Liisanlehto in Vaasa is the most energy-efficient Prisma hypermarket in Finland
A new Prisma hypermarket was completed for Osuuskauppa KPO in Liisanlehto in Vaasa. The roof of the most energy-efficient Prisma in Finland boasts more than 2,000 solar panels. Safety is also top-notch, thanks to a sprinkler system, a dedicated artificial static water supply and remote monitoring.
The oldest regional co-op in Finland, KPO, opened its first shop in Kokkola in 1905. The co-op now has operations in 36 municipalities, and the second Prisma in Vaasa was opened in March. In addition to modern retail premises and auxiliary services, Liisanlehto has a restaurant area with seating for 300 people and 1,000 parking spaces for cars and more than 200 parking spaces for bicycles. There is also a convenient online shopping pick-up point in the parking garage. The largest project in KPO’s history enabled the expansion of Prisma’s services, which has been in the works for 20 years.
“The sales volume of Vaasa’s first Prisma is among the largest in terms of floor area in Finland, but the building could no longer be expanded on the site,” says Sweco’s Electrical Design Manager Mika Toivoniemi, who has worked with KPO-Kiinteistöt Oy for more than 10 years. Ongoing joint projects are a regular occurrence in Ostrobothnia. “We know each other’s way of working well, and we have a lot of internal information about how KPO wants its sites to be run.”
Upon completion, Prisma Liisanlehto was carbon neutral in terms of energy use and the most energy efficient Prisma in Finland. “The total annual energy consumption of the building is less than 100 kWh per square metre, which is less than half of the average consumption of corresponding hypermarkets,” says KPO-Kiinteistöt Oy’s Real Estate Director Mika Mikkola. The building is heated with solar panels and 20 geothermal wells drilled in the parking garage. When waste heat recovery is added to the equation, about half of the energy demand is produced locally. Renewable energy is also obtained from wind power produced by S Group’s own energy company and the security of the energy supply for the coldest winter months is secured by district heating.
In addition, environmental responsibility and circular economy have also been taken into account on the Liisanlehto plot. A patch of forest for flying squirrels was created on the plot, and the materials of the old concrete factory that was demolished from the site have been utilised in the structures of Ratakatu in Vaasa. The site has succeeded in recycling approximately 150,000 cubic metres of aggregates and 50,000 cubic metres of stones, which has reduced lorry traffic by thousands of loads.
Robust building services engineering systems were entered into a building information system
Sweco’s electrical and sprinkler system designers were already involved in the first Big Room meetings for Liisanlehto, surveying future technology choices and space reservations. The store, with a gross floor area of approximately 38,000 square metres, contains several robust systems that were comprehensively modelled in the site’s information model.
“At the beginning of the design process, we mapped Prisma’s power needs, with about 1,000 amperes reserved for refrigeration technology alone and about 600 for ventilation technology,” says Toivoniemi. In addition, substantial accommodations have been made to increase the charging capacity for electric cars for the future, including auxiliary piping and the possibility to connect a completely new converter.
Prisma’s electricity supply is ensured with a 20 kilovolt mean voltage connection and two 1,600 kilovolt-ampere transformers, one of which can supply most of the electricity needed by the property, e.g. during the maintenance of another transformer. In addition, the regional energy company supplies Prisma with electricity with three conversion circuits instead of two. “The operation of the electricity system is monitored remotely, and electricity can be supplied quickly in the event of a power failure via a different transformation circuit,” says Toivoniemi.
According to him, all indoor and outdoor lighting in Liisanlehto has been implemented by using LED lights and the lighting is controlled by the DALI system and the motion sensors connected to it. Attention will also paid to lighting times, and it is possible to introduce daylight sensors later. “The intensity of store lighting may be adjusted down to a single fixture, even if the space actually has more than one thousand lamps. In the parking garage, on the other hand, the lighting can be intensified or dimmed one line at a time.”
Dedicated 450 cubic metre artificial static water supply
The automatic fire extinguishing system at Prisma was implemented as a traditional sprinkler system, consisting of nearly 5,000 sprinkler nozzles and 17 kilometres of pipe. The water supply is a 450 cubic metre static water supply located in the basement of the building, filled from the city’s water supply network.
“Sentinel valves and equipment and the step-up pumping station for the extinguishing system have also been placed in the sprinkler room,” says Project Manager for sprinkler system design at Sweco Tomi Leppälä. We were able to make the sprinkler room the desired size, which will significantly ease the use of the system in the future. “Room for expansion has also been taken into account.”
Other techniques that improve fire safety include mechanical smoke ventilation, smoke vents and an automatic fire alarm system. “According to emergency exit simulations, the reduced fire alarm system is sufficient to guarantee safe exit times,” says Toivoniemi. Additional security is provided by comprehensive camera surveillance and access control connected to SOK’s central remote control system.
Large 18.5 kW electric motors were selected for mechanical smoke ventilation in order to avoid having to place multiple channels on the roof. This allowed for one of the largest solar panel fields in the area to be installed onto the roof. Over 2,000 panels cover approximately 10,000 square metres of the roof’s area. “The yield of solar energy is also high, half of which is directed directly to refrigeration equipment in the hypermarket,” says Toivoniemi. The panels have exceptionally been placed in the east to west direction.
According to Toivoniemi and Leppälä, the best sign of trust and thank you for a job well done is the continuing cooperation with KPO with new projects already underway. Sweco’s electrical and audio-visual system designers are involved in the renovation of Original Sokos Hotel Royal Vaasa. The goal is nothing less than to make it the most energy-efficient hotel in Finland.