Why You Still Use Energy from the Grid with Solar Panels

If you’ve had solar panels installed, you might expect your electricity bills to disappear completely. So it can be surprising to see that you're still drawing small amounts of energy from the grid. But don’t worry: this is completely normal and expected, even with a well-designed solar system.

Solar Panels and the Grid:

How They Work Together

When your solar panels produce electricity, your home uses that energy first. If they generate more than you need, the extra energy is sent to the grid or stored in a home battery (if you have one). But when the panels aren’t generating enough — such as during the night or on overcast days — your home automatically pulls electricity from the grid to cover the shortfall.

Common Reasons You Still Use Grid Energy

1. Night-time Energy Use

Solar panels don’t generate power at night. So unless you have a battery to store excess daytime energy, your home will use electricity from the grid after sunset.

2. Cloudy or Winter Weather

In the UK, shorter daylight hours and cloudier conditions in winter mean your panels may not always meet your full energy needs. During these times, the grid provides backup energy.

3. High Energy Demand

Some appliances like electric showers, ovens, or EV chargers use a lot of power. If you’re using multiple high-energy devices at once, your solar output might not keep up — and your system will supplement with grid energy.

4. No Battery Storage

Without a battery, you can only use solar energy when it’s being generated. Any excess is sent to the grid, but you can't draw it back later without buying it again. That’s why batteries are a smart addition for many homes.

5.Inverter Start-up Delays

Solar inverters — the device that converts your solar power into usable electricity — can sometimes delay in starting to produce power. During this brief delay, your home may draw a small amount of energy from the grid before the inverter fully powers on.

Is It Still Worth It?

Absolutely. Even if you’re still drawing some power from the grid, solar panels significantly reduce your electricity bills. Plus, with smart energy tariffs and the Smart Export Guarantee (SEG), you can get paid for the extra energy you export.

How to Reduce Grid Dependence Further

• Add a solar battery: Store excess energy during the day and use it at night.

• Use energy-efficient appliances: Reduce how much electricity you need overall.

• Shift usage to daylight hours: Run dishwashers, washing machines, and EV chargers during sunny periods.

Conclusion

Drawing small amounts of energy from the grid is completely normal for solar panel users. It simply means your system is working in harmony with the grid to provide consistent power. With the right setup — including battery storage and smart energy habits — you can take even greater control of your energy use and savings.