Are data centers really bad for the planet?

Data centers are increasingly becoming a significant contributor to global energy consumption. These facilities, which house servers, routers, and other internet-connected devices, operate continuously around the clock, leading to high electricity demand. In Frankfurt, Germany, data centers consume around 41% of the city's electricity, while in Dublin, this figure is even higher at double the city's average.

The International Energy Agency predicts that this electricity consumption will double by 2030, reaching approximately 945 terawatt-hours, which is comparable to Japan's annual consumption.

The energy source for these data centers often comes from fossil fuels, which emit substantial amounts of greenhouse gases. In the United States, more than half of data centers are powered by fossil fuels, resulting in over 105 million tons of CO2 emissions annually. This high level of carbon emissions is so significant that it would require over 31,000 wind turbines running continuously for a year to offset the impact.

Moreover, old coal plants are being kept operational to meet the increasing demand, which has contributed to the emission of nearly 65 million tons of greenhouse gases in the US alone in 2023. Furthermore, new gas-fired power plants are being constructed, adding 100 GW of additional capacity to the country's energy grid, leading to even more carbon emissions.

Water is another critical resource consumed by data centers. These facilities require significant amounts of water to maintain optimal operating temperatures. A large facility may consume up to 5 million gallons of water daily, equivalent to the water usage of a town of 10,000 to 50,000 people. Typically, 80% of the water used for cooling purposes evaporates, leaving wastewater that can overwhelm local treatment systems.

In northern Virginia, the data center cluster in the "world's data center capital" uses nearly 2 billion gallons of water annually. To mitigate these environmental impacts, more efficient cooling methods, such as immersion cooling or closed-loop systems, have been developed, which can reduce freshwater consumption by up to 70%.

Data centers also contribute to urban heat islands, exacerbating higher temperatures in cities compared to rural areas. For instance, a single large data center in Phoenix, Arizona, can emit heat equivalent to that of tens or hundreds of thousands of households, raising land surface temperatures by up to 9°C (16°F) and air temperatures by up to 2°C (3.6°F) in nearby areas.

This excess heat can increase heat stress risks for residents and drive up air conditioning demand, further increasing energy consumption. However, some data centers are employing thermal energy networks to capture and reuse waste heat, reducing power demand by up to 30%.

Beyond their operational impacts, data centers also necessitate significant land use. The construction of these facilities often involves repurposing natural and agricultural lands, which can threaten local biodiversity and disrupt ecosystems. In Hattersheim, Germany, a 18-acre (7-hectare) parcel designated for agriculture and groundwater protection has been converted into an industrial zone for data centers.