Indian researchers have combined PV generation with heat from a ground-to-air heat exchanger to provide space heating and cooling for buildings. They say the proposed system could result in an annual energy benefit of 8116.7 kWh.
EAHE is a passive geothermal solution consisting of a buried pipe system that circulates fresh air. These systems are commonly used to heat fresh air in buildings in winter and cool it in summer.
“Simply put, EAHE is based on the idea of ​​using temperatures below 2-3 meters above the earth’s surface that remain constant throughout the year regardless of ambient temperature fluctuations,” researcher Basudev Pradhan said. pv magazine. “The temperature under the earth’s surface is colder in summer and warmer in winter than the air. The designed system therefore blows ambient air through a pipe installed at a certain depth from the surface, and the air warms or cools in winter and summer due to heat exchange with the surrounding soil.
Scientists designed a statistical tool for the proposed PV-powered EAHE with a response surface approach using computational and modeling software. EAHE is designed to be used The PVC pipes are tilted at a small angle so that condensed water does not get trapped inside and buried horizontally. A solar panel consists of PV panels, charge controllers, an inverter and a battery.
The researchers assumed that EAHE is used for 24 hours in all months except July and August. They said the seasonal energy efficiency ratio (SEER) is Estimated cooling 7.34 and heating 8.99. They also calculate that the annual heating and cooling potential of the system is 4158 kWh/year and 3958.7 kWh/year.
– Based on the revealed information, it can therefore be concluded that the planned EAHE system works more efficiently in the winter than in the summer season, they explained.
They said that the designed configuration with optimized parameters results in an annual energy gain of 8116.7 kWh.
“If 24-hour grid electricity is available, the payback period for the solar system is 4-5 years,” the researchers said. “Furthermore, this hybrid system has the potential to provide carbon emissions of $336.86 kWh/year. Thus, this system is an energy-saving and environmentally friendly approach for both urban areas where grid access is available 24 hours a day, and rural areas where grid expansion is not possible or feasible due to some technical barriers because of.
They presented the system in the journal “Numerical simulation of stand-alone solar PV integrated with ground-air heat exchanger for residential space heating/cooling’, published recently Renewable energy.
“Such efficient, self-contained net-zero systems can be further optimized for different location and climate conditions depending on the variation of atmospheric and ground parameters,” Pradhan said.
