The artificial intelligence race and the growing demand for services, processes and applications based on it have led in recent years to the accelerated construction of data centers around the world. Much has already been said about the enormous amounts of energy required to operate them, alongside the significant water consumption needed for cooling and the environmental, economic and health consequences of the industry.
At the center of attention are greenhouse gas emissions associated with generating the electricity needed to power data centers, particularly in countries that rely on fossil fuels — emissions that in turn contribute to worsening the climate crisis. At the same time, concerns are growing over potential harm to local electricity supplies and rising electricity prices.
When planning and operating data centers, it is necessary to consider not only their carbon footprint but also their thermal footprint
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While the Israeli government recently approved a decision that would allow for the accelerated construction of data centers in Israel, the Electricity Authority has just issued a temporary order freezing the review and approval process for connecting new data centers, including those whose applications have already been submitted, and halting the issuance of new approvals. This is due to concerns about the impact on “the stability of the electricity sector, the reliability of supply to consumers and economy-wide costs.”
Alongside the broad national and global impacts, operating data centers, even those powered by renewable energy and producing almost no carbon emissions, has a significant and often hidden impact in the form of heat released into the local environment, a phenomenon known as thermal pollution. A recently published study found that data centers, particularly large ones, are causing a new and significant phenomenon: the creation of new local climate zones, namely heat islands.
These heat islands can lead to increases of 2 degrees Celsius or more in ground temperatures and affect air temperatures several kilometers away. This directly impacts the natural environment in the area, as well as nearby communities, due to increased heat stress and reduced thermal comfort in public spaces. These effects in turn influence public health, the use of urban infrastructure and electricity consumption for cooling, while also intensifying the urban heat island effect.
This means that when planning and operating data centers, it is necessary to consider not only their carbon footprint but also their thermal footprint. Therefore, building data centers near communities requires examining their location and size based on local wind patterns and creating appropriate buffer zones. At the same time, more efficient cooling systems should be implemented, from natural cooling through placing facilities underground, to liquid cooling instead of air and water-based cooling, and the use of advanced evaporative systems. In addition, the use of emitted heat should be considered already at the planning stage, meaning that waste heat should be recycled for use in nearby systems to heat water, buildings and industrial facilities.
Prof. Adi Wolfson Photo: Dudu GrynszpanThermal pollution, caused by the release of excess heat energy into the environment from human activities, is a known yet still hidden and overlooked phenomenon, despite its impact on ecosystems, human health and ways of life. For example, power plants and industrial processes that draw water to cool turbines and return it warm to bodies of water alter conditions and life within those water systems. Likewise, heat emitted from transportation, air conditioners and buildings creates the “urban heat island” phenomenon, which causes local increases in temperatures and heat stress, rising illness rates and pressure on infrastructure and buildings. Heat emissions from data centers similarly affect nearby natural and urban environments.
According to recently published data, connection requests for data centers in Israel have reached a cumulative capacity of about 27,000 megawatts, equivalent to the release of about 27,000 megawatts of heat. Although not all of these requests will be approved and not all facilities will be built, the heat emitted from a 100-megawatt data center is equivalent to the heat released by about 67,000 two-horsepower air conditioners operating simultaneously day and night, or by about 3,000 gasoline-powered cars running nonstop 24/7. Heat emissions from data centers raise ground and air temperatures depending on the intensity of emissions, local winds and the area's topography. They are even more dominant at night, when heat emissions from buildings and vehicles decrease, and therefore they may slow the rate at which the surrounding environment cools.
A heated debate is currently taking place over the need to establish data centers in Israel, particularly regarding the formulation of policy in the field and preparations by the electricity sector for future needs. Therefore, alongside other cost-benefit considerations for the economy and society, the impact of thermal pollution and the heat island effect created by data centers must also be taken into account during planning stages and environmental impact assessments. Advanced solutions to reduce these effects at their source must be integrated.
Prof. Adi Wolfson is head of the master’s program in green engineering at Shamoon College of Engineering