US pharmacy chain says combination of energy measures have enabled Illinois store to generate more energy than it takes from the grid
US pharmacy chain Walgreens says it is on track to do better than its initial plan to take zero energy from the grid for its store in Evanston, Illinois, following installation of a ground source heat pump system from specialist GI Energy, in tandem with a transcritical CO2 system.
Jamie Meyers, sustainability manager with Walgreens and the team lead behind the Walgreens net zero store project with GI Energy said: “Over the course of this year, we are on track to realise zero cumulative energy from the grid—in fact, we hope to be net positive, to have a credit from the utility company at the end of the year.”
Walgreens, the nation’s largest pharmacy chain with more than 8,000 locations, said the installation was the result of a project to find scalable cleantech technologies for its estate. It was claimed to be the first zero net energy retail store in the US when it started operating in December.
The Walgreens and GI team presented their findings at the recent Atmosphere Americas natural refrigeration conference.
Walgreens and GI Energy point to three key findings with the geothermal system:
1. better financial performance per location thanks to reduced energy and maintenance costs and reduced refrigeration downtime;
2. preparation for the eventual phase-out of synthetic refrigerants by successfully integrating with CO2; and
3. better visibility as a sustainable brand.
Rob Olden, Director of Engineering, North America, for GI Energy said: “We are using the earth’s stable 54 degree F (12 deg C) temperature to heat and cool the store. The CO2 heat pump pulls the heat out of the freezers and coolers, and we put it right back in the space to heat the building when it needs to be heated, or we put it in the ground, to store it and then use it in the winter time.”
A combination of the 170 m boreholes, two wind turbines, and 850 solar PV panels have enabled the store to generate around 220,000 kWh against a demand of around 200,000 kWh.