How much does a solar thermal system cost?
What is the cost of a solar thermal hot water system?
The cost of solar thermal systems vary, but normally you can expect to pay between $2,500 for a pool solar heater and from $7,700 for full solar thermal installations. These figures include installation costs and all parts (solar collectors, control panel, pipes, hot water tank).
It is also possible to buy DIY solar thermal kits with all the necessary hardware, which normally cost between $2,000 and $6,000, though these are not immediately eligible for tax credits and rebates in other states if they are not installed to the right standard.
Potential differences in initial costs of solar thermal systems occur due to each site’s specifications. For example, plumbing costs may increase if the building has a complicated or antiquated water system. If scaffolding is needed, then the installation costs could be considerably higher. The costs of integration with current systems could add further expense.
The size of system (the number of collectors and water cylinder capacity) you will require depends on the hot water demand of your home, business or organisation. A general rule of thumb is that you’ll need 1m² for each person living in the building. Solar thermal collectors are usually around 2-3m², so for an average 3-bedroom house you will require 2 collectors. As the average person will use around 50 litres of hot water each day, a normal 4-bedroom house will require a 200 litre tank.
The quality of collector used also impacts upon the total initial cost of the project. As noted already, evacuated tube systems cost slightly more than flat panel systems, but are more efficient.
Potential savings when using Solar Thermal
The potential savings offered by solar thermal systems are difficult to calculate exactly and depend on a large range of factors. These include:
- Initial system cost (depending on size, quality of parts and installation).
- The energy source that you are replacing (coal, gas, electricity, LPG, oil, etc.).
- The property’s suitability for solar panels (and the total output of the system - usually between 1000-2500kWh in the US).
- The property energy efficiency.
- Any rebates such as state tax credits.
- Your geographical location and solar resource.
- Available financing incentives.
- The cost of the fuel you use for your backup water heating system, if you have one.
- Your energy needs (the solar thermal system will not provide all of your hot water needs).
Though the above range of factors needs to be taken into account when calculating the potential savings offered by solar thermal systems, it is possible to give a rough idea of how much you can expect to save.
The typical output of a domestic solar thermal installation in the US is between 1000kWh and 2500kWh, though once again this depends on individual factors. With state incentives and a reduction in heating bills, you should expect to pay off your initial investment within about ten years in most states of the US.
It is necessary to underline the fact that a solar thermal system will not fully replace your existing water heating system, and will not provide any space heating. The actual percentage of your water heating demand covered by solar thermal will depend on your energy consumption habits (though this figure is usually between 40% and 60%). Obviously, solar thermal systems are most productive in the summer, when there is most sunlight. You will therefore rely more on other, non-renewable energy sources during the winter months.
If you are planning on adding a solar thermal system to a new build or as part of a larger refinancing job as part of a mortgage, then your payments on the money lent may be considerably lower.
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