Can I combine solar thermal with solar photovoltaic (PV) panels for more energy benefits?

Yes, you can combine solar thermal and solar photovoltaic (PV) technologies to gain more energy benefits, and this combination is often achieved through hybrid solar panels known as photovoltaic-thermal (PV-T) panels.

What is combining solar thermal with solar PV?

• Solar PV panels convert sunlight directly into electricity.
• Solar thermal systems capture the sun’s heat to warm water for domestic heating or hot water.
• Hybrid solar panels (PV-T panels) combine both in a single unit: they generate electricity like a PV panel and simultaneously capture heat using a thermal system integrated on the back of the panel.

How do hybrid solar panels work?

• The photovoltaic part on the front converts about 20% of sunlight into electricity.
• The rest of the sun’s energy, primarily heat, is absorbed by the thermal component on the back as hot water or fluid.
• This hot water can be used for heating or domestic hot water needs.
• The thermal component also cools the photovoltaic cells, improving their efficiency by 5-15% because PV panels lose efficiency when they get too hot.

Benefits of combining solar thermal with solar PV for UK homeowners and small businesses

• More efficient use of roof space: Instead of dedicating separate areas for thermal and PV panels, one hybrid panel gives you both electricity and heat from the same footprint.
• Higher total energy yield: Hybrid PV-T panels can produce at least twice the energy of a conventional PV panel by generating both heat and electricity.
• Reduced energy bills: You get electricity to reduce grid reliance and thermal energy to reduce gas or electric heating costs.
• Improved PV efficiency: Cooling via thermal extraction improves the electrical output of the PV cells.
• Supports UK’s green energy goals: Using hybrid panels fits well with UK policies aiming to increase renewable energy use in buildings, including grants and incentives for solar installations.

Practical examples specific to the UK

• UK homes and small businesses can use hybrid panels to provide electricity and hot water, especially where space or roof orientation limits separate solar installations.
• Hybrid systems can be combined with heat pumps or existing heating systems to reduce fossil fuel consumption.
• Ongoing UK projects focus on improving combined PV and thermal technologies tailored to UK weather conditions, ensuring consistent heat supply even in cooler months.

Key pros and cons

Pros	Cons
Dual energy output: electricity + heat	Higher upfront cost compared to single PV or solar thermal systems
More efficient roof use	More complex system, requires specialist installation and maintenance
Improved PV efficiency through cooling	Thermal output depends on sunlight intensity, may need backup heating
Potential eligibility for government incentives	May require larger water tanks or system integration modifications

Common mistakes to avoid

• Assuming hybrid panels are plug-and-play: They require careful design and professional installation to integrate with your existing electrical and heating systems.
• Ignoring system sizing: Oversized thermal capacity without demand can waste heat; undersized systems won’t meet your needs.
• Neglecting maintenance: Hybrid systems have thermal circuits and electrical parts, so regular checks ensure optimal performance.
• Confusing hybrid panels with hybrid solar systems: Hybrid panels combine heat and electricity generation; hybrid solar systems mean PV panels connected with grid backup, which is a different concept.

Summary

Combining solar thermal and solar PV using hybrid photovoltaic-thermal panels is a practical way to maximise solar energy benefits for UK homeowners and small businesses. These systems produce both electricity and heat from a single panel, improve PV efficiency, save space and can reduce overall energy costs. While they require careful planning and a higher initial investment, their dual output and alignment with UK green energy initiatives make them a worthwhile consideration for those looking to enhance their renewable energy usage.