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The dawn of the steam age began when wood was burnt to boil water. Several railway companies continued to burn wood to generate steam in locomotives well into the 20th century. Biofuel such as wood and dried cattle effluent have continually been used in many countries to heat stoves and to heat homes during winter. The first large-scale application of using biofuel to generate electric power was the 250-Mw Thetford Power Station near London, UK. Its fuel is the effluent from nearby corporate poultry farms. A similar 50-Mw power station recently commenced operation in Kentucky, USA and operates on the byproduct from nearby turkey farms.
The Kyoto Protocol classifies biofuel as being environmentally neutral due to the ability of vegetation to absorb as much carbon dioxide during its period of growth as it or its byproduct emits when combusted. Thetford power station began operating well before the Kyoto Protocol was initiated and along with its America counterpart were initiated on an economic basis. The organic waste material from dense concentrations of commercial poultry mega-farms needed to be disposed of and biomass-fueled power stations provided a viable solution. Similar power stations may be built where densely populated metropolitan centers are located near dense concentrations of commercial poultry mega-farms.
The sheer volume of organic waste that would be produced by such operations would leave few options other than for it to be used as fuel at viable biofuel commercial power stations. The mega-farms would also produce prodigious amounts of ammonia gas (NH3) that could be carried through duct systems to the power station. Nitrous oxide (NOx) that would be created by the combustion process would react with the ammonia to produce water vapor and nitrogen: 3(NOx) + 2(NH3) >> 6(H2O) + 3N2.
The biofuel gasifier systems used at such power stations continually removes the combustion ash via auger mechanisms. Biofuel ash has a high mineral content and has been proven to be an effective plant fertilizer. This ash may be incorporated into a "closed loop" system where becomes plant fertilizer at farms that produce poultry feed for corporate mega-farms. To cope with unexpected emergencies, the biofuel gasifiers would need to be designed so that their settings may quickly be re-adjusted to enable them to efficiently process an alternate biofuel. An antibiotic-resistant avian virus could infect poultry at commercial mega-farms and result in a mass culling of birds. The sale of poultry products to consumers would be temporarily restricted during which time the biofuel power stations would temporarily operate on alternative organic waste material.
Biofuel has been criticized for its low energy content of 4,000 to 6,000-Btu's per pound of thermal energy compared to coal has 11,000 to 13,500-Btu's per pound of thermal energy. Recent advances in combustion technology could raise the thermal efficiency of future biofuel power stations. High-temperature ceramic material that has a high thermal shock tolerance can enable Ljungstrom heat exchangers to operate at elevated temperatures in external-combustion gas (air) turbine engines that burn solid biofuel. Advances in gasifier combustion research may eventually allow solid biofuel to power internal-combustion gas turbine engines. The exhaust heat from a gas/air turbine engine may be sufficient to raise saturated steam for a steam powered bottom-cycle engine. The overall thermal efficiency of such a combined-cycle power station would make biofuel power stations more economically attractive.
The use of biofuel to generate power has caused controversy when waste organic material is replaced by non-waste organic material that is grown on lands where food crops may be grown. A branch of the ethanol industry in Canada sidestepped this issue by using a modified chemical process that enables ethanol to be produced from wood waste. A segment of the lumber industry does produce biofuel for home heating and has sidestepped the controversy since much of their lumber is grown in regions that would otherwise be unsuitable for agriculture.
Genetic engineering could be applied to a variety of plants that would be grown outside of agricultural regions and become fuel for home heating and emergency fuel for biofuel power stations. These plants and vegetation could be fertilized with sewage from municipal treatment plants, as is done in certain Asian countries with several food crops. There would be public opposition to this Asian practice with regard to food crops grown in Western nations. The same practice would likely be a non-issue in regard to managed crops grown in Western nations for use as biofuel.
The recent discovery of an extensive undersea forest of vegetation growing on the bed of the Mediterranean Sea has caused concern since it is destroying traditional fish habitat, traditional fish breeding grounds and traditional sources of food for certain fish species. It may take decades for fish to adapt to this altered habitat or for it to become home to other non-traditional species of fish. The vegetation in the undersea forest could become a new source of biofuel that could be processed into ethanol or used as solid fuel to generate electric power. In the latter case, managed undersea forests could then be developed in other parts of the world to provide biofuel.
These managed oceanic forests may be located in close proximity to managed artificial commercial reefs where fish is raised for the market. Private companies may develop such commercial ventures after governments recognized and upheld private property rights over sections of ocean that lie within their jurisdiction. If natural gas and oil elicit high market prices over the long-term future, a viable biofuel industry could emerge in the absence of government subsidies, tax incentives or favorable economic regulations that restrict competitors. While such government policies win support over the short-term, they could undermine the long-term viability of the biofuel industry. If the idea of peak-oil were fact and not myth, then alternative energy sources that would be viable and economically self-sustaining over the long-term future would be needed.
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Peak oil IS fact and not myth. The question is when, and what will be the macroeconomic, financial, political and social consequences. This is where we need some answers.
Phillip T. Golden 3.27.06
While this is an interesting thought, it ignores the other options for dealing with organic waste, namely though the use of digesters which produce methan that can then be used to generate energy. One of the benefits of such power production when compared to simply burning waste is the pathogen reduction and odor limits that breaking the waste down through digestion first provides. While such power plants are no panacea, they are a key piece to solving the energy puzzle.
Adrian Lloyd 3.28.06
Mr Valentine, I do not share your optimism or enthusiasm for biomass power stations: The Thetford power station has a rated capacity of 38 MW, not 250 MW. It was the fourth power station using poultry litter, the first being the 12 MW Eye power station which was developed by the same company, Fibrowatt Ltd. Both power stations are now part of a fleet of 5 biomass power stations in the UK owned by Energy Power Resources Limited - see http://www.eprl.co.uk.
As someone who was intimately involved in arranging the finance for one of the other EPRL biomass plants, and who provided assistance to colleagues involved in the finance of Thetford, I can categorically state that none of them would have been built had it not been for the substantial financial assistance given under the Non-Fossil Fuel Obligation (NFFO) support programme. This ensured that a renewable energy plant awarded a NFFO contract received an index linked premium payment for the electricity it produced. For biomass power stations, the premium price was in the order of double the wholesale electricity price at the time of the contract award. The fact of the matter is that biomass power stations are not economical, nor are they likely to become so, unless the wholesale price of electricity rises to about £85 per MWh (US$ 147) or they can attract gate fees for their fuel. I see little chance of electricity prices rising to this level anytime soon, as coal, wind, gas, hydro and nuclear can all produce power economically for less (and building integrated solar and wave power are getting close). Gate fees for biomass are most likely (and in some cases already occur) in those parts of Europe and the US where concentrations of intensive agriculture give rise to more residues than can be disposed to surrounding farm land without causing excessive pollution. Poultry litter is one example, rice husk and olive oil waste are others. In these areas farmers need alternative disposal routes or face the prospect of having to scale back or even go out of business. Disposal then becomes the main driver and electricity generation becomes the by-product. This parallels what is happening with energy from waste; the most recent EfW plant in the UK has no support from government, it will get about a quarter of its income from electricity sales and the rest will come from the gate fees charged for the disposal of municipal waste. And it is economical.
With regard to developing biomass because of GHG savings, in the UK the NFFO was replaced by the Renewable Obligation 4 years ago, which gives each renewable generator a tradable certificate for each MWh generated. The combined value of sales of certificates, electricity and Climate Change Levy exemptions means that this year renewable generators can realise about £80 per MWh (US$ 140 per MWh). At this level, developers are again starting to look at developing new biomass power stations, but are still asking for additional capital subsidies from the Government. Interestingly, most of the proposals are for plant smaller than Thetford. In looking at economies of scale, developers have realised that capital and operational costs savings of larger plant can be outweighed by the costs and risks of having to source and transport the fuel over a much wider area. No farmer is willing to commit all of his or her land to the production of a single crop for a period of 15 years or more, so a large source area is required to ensure adequate fuel, be it agricultural residues or dedicated energy crops. A rough rule of thumb is that you need a source area of 220 square miles for each 10 MW of generation capacity.