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Heat Pump vs Solar Hot Water Heating

A heat pump is a heating system that works like a reverse air conditioner, using the ambient heat in the environment to produce hot water. A solar hot water heater uses the direct and indirect solar radiation of the sun to heat water. This type of water heater comes in different configurations, such as ground-mounted and roof-mounted. Heaters like this are also called solar thermal systems. Both hot heating systems can be used to heat pool water.

Although the heat pump and solar water heating system are both efficient and cost-effective, comparing them will help me learn which is superior and preferable to the other.

Before that, let’s see how the heat pump and solar hot water system work. Keep reading to learn more about it!

How They Work

Heat Pump

installer check pool water heat pump

A heat pump works like an AC on a reverse cycle, using the climate heat in the atmosphere to heat up water.

Technically, a heat pump water heater will pull heat from its surrounding and sends it to a water storage tank to heat it up. This is done at a higher temperature.

Solar Hot Water Heater

solar panels on garage roof heat hot water in pool

On the other hand, a solar hot water heater uses sunlight energy to produce hot water. The system comprises a collector and a tank wherein water from the tank moves through a pipe into the collector. Sunlight hitting the collector will heat water, and the water exits the collector and back into the tank.

In a situation where sunlight energy isn’t powerful enough, users can support the solar hot water system with electric or gas boosters.

Heat pump heaters and solar hot water systems are both examples of renewable heater systems. Also, they are cheaper and the best energy-saving options for families seeking to cut down costs.

Having known how they work, let’s compare both, starting with their differences, benefits, etc.

Major Differences

In terms of differences, a heat pump and solar hot water have different energy uses, flexibility, setup or installation cost, workability, and lots more. So, let’s compare both respectively.

Energy Use

A Heat pump requires electricity to operate. As such, it can be powered by any power supply generator. Additionally, it takes less energy because it absorbs hot air, unlike ACs or refrigerators that convert.

For this reason, heat pumps are compatible with solar energy and can last for a long time. Despite the little energy they consume, heat pumps can heat up water rapidly anytime they’re powered.

On the other hand, solar hot water heaters rely on sunlight energy to operate. The system is made up of collectors that look like solar panels and storage tanks.

This system can be mounted on the roof or on the ground, depending on the angle where it receives more sunlight.

The structure of a solar water heater is simple. Two pipes are connected to the storage tank, one at the bottom and one on top. The downward pipe sends water to the collectors for the sun to heat it, and the hot water returns to the tank through the upward pipe.

Solar hot water systems are slower because they depend on solar energy (sunlight), which is mostly unstable in cloudy conditions. However, they can work with electricity or gas to boost their effectiveness in such situations.


In terms of flexibility and ease of use, a heat pump can be automated using a timer. You can regulate when it comes on and off to save energy and even tariff prices.

Meanwhile, solar hot water heaters do not regulate when to heat water or not. As long as there’s sunlight energy, the system will continue to operate, maintaining the temperature of the heated water. However, in colder weather, users may need to use external energy boosters to back up the system.

Shading Issues

A heat pump can work in any environment, whether shaded, cloudy, dark, etc. It depends on electricity and the surrounding air to produce hot water.

On the other hand, solar hot water in a shaded environment will not be able to collect sufficient solar energy for heating up water. Whether mounted on the ground or on the roof, its productivity reduces once the solar energy supply is obstructed.


Heat pumps are quite easier to install. You may need an expert to guide you through picking the best one. You can research online, check out customer reviews, ask for recommendations, or even consult a retailer when buying a heat pump for your home. Also, there are some vital factors to consider, like durability, price, etc.

In contrast, solar hot water systems come with complex installation criteria, requiring an expert and accredited installer. However, if you choose to Do it Yourself to save money, it’s advisable to work under the supervision of a professional in the field of solar energy.


The average cost to purchase and set up a heat pump ranges from $1600 to $3500. Meanwhile, you can get several quotes to compare warranties, installation approaches, and costs.

Meanwhile, the cost of installation can range from $3500 to $9000. From the required materials to the size of the system, solar water heaters come at different prices. Also, the cost of maintaining the system can be huge.

If you intend to operate the solar hot water system during winter, you may consider the cost of getting a backup power supply for the system as well. In some cases, users invest in a solar PV system to provide back power for this hot water system. As such, you may also need to consider the cost of getting solar panels.

Pros and Cons

The benefits of heat pumps and solar water heating systems are unavoidable. They include zero carbon footprint, little energy consumption, low maintenance, sustainability, renewable energy, and lots more. Notwithstanding, here’s a comparison of the benefits of heat pumps hot water systems and solar hot water systems.

Pros of Heat Pump Water Heaters

Heat pump water heaters are effective, economical, and eco-friendly. They utilize environmental energy to produce hot water. It works by extracting heat (thermal energy) from the ground, air, or any local water source, after which it is converted by a heat pump to produce hot water.

Unlike many other methods, heat pump water heaters are compatible with alternative sources of energy, enhancing the environmental effect of the process. Also, it reduces electricity costs.

Notwithstanding, other benefits of heat pump water system include:

  • Low operation costs
  • Homes in off-gas areas can rely on oil as an alternative to fuel
  • High-efficiency levels, irrespective of the temperature
  • They can operate with electricity or even solar energy. So, they produce zero emissions.
  • Heat pumps are extremely quiet and can be positioned in any corner of the house.
  • They are sustainable, flexible, and controllable. They use natural energy sources and are compatible with smart home accessories.
  • They are low maintenance and can last up to 10 to 25 years in operation.

Cons of Heat Pump Systems

  • These systems are climate dependent, meaning they won’t work properly if their surrounding air is cold.
  • The initial setup of these systems is expensive.
  • Since it has some moving parts in the setup, it may require maintenance.

Pros of Solar Hot Water Pumps

Just like a heat pump system, solar hot water pumps come with various benefits as well. They include:

  • Low running costs as no fuel is needed to operate the system.
  • Low maintenance requirements as the solar panels, collectors, and inverters don’t have moving parts.
  • Zero carbon emission and noise pollution.
  • Solar hot water pump systems can last up to 25 years.

Cons of Solar Hot Water

  • It depends on solar radiation levels to operate.
  • The initial installation cost is very high.
  • Requires more water storage

Although many users can cope with these systems irrespective of their cons, it’s advisable to have a reliable alternative in case these ones malfunction in cold climate conditions.


Why Are Heat Pumps Also Called Gas-fired Pumps?

Heat pumps absorb heat from sources like natural gas, geothermal-heated water, or propane. Since their most common source of heat is natural gas, many users now refer to heat pumps as gas-fired heaters.

Does a Solar Hot Water System Need Solar Panels?

It is not mandatory to include solar panels in a solar water heating system. However, you can invest in quality panels to improve the energy output of solar thermal systems, making them run efficiently.

What Are the Cons of Heat Pumps?

The only major disadvantage of heat pumps is that their initial installation cost is quite expensive. Apart from that, they’re an ideal option for your home.

Can You Operate a Heat Pump on Solar?

Heat pumps consume very little energy because they absorb surrounding air and use it to produce hot water in return. As such, they can run on solar if the sunlight energy is efficient.


Having compared the vital aspects of a heat pump and solar hot water systems, choosing the best for your home would depend on your environment and preference.

Both systems depend on renewable energy and are also efficient, cost-effective, sustainable, durable, and pollution-free. Consider your hot water needs and environment before you pick anyone for your home.

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