Solar, biogas and groundwater-based heating & cooling at Copenhagen Hotel Crowne Plaza

Date: 27 February 2014

Solar panels on the facade, a groundwater-based heating & cooling system and a 10,000 litre tank to collect food scraps for biogas conversion are some of the green features at the Crowne Plaza Copenhagen Towers hotel.

Streamlined in a black facade, the carbon neutral Crowne Plaza Copenhagen Towers hotel boasts a wide range of sustianable technologies, incorporating solutions for energy efficiency, resource efficiency and renewable energy, making it one of the greenest hotels in the world and one of the first to achieve the EU GreenBuilding certification.

Reaping energy from the sun
2,500 custom-made solar modules in 38 different designs shape the architecture of the facade. Covering a total of 1,700 m2, the integrated solar panels generate approximately 170,000 kWh per year, corresponding to around 10% of the hotel’s annual energy consumption – the remainder of the energy being supplied by wind turbines.

Denmark’s first groundwater-based heating and cooling system
Below the hotel lies Denmark’s first groundwater-based heating and cooling system, which saves up to 90% of the hotel’s heating and air conditioning consumption.

The groundwater cooling system required two lots of drilling to a depth of 110 metres at two locations near the hotel. In the summer, cool water from the ground, at 9˚C, is pumped via one set of wells to the hotel’s cellars where it is sent through a heat exchanger and back down to a heat reservoir where the heat accumulates and is stored during the warmer months. The cooled water from the heat exchanger is circulated in the building to cool rooms to the desired temperature. No active refrigeration is required.

During winter, water from the reservoir, which has accumulated heat during the summer period, is pumped through the heat exchanger and back down to the wells. Heat from the heat exchanger is sent through two heat pumps which raise the temperature to 55˚C. This is then used to heat hotel rooms and offices.

Converting food waste to biogas and fertiliser
All food waste generated in the hotel is ground and vacuum-extracted into a 10,000 litre tank located in the basement. When the tank is full, it is emptied and the food waste is transported to a biogas plant, where it is converted into biogas. The remaining waste is later used as agricultural fertiliser, which reduces the consumption of artificial fertiliser by the agricultural sector.