Supermarket Utilizes Cutting-Edge Technology to Provide Customers the Upmost Energy-Efficient Shopping Experience

Posted Feb 03, 2020

As shoppers head out for groceries in Germany, they can now experience a unique and highly energy-efficient environment. Electrical devices at one supermarket are interconnected through an intelligent energy management system, allowing the store to sustainably generate and consume electricity.

For many supermarkets, having local produce and reusable bags are already standard practices. But the aktiv & irma supermarket in Oldenburg, northern Germany, takes sustainability to a whole new level with a 99-kWp, roof-mounted PV system, a 60-kW battery-storage system in the supply room for storing surplus solar energy and an intelligent energy management system, offering a host of benefits.

Surplus electricity stored for later use

The roof-mounted PV system has generated solar power for just over a year. That power is then either consumed directly by electrical devices in the supermarket or stored in the battery-storage system—keeping it ready for use when the sun goes down. When it is dark or particularly hot and more energy is needed, the electricity is drawn from the battery rather than purchased from the grid operator. This saves the supermarket from expensive tariffs. That stored power also benefits consumers.

Energy producers and consumers are intelligently interconnected

The supermarket’s energy system not only integrates innovative hardware and software components from SMA Solar Technology and Danfoss, but also comprises numerous monitoring systems, valves, frequency converters and controllers—in addition to the modules, inverters and battery-storage system. These components are intelligently interconnected to maximize the energy availability for consumers.

One of the latest innovations is the digital energy management system. The intelligent SMA Solar Technology ennexOS energy management platform connects different energy producers to consumers and controls energy flows to and from the energy storage system. The platform also decides when and which sources can be utilized most efficiently. To minimize energy consumption, a Danfoss system manager ensures the correct temperature and pressure levels in the supermarket’s cooling and refrigeration system.

 “We are combining the energy management system for cooling with other energy systems in the supermarket,” said Dirk Leinweber, director, food retail sales at Danfoss. The next step, which we also want to pilot, is to synchronize this new-found flexibility with the requirements from the utility grid, the aim being, if possible, to integrate all energy consumers in the building—for example, the lighting, in-store bakeries and charging stations for forklifts and electric vehicles. Our goal is a holistic energy system.”

Customers can charge their electric vehicles using stored solar power

A software-controlled battery-storage system enables the PV system in aktiv & irma to achieve self-consumption levels of more than 98 percent. As a nice side effect of this, customers can use free, self-generated PV electricity to charge their electric vehicles while shopping.

 “Around 135 MWh of our self-generated solar power have been consumed directly in the supermarket since the system was commissioned back in July 2018, saving around 65 tons of CO2,” explained Frank Reichenbach, head of market unit commercial at coneva, which developed the energy management system for the Oldenburg supermarket. “This is roughly equivalent to the annual emissions of a five-person household.”

Recycled heat reduces heating costs

The supermarket is heated almost completely autonomously through the surplus heat generated by the refrigerated counters. Since surplus heat is recycled, this helps reduce heating costs.

Benefits at a glance:

-Cost-savings thanks to less purchased power

-Self-consumption levels of self-generated PV electricity can be as high as 98 percent when accounting for production costs, which means additional savings of around 10 percent on electricity costs.

-Peak load shaving reduces the price per kilowatt of network charges by up to 35 percent

-Cross-sector energy management avoids expensive peak loads

-The energy-intensive refrigeration systems and charging infrastructure can also be used for shifting loads, potentially freeing up to an additional 20 kW for avoiding peak loads.

-The battery-storage system enables peak load shaving and dynamic load control, and reduces the costs for purchasing power.

Technical details of the energy system:

-ennexOS IoT energy management platform from SMA: Interconnects and controls all producers and consumers in the local energy system.

-Gateway via SMA Data Manger M: Records and transmits high-resolution data for further processing. This data is then used for monitoring and controlling the devices as part of dynamic load control.

-Store solar power and use it flexibly via Sunny Tripower Storage battery inverter and Tesvolt TS 70 HV: Offering 60 kW of power and a capacity of 67 kWh, the storage system in the test facility enables peak load, shaving off up to 35 kW.

-99 kWp PV system: Reduces the amount of electricity that must be purchased, saving around 10 percent in energy costs.

-Mennekes charging station for electric vehicles: Customers can use solar power to charge their electric vehicles. Energy from the battery-storage system and dynamic load control avoids peak loads.