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HEAT YOUR WATER, POOL OR HOME WITH SOLAR THERMAL
The term “solar thermal” describes one way of harnessing and reusing the energy of the sun.
In solar thermal systems, the sun’s heat is collected into sealed, liquid-filled tubes. The liquid stores the heat and circulates to warm a storage tank filled with water. The storage tank then holds the heated water until it is needed for domestic use (showers, laundry, etc.) or for space heating. Solar thermal energy is renewable, and using this kind of energy will reduce your energy bills, benefit the environment and cut your contribution to greenhouse gases.
Solar Thermal FAQ
- Is solar thermal a good fit for me?
- What kinds of solar thermal systems work best in Colorado?
- What is the right solar thermal system for me?
- How much does a solar thermal system cost?
- How much money and energy will I save?
- What should I keep in mind if I’m hiring a contractor?
- What rebates and incentives are available for solar thermal?
- Are there any laws or regulations I need to be aware of?
In order to be efficient and effective, a solar thermal system must receive adequate sunlight throughout the year. Consult with a system supplier or installer to determine whether a solar thermal system makes sense for your site, and if so, which type of system you should consider.
Solar water heating for domestic use in and to heat pools or hot tubs can be a good option in Colorado’s climate. If your building site has unshaded areas and generally faces south, it may be a good candidate for a solar water heating system.
Solar space-heating systems are most economical for buildings that would otherwise be heating with electricity, rather than with natural gas or other fuels. Unfortunately, these systems have the greatest demand placed on them at night and during the winter, when sun is in short supply. For these reasons, today’s solar space-heating technologies tend to be a less cost-effective solution for space heating in most Colorado homes.
Energy-efficiency and passive solar techniques—where windows, walls and floors are designed to collect, store and distribute solar energy in the form of heat in the winter and reject solar heat in the summer—are a good alternative to active solar space heating systems. For more information on passive solar techniques, visit our Passive Solar page.
You and your contractor will need to consider how much sunlight is available and what makes the most sense for your needs and location. You will also need to figure out if you have enough space for the size of collector that you will need to operate your system. Also, whenever you are considering a renewable energy system, you should first make sure your home is energy efficient to ensure you are getting the most value.
There are three types of solar thermal systems to choose from:
Solar water heating for buildings
One of the most cost-effective renewable technologies, a typical residential solar water-heating system significantly reduces the need for conventional water heating.
In general, you will want to get a system that will meet 90-100% of your hot water needs in the summer. Your installer can help you determine the collector area and storage volume for your needs; in the meantime, this chart can give you a general idea of the required capacity:
|Number of People in Household||Size of Solar Storage Tank||Collector Area Required|
|1-3 people||66 gallon||44 square feet|
|3-4 people||80 gallon||54 square feet|
|4-6 people||120 gallon||80 square feet|
Solar water heating for pools
In general, solar water heaters for pools and spas are used to extend the swimming season into the spring and fall. You will need a solar collector that is 50-100% of the surface area of the pool in order to create adequate heat. Adding a pool cover or blanket will significantly reduce heat loss and further extend the impact of your solar thermal system.
Solar space heating
Since space-heating systems have to store heat for use when solar energy is least available and your house is coldest—at night and during the winter months—they are generally larger and more complicated. In order to be effective and efficient, solar collectors for space-heating systems will need to span an area equivalent to 10-30% of the floor area of your house.
Active solar space heating systems are most cost effective when they are used for most of the year, that is, in cold climates with good solar resources, a description that fits at least some parts of Colorado. Solar space-heating systems are usually sized to incorporate water heating needs as well.
For more information:
Get solar heating basics from the U.S. Department of Energy.
Download the U.S. Department of Energy’s “Heat Your Water With the Sun” booklet.
Find out about solar heating for consumers from the U.S. Department of Energy.
Explore solar thermal technology.
The cost of a solar thermal system will depend on the system you choose. On average, solar thermal systems cost between $2,000 and $4,500.
Though this initial investment may seem high, this price is competitive with conventional energy sources when you consider the years of lower and more stable energy bills—and the protection from rising fossil fuel costs—that the system will provide. In addition, you will be earning an annual 6-25% tax-free rate of return on your investment, depending on how much hot water you use and how much energy you save. And finally, you may find that the system increases the value of your property and enables you to recoup costs when you sell your home.
Solar Domestic Hot Water Heating
With this kind of system, your water-heating bills should drop 50-80%. These savings will increase in value as fossil fuel prices rise. The average Colorado resident with a solar domestic water heater can expect energy savings of around $10/month ($120/year).
Solar Pool Heating
In the case of solar pool heating, you may gain more use of your pool rather than savings on your energy bill. This is because, for many people, conventionally heating a pool was simply too expensive to undertake. If you did heat your pool conventionally, the payback period for a solar pool heating system would be between 1.5 and 7 years.
Solar Space Heating
In general, a solar space heating system will provide 40-60% of your space heating needs—cutting your home heating bills by the same amount.
For general tips, including what to ask a potential contractor, how to compare bids and how to monitor quality, please visit the How to Hire a Contractor page.
In addition to the general tips on our How to Hire a Contractor page, you may need to consider some specific issues when hiring a contractor for this particular kind of work. Here are some additional things to keep in mind:
- Make sure all bids are for equivalent parts and labor. For example, bids for ground systems will be very different than a roof system. Have contractors specify system type and size, energy output, maintenance requirements and cost, including installation, start-up, hardware, permits, sales tax and warranties.
- A system warranty is crucial in comparing bids. Your local incentive programs may require a written installation warranty.
- Choose a contractor who has experience with the type of system you want to install. Solar thermal can be used for water heating, pool heating or space heating, and not all contractors have experience with each.
- Find out how many years of experience the contractor has with installing solar thermal. Ask your contractor how they will ensure that the work is compliant with the incentive program requirements you may qualify for.
- Confirm that bids include the total cost of getting the system up and running, including hardware, installation, connection to the grid, permitting, sales tax and warranty.
- There aren’t any required certifications or licensing by law in the state to do this work, but you should check with the industry certification page to familiarize yourself with the types of industry certifications you may see when you are doing your search.
- Make sure the bid includes details about the design and size of the system and includes a clear description of where the panels will be located, at what angle they will be installed, and assurance that they won’t be blocked by shade throughout the day.
- Your contractor should ask to see your utility bills to understand your energy consumption in order to size the system properly.
- If your installation will be roof mounted, your contractors should go up on the roof to measure properly.
There are a number of financial incentives and programs for solar thermal systems. See the Energy Action Planner for additional information on financial incentives in your area.
Before installing a solar thermal system, you should find out if there are permit requirements for your area. Plumbing, building and electrical permits—with mandatory inspections at job completion—may be required. Your contractor should be able to help you obtain and manage this process.
Colorado state law states that Homeowners Associations (HOAs) cannot prevent a homeowner from installing a solar system. Click here to see the language of the legislation.