Solar Assisted Heat Pumps: Everything You Need To Know About

Solar Assisted Heat Pumps

Solar assisted heat pumps are a win-win for both you and the planet

If you’re using conventional means for water heating in your home, then you should definitely consider making the switch to heat pumps assisted by solar energy. 

While you might be aware of the exciting benefits that solar energy solutions bring about when it comes to surface and water heating, their utility is quintessential. 


Well, estimates from the Energy Information Administration suggest that more than 2/3rd of the energy consumption in a typical household results from water and surface heating. And that means heating is contributing a significant proportion to your utility bills. 

Nevertheless, by simply installing a solar assisted heat pump in your home, you stand to bring down your energy consumption and bills by more than 50 percent. 

Wondering how? 

You see, among all appliances based on solar energy, heat pumps are the most unique. That’s because, unlike solar water heaters, lighting solutions, etc., heat pumps have a dual application. 

Meaning, not only will these materials heat the indoor areas of your home, but they also provide warm water to each of the faucets. 

Sounds interesting, doesn’t it? 

There’s a lot more to solar assisted heat pumps, so let’s have a look up close. 

What exactly are solar assisted heat pumps? 

Solar water heating systems

As the name itself suggests, a solar assisted heat pump is a heating solution based on an active solar or photovoltaic system. 

These heat pump systems combine thermal solar panels and heat pumps powered by solar photovoltaic cells. And that’s precisely how they fulfill both indoor heating as well as hot water requirements in a home. 

In fact, with effective integration of the air heat pump with an active solar water heater, these systems provide reliable and all round heating for medium-sized homes. 

The solar assisted heat pumps, or SAHPs as they’re otherwise called, have been on the market for a long time, starting as early as the 1970s. However, their utility and application among homes was only realized of late in the wake of rising energy costs. 

Today, households are switching over to solar assisted heat pump systems more than ever, thanks to their efficiency and dependability. 

Is a residential solar heating system worthwhile? 

Yes, heating solutions like the solar assisted heat pumps are totally worth the investment. 

Here are some benefits of these heat pump systems that make them worthwhile for your home: 

  • Contrary to the assumption that they only work on bright sunny days, solar assisted water and indoor heating system will fulfill your heating needs 24×7 and in all weather conditions. 
  • The manufacturers of these solar heating systems claim a payback period of two to three years, which means you can recover your entire investment in this time period. 
  • Even though most of these heat pumps are produced keeping in mind the needs of an average-sized home, their larger and smaller variations are available too. As such, you can have one for every purpose, including residential and commercial. 
  • Hybrid models of solar heaters are also available on the market. So you can make use of both active and passive heating systems, as might be the need.

What’s more to the benefits of solar assisted heat pumps?

Read our blog – 5 Benefits Of Installing A Solar Water Heater In Your Home.

How does a solar-based heat pump work? 

solar thermal panels

Even though a solar assisted heat pump sounds very similar to the solar panels used to produce electricity, they’re very different both in terms of working and application. 

That’s because while solar panels only need sunlight, solar heat pumps rely mostly on the sun’s thermal energy. Also, the way a solar assisted water heating system works differs for different models and variations. 

Nonetheless, there are some components that are the same for every solar heating system.

For instance, components like collectors, evaporators, thermal expansion valves, compressors, and heat exchange tanks are something that you’ll find in common across all solar heat pumps. And it’s none but these components that determine the overall working of the system. 

So let’s examine how each of the components works: 

#1. The collectors

Also known as thermal solar panels, the collectors look very similar to the photovoltaic solar panels used to generate electricity. The only difference is that instead of using the sun’s energy to produce electricity, the collectors use their absorber plates to convert the sunlight into heat. 

Thereafter, the heat generated using sunlight is transferred to the refrigerant, which then absorbs and supplies the heat throughout the heating system. 

Based on the model and type of your solar assisted heat pump, the collectors can be of various types, namely: 

Flat plate collectors

These collectors feature large and flat-shaped absorption plates meant to transfer heat to the refrigerant. 

A heat pump based on a flat plate collector is best for those areas that receive plenty of sunshine either throughout or most of the year. That’s because such a system is most efficient with the sun directly overhead. 

Evacuated tube collectors 

An evacuated tube-based collector is one with rows of transparent tubes arranged parallel to each other and connected to a heating pipe. Also, the refrigerant in these tubes is contained in the heating pipe itself. 

And while evacuated tube collectors are more efficient than their flat plate counterparts, overheating and cracking in higher temperatures is a problem. As such, maintaining one such system in an area with a hot climate can be a task. 

Hybrid collectors 

Hybrid collectors, also called PV-T collectors, use a combination of thermal solar panels and photovoltaic solar cells. Herein, the additional heat produced by the PV cells is transferred to the refrigerator via thermal solar panels. 

The major advantage of a hybrid heat pump water heater is that you can use the electricity generated by the PV cells to power the heating system’s compressor. As a result, you’ll get improved efficiency and performance on your SAHP. 

Fuhrer, the hybrid collectors, don’t have the problem of overheating and are very effective in both warm and cold temperatures. 

Thermodynamic collectors 

A thermodynamic collector traps heat from both sunlight and ambient air and passes it through its panel to heat the refrigerant. Meaning, the solar assisted heat pumps using these collectors aren’t dependent on the sun alone and, thus, can work even on cloudy days and during nighttime. 

In fact, you can install one such collector just about anywhere from the side walls to the rooftop since they don’t need direct sunlight. 

#2. The evaporator

While the evaporator is important for a heating system to work, it can be different for different solar assisted heat pumps. 

For instance, in a direct expansion solar heat pump, the refrigerant liquid is circulated throughout the collector panels, and the absorber in the system also acts as an evaporator. 

Similarly, for an indirect expansion-based heating system, the refrigerant is passed from the collectors to the heat exchanger in a closed loop. Also, in a system such as this, the refrigerant itself serves as the evaporator. 

#3. The thermal exchange valve 

This is a critical component in a heat pump unit as it increases the level of efficiency of your heating system. 

You see, the valve regulates the rate of flow of the refrigerant into the evaporator, thus ensuring an optimal flow while also enhancing heat output. 

#4. The compressor 

After the liquid refrigerant in the solar water heating systems is turned into a gas, it is passed through a compressor which concentrates the heat by pressurizing the refrigerant. 

Since compressors need electricity to run, a hybrid collector-based solar water heater can come in really handy. That’s because they allow you to use the energy generated by the PV cells to power the compressor. 

#5. The heat exchange tank 

Once the refrigerant in its pressurized form is passed through the condensers or heat exchangers, it cools down into a liquid. Further, the heat produced in the heat exchangers is used to warm up the water in the storage tank, also called the heat exchange tank. 

How much do solar assisted heat pumps cost? 

solar PV panel installation

A typical solar assisted water heating system can cost you anywhere between $2000 and $6000, depending on the model, variant, and manufacturer.   

For instance, you can expect the cost of a PV panel-based solar heating system to be on the higher end. At the same time, you can get a thermodynamic collector-based heat pump on a lower budget. 

So why such a difference in pricing, you might wonder? 

The answer to that lies in the type of components used in each of the solar water heaters. 

Take, for example, the hybrid solar heaters featuring both solar thermal and PV panels, which isn’t the case with their thermodynamic counterparts. 

Now, talking about the solar payback period, the Department of Energy estimates suggest that you can expect savings of up to or more than $274.46 every year on water heating costs alone. 

And the fact that solar assisted heat pumps save both water and indoor heating costs means that your total annual energy savings will be way more. As such, you can expect to recover the entire amount in a few years.  

Wondering how you can complement your residential solar assisted water heater?

You can go through our blog – The Best Residential Solar Energy Solutions.



Looking for free-of-charge outdoor lighting instead?

Explore our multipurpose solar-powered lights designed for sustainability and affordability.


Do solar water heating systems make you eligible for tax credits? 

Yes, they do. 

In fact, apart from the regular solar payback, you can also recover your upfront investment by availing of the tax credit schemes. And the most lucrative and equally beneficial of all tax benefits in the country is the Federal Residential Renewable Energy Tax Credit. 

Also called the Federal Investment Tax Credit or ITC, this scheme can make you eligible for up to 26 percent tax credit on your solar assisted water heating system. 

Nevertheless, there are some criteria you need to fulfill to become eligible for the scheme. For instance: 

  • At least half of the total energy consumed within your property should be generated from solar energy systems.
  • The solar assisted heat pumps or hot water systems should be either certified by the Solar Rating and Certification Corporation or a similar institution approved by your state’s government. 
  • You can’t use solar water heating systems to warm up the swimming pools or hot tubs. However, you can still use smart and eco-friendly solutions like a solar attic pool heater for such purposes, thus keeping yourself eligible for the above tax credits. 

Further, federal tax credits apart, you can also avail of the multiple tax credits, rebates, and subsidies offered by the states, municipalities, and even the manufacturers. 

That’s impressive, isn’t it? 

You might also want to read – The 8 Best Solar Street Lights.

How to determine the efficiency of solar assisted heat pumps? 

solar roofing panels

Before you invest in a solar water heating system, it is important to ensure that the unit is highly efficient. After all, it’s the optimal solar heating capacity of these systems that make them a highly sought-after solution among other alternatives on the market. 

When it comes to determining the efficiency of solar assisted heat pumps, the best approach is to compare the Coefficient of Performance. 

Also called the COP, the Coefficient of Performance is an estimate of the heating system’s efficiency based on a ratio of useful heat produced compared with the input of energy. 

So, as per this approach, the higher the COP, the more efficient the solar water heater will be. And even though the highest COP on a solar assisted heat pump is 4.5, heaters with a COP of 3.0 or more are considered high-efficiency systems. 

Pro tip: power the compressor with a PV panel for maximum efficiency on solar assisted heat pumps

The compressor on your solar heater needs electricity to run. And on a heating system with a single solar thermal panel that happens using non-solar grid-supplied energy. 

That means such a solar heat pump won’t be as efficient, given it’ll still inflate your energy bills. And that’s exactly why we suggest you compliment the system with a solar PV panel to run the compressor and thus take your residential heating entirely off the grid. 

The final words 

As you can see, solar assisted heat pumps go a long way to provide a reliable and zero-cost heating solution to your home. 

Not to forget, such solar water heating systems also help save the planet by significantly reducing your dependence on fossil fuel-based grid energy. 

And the best thing is that a system like this doesn’t break the bank while also letting you recover the initial cost. 

Now, if you’re looking for one such heating solution, you can reach out to us.

At Eco-$mart Inc, we have active and passive solar water heaters and heat pumps from market-leading brands at the most cost-efficient prices. So whatever your requirement is, we’ve got you covered on a budget.



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