Solar PV vs Battery Storage: Which Should You Install First?

Solar panels and battery storage are two of the most popular home energy technologies in the UK, and they work brilliantly together. But if you are considering investing in renewable energy for your home, you may be wondering which one to install first — or whether you need both. In this guide, we break down the key differences and help you make the right decision for your property.

Understanding Solar PV

Solar photovoltaic panels generate electricity from sunlight. A typical domestic system in the UK produces between 3,000 and 4,500 kWh of electricity per year, which can cover 50 to 70 percent of an average household’s electricity consumption. The electricity is generated during daylight hours, with peak output typically occurring around midday.

The challenge with solar PV alone is that generation and demand do not always align. If you are out during the day, much of the electricity your panels produce may be exported to the grid rather than used in your home. While the Smart Export Guarantee pays you for this exported energy, the rate is significantly lower than the cost of buying electricity from the grid. This is where battery storage enters the picture.

Understanding Battery Storage

A home battery system stores excess electricity generated by your solar panels for use later in the day. Instead of exporting surplus energy to the grid at low rates, a battery captures it and releases it when you need it most — typically in the evening when your panels are no longer producing but your household demand is high.

A typical home battery stores between 5 and 13 kWh of energy, which is enough to power most households through the evening and overnight. With a battery, you can increase your self-consumption of solar energy from around 30 to 50 percent (without a battery) to 70 to 80 percent, significantly increasing the financial return on your solar investment.

Which Should You Install First?

In almost all cases, solar PV should be installed first. Solar panels are the generation source — without them, a battery has no free electricity to store. While batteries can be used for tariff arbitrage (charging from the grid during cheap off-peak hours and discharging during expensive peak hours), this strategy alone rarely justifies the cost of a battery system.

Once you have solar PV installed and can see your generation and export patterns, you will be in a much better position to determine whether a battery makes financial sense for your household. Many homeowners install solar panels first and add a battery six to twelve months later once they understand their energy usage patterns.

Installing Both Together

There are advantages to installing solar PV and battery storage at the same time. Combined installations often cost less than purchasing each system separately, as the electrical work, scaffolding, and design can be carried out in a single visit. A combined system also allows us to optimise the overall design from the outset, selecting components that work seamlessly together.

The Financial Picture

A solar PV system alone typically pays for itself within 7 to 10 years through electricity savings and Smart Export Guarantee income. Adding a battery extends the payback period slightly but increases overall savings in the long term. The best financial outcome depends on your specific electricity consumption, tariff, and the proportion of your usage that occurs during daylight versus evening hours.