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198 • Green Project Management

Hot water from the data center is brought to the
top of the cooling tower and released onto a
material inside the tower designed to improve the
evaporation performance.
As the water flows down the tower, some of the
water evaporates. The evaporation draws energy
out of the remaining water causing it to cool down.
Air is drawn through the tower by the fan on the top.
The air enters relatively dry and exits at the top
carrying away the humidity from the evaporation.

The cooled-down water is collected at the base of the
tower and returned to the data center.

Figure 11.3
Representation of cooling tower (courtesy of Google).
The fourth effort for Google is sustainability around their disposal of
electronics (see Figure 11.4). Their goal is that 100% of their servers are
either reused or recycled. As we have stated before, there is a huge problem
in this country, and spilling over to other countries, with the disposal of
electronic equipment. With Google’s efforts along with their fifth step in

Electronic Waste Disposal

Google

U.S. Average

0 20 40 60 80 100
Equipment Percentage
Reuse and recycle Landfill, incineration, or storage

Figure 11.4
Electronic waste disposal (courtesy of Google).