refer to product pages for up to date prices.
Battery system | Availability | Type | On or Off grid | Multiple chargers | Charge/ Discharge rate |
Maximum Capacity | Typical Battery cost/kWh | Typical Kit cost/kWh | Depth of Discharge |
20.48kw GSL 5kw Hybrid | Good | All In One | On & Off grid | No | 5kW | 40.96kWh | £262 | £349 | 80% |
Turbo 5kw Hybrid / Pylontech 19.2kw | Good | Stackable | On & Off grid | Yes | 5kW | 76.8kWh | £275 | £344 | 95% |
Sunsynk 5kw Hybrid / Pylontech 19.2kw | Good | Stackable | On & Off grid | Yes | 5kW | 76.8kWh | £275 | £348 | 95% |
Sunsynk 5kw Hybrid / Sunstynk 20.48kw | Good | Stackable | On & Off grid | Yes | 5kW | 76.8kWh | £373 | £454 | 100% |
Alpha 5kw Hybrid 11.4kw | Poor | All In One | On grid | No | 5kW | 34.4kWh | £417 | £578 | 96% |
Givenergy 5kw Gen2 Hybrid 9.5kw | Good | wall or floor mounted | On grid | No | 3.6kW | 47.5kWh | £356 | £505 | 100% |
Givenergy 3kw AC 9.5kw | Good | wall or floor mounted | On grid | Yes | 2.5kW | 47.5kWh | £356 | £466 | 100% |
Solis 3kw RAI / Pylontech 19.2kw | Good | Stackable | On grid | No | 3.3kW | 29kWh | £275 | £329 | 95% |
Solis 5kw Hybrid / Pylontech 19.2kw | Good | Stackable | On grid | No | 5kW | 29kWh | £275 | £349 | 95% |
Fox HV Cube 5kw Hybrid 28kw | Good | Stackable | On grid | No | 5kW | 28.21kWh | £369 | £405 | 90% |
Fox HV Cube 5kw AC 28kw | Good | Stackable | On grid | Yes | 5kW | 28.21kWh | £369 | £394 | 90% |
Fox HV2600 5kw AC 18.2kw | Good | Stackable | On grid | Yes | 5kW | 18.2kWh | £333 | £390 | 90% |
SolaX 5kw Hybrid 17.4kw | Good | wall or floor mounted | On grid | Yes | 6kW | 17.4kWh | £338 | £432 | 90% |
SolaX 3.6kw AC 17.4kw | Good | wall or floor mounted | On grid | Yes | 5kW | 17.4kWh | £338 | £403 | 90% |