01 February 2019
Big data is way hotter than you think
Source: By Ulka Kelkar: Mint
We are very careful about switching off lights when we leave a room. But did you know that just one simple internet search is like leaving a light bulb on for 17 seconds? This is not because of the electricity used by your phone or laptop or modem but because every query is sent to a data centre physically located somewhere in the world, processed, and sent back to your device.
The same thing happens with your email, social media posts, shared work files and streamed videos. And, did you know that there are about 5 billion internet searches and 140 million hours of streamed video every day? It takes huge server farms—some larger than 1 million sq. ft—to process and store all this data. Just like your laptop gets warm, these huge data centres generate vast amounts of heat and have to be cooled with air conditioning or running water. Running and cooling of these data centres and data networks takes 2% of all the world’s electricity and emits as much carbon as the entire airline industry. Big internet companies are taking several measures to reduce the carbon footprint of their data centres.
Location, location, location: many companies are locating their data centres in Scandinavian countries so that they can use the icy Arctic air and water for cooling. Microsoft has put a small data centre into the sea near Scotland, which will release its excess heat into the surrounding sea water. But if this becomes a common practice, the heat from large server farms could adversely affect marine life.
Circular economy: The waste heat from data centres is used to heat homes in Finland, a swimming pool in Switzerland, and a greenhouse in Paris. But so far, waste heat can only be piped over short distances and used nearby.
Going green: IT companies buy renewable energy to compensate for their use of fossil fuel electricity from the grids where they operate. But this does not mean that they have stopped using electricity produced from coal, oil and gas. Worldwide, only 24% of electricity is generated by solar, wind and hydropower.
Debugging inefficiencies: IT companies are using Artificial Intelligence to detect inefficiencies in their systems and to match as closely as possible the varying availability of solar and wind power as weather conditions change during the day and over the seasons.
The cooling energy overhead of a data centre is measured by a number called power usage effectiveness (PUE)—the ratio of the total energy used by the data centre (for data processing, cooling, lighting, and maintaining equipment) divided by the total energy used by the data centre only for data processing. Conventional data centres have a PUE of 2, i.e., they use as much energy for cooling, lighting and maintaining equipment, as they do for data processing alone. State-of-the-art data centres have managed to minimize their energy overhead and achieve a PUE of close to 1.
But even with a perfect PUE of 1, the total energy used by data centres might continue to increase to meet our growing digital needs. As with any form of consumption, making supply more efficient does not reduce total consumption if demand is also not moderated.
How will our data needs change in the next 10 or 20 years? As mobile phones become powerful, will more data processing be done locally than in distant data centres? Will the use of blockchain, with data distributed across computers, increases or decreases the need for large server farms? Will the Internet of Things in our homes, cars and cities increase the need for cloud computing? Here are a few policies that can help moderate the overall growth of fossil fuel energy use and greenhouse gas emissions from data centres in India.
First, measuring and publicly reporting carbon dioxide emissions from energy use should be made mandatory for all data centres located in India.
Second, state governments can make site clearance for a new data centre contingent on the company meeting part of its electricity use by generating solar power through rooftop panels or by purchasing renewable energy. The site clearance can also be made conditional on the company offsetting its use of thermal power by planting native species of trees that can absorb the equivalent of the data centre’s greenhouse gas emissions. Siting within special economic zones (SEZs) can be encouraged so that the waste heat from data centres can potentially be used by other industrial units nearby.
Third, the Perform Achieve Trade scheme of the central government, which aims to make large industries energy efficient, can be extended to the IT industry. This would allow more efficient data centres to sell energy saving certificates to less efficient energy users.
And finally, over the long term, consider putting a tax on carbon so that renewable energy becomes relatively more attractive than thermal power for the industry.
We place a lot of hope in data and digital technologies to simplify every problem—including climate change. We also see data as non-material and environmentally benign. But every email or video is carried through physical hardware and processed in physical buildings. As long as the energy to manufacture our devices and to run data centre servers comes mainly from fossil fuels, data will be hotter than you think.