The hotel building extension at the ECCO Education and Conference Centre in Tønder, Denmark, supplies its own energy. Among other things, the autonomous energy supply is the result of a solar heating solution connected to the hotel’s booking system. The system comes from Danish Arcon Solar, a specialist in large and medium-sized solar heating plants, which also ensures its optimal operation. Shoe manufacturer ECCO uses the 4,000 m² building, which was finished in spring 2013, for both its own employees and external conference guests. The design of the building has been optimised in every way: Its circular structure guarantees the best utilisation of available space, short distances to the offices within the building and smaller heat losses because of a reduced surface area.
To make ECCO’s new hotel building both self-supplying and energy-efficient, the solar heating solution had to meet special requirements. On the one hand, it was to provide hot water for up to 100 guests wishing to have a hot bath in the morning. On the other hand, the system was to cope with low occupancy rates without wasting a lot of energy.
The company to develop and produce the solar heating system was Arcon Solar. Besides heating up utility water, the solar plant also provides energy for the heating system of the hotel and other buildings on the “ECCO Alléen” (ECCO Avenue). It retrieves energy from 300 m² of collectors, which have already been prepared for a potential 50 m² extension. According to a press release from 10 July, the collectors are mounted on galvanised steel foundations instead of conventional concrete. To support the solar heating system on less sunny days, the company installed two 60 kW geothermal heat pumps, each with 2,500 m long earth tubes.
“ECCO feels strongly about its role as a pioneer of environmental solutions. We support sustainable development, which is why it only seemed natural to us to extend the ECCO Education and Conference Centre by a zero-energy building supplying its own energy. We have chosen a flexible solar heating solution which can adjust to the building’s demand and distribute the energy to where it is needed. The system has been configured to provide 100 hot showers within half an hour. ECCO’s basic idea was to make use of the existing resources in the best and efficient way,” Jørgen Kristiansen, Facility Manager at ECCO, says in the press release.
The challenge of managing the installation has been solved by connecting it to the booking system, so that there is automatically an adequate quantity of hot water for the actual number of guests. On the technical side, there is just one hot water tank of 1,000 litres, which is supported by eight backup tanks of 2,000 litres each. When the occupancy rate is low, the hot water tank manages on its own, while the backup tanks will go into operation at peak load times. All the excess energy from the solar heating system which is not used for hot water will be distributed efficiently to serve other purposes.
“All parties involved in this project have been extremely focused on creating a solution which at all times makes the most of the energy supply. When the occupancy rate is low, the energy is passed on and used, e.g., to heat the hotel. The solar energy is available for six different processes, making the solution one of the most efficient ones in Denmark,” Søren Elisiussen, Managing Director of Arcon Solar, states in the press release.