Complexity Tarnishes Biomass Silver Bullet
Bio mass has been the buzzword for a few years now, but the silver bullet has become tarnished by hidden complexity. Our Ecogiggle researcher looks under the covers of several biomass strategies.
First, what is biomass? As far as I can see biomass refers to the feedstock used when generating energy from organic materials. Hydrocarbons (coal, tar, oil, gas, and petrol) are not regarded as organic in this view. So essentially we are left with wood and household/food waste. This will include kitchen waste, by products from timber mills, waste from food processing plants etc. Further research will probably turn up other definitions. Nor are we talking about other more direct energy conversions like tide power, wave power, wind power or solar power.
As an energy assessor (http://www.cornishenergy.co.uk) , I have discovered that the line of supply of fuels can have a considerable effect on overall efficiency. In UK households using mains natural gas, the efficiency rating is very good. Yet if a similar gas (LPG) is delivered to the household in bottles, the efficiency rating drops to reflect the inefficiency of delivering small quantities by local road transport.
This delivery mechanism effect is one of several factors that plague the Biomass solution. Another problem is competition for the feedstock. Where sugar cane or corn is grown to feed into ethanol production, there arises the fact that food is being sacrificed for fuel.
Another problem shows up if you look at the over-all ecological energy/carbon cycle. We know that the carbon-dioxide in the air is used by plants and one of the outputs is oxygen. This locks the carbon into the wood fibres until it is released again when the wood is burnt. A Biomass argument is that growing trees to burn them is a good idea because we are just re-cycling the carbon. There are two problems with this argument:
* This does not reduce the carbon-dioxide already present in the atmosphere.
* Extra carbon-dioxide is produced by the activities surrounding the growing, cutting and burning of the trees.
Beyond these mundane arguments that we mere mortals have to contend with, there are other groups of people looking at this whole thing from a different angle. ECONOMICS, POLITICS and SECURITY need to be considered. Governments will interfere on our behalf. For example the feed-in tariff for micro-generation in the EU distorts the electricity market well out of reality. Is this the right thing to do?
Ecogiggle has uncovered several news articles that explore these strands in greater depth. Have a look at Bee in the Bonnet for a continuation of this article.
Filomena Scalise http://www.freedigitalphotos.net/images/view_photog.php?photogid=851
Biofuel study looks at Nitrogen Requirement and cost to environmental diversity
Biofuel crops seem to have costs that have been overlooked. Namely the Nitrogen cost and secondly the cost to biodiversity. Ths is a consequence of growing "monocultures". That is to say growing vast areas of only one plant.
These problems are being studied by a team of scientists based at Texas AgriLife Research and Extension centers. They want to solve both problems. They are looking at the cost of nitrogen and ways to preserve habitat for valued species.
Various types of legumes have been trialled as sources of nitrogen. They are looking at sustainable production of cellulosic biomass whilst paying attention to resource conservation and wildlife stewardship.
Smith, one of the researchers, knows that legumes cause much less depletion of the soil's nitrogen supply. Cool-season legumes like clovers and warm-season legumes such as cowpeas are good examples of this feature. Not having to replace the Nitrogen has a big impact on the overall climatic equation.Questions are being asked about the most effective mix of crops and keeping the application of fertilizers as low as possible.
Additionally drought has to be considered.It would be a poor choice to use crops that need to be re-seeded after a dry spell. The crops need to be reasonably hardy. This is of particluar interest to these scientists who are based in Texas remember.
Meanwhile attention has to be paid to the wildlife that might feed off these crops. There is uncertainty about how wildlife will adapt to new crops.
A full atricle on this topic may be seen at:
federico stevanin http://www.freedigitalphotos.net/images/view_photog.php?photogid=149