Despite being a little slower to take off in the UK than its electricity-generating counterpart, solar thermal panels are an effective way to slash hot water bills. Using only free energy from the sun, this microgeneration technology can provide up to 60% of your annual domestic hot water needs. What’s more, they don’t produce any carbon emissions in the process, they’re fully automated, and they have typical working lifespans of over 25 years.
How do solar thermal panels work?
Energy from the sun warms the solar collectors fixed onto your roof. The liquid inside these collectors (a mixture of water and glycol) is heated to a suitable temperature, before it’s passed through a heat exchanger coil inside your solar hot water cylinder.
Once it’s transferred heat to the water inside your cylinder, the liquid mixture returns to the solar collector on your roof to be heated by the sun once again.
Are they suitable for my home?
Similar to solar PV, solar thermal systems don’t need direct sunlight to work, and are still capable of providing a large amount of hot water even on cloudy days. While they won’t be able to meet your entire annual hot water demand, they’ll certainly make a difference.
The amount of hot water a solar thermal system will produce depends on the following factors:
1. The roof’s aspect: Anywhere between south-east and south-west are ideal.
2. The roof’s tilt: While solar thermal collectors can be installed onto a wall, the optimal tilt for solar thermal panels in the UK is between 30° and 40°. If you have a flat roof, we can include mounts to your proposal, which perfectly angle the solar thermal panels.
3. Geographical location: In the UK, there’s approximately a 32% difference in irradiance between Land’s End and John O’Groats.
4. Shading: The less shadows from nearby trees or buildings that cover your solar collectors during the peak generation window (10am – 3pm depending on the time of year), the greater the amount of hot water your solar thermal system will deliver.
5. Number of residents: As a rule of thumb, you’ll need one square meter of solar thermal panel for every resident in your home.
Benefits of solar thermal panels
- Cut your annual hot water bills by approximately 60% annually (100% over the summer)
- Environmentally friendly hot water production
- Long lifespan of up to 25 years
- Relatively low upfront cost
- On-roof, in-roof and flat roof mounted setups available for a wide variety of applications
- Reasonably quick to install
- Usually easy to integrate with your existing heating system
- Very little maintenance required
Additionally, solar thermal panels come with a significant bonus to renewable energy systems. By significantly reducing the hot water demand placed on the heat pump, the whole system will run more efficiently and more cost-effectively at a lower temperature.
Click box (benefits of solar thermal installations)
There are a number of benefits to installing solar thermal panels. It’s common knowledge that they provide a large proportion of your annual hot water needs. However, there’s more to this renewable technology than meets the eye. Here, we go through some of the other benefits to a solar thermal install that make them such an attractive investment.
Advantages of a solar thermal install
- Solar thermals generate 100% of your hot water needs in the summertime: Hot water production is dependent on how much light your solar thermal install receives. In the summer, they should provide all of the hot water for your home. In the winter, it’s a lot less, however over the course of a whole year, roughly 60% of your hot water needs will by provided by your solar thermal install.
- Reduced energy bills: Due to the solar thermal install’s free hot water production, you’ll be paying a lot less annually for hot water through your energy bills.
- Reduces the carbon footprint of your home: this advanced technology uses free renewable energy to operate, so your home will be the cause of much less carbon dioxide production. In more practical terms, the Energy Savings Trust says that coal-fired homes will be saving approximately 540kg carbon dioxide each year with a solar thermal install.
- Robust equipment: since there are few moving parts and very little that can go wrong, a typical solar thermal install is predicted to last for 20 – 25 years. On top of that, they need very little maintenance (once every few years is recommended).
- Payback period: over the course of its working lifespan, solar thermal installs actually save homeowners money in the long run. The time it takes you to recoup the cost of the solar thermal installation will depend on your home’s location, the roof’s aspect and tilt, weather conditions etc. As standard practice, our proposals come with performance estimates along with the cost, so you can find out exactly how long it’ll take you to start benefitting financially.
- Versatile technology: with on-roof, in-roof and flat roof options available, solar thermal installs can suit a wide variety of applications.
- Quick to install: solar water heating systems usually have a quick turnaround time on installs. This is because there aren’t many parts involved in the system, and even if yours is a retrofit installation, solar thermals are usually easy to integrate with existing hot water systems.
- Much smaller roof space needed when compared to solar PV arrays: As a rule of thumb, every resident will need 1m² of solar thermal panel space on your roof.
- Increase your home’s property value: not only that, but solar thermal installs also raise the EPC rating of your property, and for new builds, they’re an effective means of adhering to modern building regulations.
Benefit to your Renewable Energy System
One of the main reasons we advise installing solar thermals in our proposals is the benefit they will bring to your renewable energy system. By significantly reducing the hot water demand placed on the heat pump, the whole system will run more efficiently and more cost-effectively.