A home with solar panels has a different water-heater opportunity than a home that simply uses grid electricity. If your rooftop solar system produces electricity during the day, a water heater can act as a useful thermal energy storage load by converting surplus solar electricity into stored hot water. This can make electric and heat-pump water heaters particularly attractive.
However, having solar panels does not automatically make every electric water heater the best choice. The size of the solar array, battery system, utility rate structure, net-metering arrangement, household hot-water demand, available electrical capacity, and whether the home has natural gas or propane all affect the decision.
This guide compares five major water-heating technologies for homes with solar photovoltaic (PV) panels in the USA: heat pump water heaters, conventional electric storage water heaters, gas tankless water heaters, gas storage water heaters, and solar thermal water heaters.
Quick Answer: Best Water Heaters for a Home with Solar Panels
| Technology | Best Models | Best Use With Solar | Main Advantage | Main Limitation |
|---|---|---|---|---|
| Heat Pump Water Heater | Rheem ProTerra 80-Gallon, A.O. Smith Signature 900 80-Gallon, Bradford White AeroTherm G2 80-Gallon | Homes wanting to maximize the value of surplus solar electricity | Very high efficiency and low electricity consumption | Requires suitable space, airflow and electrical capacity |
| Conventional Electric Storage | Rheem Gladiator XE50T12CG55U0, Rheem Gladiator XE50M12CG45U0, A.O. Smith E6-50H45D-TTP | Homes wanting simple solar-powered hot-water storage | Simple technology and easy solar-electric integration | Much less efficient than a heat pump water heater |
| Gas Tankless | Rinnai SENSEI RU199iN, Navien NPE-240S2, Rinnai RUR199iN | Homes with gas service and limited electrical capacity | High output without depending heavily on electricity | Solar electricity provides little direct benefit |
| Gas Storage | Rheem Maximus, Rheem Maximus Heavy Duty 75-Gallon, Rheem XG50S12DM40UO | Homes where gas remains the preferred energy source | Strong recovery and familiar installation | Solar PV cannot directly power the main heating process |
| Solar Thermal | Rheem SolPak RS120-64BP, Rheem SolPak RS80-48BP, Rheem SolPak RS80-40BP | Homes specifically designed for solar thermal water heating | Uses sunlight directly for water heating | Requires dedicated collectors, plumbing and installation space |
How We Selected Water Heaters for Homes with Solar Panels
- Ability to make useful use of electricity generated by a residential solar PV system.
- Energy efficiency and operating cost.
- Hot-water capacity and recovery performance.
- Compatibility with common residential electrical systems.
- Potential for load shifting or using stored hot water as thermal energy storage.
- Installation requirements.
- Reliability and maintenance requirements.
- Availability of appropriate certifications and standards.
- Whether the technology makes sense for a home that already has solar PV.
Important: Solar PV and Solar Thermal Are Different
Most homes described as having solar panels have solar photovoltaic (PV) panels. PV panels produce electricity. That electricity can then power an electric or heat-pump water heater.
A solar thermal water heater uses collectors to capture solar heat directly and transfer that heat to domestic hot water. It is a different system from rooftop PV and normally requires dedicated thermal collectors, a storage tank, pumps and additional plumbing.
For a home that already has a conventional PV system, installing a new solar thermal system is therefore not automatically the best choice. A high-efficiency heat pump water heater can often use the existing electrical infrastructure and solar generation without requiring a second solar-collection system.
1. Best Heat Pump Water Heaters for Homes with Solar Panels
Heat pump water heaters are usually the strongest technology match for a home with solar PV. Instead of converting electricity directly into heat, they use electricity to move heat from surrounding air into the water. Their substantially higher efficiency means that a given amount of solar electricity can produce considerably more hot water than a conventional resistance-electric tank.
A sufficiently large tank can also allow the homeowner to heat water when solar production is available and store that heat for later use.
Rheem ProTerra Professional Prestige 80-Gallon
The Rheem ProTerra Professional Prestige 80-gallon heat pump water heater is one of the strongest choices for a solar-equipped home with adequate installation space. The 80-gallon model has a published UEF of up to 4.07 and a 10-year warranty. Rheem also offers Wi-Fi connectivity, multiple operating modes and demand-response capability.
Why We Selected It
The combination of very high efficiency, large storage capacity and demand-response capability makes this model particularly suitable for using electricity when it is most advantageous. The large tank also gives a solar-equipped home more thermal storage capacity than a small water heater.
Relevant Certification / Standards
- ENERGY STAR qualified.
- NSF/ANSI 372 lead-content design certification.
- Demand-response ready through CTA-2045/EcoPort on applicable models.
Important Limitations
- The 80-gallon model is physically large and heavy.
- It requires suitable surrounding air volume or appropriate ducting.
- It still requires electrical power when solar production is unavailable.
- Installation may require adequate electrical capacity.
Who Should Buy It
Buy it if you have a reasonably large solar PV system, significant hot-water demand, adequate installation space and want to maximize the value of solar electricity through efficient water heating.
Who Shouldn’t Buy It
Do not choose it solely because you have solar panels if the installation location is too small, poorly ventilated or unsuitable for a large heat pump water heater.
Maintenance Considerations
- Keep the air filter clean according to the manufacturer’s instructions.
- Inspect and maintain the condensate drain.
- Inspect the anode rod and tank periodically.
- Flush the tank according to the manufacturer’s maintenance schedule.
Retailer Link
A.O. Smith Signature 900 80-Gallon Hybrid Heat Pump Water Heater
The A.O. Smith Signature 900 80-gallon hybrid heat pump water heater is another strong choice when the solar-equipped home has sufficient electrical capacity. The 240-volt models combine heat-pump operation with electric resistance backup and include smart features, leak detection and automatic shutoff on applicable versions.
Why We Selected It
The 80-gallon capacity provides substantial thermal storage, while the hybrid design provides a resistance-heating backup when hot-water demand is high. This combination works well when the homeowner wants to use solar electricity for efficient heating while retaining a high-demand backup mode.
Relevant Certification / Standards
- ENERGY STAR certified models are available in the Signature 900 range.
- Applicable models include smart connectivity and leak-protection features.
- 240-volt hybrid configurations are available.
Important Limitations
- The 80-gallon version requires substantial installation space.
- Electrical requirements must be checked before installation.
- Heat-pump operation requires appropriate surrounding air conditions.
Who Should Buy It
Buy it if you have a solar PV system, high hot-water demand and want a large hybrid tank with resistance backup.
Who Shouldn’t Buy It
Do not choose it where the installation area cannot provide the required space and airflow or where the electrical service cannot support the selected configuration.
Maintenance Considerations
- Maintain the air intake and filter as specified by the manufacturer.
- Inspect condensate drainage.
- Check the anode rod periodically.
- Flush the tank according to the manufacturer’s instructions.
Retailer Link
Bradford White AeroTherm G2 80-Gallon
The Bradford White AeroTherm G2 80-gallon heat pump water heater is a strong option for homeowners who want a large heat-pump tank and the ability to use solar-generated electricity for efficient water heating.
Why We Selected It
The large storage capacity makes it appropriate for households that want to shift some water heating toward periods when solar electricity is available. The AeroTherm platform also provides multiple operating modes and smart-control functionality on applicable configurations.
Relevant Certification / Standards
- ENERGY STAR qualified configurations are available.
- Residential safety and electrical certifications depend on the exact model configuration.
Important Limitations
- Large capacity requires substantial floor and overhead clearance.
- Heat pump operation requires suitable ambient conditions.
- Exact electrical and control requirements vary by model.
Who Should Buy It
Buy it if you want a large-capacity heat pump water heater and have sufficient space and electrical infrastructure.
Who Shouldn’t Buy It
Do not choose it simply to use solar power if your household has low hot-water demand or the installation location cannot accommodate a large heat pump water heater.
Maintenance Considerations
- Keep the air filter clean.
- Inspect the condensate system.
- Maintain the tank and anode according to manufacturer instructions.
- Use the manufacturer’s recommended operating mode for your household demand.
Retailer Link
2. Best Conventional Electric Storage Water Heaters for Homes with Solar Panels
A conventional electric storage water heater is less efficient than a heat pump water heater, but it can still make practical sense when a home already has solar PV. It converts electricity directly into heat and stores that heat in the tank. This makes the tank itself a simple form of thermal storage.
The main advantage is simplicity. There is no compressor, refrigerant circuit or outdoor-air requirement.
Rheem Performance Platinum Gladiator XE50T12CG55U0
The Rheem Gladiator XE50T12CG55U0 is a 50-gallon high-efficiency electric storage water heater with a published UEF of 0.92. It includes Wi-Fi connectivity, leak detection, automatic leak prevention and demand-response capability.
Why We Selected It
Its demand-response capability and storage design make it more useful for a solar-equipped home than a basic resistance tank. The homeowner can use stored hot water to shift some consumption away from periods of low solar production.
Relevant Certification / Standards
- UL certified.
- AHRI listed.
- Demand-response ready through EcoPort/CTA-2045.
Important Limitations
- Its efficiency is substantially lower than a heat pump water heater.
- It consumes considerable electricity during recovery.
- Solar PV production does not directly reduce water-heating energy requirements; it only supplies part of the electricity.
Who Should Buy It
Buy it if you want simple electric storage, have solar PV and do not want the additional complexity or space requirements of a heat pump water heater.
Who Shouldn’t Buy It
Do not choose it if maximizing solar-electricity utilization and long-term energy efficiency is your primary objective.
Maintenance Considerations
- Inspect the anode rod periodically.
- Flush sediment from the tank.
- Check the temperature and pressure relief system.
- Use the manufacturer’s recommended maintenance schedule.
Retailer Link
Rheem Gladiator XE50M12CG45U0
The Rheem Gladiator XE50M12CG45U0 is a 50-gallon electric storage model designed for homeowners who want a conventional tank with modern monitoring and leak-protection features.
Why We Selected It
It is a practical option for a solar-powered home where simplicity, familiar installation and a moderate storage capacity are more important than achieving the highest possible efficiency.
Relevant Certification / Standards
- UL certified configurations.
- AHRI listed.
- Demand-response capability is available across the applicable Gladiator lineup.
Important Limitations
- It uses resistance heating.
- It has lower efficiency than a heat pump water heater.
- High hot-water demand can increase electricity consumption substantially.
Who Should Buy It
Buy it if you want a conventional electric tank that can work alongside an existing solar PV system without introducing heat-pump technology.
Who Shouldn’t Buy It
Do not choose it if you have limited solar generation and are primarily trying to minimize electricity consumption.
Maintenance Considerations
- Flush the tank periodically.
- Inspect the anode rod.
- Check heating elements if recovery becomes unusually slow.
- Inspect leak-detection components where equipped.
Retailer Link
A.O. Smith E6-50H45D-TTP
The A.O. Smith E6-50H45D-TTP is a conventional 50-gallon electric storage water heater suitable for homeowners who prefer straightforward resistance-electric technology.
Why We Selected It
It provides the simplicity of a conventional electric tank and can use electricity generated by an existing solar PV system. It is especially appropriate when the homeowner does not want to change the fundamental water-heating technology.
Relevant Certification / Standards
- Applicable electrical and safety certifications are provided for the model.
- Exact certification should be confirmed on the current model documentation before installation.
Important Limitations
- Resistance heating has substantially lower efficiency than heat-pump technology.
- Solar generation must first become electricity before it can heat the water.
- Large households may require a larger tank or higher recovery capacity.
Who Should Buy It
Buy it if you want a conventional electric replacement and already have solar PV supplying some of your household electricity.
Who Shouldn’t Buy It
Do not choose it if your priority is maximum energy efficiency per unit of solar electricity.
Maintenance Considerations
- Flush accumulated sediment.
- Inspect the anode rod.
- Check the heating elements and electrical connections during servicing.
- Maintain the temperature and pressure relief valve.
Retailer Link
3. Best Gas Tankless Water Heaters for Homes with Solar Panels
Gas tankless water heaters are a different proposition. They provide high hot-water output while using relatively little electricity, but this also means that most of the energy used to heat the water comes from natural gas or propane rather than the home’s solar PV system.
They can nevertheless be attractive when the home already has gas service and the electrical system is not suitable for a large heat pump water heater.
Rinnai SENSEI RU199iN
The Rinnai SENSEI RU199iN is a natural-gas condensing tankless water heater with a published 0.95 UEF and maximum flow rate of 11 GPM. It supports recirculation and Wi-Fi and is ENERGY STAR qualified.
Why We Selected It
It provides very high hot-water output without requiring the large electrical load associated with conventional electric resistance heating. This can be valuable in a solar home whose PV system is relatively small or whose electrical panel has limited capacity.
Relevant Certification / Standards
- ENERGY STAR qualified.
- Ultra-low-NOx configuration approved for applicable air-quality requirements.
- Residential safety certifications apply to the model.
Important Limitations
- Most of the water-heating energy comes from natural gas rather than solar electricity.
- It requires gas supply and appropriate venting.
- Condensing installation requires condensate management.
Who Should Buy It
Buy it if you have natural gas, high hot-water demand and limited electrical capacity, or if you do not want your water heater to consume much of your solar-generated electricity.
Who Shouldn’t Buy It
Do not choose it if your main objective is to maximize direct use of surplus solar electricity for water heating.
Maintenance Considerations
- Inspect and clean the heat exchanger according to the manufacturer’s schedule.
- Maintain the inlet water filter.
- Check the condensate drain.
- Descale the unit where water conditions require it.
Retailer Link
Navien NPE-240S2
The Navien NPE-240S2 is a high-output condensing tankless water heater designed for residential applications. It can deliver up to approximately 11.2 GPM under specified conditions and has a published UEF of up to 0.96.
Why We Selected It
Its high efficiency and high output make it appropriate for households that want gas-powered hot-water production while reserving their solar electricity for other loads.
Relevant Certification / Standards
- ENERGY STAR qualified.
- CSA certified.
- NSF Standard 5 and low-lead compliance are applicable to the product platform.
Important Limitations
- Requires gas service.
- Requires appropriate venting.
- Condensate drainage is required for the condensing system.
- Maximum flow depends on incoming-water temperature and desired temperature rise.
Who Should Buy It
Buy it if your home has natural gas and you want high hot-water capacity without placing a large electrical load on the solar-equipped home’s electrical system.
Who Shouldn’t Buy It
Do not choose it if you have eliminated fossil-fuel water heating from your home or want solar PV to supply most of the water-heating energy.
Maintenance Considerations
- Flush and descale the heat exchanger when required by water conditions.
- Inspect the water inlet filter.
- Maintain the condensate system.
- Inspect venting during scheduled service.
Retailer Link
Rinnai RUR199iN
The Rinnai RUR199iN is a high-output condensing natural-gas tankless water heater with integrated recirculation capability. It is appropriate for households that need substantial hot-water output without converting their home’s water heating to electric.
Why We Selected It
The built-in recirculation capability can be useful in larger homes where hot-water delivery distance is an issue. It also avoids the substantial electrical heating load associated with conventional electric tanks.
Relevant Certification / Standards
- ENERGY STAR qualified.
- Ultra-low-NOx design.
- Residential safety certifications apply to the model.
Important Limitations
- Uses natural gas as its primary heating energy.
- Requires gas venting and condensate management.
- Recirculation can increase energy use if operated continuously.
Who Should Buy It
Buy it if your home has gas service, multiple hot-water fixtures and you want high output without depending on a large electrical service.
Who Shouldn’t Buy It
Do not choose it if you specifically want your solar PV system to supply the majority of your water-heating energy.
Maintenance Considerations
- Perform periodic heat-exchanger flushing.
- Inspect the water inlet filter.
- Maintain the condensate drain.
- Check the recirculation system periodically.
Retailer Link
4. Best Gas Storage Water Heaters for Homes with Solar Panels
Gas storage water heaters generally make the least direct use of solar PV because the primary energy source is gas. They remain relevant, however, where natural gas or propane is inexpensive, existing gas infrastructure is already available, or electrical capacity is limited.
Rheem Maximus With LeakSense
The Rheem Maximus is a high-efficiency gas storage water heater available in natural-gas and propane configurations. Applicable models reach up to approximately 0.90 UEF and provide rapid recovery, Wi-Fi connectivity and leak detection.
Why We Selected It
It is one of the better choices when a solar-equipped home still wants to retain gas water heating. Its higher efficiency reduces gas consumption while the electrical requirements remain relatively modest compared with electric resistance water heating.
Relevant Certification / Standards
- ENERGY STAR rated models are available.
- Applicable models meet relevant gas-appliance and low-emission requirements.
- FVIR-compliant configurations are available.
Important Limitations
- Solar PV provides little direct energy to the main heating process.
- Requires gas supply.
- Condensing versions require condensate management.
Who Should Buy It
Buy it if you already have gas infrastructure and want an efficient gas tank while keeping your solar-generated electricity available for other household loads.
Who Shouldn’t Buy It
Do not choose it if your goal is to maximize direct consumption of solar electricity for domestic water heating.
Maintenance Considerations
- Inspect the burner and combustion system.
- Maintain the condensate system on condensing models.
- Inspect the anode rod.
- Flush sediment from the tank as required.
Retailer Link
Rheem Maximus Heavy Duty 75-Gallon
The Rheem Maximus Heavy Duty 75-gallon model is intended for households with particularly high hot-water demand. Rheem lists a UEF of approximately 0.88 for the 75-gallon Heavy Duty configuration and a very high first-hour delivery capability.
Why We Selected It
Its large storage capacity and rapid recovery make it appropriate for large households that already have solar PV but still prefer gas as the primary water-heating fuel.
Relevant Certification / Standards
- ENERGY STAR rated.
- Applicable gas-safety and emissions certifications apply to the model.
Important Limitations
- Large physical footprint.
- Uses gas rather than solar electricity for primary heating.
- May be excessive for a small household.
Who Should Buy It
Buy it if your solar-equipped home has very high hot-water demand and existing gas infrastructure.
Who Shouldn’t Buy It
Do not choose it if your household has moderate demand or if eliminating gas use is a priority.
Maintenance Considerations
- Flush the tank as recommended.
- Inspect the anode rod.
- Maintain the combustion and venting system.
- Check leak-detection components where equipped.
Retailer Link
Rheem XG50S12DM40UO
The Rheem XG50S12DM40UO is a 50-gallon natural-gas storage water heater with a powered damper design. It is a practical choice where the homeowner wants to retain conventional gas storage rather than move to an electric or hybrid system.
Why We Selected It
Its familiar storage-tank design makes it a straightforward choice for homes with existing gas infrastructure. The electrical demand is primarily associated with controls and the powered venting system rather than electric resistance water heating.
Relevant Certification / Standards
- ENERGY STAR qualified configuration.
- Powered damper and applicable gas-safety certifications.
Important Limitations
- Solar PV does not provide the primary heating energy.
- Efficiency is lower than modern heat-pump technology.
- Requires natural gas and suitable venting.
Who Should Buy It
Buy it if you want a conventional gas replacement and already have suitable gas and venting infrastructure.
Who Shouldn’t Buy It
Do not choose it if you are specifically trying to maximize the use of excess solar electricity.
Maintenance Considerations
- Inspect the burner and venting system.
- Flush sediment from the tank.
- Inspect the anode rod.
- Check the powered damper and controls during service.
Retailer Link
5. Best Solar Thermal Water Heaters for Homes with Solar Panels
Solar thermal water heating is technically different from solar PV. If you are specifically willing to install dedicated solar thermal collectors, the system can use sunlight directly to heat domestic water and therefore reduce the need for electricity or gas.
For an existing home that already has PV panels, however, solar thermal should be considered carefully because it adds a second solar-energy system rather than simply using the electricity already produced by the PV array.
Rheem SolPak RS120-64BP
The Rheem SolPak RS120-64BP is a large active solar water-heating package with electric backup. It includes a storage tank, collectors, controller, adjustable-speed pump, mixing valve and other system components. Rheem lists a 119-gallon capacity and an energy factor of 3.2 for this configuration.
Why We Selected It
The large storage capacity and dedicated solar-thermal design make it suitable for homes with significant hot-water demand and enough roof or ground space for thermal collectors.
Relevant Certification / Standards
- SRCC OG-100 certification for the collectors.
- SRCC OG-300 certification for the system.
- ENERGY STAR qualified.
Important Limitations
- Requires dedicated solar thermal collectors.
- Requires additional plumbing, controls and pumping equipment.
- Electric backup remains necessary during insufficient solar availability.
- Not the same technology as using existing PV panels to power a heat pump water heater.
Who Should Buy It
Buy it if you specifically want a solar thermal system and have suitable solar exposure, installation space and sufficiently high hot-water demand.
Who Shouldn’t Buy It
Do not choose it simply because you already have photovoltaic panels. A heat pump water heater may be a simpler way to use existing PV electricity.
Maintenance Considerations
- Inspect collectors and mounting hardware.
- Maintain the circulating pump and controls.
- Check the closed-loop heat-transfer fluid where applicable.
- Inspect the storage tank and mixing valve.
Retailer Link
Rheem SolPak RS80-48BP
The Rheem SolPak RS80-48BP is an 80-gallon active solar thermal water-heating system with electric backup. Rheem lists an energy factor of 2.6 and includes an SRCC OG-300 certified system with OG-100 certified collectors.
Why We Selected It
It provides a smaller solar thermal storage option than the 119-gallon system while retaining the core components needed for active solar water heating.
Relevant Certification / Standards
- SRCC OG-100 certified collectors.
- SRCC OG-300 certified system.
- ENERGY STAR qualified.
Important Limitations
- Requires dedicated thermal collectors.
- Requires pump and control equipment.
- Electric backup is required when solar thermal output is insufficient.
Who Should Buy It
Buy it if you want dedicated solar thermal water heating and have enough solar exposure for the collectors.
Who Shouldn’t Buy It
Do not choose it if your goal is simply to make use of an existing PV array without adding another solar collection system.
Maintenance Considerations
- Inspect the collectors periodically.
- Check pump operation.
- Maintain the controller and sensors.
- Inspect the thermal-fluid loop where applicable.
Retailer Link
Rheem SolPak RS80-40BP
The Rheem SolPak RS80-40BP is another 80-gallon active solar thermal configuration. Rheem lists an energy factor of 2.4 and provides the system with solar collectors and electric backup.
Why We Selected It
It offers a lower-output solar thermal configuration for homeowners who want dedicated solar water heating without moving to the larger 119-gallon system.
Relevant Certification / Standards
- SRCC OG-100 certified collectors.
- SRCC OG-300 certified system.
- ENERGY STAR qualified.
Important Limitations
- Requires suitable solar thermal collector placement.
- Requires pumps, controls and additional plumbing.
- Electric backup is necessary when solar thermal energy is insufficient.
Who Should Buy It
Buy it if you specifically want a dedicated solar thermal water-heating system and have suitable collector space.
Who Shouldn’t Buy It
Do not choose it merely because your home already has PV panels. Existing PV can often be used more simply with an electric or heat-pump water heater.
Maintenance Considerations
- Inspect the collectors.
- Check the circulation pump and controls.
- Maintain the thermal loop.
- Inspect the storage tank and mixing valve.
Retailer Link
Solar Panels + Water Heater: Which Technology Makes the Most Sense?
| Situation | Best Technology | Reason |
|---|---|---|
| Large PV system and high hot-water demand | Heat Pump Water Heater | High efficiency allows more hot water to be produced from each unit of electricity. |
| PV system plus limited electrical capacity | Gas Tankless | Reduces the electrical heating load while retaining high hot-water output. |
| Simple electric replacement | Conventional Electric Storage | Simple technology and direct compatibility with electrical generation from PV. |
| Existing gas infrastructure and preference for gas | Gas Storage | Can retain existing fuel infrastructure while leaving solar electricity for other loads. |
| Dedicated solar thermal project | Solar Thermal | Uses solar heat directly rather than converting sunlight to electricity first. |
How Solar PV Changes Water Heater Sizing
Solar panels do not eliminate the need to size a water heater according to hot-water demand. A family that needs 60 or 80 gallons of stored hot water still needs adequate storage or recovery capacity even if the home has a large solar array.
For solar-equipped homes, however, an oversized heat pump water heater can sometimes provide useful thermal storage. The system can heat water during periods of favorable solar production and retain that energy for later use.
This does not mean that the largest possible tank is always best. Oversizing increases purchase price, physical space requirements and standby losses. The tank should be selected according to household demand, first-hour delivery requirements, available installation space and the operating strategy of the solar-electric system.
Should You Buy a Heat Pump Water Heater If You Already Have Solar Panels?
In many cases, yes. A heat pump water heater is often the most logical water-heating technology for a home that already has solar PV because it uses electricity efficiently rather than converting electricity directly into heat.
The combination can be particularly attractive when the solar array regularly produces more electricity than the home is consuming during daylight hours. Instead of wasting or exporting some of that electricity, the homeowner can use it to heat water and store the energy thermally.
However, the economics depend on the home’s utility rate, net-metering arrangement, solar production profile, water-heating demand and available incentives. A solar PV system does not automatically make a heat pump water heater financially superior in every home.
Can a Solar Battery and Water Heater Work Together?
Yes. A water heater and a home battery can perform different energy-storage functions. A battery stores electrical energy, while a tank stores thermal energy as hot water.
Because heating water with a heat pump can be considerably more efficient than heating it directly with resistance elements, a heat pump water heater can provide a relatively efficient way to convert available electricity into stored thermal energy.
Whether the water heater should run before or after battery charging depends on the home’s energy-management strategy, utility tariff and equipment controls.
Important Buying Considerations for Solar-Powered Homes
1. Check Your Solar Production
Look at your actual solar production rather than assuming that the nameplate capacity of the panels represents available electricity throughout the day.
2. Check Your Electrical Panel
A heat pump water heater may require a dedicated circuit depending on the model. Some newer configurations have lower-amperage or plug-in options, but the exact electrical requirements must be checked before purchase.
3. Consider Your Utility Rate
If your utility provides favorable net-metering compensation, exporting excess solar electricity may be valuable. If exported electricity receives little compensation, using some surplus electricity to heat water can become more attractive.
4. Consider Battery Storage
If the home has battery storage, the water heater should be considered together with the battery rather than independently. Thermal storage in the water tank can complement electrical storage.
5. Consider Hot-Water Demand
A small solar array does not mean that a small water heater is appropriate. Size the water heater around actual household demand and then determine how much of that demand can reasonably be supplied by solar generation.
6. Check Space and Airflow
Heat pump water heaters need suitable installation conditions. The surrounding space must provide adequate air volume or an appropriate ducting arrangement according to the selected model.
Final Verdict
For most homes that already have solar PV panels, a high-efficiency heat pump water heater is the strongest overall choice. It can use solar-generated electricity while requiring substantially less electricity than conventional resistance heating.
The Rheem ProTerra 80-Gallon is an excellent choice for homeowners wanting high efficiency and substantial thermal storage. The A.O. Smith Signature 900 80-Gallon is another strong large-capacity hybrid option, while the Bradford White AeroTherm G2 80-Gallon is worth considering where its installation and service network are favorable.
Conventional electric storage remains useful when simplicity and low installation complexity are more important than maximum efficiency. Gas tankless and gas storage remain sensible when the home has gas infrastructure and electrical capacity is constrained.
Solar thermal water heating is a separate option and can be highly effective, but homeowners who already have PV should compare its installation complexity and economics against simply installing a high-efficiency heat pump water heater.
Related Water Heater Guide
About the Author
ManBearPig is a part-man, part-bear, part-pig creature and a full-time expert on global warming—mostly because he has personally experienced the consequences of being extremely, extremely, super cereal.
When he isn’t roaming the wilderness, terrorizing unsuspecting humans, or demanding that people take climate change seriously, ManBearPig studies rising temperatures, melting ice, extreme weather, carbon emissions, and other inconvenient signs that the planet may not be particularly happy with us.
His research philosophy is simple:
“I’m super cereal.”
ManBearPig believes climate change is too important to discuss without facts—and too ridiculous to discuss without a little humor. Through this website, he explores global warming, climate science, environmental changes, energy, and the strange ways humans respond when their own planet starts sending them warning signals.
He has no university degree, no laboratory, and absolutely no intention of becoming a respectable academic.
But he does have hooves, claws, a snout, and an unusually strong opinion about melting ice.