Solar Central Heating Explained
With central heating and hot water accounting for around 70% of energy bills, a solar central heating system is one of the best ways to reduce that expense.
There are multiple ways to heat your home using solar, including solar thermal which generates hot water, solar PV which produces electricity and solar PVT which is a combination of them both.
Using renewable solar energy to heat your home can help to lower your energy bills and greatly reduce the carbon footprint of your property.
Can solar panels be used for central heating?
Solar is a renewable energy source that can be harnessed to generate electricity, domestic hot water or central heating for your home. Depending on the type of solar system you need, there are two different types of solar panels:
- Solar thermal: generate hot water to be stored in a hot water cylinder.
- Solar photovoltaic (PV): generates electricity that can be used to power appliances around your home, including heating systems such as heat pumps.
How does solar heating work?
If your central heating system has a hot water cylinder which stores the hot water (system and regular boilers) then a solar thermal system will be able to heat the water within it – as long as the system is compatible with solar.
Combi boilers provide instant heating and hot water as and when needed, removing the need for a hot water cylinder. Homeowners with a combi looking to reduce their energy bills through solar energy should turn to solar photovoltaic (PV) panels.
How can a solar PV system be used for central heating?
Rather than providing hot water, like solar thermal panels, a solar photovoltaic (PV) system generates electricity. This means that using them for central heating works a little differently.
Powering the electrical appliances around your home with free renewable solar energy will keep your energy bills to a minimum. This includes your boiler, as all modern boilers have electrical components. While this doesn’t mean your home is running on solar for central heating (unless you have an electric boiler) it will help to keep your energy bills down.
Solar PV can also be used to heat the water in a hot water cylinder – much like solar thermal. To do this, the hot water cylinder will need an immersion heater.
An immersion heater is a metal component within some hot water cylinders (immersed in the water) that is heated up by electricity which warms up the water. Find out more about immersion heaters: Immersion Heaters: Benefits, Costs & Free Hot Water
Is it possible to have both solar thermal and solar PV?
Anyone interested in the benefits of solar thermal and solar PV will be happy to know that solar photovoltaic thermal (PVT) systems are also available. These systems are a hybrid of solar thermal and PV, which means they’re able to provide electricity and heat for the hot water cylinder.
Alongside the solar PV panels is an extra unit which extracts heat from those panels which is then used to heat the water in a hot water cylinder. This process also has the additional benefit of keeping the solar PV panels at their optimum temperature (lower than 25°C).
Solar-compatible hot water cylinders
In the case that your existing hot water cylinder isn’t solar compatible, you’ll need to have one installed. Here’s a selection of hot water cylinders that are compatible with solar:
- Main Solar Thermal Unvented Hot Water Cylinder
- Megaflo Eco Solar
- Megaflo Eco Solar PV Ready
- Vaillant auroSTOR
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Solar-assisted heat pumps
A solar-assisted heat pump (SAHP), otherwise known as thermodynamic solar panels, is a combination of solar thermal and heat pump technologies. The thermodynamic panel, installed outside, takes heat which the refrigerant fluid is able to convert into a gas. This gas then passes through a thermodynamic unit where it’s turned back into a liquid which goes through a heat exchanger to heat up the water stored in a hot water cylinder.
How much does solar central heating cost?
Depending on the type of solar system you have installed, the costs will vary. The average price of a solar thermal system sits at between £3,000 – £5,000 (home of 4) but this can stretch to £7,000 if the hot water demands of your home are higher.
How much is an immersion heater?
Immersion heater prices vary depending on the material and size. The cheapest are copper immersion heaters, which begin at around £20. However, copper immersion heaters aren’t suitable for hard water, stainless steel heat tanks, unvented cylinders or thermal store units.
The alternatives to copper are incoloy and titanium which do tend to cost a little more (still available for under £30) but can be used in hard water areas.
Renewable Heat Incentive
Making the switch from a heating system that burns fossil fuels (natural gas, oil or LPG) to a renewable heating system, such as solar thermal, could see you earn payments through the Renewable Heat Incentive (RHI).
The RHI is a government scheme designed to incentivise more homeowners to turn to renewable heating systems such as solar thermal and heat pumps.
Solar thermal installation quotes
For anyone looking to lower their energy bills as well as their carbon footprint, solar thermal is the perfect solution. To get the installation off to the best possible start, you can get free quotes from solar thermal installers based in your area using Solar Guide.
All you have to do is take a few moments to complete our simple online form, letting us know a few details about the work you need carrying out, and we’ll match you with up to 3 fully-qualified installers in your area.
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