As it is evident, heat pumps are an affordable alternative to conventional heating and cooling systems. Many households choose a solar heat pump system to save money and the environment. It is more effective for us and our environment if heat pumps can work on solar power.
It makes perfect sense to be more energy independent because solar energy is one of the most efficient methods for producing power in terms of conserving natural resources and reducing household expenses.
Suppose you want to live an eco-friendly life without worrying about the environment and higher utility charges. In that case, switch to solar-assisted heat pumps.
The primary purpose of a heat pump is to transmit heat from one location to another.
Like a refrigerator, heat pumps work similarly. However, a fridge can only transfer heat in one direction, from the inside to the outside.
But a heat pump can work both ways. It can pump heat into your house from the ground or the surrounding atmosphere. Also, it can absorb heat from your house and expel it to the environment outside or the atmosphere. It can serve your home with both warmth and cooling.
Combining solar power with heat pumps would enable consumers to reduce their consumption during the peak winter months while also decreasing our dependence on utility companies.
Modern heat pump systems can generate three to four times as much thermal energy in the form of heat as they do electrical power. This is made possible by improvements in refrigerant technology and the increased efficiency of the compressors and motors used in heat pumps.
Now, let’s check out more about solar-assisted heat pumps.
What is a solar heat pump?
Solar-Assisted Heat Pumps combine two devices: a solar panel, which collects solar energy, and a heat pump, which uses that energy to heat or cool a space.
The refrigerant that flows through the heat pump is heated using the energy from the sun. This helps you with the power needed to run this system and makes the heat pump work more effectively.
Solar-Assisted Heat Pumps are “solar-powered heat pumps” or “solar heat pump systems.” This system aims to generate energy more effectively and inexpensively than a conventional grid-tied heat pump.
With the advancement of technology, SAHPs have become more efficient and cost-effective. They can lessen or even eliminate the requirement for grid-supplied electricity to condition spaces, making them a better substitute for conventional heating and cooling systems.
From the above discussion, I guess you have understood the meaning of “solar-assisted heat pumps.” Now I’ll tell you about how solar-assisted heat pumps work.
Working of solar-assisted heat pumps
The solar-powered heat pump has been around for a while but still faces some technical challenges. A genuine solar-assisted heat pump uses solar thermal collectors to absorb the sun’s energy instead of photovoltaic electric panels, which harvest energy to store in batteries or other energy storage devices.
Solar-assisted heat pumps operate by heating a fluid using solar energy, which is then used to run the heat pump. I’ll tell you how it’s done.
There is something we need to understand first: the solar panel does not generate electricity. It only harnesses the sun’s energy and transfers it to the fluid. The heat pump uses this fluid to generate electricity, which powers the system.
Solar energy is harnessed by the solar thermal panel from the sun and then transmitted to the fluid. So that fluid can heat up. After that, the fluid passes through the heat pump’s evaporator, which heats the refrigerant.
The refrigerant then circulates through the heat pump compressor, which transfers the heat to the ground and outside environment.
The essential components of solar-assisted heat pumps
A solar-assisted heat pump system has four main features:
- Solar thermal panel
- Heat pump
Solar Thermal Panel: As solar thermal panels capture solar energy, they are sometimes called “solar collectors.” They transfer energy collected from the sun to the fluid, which generates solar power.
The solar collector can be installed on the ground or roof. They are usually constructed as flat panels that supply the heat pump with low-temperature heat. The size of the heat pump and the amount of solar energy available determine the size of the solar thermal panel.
Two types of solar thermal panels are available: flat-plate collectors and evacuated tube collectors. You can choose between them depending on the size of your system.
- Flat-plate collectors: They are the most common type of solar collector. They consist of a metal plate coated with a material (copper or aluminum) that absorbs the sun’s energy. The plate is then enclosed in an insulated box. Conduction and convection transmit the heat from the container to the fluid. The heat is then transferred to the heat pump by the liquid.
- Evacuated-tube collectors: They are less common than the above one. This consists of a tube coated with an absorbent material like aluminum or copper. They are enclosed in an evacuated glass container. The transfer of heat from the sun to the fluid is done with the help of conduction and convection. The heat is then transferred to the heat pump by the liquid.
For working model watch this detailed analysis of heat pumps.
Heat Pump: The system’s power source, a heat pump, generates electricity by using the fluid from the solar thermal panel. Heat is transmitted from the fluid to the refrigerant by the evaporator in the heat pump.
After flowing through the heat pump’s compressor, the refrigerant flows again, releasing the heat to the environment. The component of the system that uses the most power is the heat pump, which operates on a constant power supply.
There are three heat pumps: air-source heat pumps, ground-source heat pumps, and water-source heat pumps.
- Air-source heat pumps: An air-source heat pump transfers heat between your home and the outside environment. It is less expensive to install and can be used in most climates.
- Ground-source heat pumps: A ground-source heat pump transfers heat between your home and the ground. They are more efficient than the air-source heat pump but are expensive to install.
- Water-source heat pumps: A water-source heat pump transfers heat between your home and the water. They require a water source like a lake or river and are expensive to install.
Compressor: The refrigerant is circulated throughout the system with the help of the compressor. This is the most energy-consuming component of the heat pump; it requires a steady flow of electricity to function.
Even though the compressor can typically run off the grid, the solar thermal panel can assist in reducing the amount of electricity required.
There are two types of compressors. They are reciprocating compressors and scroll compressors. You can choose one according to the needs of your system.
- Reciprocating compressor: This is the most common type of compressor used in heat pumps. A piston is used in a reciprocating compressor to compress the refrigerant.
- Scroll Compressor: A scroll compressor compresses the refrigerant using two interlocking scrolls. It is more efficient than a reciprocating compressor.
Refrigerant: A substance called refrigerant is a fluid used to transfer heat from the solar panel to the heat pump. Usually a gas or liquid, it evaporates at low temperatures and condenses at high ones.
The refrigerant transfers the heat through the heat pump’s evaporator. The refrigerant then circulates through the heat pump’s compressor, transferring the heat to the air or ground outside.
There are several types of refrigerants used in heat pumps.
- Fluorocarbon refrigerants: Fluorocarbon is the most popular kind of refrigerant used in heat pumps. Usually, they are used in air-source heat pumps.
- HCFC refrigerants: Fluorocarbon refrigerants include HCFC refrigerants. Usually, they are used in ground-source heat pumps. Since HCFC refrigerants harm the ozone layer and have been taken out of use.
- HFC refrigerants: The fluorocarbon family of refrigerants includes HFCs. They are commonly used in water-source heat pumps. This refrigerant is out of use because it leads to global warming.
- CO2 refrigerants: One category of fluorocarbon refrigerants is CO2 refrigerants. They are commonly used in ground-source heat pumps.
- Ammonia refrigerants: These refrigerants do not belong to the fluorocarbon family. Usually, they’re found in water-source heat pumps. Because they are highly flammable, ammonia refrigerants must be handled carefully.
The benefits of solar-assisted heat pumps
There are several benefits to solar-assisted heat pumps.
Reduces dependency on the grid: You can rely less on the grid using solar-assisted heat pumps. You’ll consume less grid-supplied electricity because the solar thermal panel somewhat offsets the electricity required to power the compressor. Doing this can lower your carbon footprint and save money on your electric bill.
Improves efficiency: Traditional heat pumps are less efficient than solar-assisted heat pumps. The refrigerant is heated by the solar thermal panel, which reduces the energy needed to compress it.
Less emission: Heat pumps using solar power emit zero pollutants compared to traditional heat pumps. The heat pump is more environmentally friendly thanks to the solar thermal panel, which reduces the compressor’s emissions.
Saves money: Using solar-assisted heat pumps can lower your energy costs. They use less energy because they are more energy-efficient than traditional heat pumps. This can help you save money on your electric bill.
The drawbacks of solar-assisted heat pumps
There are several drawbacks to solar-assisted heat pumps.
Higher initial cost: Heat pumps using solar assistance can cost you more than traditional heat pumps. The installation and cost of the solar thermal panel can increase the heat pump’s initial purchase price.
More Maintenance: Solar-assisted heat pumps are more expensive than traditional heat pumps and require high maintenance. Their panels need to be cleaned and maintained properly from time to time.
Non-Availability: Solar-assisted heat pumps are not available in all areas. Some areas need more sun exposure for the solar panels to be set up, and some do not allow solar panel installations.
Frequently asked questions
- How do I choose a solar-assisted heat pump?
In my opinion, there are a few things everyone should consider before choosing a solar-assisted heat pump, i.e., the type of refrigerant it uses, the size of the heater, the climate you live in, and the right size of the solar thermal panel.
- How can solar-assisted heat pumps be made more efficient?
To make your solar-assisted heat pumps more efficient, you should use thermal storage tanks, higher-efficiency heat pumps, and a solar collector of higher quality. You can also install a solar tracking system, which will help keep the solar collector pointed at the sun.
- What types of solar panels can be used with solar-assisted heat pumps?
The solar collector can be any solar thermal panel in a solar-assisted heat pump system. The hybrid solar panel is the most commonly used because it fulfills some of the heat pump’s power needs while lowering energy consumption and system expenses.
Solar-powered heat pumps are powered by a solar panel that is added to the system. Most regions can now install solar heat pumps thanks to a photovoltaic panel.
The number of solar panels required to generate enough solar energy to power the system will be lower in sunnier regions. As a result, when the weather is good, they are more affordable. Unfortunately, due to the high cost of the equipment, solar-powered heat pumps could be more cost-effective.
However, those who are committed to eco-friendly technology may want to install one to cut down on their home’s energy use and emissions of greenhouse gases. However, as the cost of technology declines, these systems will become more famous throughout the country.
Ray is an avid reader and writer with over 25 years of experience serving various domestic and multinational private and public energy companies in the USA.