Comparing solar panel and battery quotes: what should be included?

A useful solar and battery quote explains what will be installed, why it suits your property and what the total price covers. When proposals use different equipment or assumptions, the headline figures can be difficult to compare.

Start by giving each installer the same information: your electricity use, roof details, existing solar equipment and what you want the system to do. Then work through these questions before choosing.

1. What equipment is included?

Look for the number, make and model of the panels, inverter and battery. A phrase such as “solar and battery package” leaves too much open.

Check the units: - kWp describes the solar array’s rated peak power under standard test conditions. - kWh describes an amount of energy, including estimated yearly generation and battery storage capacity.

For a battery, ask for its usable capacity and charging and discharging power limits. These help explain how much energy it can store and which demands it can meet. Ask why the proposed size suits your household.

2. Is the estimate based on your home?

Ask for the expected annual solar generation and the assumptions behind it. Roof direction, shading and the proposed panel layout matter. A prediction for a typical house may not describe yours.

Any savings illustration should explain the electricity prices used, how much generation you are expected to use at home, and how exported electricity is treated. If battery charging from the grid is included, ask which tariff assumptions apply.

Discuss likely changes, such as an electric car or heat pump. Keep estimates in perspective: future weather, usage and tariffs can change the result.

3. Does the price cover the complete installation?

Ask for an itemised written quotation, including applicable taxes, and a clear list of exclusions.

Check whether the price includes: - Survey and system design - Roof mounting equipment and scaffolding - Inverter and battery installation - Cable routes and necessary electrical alterations - Testing, commissioning and documentation - Making good and removal of waste

Ask what remains subject to a survey and which findings could change the price. Roof repairs, difficult access or changes to the electrical installation should be discussed before you commit. Any optional extras should be clearly identified.

4. How will the battery fit your property?

For an existing solar installation, provide the inverter’s make and model and any available installation paperwork. Ask the installer to explain the proposed connection and whether equipment needs changing.

Confirm the battery location, access for maintenance and the installation requirements for the proposed model. Take photographs from a safe position; there is no need to remove electrical covers.

If power-cut backup is important, ask whether the quoted installation provides it, which circuits it would supply and whether extra equipment is needed. Have the agreed arrangement recorded in the quote.

5. Who handles permissions and network paperwork?

Ask who will check any planning or other permissions and who will deal with the electricity network operator.

Solar and battery connections can follow different application or notification routes, including G98 and G99, depending on the installation. Ask whether approval is needed before work starts, whether export limits apply and whether any network charges are included.

Keep the agreed responsibilities in writing so it is clear what the installer handles and what you need to arrange.

6. What happens after installation?

Ask what you will receive at handover: operating instructions, commissioning records, relevant certificates, equipment details and maintenance guidance. If monitoring is included, confirm how you will access it and who will explain the controls.

Read the product warranties and the installer’s workmanship guarantee separately. Check the exclusions, claim process and any ongoing costs. Ask who to contact if something stops working and whether any insurance-backed protection applies to your particular installation.

Before accepting a quote

Check that you have: - Named equipment and a clear design - A property-specific performance estimate - A complete price and written exclusions - Agreed installation and paperwork responsibilities - Payment terms, timetable and cancellation information - Clear handover, warranty and support details

Take time to resolve anything unclear and keep the final proposal with your property records.

Planning solar or battery storage in Stone, Stafford or Stoke-on-Trent? Read about TMMRAC’s solar PV and battery storage service, or send your postcode, recent electricity use and any existing system details through our enquiry form.