The Bloom Box fuel cell device has been the subject of plenty of controversy since its unofficial unveiling in a 60 Minutes segment earlier this week. The device, which has already been installed on the campuses of major companies like eBay, Google, Staples, and FedEx, converts natural gas into electricity. But how efficient is it? Is the box worth the money? Amy Skoczlas Cole, the Director of eBay’s Green Team, spoke with us briefly about eBay’s installation of five Bloom Boxes.

According to Cole, the boxes take up 3,000 square feet of space and produce 500 kilowatts of power–enough to take 15% of the San Jose, California, campus’s energy use off the grid. At the moment, eBay is running its Bloom Boxes off natural gas, but the company plans to switch to biogas sometime in the near future. “We’re in the stages of finalizing the contract to turn on biogas,” Cole explained. Once the system switches to biogas, the Bloom Box energy process will have net zero production of CO2.

EBay’s Bloom Boxes complement the 3,246 solar panels on the roof of the company’s LEED Gold-certified headquarters. But the Bloom Boxes are ultimately more efficient. “The solar panels takes 55,000 square feet and at their peak performance takes 18% of our electricity use off the grid, but that’s not at night or on days when we have rain,” Cole said. “Running the two side by side over the course of a year, we will get 5 times as much energy from the Bloom system.”

Bloom Boxes don’t come cheap–companies pay $700,000 to $800,000 a pop–but Cole estimates that eBay’s system will pay for itself within three years. Since the system started running seven months ago, eBay has already saved $100,000 in electricity costs compared to power from the grid. And so far, the company hasn’t had any big issues with the system. “Maintenance teams have had to come out to replace wafers in the system before, but that

was part of standard maintenance. The way the system is built there

are hundreds if not thousands of the wafers in each system, so it didn’t cause us any particular issues,” Cole said. eBay’s maintenance contract lasts 10 years, which says something about how long Bloom expects its boxes to run.

Over the past 7 months, eBay has managed to keep its system under wraps–even to employees. “The boxes sat behind a fence for a long time while they were being installed,” Cole explained. “But we gave our employees a heads up about the 60 Minutes piece.” Eventually, eBay might add even more Bloom Boxes to its main campus. “We’re actively in discussion about what more we can do together,” Cole said. “It’s a terrific new technology that we’re really excited to be early adopters of.”

[Bloom Energy]