What is solar thermal energy and how does it work?

Solar thermal energy harnesses the sun's heat to warm water or air for various applications, such as heating buildings or providing hot water. The process involves solar collectors that absorb sunlight and convert it into thermal energy. This energy is then transferred to a fluid, typically water, which is heated and can be stored for later use. This technology is a natural and efficient way to utilise renewable energy, making it a valuable asset in the transition to sustainable heating solutions.

Why has solar thermal energy been less popular compared to solar PV systems?

Solar thermal energy has historically been overshadowed by solar PV systems due to several factors. Primarily, policy support has favoured PV technologies, leading to significant subsidies that reduced costs and increased adoption. Decarbonisation policy has also been focused on electrification, putting other clean solutions in the back seat. Additionally, solar thermal has often been perceived as a residential solution, limiting its application in commercial and industrial sectors. This narrow focus has hindered its growth, despite its potential to contribute significantly to heat decarbonisation efforts alongside other technologies.

Can solar thermal energy complement heat pumps?

Solar thermal energy can enhance the efficiency of heat pumps by preheating the water they use. When a heat pump starts with warmer water, it requires less energy to reach the desired temperature, improving its coefficient of performance (COP). This synergy allows for a more efficient heating system overall, reducing reliance on electricity and making the transition to renewable heating more feasible. By integrating solar thermal with heat pumps, users can benefit from reduced energy costs and lower carbon emissions.

What policy changes are needed to support the growth of solar thermal energy?

To foster the growth of solar thermal energy, it is crucial for governments to recognise and support this technology as part of a broader strategy for heat decarbonisation. This starts with establishing clear decarbonisation targets to help align policies. Policies should be technology-agnostic, promoting a diverse range of solutions rather than favouring one over another. Additionally, government-backed guarantees for renewable energy projects could lower capital costs for investors, making solar thermal projects more attractive.

What role does solar thermal energy play in the future of energy?

Solar thermal energy is poised to play a significant role in the future of energy resilience and sustainability. Solar thermal can provide affordable, clean heat on-site, reducing dependence on the power grid. Its inherent storage capabilities allow for efficient energy management, making it a valuable asset in balancing energy demand, especially during peak times. As the world transitions to electrification and faces increasing energy demands, solar thermal can help mitigate challenges associated with winter heating and contribute to a more resilient energy system.