Central Oregonian

Helping feed the grid

Facebook opted for solar array panels that move to gain maximum sun energy

RAMONA MCCALLISTER/CENTRAL OREGONIAN

Facebook is currently installing an array of photovoltaic solar panels on the front side of their property off of Tom McCall Road.

Ramona McCallister

April 15, 2011

Facebook has been on the cutting edge of technology since it began its data center in Prineville -- and yet again, the social network giant has jumped ahead of their counterparts in the data center industry.

Facebook recently announced that the Prineville Data Center is implementing the use of photovoltaic (solar) energy to power lights and other office functions. Photovoltaic (PV) systems utilize solar panels to directly convert the sun's energy into electricity. The conversion process occurs without moving parts, is silent, and is pollution-free.

The data center is currently completing installation of an array of the solar panels, most of which has been procured from Oregon-based companies. The system was installed by Sunlight Solar Energy, Inc. of Bend, and the solar panels were manufactured by SolarWorld in Hillsboro. The system is mounted on a dual-axis tracker, which allows the panels to track the path of the sun - and is manufactured by Bend-based PV Trackers. The system will produce an estimated 204,000 kilowatt hours per year.

"I think it's another testimonial to Facebook's efforts, to take advantage of solar technology and incorporate that into their LEED certification for the building and really speaks volumes in how committed they are to renewable energy alternatives," commented Steve Forrester, City of Prineville Manager.

Ken Patchett, Prineville Data Center Manager, said that Facebook chose to go with the PV solar array panels, even though they were more expensive than flat panels.

"These are tracking arrays, so they are pre-dispositioned to follow the sun's movement so we can get the most amount of usage out of them. Originally we were going with a flat panel that just sits there and takes the sun in, but when we started looking at it, we wanted to be able to produce at least a 100 KW all-day long.

Patchett said that they opted for the panels that would constantly move to get the maximum affect of the sun's energy at all times.

"This is a 100kw right now that we are not pulling off the grid," said Patchett. "We are creating this power. This is yet another step of doing lots of little things to try to become the most efficient stewards of electrons that we consume."

He gave the example of the LED system that they use for their lights, and their building and servers are built to be as efficient as possible, and the addition of the solar array is one more thing to make it count.

"We are back feeding our grid with that, where we are putting it in," added Patchett. "It fundamentally provides enough power for all of our office infrastructure space."

Tom Furlong, Director of Site Operations for Facebook, said that the project started as a result of an incentive program they came upon, that offered a credit for cents per kilowatt hour, and it looked attractive from a financial standpoint, as well as an opportunity to learn from the process.

"There are some really valuable lessons for us to learn about how we incorporate the on-site generation into our design and operations," commented Furlong. "Normally we are used to taking power from the utility to the building and distributing it to our servers. It is more complicated when you have other power from a different direction and having to connect it in."

Furlong said that there have been several learning curves on the solar array. "We are learning lessons around it, which is valuable. It will teach us some things about how we would want to incorporate this kind of thing going forward."

Furlong explained that the data center is built to handle an interruption of utility power. Should there be such an incident, the power from the solar array would work independently from the main energy source.

"There is a lot of complicated switching that occurs to start generators and to move the load from the utility source to the generator," explained Furlong. "We have multiple power meters on the site, and it is fed into a switchboard that is connected to one of those meters."

Patchett said that he hasn't seen other data centers that use photovoltaic energy physically on site.

"At the end of the day, by conserving energy, you have a lower bill. It's in your best interests to do what you can to conserve energy and do the right thing. But it does take effort. We chose to do that because we want to see how this looks, how this works, and how we may be able to integrate it into our building as we move along. I know from a Facebook perspective, we are putting in the due diligence up front and we're making this investment up front so we can look at it very objectively and determine how and where we could best use other sources of energy other than just power from a grid."

"We've had it in our road map that we want to try to do something here in this data center that we don't see everybody else doing. We are trying to think outside the box," added Patchett.