Commercial solar panels do not automatically need battery storage. A grid-connected solar PV system can supply electricity directly to the building without a battery, with the grid covering any shortfall and accepting permitted surplus export.
A battery should be considered when the site’s consumption pattern, tariffs, export position and objectives provide a clear operating purpose.
What happens without a battery?
Solar generation is used by site loads at the time it is produced. If the building needs more power, the balance comes from the grid. If generation exceeds demand, surplus may be exported subject to the connection and commercial arrangements.
When might a battery help?
- daytime solar surplus can be used later;
- the site has high demand after solar generation falls;
- export value is low compared with later avoided import cost;
- tariffs support an appropriate charging strategy;
- peak-demand objectives are technically achievable; or
- the business has a specifically designed resilience requirement.
When might it add limited value?
If a business already consumes most solar generation as it is produced, there may be little surplus to store. A battery can also be underused if it is too large, controlled poorly or evaluated without accounting for efficiency losses and usable capacity.
How should a commercial battery be assessed?
Model solar generation and half-hourly demand together. The appraisal should state battery capacity and power, usable depth of discharge, round-trip losses, cycling strategy, warranty assumptions, tariffs, export and replacement planning.
Does a battery provide backup power?
Not automatically. Standard grid-connected equipment normally disconnects during a power cut. Backup operation requires compatible equipment, protected circuits, switching and electrical design intended for that purpose. The available power and duration must be defined.
Can a battery charge from the grid?
Many systems can, subject to equipment, tariffs, connection requirements and the agreed control strategy. Grid charging can change the financial model and should not be assumed to be beneficial in every case.
Battery storage and G100 export limitation
Generation, storage and flexible loads may be coordinated within an approved import or export limitation scheme. The distribution network operator must agree the connection approach, and compliant equipment does not remove the need to follow the relevant process.
Questions to ask
- What problem is the battery solving?
- How many cycles are expected?
- Which data supports the sizing?
- Who controls the operating settings?
- What happens during a grid outage?
- How are warranties and replacement treated?
Ask Renew-Able Solutions to assess solar and battery storage against your site’s real load profile.
