Power With A Clear Conscience
The Facts About Solar
What you need know about solar PV systems
Solar photovoltaic (also known as solar PV) systems convert light energy from the sun into electricity. In fact, unlike solar thermal panels they do not rely on heat energy and their efficiency actually marginally reduces over 25ºC.
Solar PV components
Solar PV systems can be relatively simple, with their main components being solar panels or modules, inverters, optimisers and storage batteries.
Construction
Solar panels are made of a thin layer of semi-conducting material sandwiched between a sheet of glass and a polymer resin. When exposed to daylight, the semi-conducting material becomes 'energised' and this produces electricity.
Direction
Solar panels work most effectively facing due south and at an angle that maximises their exposure to the sun, but they can also be mounted facing east or west provided they have optimisers to increase efficiency. Their effectiveness will also be impacted by shading from trees, chimney or surrounding buildings.
Efficiency
PV panels differ in efficiency and price – often according to how much of the sun's energy is used by the system per unit area. Many panels generate between 380-420kW per 2sqm panel or 190-210kW per square metre.
Lifespan
Solar panels are long lasting and require very little maintenance and some have warranties for more than 25 years. Their efficiency does reduce over the years but this degradation is minimal and will not overtly affect the performance of the panels.
The Facts About BESS
Now commonly used, Battery Energy Storage Systems (BESS) can be a valuable addition to a domestic and commercial solar PV system.
Solar Battery Storage
An energy-storage system, also called a solar battery, lets you capture electricity so you can use it at another time. You can store the electricity your solar panels generate during the day and use it at night.
Do You Need A Battery?
Solar batteries may be worth considering if you generate your own energy at home with solar panels but could use more of it outside daylight hours – or plan to start doing so.
If you have solar PV panels, or are planning to install them, using home batteries to store electricity you’ve generated will help you to maximise the amount of renewable energy you use.
Should I store or export?
While you can sell your energy back to the grid via the Smart Export Guarantee (SEG) we often find customers find are better off investing in solar energy storage instead as the cost to buy energy far outstrips the 4p per kWh paid out by some energy companies.
Some customers even choose to use their batteries to store energy from the grid at a cheaper rate than standard daytime tariffs.
Home-energy storage will also reduce the electricity you use from the grid, and cut your energy bills. If your home is off-grid (i.e. no connection to the energy networks), it can help to reduce your use of fossil fuel back-up generators.
What size solar storage battery do I need?
The average home uses around 8kWh of electricity per day. The capacity of new lithium-ion batteries ranges from around 1kWh up to as much as 15kWh.
Ideally, you want a battery that will cover your evening and night-time electricity usage, ready to be charged up again when the sun comes up.
You'll also need to bear in mind how much your solar panels can generate, as there's no point buying a battery that's bigger than they can fill.
With a battery that is well chosen for your home's energy use and your solar panels' output, you should find that you can have enough electricity to serve your evening needs for most of the year. You might find that you are still drawing on grid electricity for some of the longest winter nights.