Heating and domestic hot water with ground-source absorption heat pumps

Geothermal energy is one of the most efficient and stable renewable energy sources for heating and domestic hot water. Because it uses the almost constant temperature of the ground all year round, it delivers high efficiency regardless of outdoor weather conditions.

Ground-source absorption heat pumps combine the renewable energy stored in the ground with the energy supplied by natural gas or LPG, achieving gas utilisation efficiencies (GUE) of up to 165 %, reducing the installation’s electricity consumption and optimising the size of the borehole field.

How a geothermal installation with absorption heat pumps works

The installation captures the thermal energy stored in the ground through a circuit of vertical borehole heat exchangers or horizontal collectors. This renewable energy is transferred to the absorption heat pump, where it is combined with the energy from the gaseous fuel to produce heating and domestic hot water with high efficiency and very low electricity consumption.

Choosing a ground-source absorption heat pump

The main distinguishing feature of this technology is that not all the useful energy has to be extracted from the ground.

Because they use geothermal energy and the energy of the gaseous fuel at the same time, absorption heat pumps place less energy demand on the borehole field than many equivalent electric solutions. This reduces the drilling length, lowers the initial investment and makes the installation easier to fit into projects with limited space.

In addition, because no electric compressors are used, electricity demand is practically limited to the auxiliary equipment, reducing contracted capacity and running costs.

Benefits of the technology

• High energy efficiency.
• Lower investment in the ground loop.
• Very low electricity demand.
• High-temperature water production.
• Natural refrigerant and sustainability.
• Reliability and long service life.

Applications

Ground-source absorption heat pumps are particularly suitable for installations with many operating hours and a large demand for heating and/or domestic hot water:

• Hotels and resorts.
• Hospitals and healthcare centres.
• Care homes.
• Apartment buildings.
• Sports and educational centres.
• Industry and processes with high thermal demand.
• Energy refurbishment projects and conventional boiler replacement.

Recommended technology

The Robur GAHP GS Plus range is one of the most advanced solutions for harnessing geothermal energy with absorption technology. Its high efficiency, use of the natural refrigerant R717, very low electricity demand and optimised borehole field make it a high-value option for projects where energy efficiency and long-term profitability are priorities.