Solar thermal: Myth busting with Mesh Energy

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This week we're back busting some common renewable energy technology myths! With summer rapidly approaching, we've decided to take a look at solar thermal.


If you're looking to reduce your carbon footprint, cut your energy bills and have hot water on demand, could solar thermal be the renewable technology for you? Here are some of the myths you may have heard about solar thermal; busted and clarified so you can make the right decision for your project and individual requirements.


Here we go... Mesh Myth Busters to the rescue again!


Myth 1: Solar thermal can provide 100% of my hot water

Whilst this is not fact, it is not entirely a fictional statement either! Solar thermal can indeed contribute to 100% of a household’s hot water requirement during the summer months with reduced contribution during spring and autumn. In fact, if you are lucky enough to own a swimming pool you can put summertime excess heat into your pool saving even more money. During winter, solar thermal will contribute almost nothing to your hot water supply.


On average, over the course of a year, solar thermal can provide between 50-60% of a household’s annual demand for hot water if correctly sized and should be used as a complementary heating source in most cases.

Myth 2: Solar thermal panels only work on sunny days

This one is completely untrue. Solar thermal systems are super-efficient at converting sunlight to thermal energy and whilst there is no doubt that clear sunny days are the most productive, even bright cloudy days can produce surprising amounts of hot water.

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Myth 3: Solar thermal systems should be replaced by solar PV systems for maximum gain

It is true that solar PV systems are often put on available roof spaces due to the wide use of electricity in the home and the perceived limited single use of solar thermal. If it is electricity that is more important to you, then sure - go for solar PV. But, if you have a pool or large hot water demands in the home or commercial building then nothing beats the efficiency of a well-installed and efficiently operating solar thermal system.


Solar thermal systems are about 90% efficient in turning the sun's energy into heat, whereas solar PV is at best 20% efficient. Consider carefully the specific application before writing this technology off.

Myth 4: The bigger the installation the better

No, this isn't exactly the case. Solar thermal installations are “tuned” to match the hot water storage capacity of the home’s hot water tank in order to stop stagnation during summer months. Stagnation is a solar thermal installation killer and so it is avoided through correct design of the collector panels (heat source) and the hot water tank (hot water sink) wherever possible.

Myth 5: It's OK to 'fit and forget'

Solar thermal installations are fairly simple and only really have one moving part (the circulation pump). Nonetheless, the rigours of the extreme temperatures the solar fluid goes through in a season does justify an annual maintenance regime to check the fluid quality and to make sure the solar pump is not suffering!


We have seen many solar thermal systems that are defunct due to poor maintenance and because they are only a supplementary system to your boiler, if they are not working properly it is almost impossible to tell to the untrained eye.


Unfortunately a solar installation is only as good as the fluid and the efficiency of the moving parts, so it’s well worth keeping an eye on some simple installation details to avoid rising energy costs.

Myth 6: Solar thermal systems are simple enough for any plumber to install

The installation of solar panels is fairly simple. What's more, with panels being sold at many building and plumbing merchants, it’s tempting to get your resident plumber to fit the system. It’s always best practice and safest to get a microgeneration certification scheme (MCS) qualified product and installer to fit it. Solar thermal systems can reach temperatures in excess of 150ºC in the summer and can be very dangerous if fitted incorrectly. Why risk it?


And there you have it. Some more renewable tech myths busted for you!


We hope this post has helped to bust some common myths and that you now have more confidence in your decision making for your purchase of solar thermal. Good luck!


If you still have any questions about solar thermal,
please don't hesitate to
contact the Mesh team today.

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by Doug Johnson 9 December 2025
As the year draws to a close, the Mesh team has been out in the community helping to spread some much-needed festive cheer. From fundraising in Santa suits, food donations for local families and donating warm clothing for those who need it most, the team has embraced the spirit of giving in the run-up to Christmas. Running for a Cause: The Guildford Santa Fun Run Despite the wet weather, members of the Mesh team braved the elements for the Guildford Santa Fun Run, raising money for the children’s charity, Challengers. Joined by Jacqueline Smith from our client TALO, Mesh’s Founder and Director Doug Johnson, along with Maria Fiore and Ilianna Filippopoulou, completed the festive run in full Santa attire. The team also reached their fundraising target, helping Challengers continue its exceptional work in supporting disabled children and young people in the community. Supporting Local Families in Need through the Lions Christmas Food Parcel Appeal For another year, Mesh proudly supported the Lions’ Christmas Food Parcel Appeal, helping to provide food parcels to individuals and families in need over the festive period. Thanks to the generosity of the Mesh team and many local businesses and residents, a huge selection of donated goods is now being sorted and delivered by the incredible volunteers at Lions Farnham. This annual initiative continues to be a meaningful way for us to support vulnerable members of our local community during what can be a really challenging time of year. The Coats for All Initiative Mesh has also taken part in the Coats for All initiative, a brilliant scheme that distributes warm, good-quality coats to anyone who needs one. Through the generosity of colleagues, friends, and partners who donated pre-loved coats in excellent condition, we are helping to ensure that more people can stay warm this winter. Many local libraries are acting as collection points, making this a simple but impactful way for people to support others in the colder months — and we are proud to play our part. According to Mesh Founder and Director, Doug Johnson: “Community sits at the heart of Mesh, and it’s been inspiring to see our team give their time, energy and generosity to support such worthwhile causes - not just this Christmas but throughout the year. Whether running through the rain, collecting food, or fundraising for local charities, everyone has contributed to making a real difference — and I couldn’t be prouder.” At Mesh, we believe that small acts of kindness create meaningful impact. A heartfelt thank you to everyone who donated, participated, or volunteered this year. We look forward to continuing our community support into 2026 and beyond."
9 December 2025
As the year draws to a close, the Mesh team has been out in the community helping to spread some much-needed festive cheer. From fundraising in Santa suits, food donations for local families and donating warm clothing for those who need it most, the team has embraced the spirit of giving in the run-up to Christmas. Running for a Cause: The Guildford Santa Fun Run Despite the wet weather, members of the Mesh team braved the elements for the Guildford Santa Fun Run, raising money for the children’s charity, Challengers. Joined by Jacqueline Smith from our client TALO, Mesh’s Founder and Director Doug Johnson, along with Maria Fiore and Ilianna Filippopoulou, completed the festive run in full Santa attire. The team also reached their fundraising target, helping Challengers continue its exceptional work in supporting disabled children and young people in the community. Supporting Local Families in Need through the Lions Christmas Food Parcel Appeal For another year, Mesh proudly supported the Lions’ Christmas Food Parcel Appeal, helping to provide food parcels to individuals and families in need over the festive period. Thanks to the generosity of the Mesh team and many local businesses and residents, a huge selection of donated goods is now being sorted and delivered by the incredible volunteers at Lions Farnham. This annual initiative continues to be a meaningful way for us to support vulnerable members of our local community during what can be a challenging time of year. The Coats for All Initiative Mesh has also taken part in the Coats for All initiative, a brilliant scheme that distributes warm, good-quality coats to anyone who needs one. Through the generosity of colleagues, friends, and partners who donated pre-loved coats in excellent condition, we are helping ensure that more people can stay warm this winter. Many local libraries are acting as collection points, making this a simple but impactful way for people to support others in the colder months — and we are proud to play our part. According to Mesh Founder and Director, Doug Johnson: “Community sits at the heart of Mesh, and it’s been inspiring to see our team give their time, energy and generosity to support such worthwhile causes - not just this Christmas but throughout the year. Whether running through the rain, collecting food, or fundraising for local charities, everyone has contributed to making a real difference — and I couldn’t be prouder.” At Mesh, we believe that small acts of kindness create meaningful impact. A heartfelt thank you to everyone who donated, participated, or volunteered this year. We look forward to continuing our community support into 2026 and beyond."
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