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What is Solar Thermal?

A system that uses sunlight to heat water directly, as opposed to generating electricity.

Quick Answer

Solar thermal was popular in Ireland before solar PV became affordable. The SEAI offers grants of up to €1,200 for solar thermal installations. While solar PV has overtaken solar thermal in popularity, thermal systems remain a good choice for homes with high hot water demand. Many Irish homes installed solar thermal panels under earlier SEAI schemes.

Fact-checked by John Rooney, Solar Energy Editor. Editorial policy

Solar Thermal Explained

Solar thermal systems use collectors (usually mounted on a roof) to absorb heat from sunlight and transfer it to a hot water cylinder. There are two main types: flat plate collectors and evacuated tube collectors. Unlike solar PV, which generates electricity, solar thermal produces hot water directly — typically providing 50–70% of a household's hot water needs annually. Solar thermal systems are simpler and cheaper than PV but less versatile.

How Does Solar Thermal Work in Ireland?

Solar thermal was popular in Ireland before solar PV became affordable. The SEAI offers grants of up to €1,200 for solar thermal installations. While solar PV has overtaken solar thermal in popularity, thermal systems remain a good choice for homes with high hot water demand. Many Irish homes installed solar thermal panels under earlier SEAI schemes.

Frequently Asked Questions

Is solar thermal or solar PV better for Ireland?

Solar PV is generally more versatile and cost-effective for most Irish homes. However, solar thermal can be better for households with very high hot water demand and limited roof space.

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John RooneySolar Energy Editor

John Rooney is the founder of Solar Info and has been covering the Irish solar energy market since 2023. He fact-checks all content against official SEAI data and maintains relationships with SEAI-registered installers across Ireland.

SEAI data verifiedIndependent research3+ years covering Irish solar
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