My grandfather was a pioneer of renewable technology in the 1970s. An engineer in the ‘Alternative Energy Division’ for John Laing, he developed flywheel storage technology, bi-directional underwater turbines, and early iterations of solar, wave and wind power.

Decades ahead of his time, as a child he told me that if we put all the world’s fossil fuels into an annual calendar, we’d only have a few minutes left. Some 50 years later, we are still fighting to change energy for good.

One of the biggest net zero challenges is decarbonising heating and cooling of residential and commercial buildings, and industrial processes. Accounting for roughly half of the world’s energy demand, only 10% of heating and cooling is currently met by renewables – the other 90% by burning fossil fuels.

While the direction of policies in the UK is good, the current pace of progress should be faster. Reliable and long-term funding for renewable infrastructure is needed to increase investor and business confidence dramatically, encourage the development of innovative green technologies, help those struggling to pay their energy bills and protect the UK from future economic shocks.

However, the UK’s historic lack of consistent policy and deployment targets have led to sluggish adoption of renewable energy technologies – none more so than with solar thermal.

Advantages of solar thermal
Solar thermal can deliver numerous advantages to the resilience, security and competitiveness of any industry or sector. It offers a unique technology that can produce carbon-free heat by tapping into ‘wasted’ surfaces in manufacturing like rooftops. Solar thermal can produce heat on-site where the energy is needed. By applying this technology to heating for hot water and industrial processes, consumption of fossil fuels and demand on the grid is reduced directly.

Naked Energy designs and manufactures solar thermal collectors to decarbonise heat. One product, Virtu^HOT, is a high efficiency solar thermal collector, whilst Virtu^PVT is a hybrid product that generates both electricity and heat from a single collector. Naked Energy claims that this innovative design allows the collectors to produce three to four times more energy than traditional solar photovoltaic (PV) panels, resulting in a greater reduction in carbon emissions and significant cost savings.

Buildings like hotels usually don’t have enough roof space to hold the amount of PV required to replace gas entirely, yet they have huge energy demand given the need to provide guests with heating and hot water. This is where the combination of PV and solar thermal can really shine.

One of the key appeals of PVT technology is space efficiency. PVT is a high-energy density technology which generates more energy from roof space used in comparison to standard PV panels.

The impact of solar heat goes beyond individual buildings too. Solar district heating networks are a powerful demonstration of how entire communities can decarbonise through large-scale infrastructure projects.

These can provide a solar fraction of 90–100% when paired with inter-seasonal storage, such as, for example, pit thermal energy storage (PTES), and are widely deployed in many European countries such as Denmark, Austria and Germany. In Denmark, the technology meets 60% of the countries’ thermal demand.

Solar district heating networks not only provide cost-efficient heat generation, but also significantly reduce stress on local power grids, allowing green energy to be efficiently used for other applications.

UK lagging behind Europe
However, deployment of solar thermal in the UK is low. PV has historically received the lion’s share of attention and solar thermal is often overlooked. We believe that this slow roll-out is attributed to the UK’s historic lack of consistent policy or deployment targets.

Germany has deployed 10 times more solar thermal capacity per citizen and Austria 25 times more capacity than the UK. In Italy, solar thermal grew by 83% in 2021, owing to an innovative tax incentive scheme by the government. The dramatic increase in the country’s solar thermal adoption is proof that businesses and consumers are eager to drive the energy transition forward. Here again we believe that all that’s needed are the right conditions to drive a bottom-up approach.

Of course, solar technology will not deliver the energy transition alone.

The International Energy Agency (IEA) forecasts that renewables for heat generation will grow globally between now and 2027 by around 15%. However, to meet net zero targets they must grow by around 27%. Clearly there is still a lot to do.

The urgent need to decarbonise heat is clear. In the UK Chancellor’s recent budget, £60mn was announced in support of public swimming pool energy upgrades, alongside an extension of the ‘climate change agreements’ scheme to reduce energy use and emissions. While this is positive, the budget offered little new in the way of energy transition, which is disheartening.

The emphasis was on carbon capture technology and nuclear power, with £20bn promised over the next two decades. There is no question that these technologies will be a useful addition to the energy mix over the long term, but we need to act now to reduce carbon emissions. We already have the technology to make a real dent in our emissions and we can’t let the clock count down any longer.

Businesses and communities that can wean themselves off the grid and run on clean energy will benefit from an efficient hedge against volatile markets and ongoing energy price fluctuation.

This will require a significant level of investment. It is not a coincidence that the US implemented the Inflation Reduction Act (IRA) last year, and the European Union (EU) is now implementing the Green Deal Industrial Plan strategically supporting its local industry.

There is no denying the green transition will be expensive. But the price of not reaching net zero will be far more and is estimated to be as much as $178tn over the next 50 years.

Germany has deployed 10 times more solar thermal capacity per citizen and Austria 25 times more capacity than the UK.

The energy transition provides a huge opportunity to build domestic supply chains, revitalise national industries and mitigate the worst effects of climate change.

Solar thermal should be an integral part of this journey for the UK. The IEA predicts that the number of solar thermal systems will grow from 250mn now to 1.2bn in 2050; and will directly contribute roughly 250,000 green jobs by 2030 in Europe alone, according to research by Solar Heat Europe.

An achievable target
We need similar enthusiasm for solar thermal here in the UK. A national target of 11 GW of solar thermal installed by 2030 would put the country on par with today’s EU average, which would equal an annual growth of 26%. This is a tall order, but is possible to achieve with grant schemes like the Public Sector Decarbonisation Scheme (PSDS), the revival of the Green Homes Grant for the residential sector and other actions.

Policy like this has worked for solar thermal before – it was certainly a popular technology under the Green Homes Grant. But what we’re lacking now is clear communication around the technologies available. Investors across every sector need to know what all the options are, rather than being pushed towards any single technology.

The businesses we work with don’t want to wait for future innovations. They demand a fast and efficient solution now to reach their climate targets.

There are many success stories in other countries that can be replicated in the UK. To get there, policy must provide a systematic and technology-agnostic approach to the decarbonisation of heating and cooling across all sectors.