Fuel Cells are not new, so are they ready for prime time?
Last year eBay made headlines when it announced what gigaom.com called a “first-of-its-kind fuel cell-powered data center.” (Link to Source) According to the article the Utah data center is “primarily powered by thirty fuel cells - devices that turn natural gas into electricity through a chemical reaction.” At first look one might ask, “Why is that a first-of-its-kind since all natural gas powered electricity generating power plants use the chemical reaction of combining methane with oxygen, a chemical reaction, that then is used to produce electricity?”, and they would be indignantly correct. The thing that is missing from the gigaom.com description is the word “directly”, so that the correct phrasing would sound something like, “primarily powered by thirty fuel cells - devices that turn natural gas directly into electricity through a chemical reaction.” Think of a battery, a fuel cell turns natural gas into electricity by a chemical reaction within the fuel cell and does not need an external device, similar to how a battery works. The difference is that unlike the battery, theoretically the fuel cell could operate forever, or at least until something within its structure fails to perform properly.
The article continues noting an eBay spokesperson who describes the fuel cells as designed to supply the entire power needs of the data center; the site is linked to the local grid only for back up power. The spokesperson continued, “this architecture is not only an environmental step, but makes the data center more reliable and immune to grid blackouts.” A Forbes piece described the fuel cells as providing 6 of the 8 megawatts of power needed to run and cool the facility. The 6 megawatts are provided by five banks of Bloom Energy Servers, 30 units in total. One reason eBay is using fuel cell technology is to help meet its green energy initiatives. Bloom Energy and eBay note the fuel cells will use almost 50% less natural gas to produce electricity when compared to traditional gas fired power plants.
eBay’s Utah data center employs 30 Bloom Energy Servers that convert natural gas directly into electricity through the use of fuel cell technology
Fuel cells are not new. The earliest experiments date back to 1838, the devices used metal plates and an acidic solution, looked and operated much like the lead-acid batteries used in today’s standard automobiles.
Left: First fuel cells converted dissolved oxygen and hydrogen to electricity ( Link to Source), Right: Prototype Samsung methanol fuel cells (Link to Source) can deliver 1800 watt-hours of electricity, about as much as a small gasoline powered generator, and be recharged with methanol and water.
The Bloom Energy Server is not a “server” in the IT sense but rather describes a collection of thousands of 25 watt solid oxide fuels cells that use natural gas (methane) as a fuel. Fuel cells are sandwiched together to form stacks. Stacks about the size of an average loaf of bread is able to power the average size home. Multiple stacks are aggregated into a power module, multiple power modules are aggregated to make up the units used at eBay’s Utah data center. (Link to Bloom Energy) Other data center operators such as Apple and NTT America have also deployed the devices in some of their data centers.
Left: UC Irvine researchers (Link to Source) and Right: University of Maryland fuel cell data center projects in cooperation with Micosoft (Link to Source)
Not to be left behind, Microsoft has embarked on a fuel cell equipped server rack wherein the fuel cell is placed in the bottom of the rack and sized to provide all the power needed by the IT equipment in the rack. Rather than bringing electrical cables to the racks, natural gas lines are installed. Advantages enumerated by the joint Microsoft/UC Irvine researchers include lower capital costs for a new build and greater efficiency since the fuel cells DC output can be used directly without conversion. The researchers claim that the efficiency of the rack mounted fuel cells improves the net energy efficiency from 40% to more than 53% when compared to a centralized fuel cell installation located outside the computer room. (Link to Source) Similarly, Microsoft’s fuel cell project with the University of Maryland explores alternate approaches to data center power.
One needs to ask why is this a green technology when the efficiency of a modern combined cycle gas fired electrical generating plant is approaching 60%. (Link to Source) Transmission losses in the USA average 6%, leaving a net efficiency over 50%. The Microsoft project researchers point out one other potentially compelling reason, because each rack has its own power plant the data center is less susceptible to power outages from the grid and less susceptible to overall data center power loss. In the world of ever increasing uptime pressure this would seem to be an interesting development.
The real issue is real Return on Investment (RoI). Today’s fuel cells are not cheap. Since the installations noted above and university experiments are not rich with cost data the jury is still out as to the potential payback. In fact some question efficiency claims by commercial fuel cell providers and some have data to dispute marketing claims. Contaminated fuel cells can also generate toxic wastes during combustion of natural gas. (Link to Source) We will need to wait for the data to be released, and more than just cost data. All costs including toxic waste disposal, tax breaks, special incentives and other perks will need to be revealed to make the case that fuel cells are cost-effective alternatives. For now maybe claims about green energy and reliability will provide the marketing lift data center operators can use to entice customers their way.