Should You Get Solar Panels Before or After Buying an EV?

If you're planning both solar panels and an electric vehicle, you might wonder which to get first. It's a more nuanced question than it appears, and the "right" answer depends on your circumstances.

The case for solar panels first

You start saving immediately. Solar panels reduce your electricity bill from day one, regardless of what car you drive. The savings of £800-950/year begin accumulating while you decide on your EV.

You can size for future EV charging. If you tell your installer you're planning an EV, they can size your system slightly larger (5-6kW instead of 4kW) to accommodate future charging demand. Adding panels later is possible but costs more per panel than doing it all at once.

Battery storage makes more sense. A solar + battery bundle is cheaper to install together. The battery stores solar for evening use and can charge your future EV.

The case for the EV first

The fuel savings are larger. Switching from petrol to electric saves £1,200-1,500/year for a typical driver, even without solar. That's more than solar saves on electricity bills alone.

You immediately know your charging needs. Real-world experience with your EV tells you exactly how much electricity you'll use, what times you charge, and whether your current tariff works. This informs the optimal solar system size.

An EV tariff saves money now. You can access 7p/kWh overnight electricity for EV charging without solar panels. The tariff saving is independent of solar.

Our recommended order

For most people, the optimal sequence is:

1. Get the EV and install a home charger. Start saving on fuel immediately. Switch to an EV tariff.

1. After 3-6 months, install solar panels + battery. By now you know your real electricity consumption. Size the solar system to cover household use plus typical daily EV charging. Get solar quotes that account for your EV.

1. Optimise your setup. Use a smart charger that integrates with your solar system. Charge from solar during the day, from cheap grid electricity overnight, and export surplus at the best SEG rate.

The combined savings

A household with solar panels, battery storage, EV charger, and an optimised tariff can save:

• £800-950/year on household electricity (solar)
• £1,200-1,500/year on fuel costs (EV vs petrol)


• £300-400/year from tariff arbitrage (battery)

The green home trifecta of solar + battery + EV is the most powerful financial combination available to UK homeowners right now.