Installing a two or three panel solar thermal system that would supply an average 200 to 300 litre cylinder will cost around £4,000 to £7,000.
The cost of installing a solar thermal system in the UK can vary significantly depending on several factors, such as the system size, complexity, and location. On average, the initial investment for a domestic solar thermal system ranges from £3,000 to £8,000.
Let's compare that to the cost of producing the same energy using gas and electric: A saving of around £150 per year would give us a payback period of around 26 years on the capital cost of installing a solar thermal system, whilst a saving of circa £600 would give us a payback of just under 7 years.
Studies have found that the solar field represents the highest cost of a solar thermal power plant , , . Ehtiwesh et al. observed that the solar field had the highest cost at $17,635/h, followed by the boiler at $2,526/h and then the condenser at $1104/h.
The authors reported that solar thermal power projects were economically competitive at 7 % interest rate but uncompetitive at 18 % interest rate and recommended that favourable financing terms should be used for solar thermal power plants to make them economically viable and competitive with non-renewable projects.
The amount of energy savings and ROI depends on factors like local solar irradiance, hot water demand, and the system's efficiency. The payback period for solar thermal systems can vary widely based on installation costs, energy savings, and the availability of government incentives.