General solar FAQs

1.How does a solar electric system work?

Solar panels generate electricity using the energy from the sun. The panels produce energy from daylight, not direct sunlight, so they still produce energy on cloudy or overcast days. An inverter converts the electricity from direct to alternating current, for use in the home. The electrical energy produced is either used directly in the home, or when the system is producing more power than is needed it is exported to the grid. At night, power is imported from the grid in the normal way.

2.What happens if there is a power cut?

Solar electric systems for homes are entirely grid connected. If there is a power cut your system is automatically switched off. This is a safety measure designed to stop electricity leaking on to the national grid and to protect people who may be working to restore the power supply.

3.How efficient are solar panels?

The 'efficiency' of solar panels is less relevant than you might imagine. The efficiency determines the area of the solar panel, so the higher efficiency Monocrystalline panels are smaller than the Polycrystalline for the same power rating.

4.How can the energy benefits of the system be maximised?

Orientation, shading and the temperature of the solar system all impact on the output and must be considered at the design stage. The best orientation for solar panels in the UK is south facing at 30 – 40° slope.

5.What modules do use use?

We use Sharp modules, typically either 180w Monosilicon or 210w polysilicon.

6.Do the PV panels need direct sunlight to work?

Solar panels works from daylight. Obviously they produce more power when the sun is stronger, as opposed to when it is overcast. Shade is to be avoided.

7.How long do solar panels take to payback the energy that was used in their production?

Solar panels 'pay back' the energy required to make them in 2 to 4 years (depending on their final location) and are guaranteed to continue making energy for 25 years. See the NREL report on energy Payback.

8.What happens at night?

At night, when the solar roof is not generating electricity, you buy electricity from your supplier like normal. The system does not consume power at night.