Turun Toriparkki, an underground parking space in the Turku city center, is presumably the first zero-energy parking space to be built in Europe. With a zero-energy solution, this 30.000 m2 underground parking facility produces at least the amount of energy it uses. Energy efficiency has been guiding the Turun Toriparkki planning. Energy efficiency optimization and planning of the energy solutions are coordinated by the leading energy efficiency consultant bureau in Finland, nollaE Oy.

“The optimization of energy efficiency in such projects is an important part of the engineering to ensure the lowest possible energy consumption throughout the life cycle of the building. We have designed technically and economically the best possible energy solution”, says Nikolas Salomaa, Managing Director of nollaE Oy.

The solution designed by nollaE will reduce carbon dioxide emissions by approximately 950 tonnes annually. Innovative design combines solar energy, geothermal energy, and underground thermal energy storage. Soil surveys and heat conductivity measurement results are very positive for the project.

“Toriparkki’s location is such that the soil makes it possible to fully exploit such a solution. According to our calculations, Turun Toriparkki achieves top results in recovering and utilizing solar and thermal energy,” says Salomaa.

The solar thermal energy, which heats the market square’s surface, is collected by piping under the paving. The accumulated heat is stored with energy piles into a clay ground at a depth of 50 m below the market square. During the summer, the amount of thermal energy to be charged to the thermal storage is 11.2 GWh, and the peak thermal power of the energy solution is 6.6 MW. This is the biggest solar heating and seasonal energy storage system combination in the world. Built in the city center of the second biggest metropolitan area of Finland.

The thermal energy required by the snowmelt system of the market square is also carried out using the same system. The thermal energy stored during the summer is used for heating the underground parking space and melting the market area above it in winter.

“Turun Toriparkki wants to be a forerunner with its energy solutions in Finland. It’s great that we have such expertise and a new kind of thinking in optimizing the energy efficiency of buildings and in designing energy solutions”, says Jari Pölönen, Managing Director of T-Park.