Solar thermal vs solar PV

Heating water accounts for around 17% of the average UK household’s total energy consumption. Every year, British residents use approximately 840 billion litres of water, spending around £2.3 billion on heating it.

What are solar thermal panels?

Solar thermal panels are devices that harness the sun’s energy to heat water for your home. These systems usually consist of solar collectors mounted on a roof, a heat exchanger, a hot water cylinder, and a backup heater. Solar collectors can either be flat plate collectors or evacuated tube collectors, both designed to maximise solar radiation absorption and convert it into usable heat. These systems are a sustainable alternative to traditional water heating systems.

How does a solar thermal collector work?

A solar thermal collector captures solar energy and converts it into heat. There are two main types:

• Flat plate collectors (FPC)
  These have a flat, heat-absorbing plate which captures sunlight, heating the fluid within.
• Evacuated tube collectors (ETC)
  These use vacuum-sealed tubes to collect and store solar heat, and are often more efficient than FPCs.

A solar thermal system also typically includes:

• A controller system, which manages the system’s operation
• A heat exchanger, which transfers heat from the collectors to the water
• A backup exchanger, to ensure hot water supply during periods of low solar input
• A hot water tank, which stores the heated water

How efficient is solar thermal?

Solar thermal systems are highly efficient at converting sunlight into heat. Efficiency can vary based on the type of collector and installation specifics, but generally, solar thermal systems can meet around half of a household’s hot water needs, providing almost all hot water in the summer months and less during winter.

How long do solar thermal panels last?

With proper installation and regular maintenance, solar thermal panels can last around 20 years. Regular maintenance is crucial to ensure your solar thermal system remains efficient and functional over its lifespan.

Where is solar thermal energy used?

Solar thermal energy is used in many residential, commercial, and industrial settings. It’s primarily used for heating water, but can also be used for space heating and cooling, as well as in industrial processes that require heat.

Can solar thermal generate electricity?

No, solar thermal systems cannot generate electricity. For electricity generation, solar photovoltaic (PV) panels are used. These panels convert sunlight directly into electricity, which can be used to power household appliances and lighting.

Does solar thermal work in the winter?

Solar thermal systems can work in the winter, although their efficiency may be reduced due to shorter days and lower solar intensity. Proper insulation of the system can help minimise heat loss.

Are solar thermal panels worth it?

Solar thermal panels can reduce your energy costs and carbon emissions related to water heating. They are more beneficial in regions closer to the equator as they have higher solar radiation. Their effectiveness can be limited in cloudier regions, and they do require space for a hot water storage tank.

Solar thermal vs. solar PV: an alternative

While solar thermal systems use sunlight to generate heat, solar PV systems convert sunlight into electricity.

There are two types of residential solar PV systems:

• On-grid
  These systems allow for feeding excess electricity back to the grid, often with monetary incentives.
• Off-grid
  These systems operate independently of the electrical grid.

Benefits of solar PV

Solar PV systems offer numerous benefits for homeowners looking to reduce their energy costs and carbon footprints.

• Save money on your energy bills
  Utilise the free energy from the sun to power your home. You can even get paid for excess electricity you generate, by signing up to a Smart Export Guarantee (SEG) tariff.
• Reduce your carbon footprint
  Contribute to a greener future by generating your own clean, renewable energy.
• Energy independence
  Benefit from greater autonomy from the electricity grid, providing energy security and stability.
• Maximise your self-consumption with a home battery
  Store excess electricity generated throughout the day for use at night, further increasing your grid independence and giving greater savings on your energy bills. 
• Make the most of time-of-use tariffs
  Charge your home battery using cheaper, off-peak electricity tariffs and use this energy during peak rate times, saving you even more on your energy bills.
• Backup power
  Ensure you have a reliable power supply during grid outages.

Using solar PV for hot water

Solar PV systems can power a heat battery, such as the Sunamp Thermino, which stores energy more efficiently and compactly than traditional hot water cylinders.

Advantages of Sunamp heat batteries

• Space saving
  Sunamp heat batteries are up to 4-times smaller than the equivalent hot water tank. It’s compact design fits in tight spaces, freeing up space in your home.
• Works seamlessly with solar PV
  Charge your Sunamp using your solar panels to further reduce your carbon footprint and save money on your energy bills.
• Hot water at mains pressure
  Enjoy the luxury of mains pressure, on-demand hot water throughout your home.
• Hassle-free
  Sunamp heat batteries are easy to install, with less pipework than typical water heating systems. They require no mandatory annual maintenance too!
• Super efficient
  Ultra low heat losses thanks to Sunamp’s pioneering use of phase change materials to heat your hot water.
• Save money on your energy bills
  Charge your Sunamp using cheaper, off-peak energy tariffs or with free solar electricity.
• Protects against Legionella
  Sunamp’s innovative design protects against the risk of Legionella, as very little hot water is stored.

Solar thermal vs solar PV

Switching to solar PV systems can significantly reduce your energy costs and your carbon emissions. The UK Government have announced a VAT exemption for solar PV and home battery installations, effectively saving you 20%. Now is an excellent time for UK homeowners to consider installing solar PV with a Sunamp heat battery.

We are certified Sunamp installers and MCS accredited for solar PV and home battery installations. Get in touch today and we can help you choose the best renewable energy solutions for your home.