A New Solar Water Heating System Goes Online as Its Developer Enters the US Market

Solar thermal energy could be a “sleeping giant” in the push to reduce emissions from heating and cooling.

From a distance, the energy system on top of a college residence hall in Omaha, Nebraska looks like photovoltaic panels.

But as you get closer, it becomes clear that this is something different, with rows of vacuum-sealed glass tubes that are converting the sun’s energy into heat, as opposed to electricity.

The project, which went online this summer at Creighton University, is a carbon-free system for heating the water used by the 400 or so freshmen who live inside.

The system is an example of solar thermal energy, something at the fringes of today’s market that will need to grow a lot in the coming decades if the world is going to make a transition away from burning fossil fuels for heating.

“It’s very visible,” said Andrew Baruth, Creighton University’s director of sustainability and a physics professor. “You can’t walk down our central mall without seeing it. And so it gets students curious, it gets students thinking, it gets them to ask people like me, ‘What are those things?’”

The United States had 373,055 solar thermal systems in operation at the end of 2021, according to the International Energy Agency, which isn’t a lot considering the country’s size. For perspective, that’s less than one-tenth the number of solar photovoltaic systems in the country.

The system at Creighton, made by Naked Energy of the United Kingdom, converts the sun’s energy into heat to increase the temperature of a liquid. The liquid circulates in a closed loop between the roof and a water storage tank in the building. The process transfers heat to the water, which is then used in sinks and showers.

This is Naked’s first project in North America, a showpiece that the company plans to use to attract other customers.

The use of solar energy for water heating reduces the building’s need for natural gas, which is the backup heating source. The avoided emissions are about 40 metric tons per year for this project, which is like taking nine cars off of the road.

One reason I wanted to write about the Omaha project is that it provides an excuse to talk about solar thermal energy, which is an old technology that could be an important part of reducing emissions.

Global energy consumption for heating and cooling is about 50 percent of all energy consumption, and the share hasn’t changed much in recent years, according to the IEA.

There are many approaches to reducing emissions from heating and cooling. Often, the most cost-effective option is to get rooftop solar and pair it with a heat pump, which is an electric heating system.

The low cost of rooftop solar has helped it to grow globally, while solar thermal systems have had sluggish growth.

But there are some buildings, depending on their location and their patterns of energy use, where solar thermal makes economic sense, said Max Lainfiesta, a Guatemala-based program manager for RMI, the clean energy research and advocacy group.

He views solar thermal as a “sleeping giant” in the race to decarbonize heating. His larger point is that everyone is better off if there is competition and innovation in a variety of zero-emission heating technologies.

While I’m mostly talking about solar water heating, solar thermal also can provide space heating, although that’s not a common use in the United States. Most of the solar thermal systems installed here in 2021 were for heating swimming pools.

China leads the world in solar thermal by a long stretch, followed by India and Turkey. The United States ranks fifth.

But it’s more instructive, I think, to look at the per-capita leaders. Cyprus is first, followed by Israel and Greece. These are places that get a lot of sun and where the markets for solar thermal have built momentum over time. They also tend to have high energy costs, which makes solar water heating more attractive.

“In Israel, you won’t believe it, you will see these things on top of every single house and building,” Lainfiesta said. (He’s exaggerating, but you get the point.)

Households in the United States can buy solar water heating systems from familiar brand names like Rheem, and from companies that specialize in the technology, like AET. The costs start at between $1,000 and $2,000, and can go much higher depending on size and features. This doesn’t include installation, which can add several thousand dollars.

As with buying rooftop solar, one of the key considerations is how much the system will reduce your energy cost and how long it will take for those savings to cover the equipment and installation.

Buyers of large solar water heating systems, like the one at Creighton, go through their own versions of this analysis.

It may seem random for a U.K.-based company like Naked Energy to make its North American debut in Omaha, but it makes sense when looking at who helped to put the project together.

The building is called Graves Hall, after Lee and Judy Graves, who made a major donation to Creighton. Lee Graves is founder and chairman of ELM Solar, which has a partnership with Naked Energy that includes manufacturing the systems for the North American market. 

ELM worked with the university to make climate-friendly technologies part of the project, including the solar water heater. Neither Naked nor ELM would say how much the solar water heater cost.

Creighton has a goal to cut emissions 50 percent from 2010 levels by 2028, which would be in time for the university’s 150th birthday celebration.

As of last year, the university had cut emissions by 38 percent. The new building should help to increase that number in 2023, but it’s too soon to say how much, according to Baruth, the sustainability director.

Naked Energy is a small company, with just 20 employees, and it is young, having completed its first installation in 2018.

The partnership with ELM, which has about 1,200 employees across several U.S. divisions, gives Naked Energy the ability to make a strong push to build a following here.

I asked Frank Bruce, who leads Naked’s marketing, what’s appealing about the North American market.

One of the big factors, he said, is the Inflation Reduction Act, the 2022 law that has incentives for opening factories for clean energy components and for customers who buy the finished products.

“It’s a huge incentive for businesses and communities to decarbonize,” he said.

His company’s decision to begin operating here is one of many examples of how the law is having its intended effect.

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Editor’s note: This story has been modified to specify that the solar system is converting the sun’s energy into heat, as opposed to simply absorbing heat.