It is always heartening to see when someone (especially a politician) finally delivers on a promise. In passing the US Energy Bill in August, US president George W. Bush said: “When I ran for president in 2000, I promised to invest – or asked Congress to invest – over $2 billion over ten years to promote clean coal technology. So far, working with the United States Congress, we’ve provided more than $1.3 billion for research in innovative ways to improve today’s coal plants and to help us build even cleaner coal plants in the future. And the bill I sign today authorizes new funding for clean coal technology so we can move closer to our goal of building the world’s first zero emission coal fired power plant.”
But please don’t get me wrong, I am by no means singing the praises of Mr Bush. At last he has a plan, and a sensible one. Yet sometimes I wonder how much time and money should be spent on developing systems that realistically may not see the light of day in our lifetime?
It was interesting to read that GE Energy had been selected by the US Department of Energy (DOE) to develop a highly efficient multi-megawatt solid oxide fuel cell-based system that operates on coal. Under a 10-year, three-phase agreement with the DOE, GE Energy’s Hybrid Power Generation Systems (HPGS) business will design and demonstrate an integrated gasification fuel cell (IGFC) system that incorporates a hybrid SOFC/gas turbine as the primary power generation unit.
Certainly, there should always be forward looking research and development but the question here is: how likely is it that a coal based fuel cell system will ever become a commercial reality?
The reasons for focussing on coal are clear. According to the DOE, coal reserves in the US are more than the total recoverable oil reserves in the world and a key goal of the bill is to reduce US dependence on imported fuel.
But combining two technologies – neither of which have had any real commercial penetration – will present a huge challenge. IGCC has so far failed to make an impact predominantly because of high costs. Typical overnight installed costs for an IGCC plant are in the $1300/kW – $2000/kW range depending on size. This compares to about $1000/kW for a pulverized coal fired plant.
Similarly, fuel cells are also yet to make an impact. Again, cost is a big challenge. Although some argue that costs will come down as volumes increase, at about $3000-$6000/kW there is a long way to go. Tim Regh, general manager of GE Energy’s HPGS business acknowledges that cost will be a big challenge and added that the other major issue is scalability.
“The main challenges are cost and scalability and these are key focus areas of the new programme with the DOE. Coal plants are large and will require fuel cells much larger than those available today. The cost of fuel cells also needs to come down considerably. But GE is making good progress on both cost and scale. As part of the ongoing Solid State Energy Conversion Alliance (SECA) programme that started in 2001 at the DOE, GE has developed small-scale planar SOFC technology with a cost potential below $800/kW. We will be driving that cost potential to below $400/kW over the next six years in Phases 2 and 3 of the SECA programme.”
GE sees the main market for IGFC systems being in countries that have large coal reserves and generally opt for large centralized power stations e.g. India and China. In these markets, achieving large unit size is critical.
So far, GE has developed a 40 cm planar cell (as opposed to tubular) that is said to be about twice as large as any cell previously developed. According to GE, planar cell sizes such as this have a “tremendously favourable” impact on cost and will eventually allow SOFC stacks of a few hundred kW, which is a suitable building block size for coal-based power generation units.
The DOE IGFC programme will begin in October this year. Phase 1, which will last three years, will focus on system design of the IGFC power plant, IGFC and proof-of-concept (POC) system cost analyses and SOFC technology advancement. Phase 2 will further advance the design of the IGFC and POC systems and will extend through 2010. Phase 3, beginning in the fifth year of the programme, will culminate in the demonstration of the POC system at an IGCC combined cycle plant.
“We are targeting natural gas fuelled hybrids for commercialization early in the next decade. The technical challenges on natural gas, particularly with respect to scale, are not as significant as they are for coal, which will result in earlier commercialization. Coal-based hybrids would follow a few years later, 2015+”
The Energy Bill was a long time coming – America has not had an energy policy for more than a decade. But it came eventually. And although it is exciting work, I fear that commercial penetration of a system integrating IGCC with fuel cells will be an even longer time coming; if indeed it ever comes at all.
Publisher & Editorial Director