Synopsis: Cochise County Planning and Zoning Commission on March 14, 2007, voted 5-4 to approve the Master Development Plan (MDP) for Bowie Power Station submitted by SouthWestern Power Group II, LLC (SWPG). The plan involves a rezoning and covers the Bowie Power Plant, a 600 MW Integrated Gasification Combined Cycle (IGCC) coal-fueled electricity generating station, a University of Arizona Research Center, a commercial greenhouse, temporary construction housing, possible permanent (workforce) residences, a convenience store, open space for recreation, and buffering the plant from the surrounding area. Planning and Zoning staff recommended approval of the plan with some conditions. The Board of Supervisors originally planned to vote on the MDP on April 3, but, owing to the publicity, controversy, and complexity of the project, scheduled a work session on April 17 in which SWPG officials outlined details of the power station. After some delay, a consultant was hired by the County on July 24 to help evaluate the MDP and assist with air and water quality issues as well as assessing the carbon dioxide sequestering. The consultant will present the evaluation at an August 21 work session prior to the Board of Supervisors meeting at Bowie on September 10. If the Board of Supervisors votes against the power station, it will not be built. State regulators at ADEQ and ACC are basically waiting until the County hearings have concluded.
Obtaining state and federal permits will take a while, and they anticipate construction to begin in 2009 and finish in 2012/13. A transmission line will run north-west about 15 miles from the power station to a Tucson Electric Power (TEP) line, where a switching station will be built. They hope to sell some power locally (50-100 MW to Sulfur Springs) and more to TEP.
IGCC: In an IGCC plant, coal, water and oxygen are fed into a high pressure gasifier where the coal is partly combusted to produce “syn gas” (CO + H2) and the ash in the coal is converted to glassy slag. The syn gas is next cooled and cleaned of particles. Sulfur and other pollutants such as mercury are removed; the fate of arsenic and selenium is less clear. The syn gas is fired in a combustion or gas turbine that produces electricity, and the hot exhaust from the gas turbine is fed to a heat recovery steam generator, which drives a steam turbine. Water from the gasifier is recycled up to nine times before going to an evaporation basin as sludge. Water used with the steam turbine is cooled and reused up to 15 times. Plans for the Bowie plant specify two gas turbines and one steam turbine. There are more details on the IGCC process at http://en.wikipedia.org/wiki/Combined_cycle , http://www.clean-energy.us/facts/igcc.htm , and http://www.fossil.energy.gov/programs/powersystems/gasification/howgasificationworks.html .
The Wikipedia article points to reliability problems with the two existing IGCC plants in the U.S. There’s no mention of these problems on the DOE Web site at http://www.fossil.energy.gov/programs/powersystems/gasification/gasificationpioneer.html , but these plants are over ten years old, and it is only recently that we’ve seen renewed interest in building IGCC power stations. There are additional efficiency and reliability problems associated with running gasifiers and gas turbines at higher altitudes. Bowie is 3,700 feet above sea level; both operating IGCC plants are at or close to sea level.
An additional concern relates to fuel. SWPG’s submissions in the Master Plan and their presentation at the work session emphasized a 3:1 mix of coal (mostly from the Powder River Basin in Wyoming) and pet coke (oil refinery end product). Lately, they have backed away from that saying the fuel will probably be all or mostly coal. The reason may be that pet coke is less available as some refineries now use it to generate their own electricity. Both IGCC plants in this country use pet coke in their fuel mix, and reliable IGCC plants in Europe use even more pet coke.
IGCC plants can be expected to cost at least 20-25% more than a comparable SCPC (super-critical pulverized coal) plant, the standard “dirty” plant that’s been built for the last 30 years. Against that they are far less polluting and may reflect more accurately the true cost of generating electricity. This additional cost figure does not include expenses for sequestering carbon dioxide.
IGCC Proposals with Problems: Although there are numerous IGCC plants being proposed, several are encountering barriers to approval. Opposition stems from lack of or inadequate carbon dioxide sequestering, cost overruns, poor planning stemming from inexperience with this technology, and uncertainty about the future cost to curb carbon dioxide emissions (http://www.counterpunch.org/blair01232007.html ). Some of the problems encountered can be viewed at http://nwenergy.org/publications/the-transformer/2007/the-transformer-february-7-2007/ , http://www.mncoalgasplant.com/ , & http://www.sierraclub.org/environmentallaw/coal/plantlist.asp . Conventional (or SCPC) coal plants are still being planned across the country but with considerable opposition. One such plant, Desert Rock, to be built near Burnham, N.M., to supply power to Las Vegas and Phoenix, has become very controversial (http://www.indianz.com/News/2007/004120.asp ). Sentiment has swung sharply against coal in Florida where the Public Service Commission is now authorized to give priority to renewable energy and conservation programs before approving construction of conventional coal-fired power plants.
Bowie Power Station and SWPG: Although the proposed Bowie Power Station can be expected to be far less polluting than any currently operating coal plant in Arizona and may meet emission levels of a natural gas plant (but not for carbon dioxide without some sequestering and possibly not for oxides of nitrogen), there are still several issues to worry about.
CO2 Sequestering. MIT's recently released study, "The Future of Coal in a Carbon Constrained World," (http://web.mit.edu/coal/ ) stated that "coal faces a bleak future" without carbon capture and storage, and further recommended "no new coal plant be built without carbon capture technology." SWPG announced a carbon sequestering plan at the work session using greenhouses and tree seedlings. They claim they’ll be sequestering 40% of the carbon dioxide, but, as this figure includes the carbon dioxide that the young trees will take up under ideal conditions over a ten-year period after being planted in the field, the actual amount of carbon dioxide sequestered on site would be considerably less. The figures used in the study cited on the bowiepower Web site are based on raising lettuce and tomato plants and eucalypt seedlings in the greenhouse (http://www.bowiepower.com/assets/0607_U%20of%20A_Sequestration%20Study.pdf ). However, Eucalyptus seedlings grow very rapidly when young and are unsuited for plantations in much of the United States. I suspect CO2 absorption by seedlings more suited to reforestation would be lower. On July 7, SWPG officials appeared to be backing away from this plan by stating that the greenhouses are dependent on University of Arizona researchers obtaining grant funding for the greenhouses. Although SWPG has mentioned working with Eurofresh to grow tomatoes in greenhouses with elevated CO2 levels, there are to this date no commitments or agreements – just speculation and wishful thinking.
The site was originally selected for a natural gas-powered plant, as it is close to the natural gas pipeline and existing high transmission lines. It is less suited for a coal plant as the geology in the area precludes underground sequestering and the higher elevation will reduce the efficiency of the gasifier and gas turbines. Figures read from slides shown at the work session are (as pounds of CO2 emitted per MW hour) – IGCC without sequestering 1,300, natural gas 750, IGCC with sequestering 600. They said the last figure reflected 40% sequestering, but that doesn’t seem right. Without some CO2 sequestering, SWPG will not be able to match emissions from a natural gas plant, something they have stated the ADEQ would like them to do. Furthermore, permitting and operating this plant without carbon sequestering would run contrary to and violate the spirit of the Western Regional Climate Action Initiative, a joint effort among five western states to reduce greenhouse gas emissions and address climate change (http://www.pewclimate.org/what_s_being_done/in_the_states/regional_initiatives.cfm ). It is clear that, following the recent Supreme Court decision, CO2 emissions will be regulated and possibly taxed before long.
Sludge Ponds. ADEQ regulates the evaporation ponds, the coal piles, and the byproducts storage facility (aka the slag pile). The coal piles have liners, and rain water runoff from the coal pile will be collected and treated. The evaporation ponds hold the water slurry from the gasifier. The evaporation ponds will have dual liners with a drainage layer between them and a clay layer in mesh below. The liner system is monitored, and any breaks or ruptures must be repaired immediately. There was some discussion in the submissions to Planning and Zoning to sell the evaporated sludge, but the plan now is to leave all the material in the ponds and to eventually close them. Very little information is available on the likely chemical composition of the evaporation ponds, but it’s obviously far from pristine. Even if the ponds are fenced and dust is minimized, are they poisonous and will they attract birds?
Slag Heaps. The solid residue from IGCC plants is called vitreous slag. It is not water soluble and is largely inert. The two operating IGCC plants sell their slag as road base material. SWPG proposes a large storage area for slag – 8’ deep, up to 40’ high, 6.5 million cubic yards capacity. They hope to sell the slag for road base, but, if they can’t, this facility should hold all the slag generated over the projected 30-year life of the plant. When it’s over, the slag will be covered with 2 feet of soil, and native vegetation will be reestablished. Given hauling costs, the slag will probably only be used for nearby projects, so a large slag pile will probably develop. Even if all works out well and native vegetation is reestablished, the area will not be suitable for agriculture or housing.
Bowie and Cochise County: Plant construction will involve 800-1,000 workers, the operational plant will employ 100-120 people, and additional business spinoffs are possible. The economic benefits of the power station are presented in http://www.bowiepower.com/assets/060107_UofA_Bowie%20Econ%20Impact%20Study_final.pdf , and this study predicts significant tax revenues and employment income. It’s clear that numerous Bowie residents feel that the plant could be their and Bowie’s salvation. However, it’s highly unlikely that all the permanent plant employees will live in Bowie. Also Bowie residents may not be counting the busier roads, increased rail traffic, and other issues that the plant will bring. Finally, is it appropriate for Bowie to have a disproportionately loud voice in a project whose effects will be felt over much of the county?
There is considerable interest in and some opposition to this project. Other articles on the power station are http://littlebigdog.net/bowieplant.htm and http://bowiepower.blogspot.com/ . Both are well worth reading and they cover different material from a slightly different perspective. SWPG presents its version of the project at http://www.bowiepower.com/ and http://www.southwesternpower.com/ .
