Energy Adviser: Greener choices in water heaters



What if you requested a free in-home energy review and it uncovered something unexpected? In one case, a home had a solar water heater the new owners didn’t know about. Perplexed because they had hot water, despite what can be at times dreary Northwest weather, Clark Public Utilities energy counselor Bob West showed them the unit and then the almost invisible solar collector on their roof.

According to John Zagunis, Act on Solar owner, solar water heaters come in two types — single- and two-tank systems. The couple owned a two-tank system that was designed to heat water with solar energy, then pump it into a preheat tank located near the backup electric hot water heater.

“Since this couple didn’t even know they had solar heating, they were only using the backup system,” said West. “Once they got the system optimized their water heating costs went way down.”

In contrast to the two-tank system, a single-tank SWH system combines solar preheated water and backup heating into one tank. Although the initial investment can be high, both single-tank and two-tank solar hot water heating systems can save on energy costs in the long run.

“Homeowners can expect to spend up to $10,000 for solar water heaters with copper solar being on the high end,” said Zagunis. “Polymer solar doesn’t collect as well as copper in the winter, but it’s still a good choice and runs about $4,000.”

Even with incentives and tax credits, the investment for a SWH can have a long payback. “People choose solar heaters because they feel like they’re doing something good or they want a smaller carbon footprint,” Zagunis said. “But because of the upfront cost, solar makes the most sense where high volumes of hot water are consumed, like apartment buildings, condos, athletic clubs and schools.”

West agrees. When customers ask him about SWH, he suggests they first consider other energy-saving options with a shorter return on investment. “Even though the technology works, installing a solar water heater just doesn’t pencil out for a couple looking to cut expenses for retirement when better weatherization or installing a heat pump can offer greater comfort, savings and a faster return,” West said.

Another option for my efficient water heating is a heat-pump water heater, sometimes called a hybrid water heater. They work like your refrigerator, but in reverse. A refrigerator pushes heat from inside the unit out into the air surrounding it, while a HPWH uses fans and an evaporator to pull heat from the surrounding air and transfer it to water in a storage tank.

“Many customers who are good candidates for ductless heat pumps are also good candidates for heat pump water heaters,” stated Jill Reynolds, manager of the Northwest Energy Efficiency Alliance heat pump water heater initiative.

Reynolds said heat pump water heaters can cut consumer energy costs for heating water by 25 to 50 percent and noted that

a recent study conducted by NEEA found that 55 percent of the homes in our region use electricity to heat water. If all owners of electric water heaters switched to a HPWH, the region would save 500 average megawatts by 2029, enough to power 381,500 homes every year — more than twice the number of homes in Clark County.

HPWHs are relatively new and a bit more pricey than traditional options. Conventional electric water heaters are in the $300 to $1,000 range, while a HPWH runs $1,000 to $2,000. Federal tax credits are available for qualifying HPWH units, however, and may save consumers up to $300.

Both solar and heat pump water heaters will dramatically lower energy use, but the lower initial cost for heat pump technology makes the return on your investment shorter. Customers of Clark Public Utilities interested in replacing home heating or water heating systems are encouraged to contact an energy counselor with questions about approved solar and heat pump contractors and advice on which technologies are the best fit for the home.

Energy Adviser is produced by Clark Public Utilities and relies on the expertise of utility energy counselors and staff, who provide conservation and energy use information. To contact us call 360-992-3355, email or visit