More than two thirds of our energy consumption occurs at the points of sale. The leverage effect for greater energy efficiency is particularly high here. Thanks to technical innovations, our points of sale are becoming increasingly resource-friendly and efficient.
Since 2007, we have been realising all new and renovated sales outlets in accordance with the Minergie standard. As a result, they consume around 20 per cent less electricity and 40 per cent less heat. For buildings that we do not own ourselves, we apply Minergie standards for the building services. In total, we operate over 414 sales outlets in accordance with the Minergie standard.
We equip our supermarkets with LED lighting for all new builds and refurbishments, as this technology requires up to 50 per cent less electricity. We have been lighting our restaurants exclusively with LEDs since 2010, and our supermarkets have also been 100 per cent LED since 2015. Our logos are also 100 per cent lit with LEDs, which saves us around 2 gigawatt hours of electricity every year. They are switched off at night to save electricity and minimise light pollution.
The refrigeration and freezing of our products account for almost half of the total electricity consumption of our sales outlets. Conventional refrigerants still have a major impact on the climate. This is why we have been using CO2as a refrigerant in permanently installed systems at points of sale since 2010. These modern CO2systems require a quarter less electricity and their impact on the climate is up to 4,000 times smaller than that of conventional refrigerants. We also utilise the waste heat generated by the cooling systems to heat and preheat hot water. This allows us to reduce our energy consumption even further.
We are increasingly focussing on energy production using renewable energy sources. For example, by installing a modern wood chip system with flue gas cleaning: We use one of these for the supermarket and restaurant in the Muripark shopping centre in Muri. Compared to using conventional oil heating systems, this saves us 90 tonnes of CO2e per year.
In addition, we have installed over 100 photovoltaic systems with a total output of over 30,000 kilowatts on our properties. These systems produce around 27 million kilowatt hours of solar power every year, which covers the average annual electricity requirements of up to 8,000 Swiss households. Most of this environmentally friendly electricity has been consumed in our sales outlets since 2016.