Bloom Energy and fuel cells
by Ray Block
I have never been as excited in alternative energy technologies, such as wind and solar, as I am about fuel cells, now powering hydrogen fuelled vehicles. My interest here is in small stationary fuel cells, a segment of the market, which is starting to take off in a big way, although total revenue numbers are still small (under US$ 1 billion).
As a reference source puts it modestly: “fuel cells are the perfect melding of benefits from energy sources.” They combine the benefits of easy refuelling and continuous operation potential of internal combustion engines, and the efficient and quiet operation of batteries. So they are the ideal energy alternative.
They don’t require recharging as batteries do, and they are pollution free, unlike batteries and combustion engines. However, they do require refuelling, although this can be as simple as using low cost biogas.
“Fuel cells work via an electrochemical reaction that converts the chemical energy stored in a fuel directly into electricity. There are five types of fuel cells, which utilise different electrochemical reactions, but the general process is always the same. Fuel is oxidised at the anode, electrons flow through an external circuit to do electrical work, and then fuel is reduced at the cathode.”
The different fuel cell technologies are PEM (polymer electrolyte membrane); PA (phosphoric acid); SO (solid oxide); AFC (alkaline); (MC) molten carbonate; DM (direct methanol)
Fuel cells first came to light back in 1838, when “William Robert Grove arranged two platinum electrodes with one end of each immersed in a container of sulphuric acid and the other ends separately sealed in containers of oxygen and hydrogen, a constant current would flow between the electrodes.”
Fast forward to the late 1930s, when Frederick Thomas Bacon began researching alkali electrolyte fuel cells. During the second world war, Bacon worked on developing a fuel cell that could be used in Royal Navy submarines. In 1958, he demonstrated an alkali cell using a stack of 10 inch diameter electrodes for UK’s National Research Development Corp. Bacon’s fuel cells proved reliable and attracted the interest of Pratt & Whitney. The US company licensed Bacon’s research work for the Apollo spacecraft fuel cells.
United Technologies Corp is the parent company of Pratt & Whitney, and today UTC Power is a world leader in fuel cells using the phosphoric acid technology.
UTC Power’s latest 400kW fuel cell system is to be installed in Whole Foods Market 50,000 sq ft store, currently under construction in South San Jose CA). This will be the third Whole Foods fuel cell supermarket installation. “The UTC Power fuel cell system will generate 90 per cent of the store’s electricity needs and its thermal energy waste heat will be used for store heating, cooling and refrigeration for an overall efficiency of approximately 60 per cent, nearly twice the efficiency of the US electricity grid.”
The market research firm Fuel Cells Today says that to date more than 80 per cent of the small stationary market is held by companies producing polymer electrolyte membrane fuel cells (PEMFC).
As to the new sensation of Bloom Energy, with the technology of solid oxide fuel cells, which Science Daily (May 29, 2009) says has great potential for stationary and mobile applications. Stationary uses ranges from residential applications to power plants. Mobile applications include power for ships at sea and in space, as well as for autos. In addition to electricity, when SOFCs are operated in reverse mode as solid oxide electrolyzer cells, pure hydrogen can be generated by splitting water.
“The flaw in solid oxide fuel cells, which has delayed commercial production is in the integrity of the seals within and between power producing units. Composed of ceramic materials that can operate at temperatures as high as 1,000C (1,800 degrees F). SOFCs use high temperatures to separate oxygen ions from air. The ions pass through a crystal lattice and oxidize a fuel. The chemical reaction produces electrons, which flow through an external circuit creating electricity.”
“To produce enough energy for a particular application, SOFC modules are stacked together. Each module’s compartments must be sealed, and there must be seals between the modules in a stack, so that air and fuel do not leak or mix.”
Bloom Energy, unlike other fuel cell systems makes a distributed energy system replacing the electricity grid, with its solid oxide fuel cells. The unveiling of Bloom attracted around 900 articles in February 2009 in “unprecedented publicity” across major TV, newspaper and internet blogs. According to Google News, Bloom attracted one of the highest ever hit rates for a single product launch.
Commenced in 2002, with sales of Bloom 100kW systems from 2009, the company will have its initial public offer in 2010, with John Doerr the doyen of venture capitalists of Kleiner Perkins Caulfield Byers, who floated Google so brilliantly, as the pivotal force behind the public float. Judging by the recent overwhelming successful IPO of Telsa Motors, Bloom Energy will be the big US float this year.
KR Sirdah, Bloom’s chief executive headed NASA’s fuel cells systems for use in the Apollo Mars probe, and when that mission was axed on the grounds of high costs, he took his scientific team with him. Bloom Energy located at Sunnyvale, Calif. first started raising venture capital in 2001, and was the first alternative energy company to be funded by Kleiner Perkins.
Four Bloom 100kV SOFCs have already been installed at Google’s Mountain View Californian headquarters. The 100-kilowatt modules are made of small flat 25-watt fuel cell wafers made of zirconium oxide that are stacked together.
This eliminates the problem of leaks, which as stated above, has slowed the development of this technology. The stacks are made of ceramics and metal. The Bloom box sells for US$700,000 to $800,000. Larger Bloom Boxes of 400 kW systems provides electricity to a Google building housing an experimental data centre, and similar systems are installed in Walmart’s stores.
The company is also partnering with other blue chip companies,such as Bank of America; Coca Cola; Cox Enterprises (diversified media and communications group); eBay is said to have five Bloom Boxes; FedEx; Staples Center, (the Los Angeles sports and entertainment landmark) The Bloom box operates at high temperatures (over 600 C).
Posted under Climate Change, Global Warming, Low Carbon Economy, Renewable Energies, World Inflation
