Ongoing data centre upgrade projects contributed to a decrease of 1% in energy consumption at our data centres in 2015 despite increasing online delivery of our products and services. Total energy consumption decreased by 7% against 2014, due in part to improved energy efficiency at our offices. In the year, 83% of the electricity assigned to our data centres was classed as renewable energy.
In 2015, we purchased 50% of our electricity from renewable energy and renewable energy certificates (RECs) compared with 46% in 2014. We aim to increase this to 60% in 2016, and to purchase renewable electricity equivalent to 100% of our global electricity consumption by 2020. As we are predominantly in leased locations with few opportunities for onsite generation, we rely on green tariffs and RECs, while investigating options for renewable energy supply. In 2015, the Group was listed as a Leader by the US Environmental Protection Agency’s Green Power Partnership, and was one of the first organisations to join the RE100 campaign promoting corporate purchase of renewable energy.
In 2015, 70% of our revenue came from online products and services. This was mirrored in energy use at our data centres, now responsible for 46% of total energy usage (offices account for 49% and warehouses 5%). Data centre efficiency therefore remains of critical importance. Following a data centre energy study in 2011, we have taken measures to improve efficiency, including space redesign and upgrades to air handling and cooling systems and hardware.