The fish stays fresh! Blackout security for the supermarket.

A project by Baumann Haustechnik GmbH

The scenario of a power failure in a supermarket is not a pretty one. If the refrigeration fails, all the goods are ripe for disposal – from fresh vegetables to frozen pizza. For this reason, the SPAR supermarket in Kestenholz decided to protect itself. With a complete roof renovation, a new photovoltaic system and a salt battery storage system, not only will the electricity bill be reduced, but from now on the fish will stay fresh even in the event of a power failure!

The roofs of the SPAR market and the adjoining residential building with six tenants were in need of renovation. Mr Bürgi, owner of the supermarket, does not do things by halves. Together with the company Baumann Haustechnik GmbH, he planned with foresight and cost-efficiently. The existing Eternit roof was completely dismantled, the sub-roof newly insulated and re-roofed with an in-roof photovoltaic system from Megasol. The 50 kWp now produce green electricity for the consumers in the shop and the residential building. And the tenants in the attic flats are happy about moderate temperatures in summer.

For night-time operation, there is a salipro® salt battery storage system from innovenergy® in the basement with 45 kWh storage capacity and 30 kVA inverter power. The freezer counter alone consumes 5.6 kWh. In addition, there are refrigerated service and self-service counters, lighting, cash registers and automatic doors. All together – from the entire shop to the flats – about 250 kWh of energy are needed within 24 hours, i.e. an annual consumption of about 90'000 kWh. One third of the energy from the photovoltaic system goes directly into the AC grid for the consumers. Two thirds are designed as an off-grid system. In the event of a power failure, the PV system can continue to serve the consumers and the storage unit.

Owner Bürgi's goal was to achieve the best possible energy self-sufficiency, the highest possible self-consumption and energy savings. This visionary entrepreneur has been practising the latter for some time now with an electricity-saving device that transfers 230 V into 215 V electricity. This very even current without any fluctuations increases the service life of all the appliances connected to it and saves between 8-10 percent electricity. But that is not all. Mr Bürgi is planning wallboxes for charging e-vehicles for his tenants and his customers.

«I didn't want to have any rare earths in my storage. It was important to me that my green electricity is also stored green. That's why I chose a salt battery storage system from innovenergy®

Baumann Haustechnik GmbH is the planning and implementation partner in this project. Their motto is: Everything from a single source throughout Switzerland - from consulting and planning to sales and installation for the complete building technology.

Christian Schori
Electrical Department Manager

Baumann Haustechnik GmbH