What should a solar battery storage quotation include?

A useful quotation should let you compare the whole installed system, not just the battery price. It should show how the system has been designed for your home, what the installation includes, which assumptions support the financial estimate and what happens after commissioning.

Start with the proposed system. The quotation should identify the battery model, usable storage capacity and maximum charge and discharge power. Usable capacity matters more than the headline figure because some stored energy may be held in reserve by the controls. The quoted figures should make clear whether they refer to the battery alone or the complete system.

Your existing solar installation may limit the way a battery can be added. The quotation should explain whether the proposed system uses the existing inverter, adds a separate battery inverter or replaces equipment. If you do not already have solar panels, it should show how the panels, inverter and battery work together. It should also state whether the battery can charge from the grid, export energy or operate with a time-of-use tariff.

The design should relate to your electricity use. A larger battery is not automatically a better choice. If your evening and overnight demand is modest, extra capacity may sit unused. If you use an electric vehicle, heat pump or electric heating, your demand pattern may justify a different design. The quotation should explain the expected charging and discharge pattern rather than selecting a size without evidence.

Ask to see the information used for the design. This might include electricity bills, half-hourly smart meter data, solar generation records and details of major electrical loads. If those records are unavailable, the quotation should say which estimates have been used and where the result may be less certain.

The financial section should show its working. A credible estimate separates the value of solar energy used in the home, energy bought from the grid, exported electricity and any saving from shifting consumption to cheaper periods. It should state the tariff assumptions, export rate, annual electricity use and expected solar generation. If your tariff changes, the result will change too.

The quotation should not present a single payback period as a promise. Ask whether the estimate includes battery losses, standing charges, future changes in tariffs, degradation and the cost of replacing equipment outside its warranty. A simple explanation of the assumptions is more useful than an attractive figure with no supporting detail.

Check every part of the installation scope. The price should say where the battery will be installed and how the cable will reach the consumer unit, inverter and meter position. It should cover the mounting system, isolators, protection devices, labour, commissioning and removal of packaging or redundant equipment where applicable.

Your consumer unit may need additional protection or modification. Older wiring, an unsuitable location or limited spare capacity can add work. A good quotation identifies this after a survey, or clearly marks it as an item that depends on further checks. It should not leave electrical remedial work to an undefined extra charge.

External cable runs, drilling through thick walls, loft access, listed-building restrictions and difficult parking can all affect the installation. If scaffolding, lifting equipment, joinery, asbestos checks or remedial building work might be needed, the quotation should state whether these are included, excluded or subject to a separate price.

Location and safety need a written explanation. The quotation should show the proposed position and explain why it is suitable. The room, wall or outbuilding must provide appropriate access and protection from damp, extreme temperatures and accidental damage. The route should also work with the manufacturer’s installation requirements and the relevant electrical regulations.

If the preferred position is inside a garage, loft or utility room, ask how temperature, ventilation and access will be managed. If the battery cannot go in the ideal location, the quotation should explain the practical alternative and any additional cable or protection costs.

Grid and export arrangements should be clear. The quotation should state who will deal with any required distribution network notification or approval and whether that work is included in the price. It should also explain how the system will connect to your meter and export electricity safely.

MCS certification matters if you want the installation to support a Smart Export Guarantee application. It also allows us to make a Boiler Upgrade Scheme grant application on your behalf when a heat pump is part of a wider project. For a solar and battery quotation, check that the certification and handover documents needed for export registration are included, and ask who submits each part of the application.

Warranty terms need more detail than a headline duration. The quotation should identify the battery, inverter and installation warranties separately. It should explain the warranty period, any throughput or cycle limit, the minimum retained capacity and the process for making a claim.

Some warranties depend on correct commissioning, remote monitoring, software updates or registration with the manufacturer. Others exclude damage caused by unsuitable temperatures, unauthorised alterations or use outside the stated operating conditions. These conditions should be easy to find before you accept the quotation.

Ask who will investigate a fault and whether the installer or manufacturer handles the first response. The quotation should state what is covered if the battery stops charging, the monitoring system loses connection or the inverter reports an error. It should also distinguish a warranty repair from chargeable maintenance or replacement work.

Monitoring and handover should be part of the price. The quotation should say which monitoring platform you will use and what it shows. Useful information includes solar generation, household consumption, battery state of charge, import and export and system faults. It should also explain whether an internet connection is required and what happens if the connection is lost.

At handover, you should receive operating instructions, certificates, warranty registrations, commissioning records and details of the equipment fitted. We explain the controls and show you how to read the system rather than leaving you to interpret an app without context.

Read the exclusions and payment terms carefully. The total should show VAT and identify any assumptions about access, existing wiring, the meter and the internet connection. It should also state the deposit, stage payments and balance date, along with how long the quotation remains valid.

Look for exclusions covering scaffolding, consumer unit replacement, cable routes, building repairs, meter work, tariff changes and extra travel or access requirements. An exclusion is not necessarily a problem; an unclear exclusion is. You need to know what could change the final price and how you will be told before extra work starts.

Our written quotations set out the agreed work before it begins. If a survey finds an issue that changes the scope, we explain it and price it before proceeding. Engineers work tidily and leave the property as they found it, but the quotation should still tell you what disruption to expect, including drilling, cable installation, power isolation and access to the consumer unit.

Before comparing quotations, check that each installer has priced the same outcome. One price may include a replacement inverter, upgraded protection and commissioning, while another may show only the battery hardware. Compare usable capacity, power, control features, installation scope, warranties, paperwork, exclusions and aftercare together.

If the quotation does not explain the design, assumptions or responsibilities, ask for those points in writing. A clear document gives you a realistic basis for deciding whether storage fits your electricity use and property, rather than asking you to choose on price alone.