Solar panels with battery storage
in Chelmsford.

Compare panels-only and battery quotes

Request two written options using the same roof layout and panel specification. Both should use the same household demand and tariff assumptions. Ask the installer to show the extra battery cost separately. The quote should also show the change in forecast electricity imports and exports. That makes the storage decision clearer than comparing two unrelated package prices.

Check how each proposal accounts for energy lost during charging and discharge. Ask which assumptions would change if your daytime use increased or your tariff changed. A battery can shift energy into the evening or another useful time. This page does not promise a saving or payback period.

Check usable capacity and warranty conditions

Ask whether the quoted capacity is nominal or usable. Check how much remains after any backup reserve is set. Request the written warranty and ask which time, usage or retained-capacity conditions apply to that model. Compare these with the installation and support terms. One headline number is not the whole specification.

Energy Saving Trust: battery storage · checked 14 September 2026. Capacity and suitability depend on the system and household.

What is included in battery backup?

Ask for a list of backed-up circuits and any appliances excluded from it. Request the discharge limit and the expected duration under your chosen loads. Check how much reserve is kept for outages. Whole-home and selected-circuit backup are different plans. The installer should explain what the actual equipment and wiring support.

Manufacturer documentation is specific to its products. For example, Tesla explains whole-home and partial-home backup arrangements. Use this source to prepare questions. It is not a brand recommendation, and it does not claim that every battery provides those functions. Source checked 14 September 2026.

Where could the battery be installed?

Mark the planned battery and inverter positions on the survey drawing. The installer should explain access, cable routes and the manufacturer’s installation rules. Avoid choosing a location from cabinet dimensions alone; the installer needs to assess the complete installation.

For homes near the Chelmer, Blackwater or Crouch, use the exact address for the flood check. Do not rely on the town name. If the GOV.UK long-term flood-risk service identifies a concern, raise it before agreeing the equipment position. The tool is a starting point for discussion, not an installation design. See the guide for your town for local property checks.

Export electricity or store it?

Ask how much of the proposed generation you would use directly, store and export. Check export-tariff eligibility and metering rules with the supplier. Ask how it treats a system that also charges from the grid. Do not assume the purchase price and export payment for a unit of electricity are the same.

Ofgem: Smart Export Guarantee explains the scheme. Use the supplier’s current written terms when comparing options; this page does not quote a tariff.

Keep access to the system data

Confirm who creates the monitoring account and which readings it shows. Check whether the homeowner keeps access if the original installer stops providing support. Ask how faults are reported, which alerts require action and whether monitoring support carries a separate charge. Put any app, gateway or internet need in the written scope. The handover should cover more than switching the battery on.

Bring a complete brief to your solar enquiry

• Annual electricity use and when the household needs power.
• Roof photographs taken from the ground and any known roof work.
• Whether your priority is using more solar generation, tariff flexibility or backup.
• Proposed equipment location and any access or property constraints.
• Two quote scopes covering equipment, scaffolding, electrical work, exclusions, commissioning and support.

This site handles enquiries about batteries as part of a new solar installation. Existing-system repairs and standalone battery retrofits are outside the advertised service. An installer must confirm coverage and suitability before offering work. Use our quote and paperwork guide to check the wider installation scope.