At a Glance


Internet, Software, Hardware and Technology Services

Project Type

Industrial Energy Efficiency




San Jose, CA

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Annual kWh Savings:

1,700,000 kWh

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Annual CO2 Reductions:

400 metric tons


Working with HGST for the summer of 2015, EDF Climate Corps fellow Wendy Yu found energy-saving opportunities for cooling water, lighting, air handling and vacuum systems.


HGST is a global leader in data storage. Through its Real Estate and Site Operations organization, the company has actively pursued energy efficiency projects since 2008. These have included lighting retrofits and process adjustments, with the goal of reducing energy use by one percent each year.

In the summer of 2015, Wendy Yu was brought onto the team as an EDF Climate Corps fellow to augment and accelerate these efforts at the company’s manufacturing site in San Jose, California. Her task was to evaluate several energy-efficiency opportunities to determine which would be the most feasible for implementation.


After evaluating several opportunities around the Great Oaks Campus, Yu identified four projects that could provide HGST significant energy savings.

  1. For process cooling water systems, which regulate the temperature of tools used on the manufacturing line, she discovered that installing a free-cooling fluid cooler could reduce energy use. This type of cooler uses lower nighttime air temperatures to cool the water, which takes less energy.
  2. In terms of lighting, Yu showed that retrofitting lighting from T8s to LEDs in clean rooms, which are run 24/7, could save on both energy and labor costs. Not only do LEDs use less energy, but also they have a longer lifetime, which reduces the amount of time the maintenance crew spends replacing bulbs.
  3. Yu also found that some air handlers that feed air into the clean rooms were pushing in more air than required. A slight adjustment to fix this should reduce the amount of energy used.
  4. Lastly, Yu recommended a smarter vacuum system that could analyze the current vacuum system versus any alternative offline systems to determine if energy could be saved by moving to a smaller system.

Potential Impact

Annually, Yu’s projects have the potential of reducing annual electricity use by more than 1.7 million kilowatt hours.  This equates to a reduction of more than 400 metric tons of carbon dioxide emissions.

At the end of her fellowship, Yu presented her findings to the head of maintenance and operations, as well as specific stakeholders for each project. The implementation of these projects will very likely help HGST achieve its goal of reducing energy use by one percent each year.

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