New heat pump that links to solar panels could soon provide your home's hot water

Interest in solar panels is rising as energy prices fluctuate
Interest in solar panels and heat pumps is rising as energy prices fluctuate (Image credit: Department of Mechanical Engineering, Bannari Amman Institute of Technology)

Scientists have developed a new type of solar-air dual-source heat pump (SAHP) that can be used to heat water throughout the day. 

Researchers from India's Bannari Amman Institute of Technology, Sri Krishna College of Technology and Malaysia's Sunway University, say the tech “contributes significantly to advancing SAHP technology, paving the way for more efficient and sustainable water heating solutions in regions with diverse ambient conditions”.

We provide all the details about the innovative air source heat pump and how it compares to other water heating systems.

How does the Solar-air dual-source heat pump work?

Heat pumps move heat from one place to another using a compressor and a circulating structure of liquid or gas refrigerant to extract heat from outside sources and pump it indoors using electricity.

Air source heat pumps absorb heat from the outside air, while ground source heat pumps use pipes buried in the garden to extract heat from the ground.

The new system uses a blower fan that enables forced convection from solar panels during partial sunshine and diffuse light conditions. Forced convection extracts the ambient thermal source to the refrigerant flow in the same way as natural convection in regular solar-air dual-source heat pumps.

Will it provide heating throughout the day?

Interest in solar panels is rising as householders seek out ways to lower their bills with continuing energy price rises and help save the planet while they’re at it, but many have concerns that they only work in the sun.

Unlike conventional dual-source heat pumps, which rely solely on natural convection for extracting ambient thermal sources during partial sunshine and dusky hours, the Direct Expansion Modified Solar-Air dual-source Heat Pump (SAHP-MDX) incorporates a dual-source evaporator adapted with forced convection, effectively removing the dual-source energy throughout the day.

Snow on solar panelled roof in winter

Some solar panels fail to provide hot water throughout the day but the solar-air dual-source heat pump claims to have solved by storing heating for use throughout the day (Image credit: Getty Images / Ashley Cooper)

How does it compare to other water heating options?

To test the effectiveness of the SAHP-MDX the COP (coefficient of performance) was compared with other water heating systems.

In the case of a heat pump, its efficiency is the ratio of useful heat energy produced to electrical energy consumption. A COP of 2.5 means that the heat pump supplies 2.5 times as much heat energy to the system as it consumes in electrical energy. It becomes more environmentally friendly if combined with renewable energy.

The average daily COP of SAHP-MDX is approximately 3.22, compared to a standard gas boiler, which typically has an efficiency of around 0.93.

The scientists in the Science Direct stated: “Overall, the proposed SAHP-MDX outperforms comparably conventional dual-source heat pumps that exist in practice. It can be used as a feasible substitute for water heating applications in real-world settings with unpredictable weather, ambient air temperature, and solar radiation.”

Sam Webb

Sam is based in Coventry and has been a news reporter for nearly 20 years. His work has featured in the Mirror, The Sun, MailOnline, the Independent, and news outlets throughout the world.  As a copywriter, he has written for clients as diverse as Saint-Gobain, Michelin, Halfords Autocentre, Great British Heating, and Irwin Industrial Tools. During the pandemic, he converted a van into a mini-camper and is currently planning to convert his shed into an office and Star Wars shrine.