DCN October 2017 - Page 23

Green IT applying a GREEN strategy: Grid services, Renewable inputs, Energy efficiency, Environmentally friendly materials, Net zero energy solutions. First, data centres typically have capacities that are potentially valuable to the electrical grid. They have local generation capacity that automatically helps in stabilising the grid, as on-site production reduces the load on the grid if there is an unbalance. Taking this possibility one step further, the distributed excess capacity could further mitigate the problem by feeding the grid with electricity input. Moreover, batteries installed in UPS systems can serve as an energy storage which is a valuable complement to intermittent renewable power generation based on hydro, wind and solar energy. Second, purchasing renewable electricity makes a significant difference to the carbon footprint of computing. As large consumers of electricity, data centres have an impact on the supply of renewable electricity either by purchasing power from plants that would otherwise not have been built, or by purchasing power in markets where renewable power supply will expand as a market response thanks to supporting incentives and regulations. Third, the ongoing structural change that is caused by the growth of IT-as-a-Service has significant implications for efficiency. Virtualisation and cloud services have reduced the number of dormant servers and increased utilisation many times. As a result, the same services can be provided with less energy and less inputs. Fourth, inputs to data centres include not only electricity but also machinery and construction materials. Designing and building data centres that use space efficiently make one contribution to green computing. Avoiding concrete and choosing recyclable materials and climate-friendly refrigerants make another. Fifth, net zero is feasible. This is rather trivial from the perspective of physics as very little mechanical work is done by ICT-equipment. Instead, essentially all electricity is transformed to heat. By harvesting and recycling - rather than rejecting - the heat, a data centre can close-the-loop and preserve energy, thus reaching a net zero energy outcome. Motives and means Business objectives depend on circumstances. In Northern Europe, sustainable solutions tend to be commercially and financially motivated. Green computing October 2017 | 23