Energy Foundation Piles are a foundation element and a sustainable energy source in one. When connected, these foundation piles can be used as a closed source system. R&R heat exchanger systems are placed in the foundation piles during production. A closed system is created by linking the foundation piles in sections to a supply and return line, which are connected to a heat exchanger. This provides a sustainable method of extracting and distributing heat and cold in the ground around the foundation pile. Because the surface area for the distribution and absorption of energy is greater than the exchange surface of a normal, closed system ground heat exchanger (U loop), the return of an Energy Foundation Pile is approximately 30% higher per metre. This leads to high yields of up to 40 W/per square meter (depending on the soil conditions).