solar heating

Solar heating systems explained

You already know that solar panels can generate electricity for your home, but that’s not all that solar energy can do – there are other solar technologies that make use of the sun’s thermal energy to help heat up homes and lower one’s heating bills.

Solar heating: what you need to know

Photovoltaic solar panels generate electricity, but energy from the sun can be used in different ways. One common way to use solar power is with solar heating systems, which convert solar energy into usable heat instead of electricity.

There are many ways to use solar energy to generate heat. Among the many uses for solar heat are the following:

  • Solar water heating
  • Solar space heating
  • Solar pool heating

Below, we’ll briefly talk about each of these systems and discuss the pros, cons, and applications of each.

Solar water heating systems

If you’re looking to reduce the cost of heating water for your home or business, solar water heating (also known as solar hot water) is a great solution. With a solar water heating system, you can use the power of the sun to reduce your reliance on traditional heating sources (such as oil, electricity, and natural gas) in favor of an abundant and environmentally friendly energy source – the sun!

Solar hot water systems capture thermal energy from the sun and use it to heat water for your home. Systems can either be passive or active – while passive systems use gravity and natural circulation, active systems use pumps and controls to circulate water.

Payback periods for a solar water heating system vary depending on how you currently heat your water. For example, the payback period for a solar hot water system that replaces natural gas will be longer than one that replaces electricity or gasoline because natural gas is a comparatively less expensive fuel. If you install a solar water heating system on your roof, you can expect significant annual returns dependent on your water use and the previous method of water heating. Plus, using a solar water heating system reduces your emissions and your home’s impact on the environment.

Solar space heaters

Solar space heaters use the energy of the sun to heat your home. While similar to solar water heating, these systems typically require more collectors (and consequently, more roof space), as well as bigger storage units to get the job done. The thermal energy is harnessed at the solar collectors and used to heat either a liquid or air, which is then circulated to disperse heat.

Like solar water heating systems, there are both passive and active solar space heaters. Passive systems work like greenhouses – the collectors gather energy, and the resulting heat is trapped and circulated naturally. Active solar space heaters use pumps and other mechanisms to circulate heat.

Solar space heaters can reduce heating costs by up to 70 percent. However, most building codes require a backup heating system, so your solar space heaters should be integrated with an existing heating system.

Solar pool heaters

One specific way to use solar water heating is for pools – solar pool heating systems are a great way to harness the sun’s thermal energy.

A solar pool heater uses solar thermal panels (also known as collectors) that collect heat from the sun and transfer it to pool water that is pumped through them. These solar collectors usually look similar to photovoltaic panels but have space inside them for pool water to flow through and be heated up.

Solar pool heaters require little to no maintenance and will generally work well if they are properly installed for 10 to 20 years. Many homeowners can break even on a solar pool heater investment in under 7 years.

Installing solar heating options with solar panels

These are just a few of many solar technologies that can help you save money on your energy bills (isn’t the power of the sun incredible?). Not only do all of these technologies use the sun, but they also share a multitude of other attributes:

  • They help homeowners save money
  • They’re often eligible for many of the same incentives and rebates
  • The systems do the best on sunny, shade-free roofs

If you are interested in installing any of these systems in your home, we recommend having an experienced, licensed contractor do the job. Make sure to register your property on EnergySage to get quotes for a solar panel installation first, and then specify your interest in other solar technologies as well. Many of our solar installers have experience installing other solar technologies like solar water heating and solar space heaters, and it will often be more cost effective to tackle all these home improvements at once.

This entry was posted in Environment and Clean Technology on by .

About Kerry Thoubboron

Kerry is an expert in all things solar! She's worked in the industry for more than 6 years, starting her career as an Energy Advisor dedicated to helping customers compare their options and make well-informed solar decisions. She graduated from Boston University with a degree in Environmental Analysis and Policy. Outside of work, you can find Kerry snowboarding, watching The Office, or having passionate debates about which New England state is best (spoiler: it's Vermont).

7 thoughts on “Solar heating systems explained

  1. opera youtube

    I’ve been PV heating water for years at my camp. I have a system that harvests any energy not used for battery charging and sends it to the water heater, be it 5W or 500W. The controller has a fixed PV power point voltage. When the array goes over that set point (indicating a light load) enough energy is diverted to the water heater till the voltage drops back to the set point. This is proportional and about 97% efficient. This same system could be used as supplemental heating to a residential water tank. The energy savings and payback of a 500W to 800W PV array would be comparable to that of a Heat Pump Water Heater. With a small array, you guarantee 100% of the panels potential energy production is always utilized. That is the best payoff in solar where a lot of free energy is just wasted. These controllers are fairly simple to build.

  2. Greg Field

    Great article. We are an Arizona solar hot water manufacturer that have been building our solar hot water systems for over 35 years, Our system after tax credits and rebates net costs for the same or less as a conventional water heater. Our payback is within 3 years typically and we use a lifetime warranty, stainless steel tank that should never have to be replaced. Our operating cost annual is definitely less than a hybrid tank. Why pay to heat water in the Arizona sun? Contact us to learn more.

  3. Art

    Good article, but past 2015 it makes no logical sense to install solar water heaters. A customer would spend $6-8k on an install, save $300 a year (no service) and have the system last 10-12 years before the tank or collector fails, and they all fail. Longest warranty I have seen is 10 yrs. Pumps tend to go out every 3-4 yrs ( depending on water quality and scale buildup). Many licensed plumbers don’t know how to do a proper install from the first time, and either have to redo the install or fix the roof.
    Much better are new technologies as Hybrid water heaters, with install is $1300-$2000, annual operating cost is $100-130, so you will save $450+ per year and other benefits, so in the third year the W/H already paid for itself.
    I have been a plumber for 15+ years and a state plumber inspector for 2 years.
    Please do your due diligence and research before spending so much money. Get minimum 3 bids and go with the middle bid.

  4. Ellie Davis

    My husband and I are building a home and I think we should get a solar water heating system installed. Thank you for pointing out that this is a great way to save us money. I’ll have to look into finding the best company to come and install this for us.

  5. Millie Hue

    Thanks for helping me understand that the payback time of installing solar water heaters depend on the usage of the homeowner. This has helped me make a decision if I should go with a solar water heater. I have always been meaning to do so since we want to cut costs, especially that everything is rising when it comes to prices.

  6. Michael & Christine O’Grady

    We need a licensed Solar Hot Water/Heater technician/company on Long Island to give us an estimate.


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