From Singapore to Seattle, more cities are investing in smart homes, neighbourhoods and workplaces. The rapid deployment of smart solutions and explosive growth in data centres to support them, however, could throw a spanner into the fight against climate change.
While data centres worldwide are estimated to account for just 0.3 percent of greenhouse gas emissions and one percent of electricity consumption, their environmental footprint may grow in tandem with the ongoing digital revolution if no action is taken to curb it.
In 2018, China’s data centres alone produced 99 million tonnes of carbon dioxide, equivalent to putting 21 million cars on roads, and this is slated to rise to 163 million tonnes by 2023, according to a study by Greenpeace and the North China Electric Power University.
To reap the benefits of smart systems and devices without compromising sustainability, more must be done to ensure data centres’ eco-friendliness. Here are seven ways that data centre firms and managers can maximise their efficiency and minimise their environmental impact.
Go hyperscale
Currently, most data centres have small capacities of about 5 to 10 megawatts, which will be increasingly insufficient for the needs for smart societies. Large hyperscale facilities, on the other hand, can not only meet those needs but achieve economies of scale.
As an example, data centres’ power usage efficiency (PUE) is calculated by dividing their total energy use by the energy used for computing. A PUE of 1.0 is thus ideal. Conventional data centres usually have a PUE of 2.0 while hyperscale ones have attained a PUE down to 1.2.
Furthermore, in 2016, the Lawrence Berkeley National Laboratory in the United States estimated that if 80% of the servers in the country’s small data centres were moved to hyperscale facilities, the sector’s energy use would fall by 25%.
Design for sustainability
Data centres’ design also play an important role in determining their electricity and water use. Some data centre operators have installed external shields on the top of their buildings to reduce the amount of direct sunlight hitting the buildings.
Others have incorporated louvres on their facilities’ facades for the same purpose. Both measures lower the ambient temperature within the data centres and decrease the need for artificial cooling.
Calculate components’ true cost
Most data centres are designed and built to last 25 years. While a cheap chiller may incur less upfront cost, it may cost more to run and need to be replaced after a few years, and thus multiple times over the data centre’s intended lifespan, causing more waste and financial pain in the long run.
Analyses of equipment’s true cost must also consider their production and disposal costs. While lead acid batteries may be less expensive than lithium-ion ones, they are more toxic and require special treatment at the end of their use to be disposed of properly.
By developing a scoring matrix for each piece of equipment that includes its financial and environmental costs in the long term, data centre firms and operators can more easily identify those that are the most cost-effective and least carbon intensive.
Source cleaner power
As data centres continue to proliferate, powering them with cleaner and renewable energy will also be essential to boosting and maintaining their sustainability. This will require siting them in areas with such electricity sources.
A data centre that runs on natural gas produces 2.3 units of carbon per kilowatt hour, while a more conventional facility emits 4 units of carbon per kilowatt hour. Centres that use renewable energy such as geothermal or hydro power are better still for the environment.
Generating power on-site
Despite equipment and administrative costs, generating power on-site can yield substantial performance improvements, including by raising supply reliability and reducing harmonics. The latter are current and voltage distortions that lead to higher temperatures and increase the need for cooling.
By producing their own power on-site, data centres can also minimise the transmission and distribution of electricity. These processes usually involve voltage transformations that result in efficiency losses over long distances.
Recycle waste heat
Generating power on-site can unlock other benefits too. Gas engines produce heat that can be tapped for cooling. This waste heat comes from the engines’ exhaust as well as the jacket water that circulates around them to keep them cool.
Feeding the waste heat into absorption chillers is a more sustainable way of creating chilled water to cool the data centre. Some firms and operators have also inked partnerships to use their data centres’ waste heat to heat nearby homes and office buildings.
Innovate for the environment
As technologies advance and mature, some will be useful in shrinking data centre emissions by improving overall efficiencies. One example is thermal wall technology, which is used to cool data centres.
Thermal walls house large coils on the data hall perimeter and pass air horizontally across the data hall, providing a wider surface area compared to conventional cooling systems.
This approach reduces the surface tension of the air passing the coil and therefore reducing the energy required to cool the air. Thermal walls also use less space within the facility to provide the same amount of cooling as conventional systems.
Artificial intelligence software can also enable predictive maintenance. Long before a piece of equipment may fail, it often operates inefficiently and wastes energy. By using sensors to constantly measure equipment performance, artificial intelligence tools can predict and alert operators to avoid such inefficiencies or even outages.
Such digitalisation and artificial intelligence will be indispensable as data centres continue to grow. In the past, when data centres were smaller, engineers could individually check the status of each piece of equipment, but this is already impractical in today’s larger facilities.
As smart technologies become a common feature of everyday life, sustainable data centres will be vital in curtailing the sector’s environmental burden. In the data centre industry as in many others, the future is, and must be, green.
