A typical mission-critical data centre predominately relies on centralised, distributed power, transmitted over a grid, with onsite generators as its backup in case of a power outage.
Depending where the data centre is located, the source of power for the grid is most likely generated by means of burning fossil fuels such as black or brown coal, natural gas and oil.
Only a small portion of centralised, distributed power is sourced from hydroelectricity, which is considered a renewable means of power generation.
This current regime of power generation has four main issues:
- power losses in the distribution system
- greenhouse gas emission due to burning fossil fuels (coal being the least environmentally friendly)
- finite quantities of fossil fuels available to industry
- the environmental impact of mining fossil fuels.
As I mentioned in my article The IoT, what it can do and its worrisome side, the number of devices connected to the internet is exponentially increasing and, as a result, so is the demand for more servers and IT equipment.
Invariably, this equipment ends up in data centres, meaning higher power demand in this space.
And, bearing in mind the current power generation issues mentioned above, planning to power data centres from renewable energy sources seems to be the most prudent approach to secure the future.
What’s realistically achievable considering renewable energy limitations?
Businesses have been reluctant to invest in the renewable energy sector.
Mainstream technologies such as solar energy, wind power and biomass are the main sources of power generation for large-scale power demand.
However, each of these technologies has its own limitation.
With solar energy, power can be generated only during daylight hours when solar radiation is available.
Whereas with wind power, regardless of time of a day, power can be generated as long as there is sufficient wind available to run wind turbines. The wind factor can vary substantially between different seasons, so it’s seasonally dependant.
When it comes to biomass, there’s no timeframe constraint, which is its biggest advantage over the other types of renewable energy.
Although there have been significant improvements and advances in efficiency in biomass technology, the ability to convert ample biomass into biofuel to generate power, without disturbing the food supply chain and the environment, is still uncertain for large-scale applications such as data centres.
Having said that, using hydrogen as the main biofuel in fuel cells has proven that food supply chain issues can be avoided, as hydrogen can be produced from water.
The cost of using fuel cells with hydrogen has been significantly high and not financially viable. But with advances in this technology, it’s now feasible to produce and use hydrogen commercially.
Knowing the limitations with renewable energy, how can the data centre industry take advantage of the abundant sources of solar energy, wind energy and biofuel?
In the last decade, a new concept has become popular which takes advantage of combining two or all three of these renewable energies.
This concept is known as hybrid renewable energy system (HRES).
The application of HRES is for both standalone and grid-connected sites.
Some examples of power systems and data centres currently using HRES are:
- a standalone hybrid power system for the Kahnouj area in the southeast of Iran
- the GreenStar Network for data centres
- 100% renewable energy powering Apple data centres, including a facility in Reno, Nevada
Renewable energy is the answer to addressing the ongoing power demand of data centres
Google, Apple, Microsoft, Facebook, ebay and some other big players have already built or planned to build data centres primarily powered by renewable energy and using HRES.
It’s anticipated that more data centres across the globe will adopt the HRES approach and rely less on conventional power generation methods which burn fossil fuels.