While the grid in the neighboring city of Oranienburg cannot accommodate new electrical connections, a new development in the Berlin district of Pankow has taken a completely different approach: in the future not only will heating be cheaper, but electricity will also be cheaper. .
Most of the community eco-district's 84 semi-detached and semi-detached homes are already built. The residential area in the French Buchholz district of Pankow is run by the Berlin developer INCEPT GmbH. The green energy supplier naturstrom AG is responsible for and develops the energy concept.
A warm geothermal local heating network supplies sustainable heat to houses in northern Berlin. Roof-integrated photovoltaic systems provide green electricity for two central heat pumps and solar energy is also available to residents as affordable electricity for household needs and for wall boxes.
The building is welcomed in the Berlin House of Representatives as an “important element for the urban energy transition.” Johannes Kraft, who is also a member of the Urban Development, Building and Living Committee, praises the new urban district: “This makes it possible to optimally use local energy sources, even in cities. “We need this networking of the electricity, heat and mobility sectors to quickly move closer to the goal of climate neutrality.”
More heat for less money
“The heart of the energy concept is our geothermal local heating network,” explains Sarah Debor from Naturstrom AG. “At a depth of about 100 meters below the district, 68 geothermal probes extract thermal energy from the ground at a constant temperature of 10 degrees Celsius. Two central heat pumps raise the temperature and then increase it to 40 degrees.”
An insulated low-temperature local heating network, almost 1,200 meters long, then delivers the thermal energy to the buildings. “Thanks to the high construction standard according to BEG 55 and modern underfloor heating, it is possible to create a comfortable environment in the houses even in these warm temperatures,” explains project manager Anna Tsuchiya. “And not only fuel-free and emissions-free, but also particularly efficient.”
In summer, the energy flows are reversed and used for cooling. Excess heat is then removed from the buildings and returned to the ground by the local heating network. “In addition, a dry refrigerator on the roof of the energy center extracts additional thermal energy from the air when it is hot, which is then stored in the ground,” explains Debor. “In this way, a completely renewable energy cycle is created, thanks to which we were able to significantly reduce the number of geothermal probes. “Sustainable planning is also worthwhile from an economic point of view.”
Local solar energy joins sector coupling
Energy from nature is also used above ground: photovoltaic systems integrated into the roofs of the 84 residential buildings with a total power of up to 300 kilowatts supply the energy center with local green electricity. This is also available as a tenant electricity tariff for homes and at Wallboxes. “The intelligent interconnection of the electricity, heating and e-mobility sectors enables particularly efficient use of energy,” says Debor. “With the on-site supply concept, one third of local electricity needs can be covered.”
“From the beginning, it was important for us at Kokoni One to make not only the operation but also the construction as sustainable as possible,” says Tsuchiya. “Thanks to the wooden construction, the neighborhood is from the beginning much more climate-friendly than conventional construction projects. When high-emission materials are used, the wood used in the building structure and façade stores CO2 for decades.”