Last year, Wageningen University & Research invested heavily in a heat and cold storage (ATES) system on Wageningen Campus. New wells have been drilled for this purpose and all heat and cold wells are interconnected with two ring lines. A number of the buildings have now been connected to the ring lines. As soon as all buildings are connected, WUR will save 1.3 million m3 of natural gas every year and thus about 2,400 tons of CO2 emissions.
The ATES construction is part of WUR’s energy transition plan and is in line with the climate agreement and the agreements of the VSNU for 2030. The energy transition plan is based on three pillars: saving energy, generating energy and reducing the use of fossil fuels. WUR generates energy, among other things, with solar panels and wind turbines. This already generates more electricity every year than WUR uses! The ATES saves energy and, in particular, reduces the use of fossil fuels.
A number of the recently inaugurated buildings on the campus are already equipped with a building-related thermal energy storage system. But to meet the full demand for warmth and cold, especially in the older campus buildings, additional cooling installations and gas-fired central heating systems were still needed.
By connecting all campus buildings to the ATES ring and expanding it with more wells, the old cooling machines and central heating systems can make way for heat pumps that get their energy from the ground. To make it even more energy efficient, the ATES ring allows buildings to use each other’s surpluses and deficits which makes the additional installations virtually no longer necessary.
Natural gas free
In most older buildings on the campus, the central heating installations have to be replaced within five years. A simultaneous switch to ATES makes these replacements also cost-efficient. At the moment, for example, Orion and Helix are almost natural gas-free. The latest new building, Aurora, is the first to be built completely natural gas-free. The conversion of the campus buildings to ATES is expected to result in a 95% reduction in natural gas consumption and a 63% reduction in gas-related CO2 emissions.
Becoming natural gas-free is one thing, but the many pumps and installations do require electricity of course. For this, WUR uses its own electricity generated by solar panels and wind turbines.
Warmth and cold wells
For heating and cooling, through heat exchangers an ATES uses previously stored warmth from the summer period in the ground water and stored cold from the winter period. The warmth that is extracted when cooling a building goes through the heat exchanger and warm ring to a warmth well, or to a location that needs warmth at that moment. And vice versa, the cold that is expelled during heating is returned via the same heat exchanger and the cold ring to a cold well, or a location that needs cooling.
The heat stored in the ground can be pumped up again in the (next) winter and used, together with the heat pump, to heat the building. This also applies to the cold water, which can be used for cooling in the summer. The wells on Wageningen Campus are approximately 95 meters below ground level. At that depth, the groundwater moves only one meter per year. The deep groundwater functions as a large battery, as it were.