Solar thermal: Myth busting with Mesh Energy

Doug Johnson • 19 June 2021

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.

Underfloor heating: 7 myths busted! Mythbusting with Mesh Energy

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.

SHARE THIS POST WITH YOUR NETWORK

by Doug Johnson 24 March 2025
Mesh Team Blasts Half Marathon for Cancer Charities
by Doug Johnson 24 March 2025
Offsite housing specialists TALO and building performance consultants Mesh Energy have announced a collaboration agreement to accelerate the delivery of ultra-low energy homes. The collaboration will combine TALO’s advanced timber superstructure technology from Finland with Mesh’s experience of providing net zero building performance and engineering services for housebuilders, architects and residential property developers. Working closely together, TALO and Mesh will aim to significantly increase the energy efficiency of new homes for market sale, rent and affordable housing, exceeding both Passivhaus energy standards and Future Homes standards, in compliance with the latest regulations. Doug Johnson, Director of Mesh Energy: “TALO’s timber superstructure solutions for low rise housing are the very best we have seen in the UK in terms of energy efficiency, air tightness, cost and quality. Their latest projects are achieving at least a 30 per cent improvement on Passivhaus energy standards and at no cost premium. We don’t believe there is anything like this on the market today and yet it is very needed. Some of the biggest issues facing housebuilders and developers are managing risk and addressing skills shortages. TALO’s system addresses both of these challenges extremely well. New regulation is coming which will make it increasingly difficult for developers to balance the rising cost of building new homes to the required energy and air tightness standards and the risk of non-compliance. New homes simply need to perform better. And yet the risk for developers is in the fabric and performance of each home. Our new collaboration will give housebuilders the benefit of much greater certainty of delivery to the required quality, air tightness and energy standards from the inception of a project. Our work on the energy strategy, data and compliance will support TALO’s extremely efficient way of building new homes to reduce risk for residential property developers.” TALO and Mesh have already collaborated on a number of projects. Under the new agreement, both businesses can leverage their respective experience to enhance the efficiency and economics of new residential projects. Dr Anthony Greer, Corporate Strategy Director of TALO said: "Our vision is to transform UK housebuilding by taking proven technology which has been used to build thousands of units in the Nordics – in one of the most extreme climates in the world. Our goal is to address some of the difficult problems that have been challenging the UK construction industry for many years – skills shortages, speed of delivery, sub-standard quality, and poor energy efficiency. Our ultimate goal is the offsite construction of high quality, ultra-low energy homes that can eradicate fuel poverty and snagging. By radically reducing time on site, developers can achieve a faster return on investment. They need fewer trades on site because we are using highly efficient offsite technology. Our processes are entirely dry – from forest to site – which means better air tightness performance and more accurate programme scheduling for the fitout phase to further reduce risk. Homes built by TALO exceed Passivhaus energy and air tightness standards at no cost impediment. This means homeowners and tenants will have hugely reduced energy costs that are verified by A-rated EPC certifications. Our housebuilding solutions will be enhanced with our collaboration with Mesh, helping to solve the technical and economic challenges that are constraining the sector and compounding the housing and cost of living crises.” In the new arrangement, Mesh will provide the energy strategy, data analysis and compliance work to support TALO’s delivery of the offsite superstructures for low-rise housing projects – which range from terraced housing, semi-detached family homes and larger executive schemes for developers and housebuilders across the UK.
by Pablo Jiménez-Moreno 29 April 2024
Discover the critical role of a feasibility study in integrating renewable technologies into your home. Learn how to make informed decisions for sustainable living.
by Doug Johnson 11 January 2024
As we come out of our end of year hibernation period for 2023 and try to both digest and interpret what 2023 had in store for us, how we dealt with it, and what we would change if we could; we drag ourselves out into the blinding light of 2024 and hope for a less tumultuous year in the UK’s sustainable construction sector. I am an optimistic person and ‘glass half-full thinking’, as well as doing my best to gaze into the future, is my default position. When working with a team on the sharp end of sustainable building design, there are some trends which simply cannot be ignored and hold great promise for 2024. The following trends are in areas we’ve seen growing design time and client fees being spent to great effect, and that’s why these are my top four sustainable construction prediction of 2024.
by Doug Johnson 7 December 2023
In recent years, sustainability has seen a massive increase in priority within the construction industry. As climate change and its effects worsen around the world, architects, builders, and developers are now feeling more compelled to adopt more environmentally friendly practices. While pursuing sustainable building design is definitely a commendable course of action, the process itself has its own set of challenges; introducing potential risks to the construction industry that must be addressed.
by Rebecca Boehme 3 August 2023
In May 2023, we discovered we’d been included in The Sunday Times’ ‘Best Places to Work in 2023’ list . This phenomenal achievement was the icing on the cake of what’s been a great few years for Mesh as an employer. From achieving our B Corp in November 2021, to being recognised in B Corp’s ‘Best in the World’ category for workers in March 2022, to growing the business to the 22-strong team it is today, it’s been both incredible to see our recognition grow, and a mammoth effort to get here.
by Doug Johnson 27 July 2023
Incorporating low-energy solutions like solar PV, battery systems, and other energy-efficient technologies into commercial buildings offers several key benefits. We cover the top 5 in our latest blog.
by Doug Johnson 20 July 2023
In this second blog on the technology behind low-energy commercial projects, I'll be exploring why solar PV, energy storage, EV charging systems, and LED lighting are crucial assets to any low-energy commercial building.
by Doug Johnson 13 July 2023
It's estimated that commercial buildings contribute around 8% of the UK's total annual carbon emissions, and carbon associated with heating, ventilating, and cooling buildings makes up about 40% of a building's total annual energy usage.
by Lewis Caudy 5 July 2023
When it comes to sustainable and energy-efficient building design, architects are increasingly turning to geothermal technology as a viable option.
More posts

Subsribe to memo from mesh