Home battery storage and solar PV: choose, install and use with confidence

Battery storage first

A home battery, also called a battery energy storage system or BESS, holds electricity for use later. It does not generate electricity.

It can be charged from the grid when your tariff makes that worthwhile. If you add compatible solar, it can also store some electricity your panels generate. The opportunity depends on your household’s usage, available charging periods and system settings.

Solar PV

Solar photovoltaic panels, or solar PV, turn daylight into electricity. Generation varies through the day and year. Roof orientation, shade and the installation affect the result.

Solar can supply your home, charge a compatible battery, or export surplus under the appropriate arrangements. A bigger array is not automatically the best match for every household.

What the inverter does

The inverter converts electricity between the forms used by the panels, battery and home, according to the system design. It also works with the controls that manage energy flows.

Pretium’s battery-first packages use a matched hybrid inverter and battery. Solar-only packages can use a PV-only inverter. Through Pretium’s offered hybrid route, adding storage to a PV-only package later requires an inverter upgrade. Ask about future storage when choosing the original system.

These describe Pretium’s offered packages. Other architectures exist. Future additions and integration with existing equipment need assessment.

Bills, export payments and backup are separate questions

Energy-management software may automate charging or export, but capability and tariff participation vary. Do not assume every battery automatically trades electricity or chooses the most profitable action.

In the tool: tell us your main priorities and whether you already have solar, storage or both.

Choose battery capacity and power together

Nominal capacity is the stated total battery energy capacity. Usable capacity is the part made available for normal operation under the product’s specified conditions.

An emergency reserve, operating limits and losses can reduce what is available for everyday use.

For illustration, 10 kWh supplied steadily at 2 kW would last five hours in an ideal calculation. Actual duration depends on usable energy, losses, reserve settings and changing loads. This is not a promise of backup duration.

Ask the installer to explain:

• usable capacity and the reason for the proposed size;
• continuous charge and discharge power, and any short-duration limits;
• whether it can recharge within your intended tariff window;
• how simultaneous household loads affect the result;
• expansion limits, module-matching conditions and future availability.

A larger battery may cost more without enough useful daily charging or demand to justify it. Sizing should reflect your usage rather than simply selecting the largest option.

In the tool: select a starting size, or ask for a recommendation. Share annual electricity use and tariff details if you know them.

Compatibility: the exact models matter

An inverter and battery are not necessarily compatible because the brand names match. Supported module quantities, firmware, voltage ranges, communications and configuration limits can matter.

Ask for the exact inverter, battery and controller references in the proposal, with confirmation that the selected arrangement is supported. Changing one component can change power, capacity, backup, monitoring or expansion options.

For an existing installation, provide the models and paperwork if available. Let the installer assess the integration before assuming equipment can be retained.

Make optional solar an informed choice

Compare panels using the exact model and generation, including rated output in watts, dimensions and suitability for the space, appearance and finish, product and performance warranty conditions, and the resulting array layout and total installed scope.

Different Aiko models or generations can have different dimensions, appearance and wattage. A brand or generation name alone is not a complete specification.

“Tier 1” is a manufacturer classification associated with market and financing criteria. It is not a technical quality grade for an individual panel.

kWp is rated array power, not yearly electricity production. Ten 490 W panels equal 4.9 kWp. A generation estimate in kWh per year needs site-specific assumptions and should explain seasonal variation.

Where could the panels go?

An existing carport or pergola is not automatically suitable. If weatherproof cover is part of your requirement, have it specified.

In the tool: identify possible locations and whether they are additions or alternatives. Unknown details can be assessed at survey.

The mounting system deserves its own specification

Panels need a suitable support system. Ask which mounting manufacturer and range will be used, how it attaches to your roof or structure, and how the design deals with weather exposure, roof interfaces and access.

The quotation should identify relevant rails, clamps, attachments, structural or roofing work, weatherproofing and warranties. Appropriate mounting remains necessary at every panel price level.

Optimisers and the SolarEdge approach

Optimisers manage panel-level electrical performance within a compatible design. They can help address certain mismatch effects, but they cannot remove the physical loss of daylight caused by shade.

Conventional string systems may be appropriate without additional optimisers. Where additional optimisation is proposed, ask why, which models, how they will be deployed and what monitoring equipment is included. Tigo deployment options have specific design and monitoring conditions.

SolarEdge uses a coordinated inverter and power-optimiser approach for the applicable PV systems. Required compatible optimisers are part of that system, not a generic optional accessory.

SolarEdge’s SafeDC feature is designed to reduce each power optimiser’s output to about 1 V when the inverter is switched off or its AC supply is disconnected. Where one optimiser is fitted to each panel, that is about 1 V per panel, so the voltage on the cables between the panels falls with it. SolarEdge also describes this as rapid shutdown of the array’s DC side. Great Britain does not currently impose the United States rapid-shutdown rule. The feature still does not make panels, connectors or wiring safe to handle.

In the tool: treat optimisation as a system choice or a request for assessment. The designer confirms the arrangement.

Compare complete installed proposals

A higher-priced option should have an explainable benefit for your needs: usable capacity, power, appearance, supported controls, expansion, warranty or another verified feature.

Compare the complete scope, including controllers, monitoring, mounting, access, electrical work and backup where requested. A subtotal excluding unpriced work is not the final project price.

Product safety and competent installation work together

Choose traceable equipment from reputable manufacturers and suppliers, with clear documentation, support and supported combinations. Ask the installer to explain relevant product conformity evidence. A logo alone does not establish that the complete installation is suitable.

Installation should be designed, inspected, tested and commissioned by people competent in the particular technology. Ask who is responsible for electrical design, roofing or structure, and final handover.

The electrical design must address wiring, connections, earthing, isolation and appropriate protection. Surge protection and RCD or RCBO requirements depend on the design and equipment. Inverter characteristics, including possible DC residual currents, must be considered. These are decisions for the designer, not accessories for you to select from a checklist.

Solar wiring needs specialist care too

Solar panels produce DC electricity in daylight. Their wiring needs an appropriate design for fire and shock protection, including suitable cables, protected routes and correctly selected connections. Turning off the home’s mains switch does not necessarily make the solar side safe. On a SolarEdge system, shutting down the inverter is designed to lower the optimiser outputs to about 1 V each. Other designs can leave a high DC voltage on the panel cables while the panels are in daylight.

Ask how the installer will protect the wiring and connections, provide the required isolation and labels, and explain shutdown. Do not disconnect panel connectors, open isolators or investigate roof wiring yourself.

Fire risk

Lithium-ion batteries can fail in a way that produces intense heat and hazardous gases. Product design, battery management, installation conditions and maintenance all matter. No battery chemistry or certification should be presented as making a system fireproof.

Choose the battery position before committing

PAS 63100:2024 addresses domestic battery fire safety. Its approach favours outdoor siting where practicable. Indoor positions require additional consideration of ventilation, fire separation and detection. It does not permit battery siting in locations including sleeping rooms, escape routes and loft or roof voids. Its scope has limits, so complex properties need an appropriate design assessment.

Ask your installer to explain the proposed location, clearances from openings and escape routes, environmental suitability and any fire-alarm work. Battery and inverter siting are separate design questions. They do not necessarily have identical location rules.

For an existing battery in a concerning position, seek a competent assessment. Do not move it yourself.

Everyday care

• Keep the specified clear space around the equipment. Do not turn it into a storage shelf.
• Keep access and escape routes clear.
• Protect equipment from knocks, vehicle impact, flooding and unauthorised access as advised.
• Follow the manufacturer’s instructions for cleaning, servicing, updates and alarm testing.
• Report faults. Do not open enclosures, repair connections or alter safety settings yourself.

For unexplained repeated faults, unusual heat or noise, scorching, swelling, physical damage or water ingress, stop using the system and contact the installer or manufacturer promptly. Only use a normal shutdown procedure if it is safe to do so and you have been shown how.

The emergency note is at the top of this page.

You should not have to navigate the approvals alone. Before ordering, establish who checks, applies, pays and supplies the evidence.

MCS is not a legal condition of the installation itself. Where a scheme asks for MCS, an equivalent accreditation can also be accepted. Insurance-backed protection is a separate document, with its own limits. The DNO notification, the Electrical Installation Certificate, and the building-regulations duty are required. An MCS certificate does not replace them. A warranty does not replace them either.

Wiring standards change

At this guide’s check date, the IET identifies BS 7671:2018+A4:2026 as current after the previous transition ended on 15 October 2026. Ask the installer which requirements the new work is being designed and certified to. This guide does not reproduce the installation rules.

Network approval and export limits

Your Distribution Network Operator, or DNO, manages the local electricity network. It is different from the supplier that bills you.

The installer determines the applicable G98 or G99 connection process and whether prior approval or notification applies. Export-limiting equipment can involve G100. Existing and proposed equipment need to be considered together.

Do not assume that battery-only or zero export removes the connection requirements. Confirm the permitted operating and export limits, and who handles the paperwork.

Planning, building work and permissions

Some domestic solar installations can use permitted development rights, subject to conditions. Listed buildings, protected areas, ground arrays and new structures can need different treatment.

Planning permission and building-regulation compliance are separate. Roof strength and the installation’s electrical aspects still need attention. England, Wales and Scotland have different procedures. Confirm locally. Obtain any landlord, freeholder or management consent, and tell your insurer about the proposed work as required.

Export tariffs are a separate arrangement

Eligible solar generators in Great Britain can apply to an electricity supplier for Smart Export Guarantee payments. Metering, certification and supplier conditions matter.

A battery alone does not automatically create eligibility for SEG payments for grid-bought electricity. Ask whether a particular tariff pays for stored-energy exports and how it treats their origin. Do not assume export rates equal import rates, or that payments begin automatically on installation.

Before accepting, check the whole proposal

Ask for a written specification covering:

• exact equipment models, quantities, usable storage and power;
• panel layout and generation assumptions, if applicable;
• mounting, roofing, structural and access work;
• wiring, protection, monitoring, communications and controls;
• backup circuits and equipment, where requested;
• permissions, network applications and certification responsibilities;
• the total price, applicable VAT, exclusions and treatment of unforeseen work;
• payment stages, timing, warranties, aftercare and complaints;
• cancellation instructions and any survey fee or other separate agreement.

Do not treat a savings estimate as a guarantee. Ask which usage, generation, tariff, efficiency, export and equipment-life assumptions were used. Keep the explanation and the version of the quotation you accept.

Your legal rights sit alongside warranties

Under the Consumer Rights Act, supplied goods must meet standards including satisfactory quality, description and relevant fitness for purpose. Agreed installation must be correct. Services must be carried out with reasonable care and skill.

Depending on the problem and circumstances, remedies can include repair, replacement, repeat performance, a price reduction, or rejection and refund. Contact the business you contracted with. A manufacturer warranty is additional protection, not a replacement for your rights against the trader.

Understand cancellation before ordering

For many online, telephone and at-home contracts, a statutory 14-day cancellation period applies. The starting point depends on the contract.

For goods supplied with installation, the usual sales-contract period ends 14 days after the day you receive the goods, or the last item where applicable. A separate service-only contract usually runs for 14 days after the day it is made. Exceptions and particular circumstances can affect the position.

If you request work during that period, applicable consent and information rules, and proportionate service charges, can matter. Installation does not automatically remove every goods cancellation right. Ask for the rules and return or removal arrangements in writing. Do not attempt to disconnect equipment yourself.

Deposits, payments and finance

Know which business receives payment, what each stage covers, and what happens if the project changes or the business fails. Check whether deposit protection or an insurance-backed workmanship policy actually covers your contract, its limits, and who provides it. Membership alone is not a promise that every loss is insured.

Credit-card or qualifying linked-credit purchases may have additional protection. Section 75 can apply to qualifying goods or services with a cash price over £100 and no more than £30,000, subject to its conditions. The cash price matters, not simply the deposit paid. Payment arrangements can affect eligibility. Ask the provider if you are uncertain.

Cancelling a finance agreement is not necessarily the same as cancelling the equipment contract.

If something goes wrong

Explain the problem to the contracting business in writing and keep photographs, fault records, quotations and correspondence. Ask for its complaints procedure and proposed remedy.

If unresolved, use the relevant certification body’s, consumer scheme’s or alternative dispute resolution process where applicable. Independent consumer advice is available through Citizens Advice in England and Wales, and Advice Direct Scotland in Scotland. These routes do not replace emergency action for an immediate safety concern.

Before the visit

Have useful information ready:

• photos of the meter and consumer-unit area and proposed equipment locations, taken without opening covers;
• existing-system models, certificates and warranty details;
• electricity consumption and tariff information if available;
• known roof condition or work, access restrictions, permissions and connectivity;
• your backup priorities and any critical equipment that needs its own continuity plan.

Your installer confirms the route, supply, roof or structure, equipment position and shutdown arrangements. Ask about planned power interruptions. Do not use a future battery proposal as the continuity plan for essential medical equipment.

What to expect during installation

The work follows the agreed design and safe working arrangements. Necessary changes should be explained, with any price or scope variation agreed rather than assumed.

Before completion, the team tests and commissions the system, checks settings and controls, and explains relevant operating limitations. Network, export and backup behaviour must match the approved arrangement.

Your handover pack

• the accepted specification, layout and system diagram;
• exact models, serial numbers and datasheets;
• electrical certification and test schedules;
• applicable MCS and building-control documents;
• DNO approval or notification evidence and limits;
• warranty and registration information, and any insurance-backed cover;
• commissioning and settings record, app access and support contacts;
• normal shutdown, fault and emergency instructions;
• inspection and maintenance recommendations, and any alarm instructions.

If an item will follow later, ask who supplies it and when. Obtain your own customer access to monitoring where it is included. Confirm remote-support permissions and any subscription or connectivity costs.

Day-to-day use

Understand the chosen mode: solar self-use, tariff scheduling or another supported service. Coordinate schedules so the battery, EV, other controls and supplier instructions do not work against one another.

Monitor energy flows and alerts. Lower winter solar generation, or a battery keeping an agreed reserve, need not indicate a fault. Unexpected persistent behaviour should be checked.

Retain the manufacturer’s safety settings and follow its maintenance guidance. Ask whether changes to tariffs, Wi-Fi, EV charging, heating or existing equipment require a settings or design review.

Warranties and long-term ownership

Compare product warranty, battery capacity-retention and throughput conditions, panel performance warranty and installation workmanship cover separately. A long performance warranty is not necessarily a promise to pay all removal, access and labour costs.

Ask who handles claims, what registration or maintenance is required, and how changes or future expansions affect cover.

If you move home, arrange transfer of monitoring access and provide the documents to the new owner. Check which warranties and tariff arrangements transfer. At end of life, arrange competent decommissioning and appropriate recycling. Do not disconnect or dispose of a home battery as ordinary household waste.

Contact Pretium for help with your proposal or aftercare. Keep the emergency instructions supplied with your system accessible.

Can I start with a battery and add panels later?

Yes, that is a route offered by Pretium. The later array still has to suit the inverter limits, the property and the network arrangements. “Hybrid” is not a guarantee of compatibility with every future product.

Will everything work in a power cut?

Only equipment and circuits covered by the designed backup arrangement, within its limits. Confirm the backup hardware, power, usable reserve, changeover behaviour, and whether solar can operate or recharge the battery during an outage.

Does a bigger battery mean more powerful backup?

Not necessarily. Energy capacity, inverter output, battery power and supported circuits all matter.

Are optimisers essential?

They are part of applicable SolarEdge systems. Other arrangements may or may not need additional optimisation. The designer must assess the selected products and layout.

Is the cheapest quote unsafe?

Price alone does not establish safety or suitability. Compare the exact products, complete installation scope, competent delivery, evidence, warranties and aftercare.

Is certification a guarantee that nothing can go wrong?

No. Certification provides evidence within a defined scope. Correct design, commissioning, appropriate use, maintenance and a clear route for help remain important.

Does saving my configuration commit me to buying?

Sending your plan asks Pretium to contact you. It does not place an order. We’ll review your preferences, arrange a survey where one is needed, and send a formal quotation for you to accept or decline. Read any separate survey agreement and charges before agreeing to them.