Solar PV (or solar photovoltaic) panels convert solar radiation into electricity. The stronger the sunshine, the more electricity they produce.
No. Solar PV panels don’t need direct sunlight to work – you can still generate some electricity even on a cloudy day all year round. They do though generate more electricity on sunny days between April and September.
Because both technologies use the sun’s energy and involve panels on roofs, the two are easily confused.
Solar PV panels convert sunlight directly into electricity.
Solar thermal panels use sunlight to heat water for showers, baths and taps.
PV panels installations usually use more space than solar thermal panels as any excess electricity can be exported to the National Grid whereas hot water cannot.
You need a roof or wall facing anywhere between east and west that isn’t overshadowed by trees or buildings. If the panel is in shadow for parts of the day it will produce less electricity. More than one surface can be joined in a single PV installation for maximum electricity generation. You will need at least four square metres space to make PV worth considering on a house. Larger systems for farms, businesses or factories are likely to need three phase electricity provision.
A 2.2 kWp system can generate up to 50% of an average household’s yearly electricity needs and generate savings and income of around £1,000 per year from the Government’s Feed-in Tariff scheme.
Under the Feed-in Tariff scheme, generators are paid for every unit of renewable electricity they produce, whether they use it themselves or export it to the grid.
The income produced is tax free and index linked making it inflation proof.
The payback time can be as little as 10 years.
The Feed-In Tariff scheme for PV runs for 25 years providing a healthy income stream after payback.
As the lifespan of a solar PV system is at least 25 years, it is a very attractive financial option!
PV supplied by an MCS accredited company such as Ace Energy start at around £6,500.
For a household probably not, but you should always consult your local planning office for guidance, especially if your home is a Listed building or is in a Conservation Area or World Heritage Site. Most business or agricultural sites will need planning approval. Larger systems – typically above 4 kWp – will also need permission from the Distribution Network Operator (DNO).
Panels are performance guaranteed for 25 years – to 90% during the first 10 years and to 80% during the following 15 years. The inverters are usually guaranteed for five years but this is extendable for up to 25 years.
There are grants and discounts to help with energy efficiency measures. The Energy Saving Trust has a simple questionnaire here that will tell you what schemes you are eligible for.
Very little. You’ll need to keep the panels relatively clean though much of the year they are cleaned by rain fall. It is also important to make sure that trees don’t begin to overshadow them.
It is possible to use electricity produced from a PV system to heat water with an electric immersion heater. However, it is normally more cost-effective to use solar thermal panels for hot water.
Yes. And that is now a very attractive option because from June 2011 solar thermal systems qualify for payments from the new Renewable Heat Incentive scheme (RHI).
You are allowed under the Feed-In Tariff scheme to take the PV system with you and still retain the income stream, however having a renewable energy system such as PV installed will add substantially to property’s value.
Yes. The Feed-In Tariff payments can be diverted to you wherever you live.