Advantages and Disadvantages of Solar Hot Water

by James SheaNovember 20, 2018

The idea of solar hot water isn’t complicated. It’s like a greenhouse where solar energy is captured and used to heat the water. The use of solar energy to heat an object has been around for centuries. In 18th century, Horace-Benedict de Saussure designed a solar oven with three panels of glass. He was able to heat the box to over 200 degrees and bake items. The design was later adapted and used by Sir John Herschel when he explored Africa.

People realized that the same principles could be used to heat water. The first commercial solar water heater was patented in 1891, and within five years, about 30 percent of the homes in Pasadena, California, had solar hot water systems installed. The industry continues to spread but nearly died out during the copper shortage of World War II.
Solar panel on a red roof reflecting the sun and the cloudless blue sky.
“It almost entirely killed the industry and stopped virtually all [renewable energy] technological development in this country,” said Christel Bieri, the vice president of marketing at Heliodyne, Inc.

What is Solar Hot Water?

With a solar hot water system, solar panels are installed on a home’s roof. Unlike a traditional solar system, a solar hot water system isn’t designed to create electricity. The panels are designed to trap the heat from the sunlight. The heat energy is then transferred to the water. The water is heated and stored.
Solar water heater on roof top, beautiful blue sky background.


  • Save Money on Hot Water

    Homeowners spend a huge amount of money on electricity and natural gas to heat hot water in a home. According to data from the federal government, 18% of a home’s energy use is heating of hot water. Once you have paid to install the system, you pay absolutely nothing for hot water and will see a significant reduction in your energy bills. You’ll save an average of $781 on energy annually.

  • Increase Home’s Value

    Many home buyers want to save money and are looking for homes with renewable energy systems. Studies have shown that a solar system can increase a home’s value between 3% to 4%. That means a $300,000 home could increase nearly $10,000 in value.

  • Tax Credits

    The 2017 tax reform bill kept many of the tax credits for renewable energy investments. Homeowners get a 30% tax credit based on the cost of the materials and the installation. The tax credits decrease to 26% in 2020 and 22% in 2021. Existing homes and new construction both qualify for the credit. The water must be used inside the home, and isn’t available to systems that heat swimming pools or hot tubs. Individual states also offer tax credits for solar systems.

  • Environmentally Friendly

    It takes a lot of energy to heat water and keep it at a high temperature. Normal hot water heater produces greenhouses gasses. They’re the byproduct of electrical power generation, as well burning natural gas to heat a hot water tank. A solar water system relies on 100% renewable energy. It takes the sun’s clean energy and converts that to energy to heat the hot water.

  • Less Space

    The solar panels used in hot water systems take up a lot less space on a roof than photo-voltaic systems. Houses normally require two or three small panels, because solar hot water panels are more efficient at converting energy. They convert approximately 80% of the sun’s energy. That means your house isn’t cluttered with massive solar panels on the roof.

Workers installing alternative energy solar panels on roof


  • Upfront Costs

    It costs money to install a solar hot water system and often requires a qualified expert to install. A solar hot water system runs anywhere from $1,000 to $3,500 installed, but high-end systems can cost as much as $7,000. Financing can be a challenge. Homeowners can take out a home equity line of credit, and companies offer financing for renewable energy projects. These types of loans can be expensive, however.

  • Needs Proper Roof Space

    Even though a solar water system requires less roof space than a photo-voltaic system, it still requires some space. In addition, the roof needs to be able to capture heavy amounts of sunlight. If the house is oriented in the wrong direction, it might not be able to have a system installed. In addition, a tree-covered area blocks too much light.

  • Won’t Work Well on Cloudy Days

    Solar hot water systems require bright, direct sun, and they usually can’t capture enough energy on a cloudy day. That is why they work best in places like Arizona or Colorado, where the sun shines a majority of the time. Often times, homeowners must utilize traditional power sources on cloudy days.

  • Maintenance Costs

    Like anything in a home, a solar hot water system must be maintained. Things break in a complex system, and parts need to be replaced. Experts say 2% of the cost to install the system could end up going to maintaining the system each year, and it can be challenging to find someone who is qualified to work on the system. Many companies that install solar systems offer maintenance contracts.

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About The Author
James Shea
James Shea is an award-winning journalist and author. He owns Media Lab, a content marketing and search engine optimization company is Richmond, Virginia.