Solar pool heaters represent the majority of solar water heating systems installed in the United States. In fact, in many climates, they are the most cost-effective type of solar energy system. Their initial cost is competitive with gas and heat pump pool heaters, they last longer, and they cost much less to operate year after year.
Solar pool and spa heaters are simple technologies that require little maintenance. A typical system costs $3,000 to $4,000, and will pay for itself within two to seven years. What’s more, these heaters reduce greenhouse gas emissions, air pollution, and demand for fossil fuels.
Whether you heat your pool with a solar or conventional heater, a pool cover can help reduce heat loss and evaporation. Insulated pool covers are good at keeping heat in but they do prevent some of the sun’s heat from warming the pool on sunny days. An alternative is a “solar” or “bubble” pool cover. These products, which typically look like bubble-wrap packaging, are less expensive than insulated covers. Compared to an insulated cover, they let in more of the sun’s heat during the day to warm the pool, but because they’re thin and transparent, they don’t do as good a job of retaining heat when the sun isn’t shining.
This article focuses on solar heating systems for pools and spas. For heating water used inside your home, check out the “Solar Hot Water for Your Home” article or our “Fuel Cell article“.
Solar pool heaters have three basic components: a pump, a filter, and a collector. The pump (often the existing pool pump) moves pool water through a filter to strain out leaves and other debris. Then it pumps the water into the solar collector, a series of flat panels mounted on a sunny area of the roof or ground. As the water moves through the collector, it heats up and is pumped back to the pool. Unlike solar water heaters for your home, there’s no need for a storage tank since the pool provides storage.
If you live in a region with very hot summers, you can also use the collector to keep the pool cooler by circulating the water through the collector at night, when air temperatures are lower.
If you are using a solar heater with a hot tub, you may also need a conventional backup heater to raise the temperature higher or heat it at night. A cover over the hot tub will reduce temperature loss when you’re not using it and minimize the need for backup heat.
Solar pool heaters last for 10 to 20 years. Although taking care of them is no big deal, they do require periodic inspection and routine maintenance; check with your contractor and owner’s manual for details.
You’ll need to choose between unglazed, uninsulated collectors and glazed, insulated collectors. The unglazed ones, which are made of a tough rubber or plastic material and don’t have a protective glass covering, are popular because they’re less expensive. But they can’t be used in the winter in climates where temperatures dip to freezing. If you live in a cold climate and have an unglazed collector, you’ll need to drain it in the winter to prevent freezing. Unglazed collectors can only be used for pools and spas, because they don’t require water that is as hot as is needed for household use. Glazed collectors for pools and spas are the same as the collectors used for heating household water. (See the article “Solar Hot Water for Your Home.”)
The collector is typically mounted on an unshaded portion of the home’s roof. It can also be installed on an unshaded area of the ground. Collectors perform best when facing south and tilted for maximum exposure to the sun. A solar contractor can evaluate your site and determine the best location, solar orientation and tilt for the collector.
The collector’s size depends on a number of factors, including the pool size, climate, the length of the swimming season, your water temperature preferences, how much sun the site gets, and how efficient the collector is. As a rule, the collector size needs to be 50% to 100% of the pool’s surface area. (The larger the collector, the longer you’ll be able to extend the swimming season.) If you use a pool cover, you’ll be able to get away with a smaller collector area.
Before hiring a contractor, ask the following questions:
For general advice on what questions to ask contractors and other tradespeople, see our “What to Ask Your Contractor” article.
Across the globe, millions of people power their homes and heat their water with clean, abundant, renewable energy from the sun. Solar energy systems have been around for decades. But in the United States, their acceptance has been slow because of their high upfront cost.
Attitudes are changing, however. With concern mounting about carbon dioxide emissions, rising energy costs, and dependence on imported oil, having a power plant on the roof sounds awfully attractive. In fact, after tuning up your house to make it as energy efficient as possible, installing a solar energy system is one of the most powerful steps you can take to green your home. 
Who ever said walls were just for hanging pictures? A Trombe wall is a sun-facing wall designed as a passive solar collector; people can enjoy its benefits in the toasty comfort of their homes. Instead of running your home heating system, you can use the radiant heat flow from an original design. The Trombe wall, also referred to as a solar wall, was popularized by Felix Trombe in 1964 although it was patented by Edward Morse in 1881. The system is becoming an increasingly popular addition to home designs because of its heating benefits, energy efficiency, low maintenance, inexpensive, and quick construction. In addition, its ability to be incorporated as a functional yet beautiful part of interior decorating makes it a top choice for ‘green’ living or remodeling. The wall is built from materials that act as a thermal collector: stone, metal, concrete, adobe or water tanks. In the original design by Felix Trombe, the heat flow moved freely between the interior and exterior of the wall, once the outdoor temperature decreased the home received little heat. Modern engineers solved the issue of heat loss by adding a few adjustments to the design and construction.
Solar water-heating systems are different from the solar devices that make electricity. Collectors on your roof still grab energy from the sun, but in this case the energy is used to heat water. Of course not everyone has the right roof or enough sun to do the job. But the average U.S. household spends 11% of its energy budget heating water. So why not investigate your home’s potential to provide you with a hot shower from this abundant, free source?
Besides saving you money, solar water heaters also provide big benefits to the planet by reducing greenhouse gas emissions, air pollution, and demand for fossil fuels. According to the U.S. Department of Energy, replacing an electric water heater with a solar water heater offsets the equivalent of 40% to 100% of a typical passenger car’s CO2 output.
By the way, if you had a solar water heater in the 1970s that didn’t last, don’t hold it against today’s products. There’s been a dramatic increase in reliability and efficiency since then.
This article covers solar water heating for your kitchen, bathrooms, and laundry–and even for heating your home. See our “Solar Heating for Pools and Spas” article for information about heating swimming pools and hot tubs.
Daylighting Saving Time
You probably have a dark secret. No, not the one you begged your friends to take to their grave. It’s the one in your kitchen, or bathroom or hallway. It’s that spot that always seems to be dark, even with the lights on. The place where no natural sunlight can reach and the place you just wish you could go without the need of a flashlight. Unless your home was optimally designed to take advantage of natural light, odds are you have a few dim spots that could use some brightening.
Not too long ago, your only option would have been to cut a large hole in your roof and insert a skylight – literally a window to the sky. Unfortunately, the skylight probably had too many disadvantages to ever become a popular option. They tended to be leaky, they let in too much heat and after a couple of months there was a thin layer of crud blocking the view and you had to risk serious injury or death by climbing up on your roof to clean it. They have improved since those early days, but there’s still no good option to keeping them nice and clear other than a ladder and a squeegee. Nowadays we have a few more options for bringing in natural light and you don’t have to risk life or limb as most are relatively maintenance free.
Any company that installs solar electric systems (also known as photovoltaic, or PV, systems) can help you figure out if PV makes sense for your household. But as with any home improvement project, buyer beware. While reputable companies won’t try to talk you into a deal that doesn’t make sense, unscrupulous companies may overpromise on performance, overestimate how big a system you need, or underestimate potential problems at your site. Take the time to learn about the basics of PV, so that when you talk to the pros you can ask good questions, make sense of the answers, and know if you are getting the straight scoop.
It’s also wise to add up the cost of a solar electric installation in your area. In 2007, the average cost in the United States in 2007 was $7.62 per watt, after available state and federal incentives. That comes to roughly $15,000 to $30,000 for a typical 2 to 4 kilowatt system. But with a newly expanded federal tax credit and an increasing number of cities, states and utilities offering residents cash or loans to install photovoltaic (PV) systems, there’s never been a better time to go solar.
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treets paved with recycled concrete. Eco-friendly siding on suburban homes. Hybrid and electric cars parked in every driveway. Sounds like a perfect eco-friendly neighborhood. What’s missing? The perfect eco-roof.
An ideal roof serves as an efficient barrier between the elements and the interior, is well insulated, and may even have solar modules. If you are looking for an elegant, simple, solar, and space-conscious solution, invest in solar shingles. This new solar product is a great esthetic alternative to photovoltaic (PV) panels. If you’re an environmentally-aware homeowner who is searching to lower utility bills in a tasteful manner, solar shingles are for you.
Solar electric systems power a vast array of items, from credit card-sized calculators to communications satellites, highway traffic signs, and homes, schools, and warehouses. Also called photovoltaic (PV) systems, they work by converting light energy into electricity. “Photo” comes from the Greek word for light, while “voltaic” refers to the production of electricity.
The basic building blocks of this kind of solar system are PV cells. They are small, thin, square-shaped pieces of a semiconductor material, most often silicon. When light hits a cell, it generates a small amount of electricity, typically 1 or 2 watts. Linked together in modules, cells can produce large amounts of electricity.
Unless you are experienced with wiring and construction, you’ll probably opt for professional installation of your home solar electric system. That will save you time and trouble, but you’ll still need to manage the home solar installation process and take care of the system once it’s installed. Here’s what you need to know to do both effectively.
If hiring an installer, it’s a good idea to get proposals from at least three companies. Be sure to ask the following:
If solar electricity or solar water heating isn’t your cards right now, there are plenty of other ways to take advantage of the sun’s energy–for little or no money.
One of the simplest is hanging your wet duds on a clothesline. It only takes just a couple more minutes of your time than throwing them in the dryer. Plus it’s a good excuse to get outside on a sunny day. Find more energy-saving laundry tips in our “Washers and Dryers” article.
As long as you’re taking the time to smell the sun-warmed sheets, why not get dinner started too? With a solar oven you can cook a casserole, make a pot of rice and even bake some cookies-using only the power of the sun. You can make your own solar oven from low-cost materials or buy one already made. Find out more in our “Ovens and Cooktops” article.
If you’re wondering what to cook in that solar oven, how about some homegrown spuds from your own organic garden? Plants do a miraculous job of transforming the sun’s energy into nutritious, delicious food, and growing your own helps you slim down your carbon footprint. Check our “Healthy Eating” article for more fodder for your green kitchen.
While you’re in the kitchen, take a fresh look at your lighting. Making the most of daylight lets you keep electric lights off when the sun’s shining. What’s more, most people just feel better when they’re in daylit spaces. Our “Windows, Skylights, and Doors” article has bright ideas for saving energy and letting in more light.
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