Between 2010 and 2018, the number of compute instances in the world increased by 550%. The global energy consumption of data centres also increased—but only by 6%. This means that data centres managed to deliver an annual decrease in their energy intensity of 20%, a huge achievement.
This achievement was delivered through technological advances and innovations in both the IT itself (the servers and hardware used in data centres) and improved data centre infrastructure. For example, one of the most obvious changes to make is to reduce the reliance on air conditioning. Instead, 80% of new projects now use outside air cooling, also known as free cooling.
To enable all data centres to become as good as the best, France Datacenter, the trade association for French data centres, has gathered together and published a selection of best practice. Here are the highlights.
Committed participants
France Datacenter notes that one of the most important aspects of reducing environmental impact is the commitment of data centre operators. This cannot be treated as a ‘box-ticking’ exercise. Data centre operators have demonstrated their commitment by taking responsibility for measuring their own environmental impact, for example, through models like those provided by DATA4. They have also implemented ISO standard frameworks and other European standards frameworks, to ensure that their data centres follow best practice.
Many have also embraced elements of the circular economy and biodiversity. For example, CIV repurposes its servers at the end of their lives, using them as computers to provide heating to other buildings. Schneider has started to recycle its product components much more extensively. The final element in this section is training staff on best practice in energy conservation, to increase awareness and commitment.
Improvements to data centre design
There are many ways in which data centre design has contributed to improve energy efficiency. These include:
- Innovative cooling systems, including one company that draws water from an underground canal, which is therefore cool all year round, even during summer. The water is then allowed to cool to reduce the impact of returning it to the sea.
- Some companies now harvest the heat generated by their data centres, and use it to heat offices and homes. One site in Paris, run by Dalkia, uses the heat generated during the cooling process to heat the local business park.
- Separate hot and cold aisles in the data centre, with physical partitioning to improve efficiency.
Better operational practices
Similarly, better operational practices can also contribute to improved environmental performance. Small changes can have a much bigger impact. Options include increasing airflow temperatures, and maintaining constant air pressure to stop any hot spots developing. Energy audits can also help to highlight areas for improvement.
Some data centre operators are also starting to use artificial intelligence to control their ventilation. AI-powered systems use sensors to measure temperature in server rooms, and then use models to predict how best to optimise the performance of ventilation systems. This can eliminate over 90% of the hot spots in a server room, hugely increasing efficiency.
Several operators have invested in renewable energy, often consuming the energy directly. One operator, for example, has installed a solar farm that generates enough energy to provide for 3% of the site’s needs. This may not seem much, but the company plans to expand its generation capacity—and over 10% of its employees have also decided to install solar panels as a result of the scheme.
Using energy efficient equipment
The final area for improving energy efficiency is the equipment used in data centres. Many of these solutions are relatively simple—but have a disproportionately large impact on energy use. For example, there have been a number of changes to IT hardware over time, making newer hardware much more efficient. Similarly, replacing older chillers with newer, more efficient designs can make a big difference to energy consumption. One operator found that it could improve its energy efficiency by three times by using an air cooling system.
Another option includes evaporative cooling, by spraying water droplets outside to evaporate, which cools the air. This air can then be used for cooling purposes. Using speed variators on pumps can reduce energy consumption so much that data centre operators will achieve a full return on their investment in less than 2 years. Similarly, the use of a flywheel can help to reduce the demand for energy to create uninterruptible power supplies.