Commercial battery installation: worked examples
These are illustrative scenarios, not real projects. Each shows how the connection, siting and switchgear would need to be engineered and commissioned for a site of that kind. No client, site or installation is claimed.
Worked example: 500 kW / 1 MWh containerised battery at a manufacturing site
Illustrative scenario, not a real project. A manufacturer wants to add production load but the DNO has quoted a long reinforcement for extra import capacity. Existing rooftop solar exports surplus at midday. The site has yard space but no spare plant room. The installation challenge is siting a container safely, tying into live HV switchgear without stopping production, and connecting on a constrained network.
- System (illustrative)
- 500 kW / 1 MWh LFP containerised BESS with G100 import/export limitation, integrated with existing 400 kW PV
- Saving (illustrative)
- £96,000/yr modelled (illustrative)
- Payback (illustrative)
- 6.6 years
- Commissioning
- Should be witnessed
In this scenario the container would be craned onto new hardstanding with separation and firefighting access agreed with the insurer; the HV tie-in would be planned into a single pre-agreed outage; a G100 limitation scheme could let the site add production load inside its existing capacity; and commissioning would be witnessed, with the O&M and fire documentation handed over. Submitting G99 at survey keeps the DNO milestone from extending the programme.
Worked example: 1 MW / 2 MWh battery for EV charging at a constrained depot
Illustrative scenario, not a real project. A distribution depot wants to electrify its vans and add rapid chargers, but the DNO has quoted a reinforcement and a long wait for extra import capacity. The existing connection is close to its limit at peak. The battery has to buffer charger spikes and keep the site within its agreed import capacity.
- System (illustrative)
- 1 MW / 2 MWh LFP containerised BESS with G100 import limitation, installed with the charging infrastructure
- Saving (illustrative)
- Modelled (illustrative): avoided reinforcement cost plus off-peak charging and demand-charge savings
- Payback (illustrative)
- 7.2 years
- Commissioning
- Should be witnessed
In this scenario the battery and chargers would be designed and commissioned together on the existing connection, with a G100 scheme holding the site within its agreed import capacity and buffering charger spikes. Whether that beats waiting for reinforcement depends on the DNO's quote and timescale, so compare both in writing.
Worked example: 200 kWh indoor battery cabinet for a cold-storage site
Illustrative scenario, not a real project. A chilled-distribution site relies on an ageing diesel standby generator and cannot risk its stock in an outage. There is no external compound, so the battery has to go in an internal switchroom, with an islanding design for the refrigeration critical load, in an occupied building.
- System (illustrative)
- 100 kW / 200 kWh LFP indoor cabinet with islanding capability for the refrigeration critical load
- Saving (illustrative)
- £26,000/yr modelled (illustrative), plus avoided diesel running
- Payback (illustrative)
- 7.8 years
- Commissioning
- Should be witnessed
In this scenario the cabinet would sit in a compartmented, detected and ventilated switchroom designed to the IET Code of Practice and the building fire strategy, with the insurer engaged up front; automatic transfer would be engineered into the existing distribution; and commissioning would be witnessed, with fire and electrical certification issued.
These worked examples are illustrative scenarios written for this guide. They are not real projects, the figures are illustrative rather than measured, and no client, site or installation is claimed. This site is an information site, not an installer.