How to Quote and Run a Residential Solar PV and Battery Storage Package

What you will learn

• How to sequence system design correctly - solar generation sizing must be confirmed before battery capacity is chosen.
• How to structure a combined quote that itemizes solar components, battery components, and shared installation costs separately.
• What MCS compliance covers for both solar PV (MIS 3002) and battery storage (MIS 3012) on a single installation.
• How the 0% VAT deadline on qualifying residential battery storage affects how you present combined package quotes.
• Where combined package margins are most commonly lost - inverter compatibility, scaffolding allocation, and commissioning time.
• How to build a dual-technology handover pack that covers warranties, certificates, and SEG registration guidance.

Residential solar PV and battery storage have been sold separately for years, but the market has shifted. Homeowners now expect a single package quote, a single installation visit, and a single point of accountability. That changes the operational challenge for the installer. Combining two technologies in one job means two MCS standards to satisfy, an inverter choice that affects both systems, shared costs that need splitting correctly across the quote, and a handover pack that covers two separate compliance certificates. Installers who treat the combined package as two separate jobs bolted together find margins disappear faster than they planned.

Step 1: Survey the Site for Both Technologies Together

A combined solar and battery survey covers different ground than a solar-only assessment. The roof inspection and shading analysis are the same, but the survey also needs to establish battery location options, cable run distances from roof to battery to consumer unit, inverter mounting space, and whether the existing consumer unit can accommodate the additional circuits.

The critical question to answer at survey is inverter strategy. A new solar and battery installation can use either a hybrid inverter (which manages both solar input and battery charging from a single unit) or two separate units - a solar inverter and an AC-coupled battery. A hybrid inverter is typically lower cost and simpler to commission, but it must be sized to accommodate both the solar array and the expected battery discharge rate. If the homeowner is also considering an EV charger or heat pump, note this at survey - it affects inverter specification.

Battery location also needs establishing at survey, not at the quoting stage. The distance from the battery to the main consumer unit determines cable length, and cable length has a direct impact on materials cost. An internal garage wall close to the consumer unit is the ideal scenario. A remote utility room on the opposite side of the property adds cost. Note the proposed location on the survey record and photograph it, because this is what the quote price is based on.

Step 2: Design the System in the Right Sequence

The most common design error on combined packages is starting with battery capacity and working backwards. The correct sequence is: size the solar array for the property's daytime consumption and roof space, then size the battery to capture the surplus generation that would otherwise be exported.

A 4kW solar PV array generating around 3,400-3,600 kWh per year in the south of England will typically produce a meaningful surplus for a household with moderate daytime usage. A battery sized at 5-10kWh captures that surplus for evening use. Sizing the battery much larger than the daily surplus generation adds cost without proportionate benefit - the battery simply charges from the grid at a higher rate than the export value it replaces.

The Ofgem electricity price cap as of Q3 2026 has pushed unit rates to significant highs, which improves the financial case for self-consumption storage. However, avoid making payback calculations for the customer using specific unit rate projections. Energy prices have been volatile. Present the self-consumption increase - battery storage can increase the proportion of solar electricity used on-site from around 35% to 75%, according to industry guidance - and let the customer apply their own view of future energy costs.

Step 3: Build the Quote as a Combined Package

A combined solar and battery quote should itemize three distinct cost groups: solar components, battery and storage components, and shared installation costs. This structure serves two purposes. It allows the customer to understand what they are getting for their money, and it protects you when a customer asks to remove the battery or upgrade the solar array mid-quote - you can price the change without rebuilding the whole document.

Solar components to itemize: panels (quantity and model), mounting rails and fixings, DC cabling, and the solar inverter or hybrid inverter. Battery components to itemize separately: the battery unit, battery management cabling, any AC coupling equipment if not using a hybrid inverter, and the battery monitoring system.

Shared installation costs cover: scaffolding, labour time (which should be allocated proportionally between solar and battery if you need to separate them later), consumer unit work, earthing, electrical protection devices, and commissioning. If the scaffolding spans more than one day, separate the daily hire cost explicitly so it is visible.

Two VAT treatments apply on a combined quote in 2026. Solar PV installation qualifies for 0% VAT on a qualifying residential installation. Battery storage installed alongside solar PV as part of the same installation also qualifies for 0% VAT until 31 March 2027, when the rate reverts to 5%. Note the VAT position clearly on the quote and flag the March 2027 rate change if the customer is deciding between this year and next.

As a guide to typical package costs sourced from UK installer data in 2026: a combined solar PV and battery storage installation typically runs from £10,000 to £14,000 or more for a standard residential property, depending on array size, battery capacity, and installation complexity. This combines a solar PV system in the range of £5,500 to £8,000 for a 4kW array, plus battery storage typically adding £4,000 to £8,000 depending on battery size and inverter setup. These are indicative ranges - your actual quote depends on the specific equipment specified and site conditions.

Step 4: Procurement and Ordering

Combined package procurement has a dependency that solo installations do not. The inverter must be confirmed before either the solar panels or the battery can be ordered, because the inverter determines compatibility for both.

If you are using a hybrid inverter, confirm the model and firmware version before ordering panels - some hybrid inverter ranges have string size restrictions that affect how panels can be configured. If you are using separate solar and battery inverters, confirm that the battery is compatible with the solar inverter's communication protocol before committing the battery purchase order.

Raise separate purchase orders for solar equipment and battery equipment, even if both come from the same supplier. Delivery timing often differs, and having separate orders gives you visibility of which technology is running late. Panels and mounting hardware can typically be delivered the day before installation. The battery should arrive on installation day to avoid it sitting in a residential property for days before it can be secured.

If scaffolding is required, book it as a separate purchase order and confirm the access window with the customer. Combined installations typically require one full day of scaffolding access for the roof work, with the battery installation often continuing inside while the scaffold is still up.

Step 5: Installation, Commissioning, and MCS Compliance

A combined solar and battery installation requires MCS certification under two separate installation standards: MIS 3002 for solar PV and MIS 3012 for electrical energy storage. Both certificates are issued by your MCS certification body at the end of the job, but the site records, commissioning data, and documentation must satisfy both standards.

The installation sequence for a combined package is: roof mounting and panel installation, DC cabling and array commissioning, inverter installation and connection, battery installation and integration, consumer unit work and protection devices, full system commissioning and monitoring setup, and final electrical inspection.

Commission the solar array independently before connecting the battery. This confirms the solar side is generating correctly before you introduce the battery circuit. If there is a commissioning issue, you will know whether it belongs to the solar installation or the battery integration.

The Electrical Installation Certificate (EIC) covers the electrical installation work across both technologies. Issue a single EIC for the combined job unless your certification body advises otherwise for your specific setup.

For the Smart Export Guarantee (SEG) application, the customer can only register once MCS certification is confirmed. Make this clear at the quotation stage. Some customers expect to start exporting immediately; the registration process takes several weeks after the MCS certificate is issued. Walk the customer through the monitoring app setup during handover and confirm they understand what the system shows.

Step 6: Handover Pack and Closeout

The combined package handover pack contains more documents than a solo installation and the customer needs to understand what each one is for.

Include in the handover pack: MCS certificate (or certificates if issued separately for solar and battery), Electrical Installation Certificate, Building Regulations compliance notification (issued by a Part P registered electrician), equipment warranties for panels, inverter, and battery, monitoring app login credentials and setup confirmation, inverter and battery user manuals, and the SEG registration guidance.

The warranty documents require particular care. Solar panels typically carry a 25-30 year performance warranty. The inverter warranty is separate and shorter - commonly 5-12 years depending on the manufacturer. The battery warranty is separate again, typically 10-12 years at a guaranteed cycle count or minimum retained capacity. Lay these out clearly so the customer knows who to contact and under what terms for each component.

Close out the job in your job management system once you have: confirmed the MCS certificates are registered, issued the final invoice, confirmed the EIC has been issued, and followed up on the SEG registration. Combined package jobs frequently have loose ends on the MCS and SEG side that get lost because the installation team treats the physical work as the finish line.

Businesses managing combined package volumes find that tracking each stage - survey, design approval, quote, order, installation, commissioning, and certification - across multiple live jobs requires more than a shared spreadsheet. Zigaflow's jobs and quotes features let renewables installers manage combined packages as a single structured job record, with purchase orders, stage tracking, and documentation attached to the same job reference. That keeps the solar components, battery components, and shared installation costs visible in one place from quote to final invoice. See how other renewables businesses use Zigaflow to manage this kind of operational complexity.

Sources

• Home Battery Storage Cost in the UK: 2026 Prices, Installation & PaybackHeatable · accessed 2026-08-27
• How much do Solar Panel Systems Cost? UK Prices 2026Renewable Energy Hub · accessed 2026-08-27
• Solar Battery Storage Costs in 2026Checkatrade · accessed 2026-08-27
• MCS Certification for Solar Installers UKElec-Mate · accessed 2026-08-27

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