Photovoltaic pipe pile energy storage

How does pile size affect solar energy storage?

As the pile diameter increases, there has a relatively larger volume of concrete for solar energy storage, leading to a lower pile temperature. As a result of its lower temperature, a higher rate of solar energy storage is observed for cases with larger pile diameters.

How much solar energy can a 10 m-long energy pile store?

Under the specific thermal boundary conditions adopted, the maximum daily average rate of solar energy storage reached 150 W/m for the 10 m-long energy pile. It decreased to about 35 W/m as the pile length increased to 50 m.

Can energy piles be used for underground energy exchange?

Energy piles, which are combinations of BHEs with pile foundations, could be used for underground energy exchange without the need for drilling holes [ , , ]. Energy piles have been combined with ground source heat pump (GSHP) systems for building heating or cooling for years [ 33 ].

How is solar energy collected?

A bridge deck embedded with heat exchange tubes was employed for solar energy collection, which can provide thermal energy to the energy pile. A full-scale pile foundation with a spiral-shaped tube in the pile shaft was employed for storing the collected solar energy underground.

How much solar energy is stored in a case?

The maximum daily average rate of solar energy storage decreases from as high as 150 W/m for the case with L = 10 m to about 35 W/m as the pile length increases to 50 m. The maximum daily average rate of solar energy storage for the case with L = 30 m is slightly over 50 W/m.

Should mass flow rate be reduced for underground solar energy storage?

When used for underground solar energy storage, the results suggest that the mass flow rate should be reduced to save the operational cost of the circulation pump. This only causes a slight sacrifice of the rate of solar energy storage, less than 2%, as the mass flow rate is reduced from 0.3 to 0.05 kg/s.