Solar + battery
Solar panels and battery storage for your home
Panels decide how much electricity you generate. Storage decides how much of it you actually use. Designing them together is what makes the difference.
Why the two are designed together
An array and a battery share an inverter strategy, a grid connection notification and a set of physical constraints. Choices made for one constrain the other: an inverter selected purely for the array can limit storage options later, and a battery specified without knowing the array's realistic surplus may rarely fill.
Treating them as one system also means one set of paperwork and one commissioning visit, rather than repeating the process when storage is added afterwards.
Decisions that span both
- Inverter type and sizing, including hybrid options that support storage directly
- How much surplus the array genuinely produces across the year
- Where equipment is located, and the cable routes between it
- The grid connection notification for the combined installation
- Whether backup circuits are required
Using more of what you generate
Self-consumption is the proportion of your generation used in the home rather than exported. Without storage it is set by how well your daytime occupancy matches the generation curve. With storage, the surplus is shifted into the evening and overnight hours, so a larger share of what your roof produces displaces electricity you would otherwise buy.
How it fits together
Generation, storage and household demand
Through the day
Daylight
Daylight reaches the panels on your roof.
Panels + inverter
DC generation is converted to usable AC.
Your home
Your home uses whatever it needs first.
Battery
Surplus can charge storage instead of exporting.
Evening and overnight
Battery
Stored electricity is released after dark.
Your home
Evening use is met from storage where possible.
Grid
The grid covers anything still needed.
Whether surplus generation is stored or exported depends on your system design, battery capacity and how your home uses electricity at the time.
Sizing the pair as one system
The array is sized from your roof's usable area and your annual consumption. Storage is then sized from the part of that consumption falling outside daylight hours, and from the surplus the array is expected to produce. Both figures are preliminary until a technical review confirms the roof, the electrics and the connection.
Bigger is not automatically better in either direction. An array whose output you cannot use, or a battery that seldom cycles, both represent capacity paid for and not worked.
EVs and heat pumps change the picture
An electric vehicle adds a large, flexible load that can often be scheduled into daylight hours or cheap overnight periods. A heat pump adds substantial demand weighted towards the colder months, when generation is lowest. Both raise annual consumption enough to change the appropriate array and battery size, so they should be declared even if the purchase is still a plan.
Grid connection considerations
Because a solar and storage installation exports into the local distribution network, it must be notified to, or approved by, your Distribution Network Operator under the industry connection rules. Which route applies depends on inverter capacity, whether your supply is single or three phase, and any generation already installed at the property.
Until those details are confirmed, we describe the position as to be confirmed rather than guessing at a category. Every online figure is subject to final system design and DNO or grid connection approval where required.
Solar and battery FAQs
Do I need a battery?
No — solar works perfectly well without one. A battery matters if a lot of your electricity use happens outside daylight hours, because it stores surplus generation for the evening instead of exporting it. If you are at home during the day and already use most of what you generate, a battery adds less. We look at your usage pattern before suggesting one either way.
What size battery do I need?
Battery sizing is driven by how much electricity you use outside generation hours, your annual consumption, the size of your array, any EV or heat pump, your tariff and whether you want backup capability. A common domestic range is roughly 5–15 kWh of usable capacity, but the right figure is the one you can genuinely cycle most days. Bigger isn't automatically better: capacity that sits unused still costs money.
Can solar charge an EV?
Yes, and it is one of the best ways to use your own generation, because charging is a large, flexible load that can be shifted into daylight hours. A compatible EV charger can prioritise surplus solar, and some tariffs let you top up cheaply overnight as well. If you already have an EV or plan to get one, tell us at assessment stage — it usually changes the appropriate system and battery size.
Can solar work with a heat pump?
They work well together, and both run on electricity, so a heat pump raises your annual consumption and makes more of your own generation useful. The caveat is seasonal: heat pump demand peaks in winter when solar output is lowest, so solar offsets part of the annual running cost rather than most of the winter heating load. Sizing needs to reflect that.
Can I add a battery later?
Usually yes. A battery can be retrofitted to an existing solar installation, typically using an AC-coupled battery with its own inverter, or a DC-coupled battery where a hybrid inverter was installed at the outset. Planning for storage at design stage keeps the later upgrade simpler and can avoid replacing the inverter, so it is worth telling us your intentions early.
Do I need DNO approval?
Whether your system needs prior approval or notification after installation depends on inverter capacity, the number of phases at your property, any battery storage, any existing generation and the local network. Panel count alone does not determine it. Where an application is required, we prepare and submit it as part of your project, and we never describe a system as approved before it is.
Start with your roof
A free satellite assessment shows your realistic panel count in under a minute. No obligation.