The Chinese manufacturer has unveiled a hybrid photovoltaic-geothermal heat pump system that uses solar energy to directly power the unit, increasing efficiency and self-consumption. The 8–112 kW ground and water source system provides heating, cooling and domestic hot water with coefficients of performance often higher than 4–5, while smart controls and the ground loop act as a thermal battery to optimize performance all year round.
Chinese heat pump manufacturer Nuliet New Energy has introduced a hybrid photovoltaic and geothermal heat pump solution for residential and commercial environments.
“In combination with a standard electric resistance system or an air heat pump, solar panels can offset part of the energy bill. But when combined with a Nulite geothermal system, the synergy becomes exponential,” the manufacturer said in a statement. “The ultra-low electricity consumption of the geothermal system means that a modest PV array can cover almost 100% of the system’s operational energy needs.”
In the proposed system configuration, solar electricity is supplied to directly power the heat pump, which reduces operating costs by using self-generated power instead of electricity from the grid, while increasing self-PV consumption and overall system efficiency.
In summer, peak solar energy generation provides highly efficient cooling by transferring heat to the cooler ground. In winter, the system extracts stable heat from the ground.
“Although the PV array may not cover 100% of the energy needs during the darkest months, the net metering credits collected during the summer months often make up for the shortfall in the winter. For off-grid applications or areas without net metering, Nulite’s drives allow the system to ‘charge’, with the system running primarily during sunny hours during the day and relying on minimal battery storage at night.
Smart controls allow operation to be tailored to the availability of solar energy during the day, reducing dependence on storage. In addition, the soil acts as a natural ‘thermal battery’, storing excess energy to improve system performance in the long term, according to the manufacturer.
The 8 kW–112 kW geothermal heat pump is a ground and water source system designed for heating, cooling and domestic hot water applications. It features a Mitsubishi inverter compressor and runs on single-phase supplies of 220–240 V or three-phase supplies of 380–400 V.
The unit offers rated heating power from 2 kW to 36 kW and cooling power from 10 kW to 33 kW, ensuring flexible performance across different load requirements, the company said. “By circulating fluid through ground loops, these systems use the earth as a heat sink in the summer and a heat source in the winter,” the report also explains. The result is a coefficient of performance (COP) that is often higher than 4.0 or 5.0, meaning that for every unit of electricity consumed, four to five units of heating or cooling are produced.”
The system is said to offer a maximum outlet water temperature of 60C. The smallest system in the range measures 670mm x 454mm x 830mm, while the largest measures 800mm x 572mm x 1,070mm.
Founded in 2003 and headquartered in Guangzhou, Nuliet New Energy produces a range of heat pump technologies, including air source heat pumps. The company reports exporting products to more than 100 countries, including several European markets.
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