Butterworth, W.R., Land Network International Ltd(free)
This paper is NOT about “renewable” fuels. It IS about the cost of fuels which are renewable and sustainable. The use of wastes to “feed” crops and algae is highlighted with respect to harvesting the energy of the sun. Reference is made, using diagrams, to the energy used and produced in using wastes to fertilise crops and produce biofuels.
Keywords: Energy, sustainable, wastes, costs, green leaf, crops, AD, TAD, liquid fuels, efficiency.
The basic approach to efficiency of new processes is simple enough but actually making decisions depends on the depth and credibility of available data which is, in practice, likely to be inadequate. For biosolids, other organic and inorganic wastes, and co-mingled wastes, there are many options. The key questions are about the cost of building and running the facility, its reliability and whether more energy comes out than goes in. There is a series of questions about efficiency, renewable and sustainable. These words are widely and maybe too easily used. It is observed that being efficient and renewable is only of short term value if the system concerned is not also sustainable. “Sustainable” means: Can we do this for 1000 years and then do it again for another 1000? It also asks; will the process get more energy out than you put in?
Buck Rodgers, sometime boss of IBM, made the famous remark; “Nobody ever got fired for buying IBM”. Then a relative upstart came into the market with a tiny computer called “Apple” which took IBM close to collapse. Currently, we might tweak the quote and say “Nobody ever got fired for buying expensive”. There appears to be a similar fashion of accepting higher and higher capital costs in AD, MBT, pyrolysis and, no doubt, more and more centralisation and, inevitably, there will be more and more tonne-truck-miles to feed in and out of these installations. Common sense says they may not be sustainable financially or environmentally. AD and ATT (Advanced Technologies Treatments) of food and carbon-molecule wastes is accompanied by an apparently fashionable, or is it desperate, acceptance of a rising level of capital cost. However, it does not necessarily have to be that way; there can be lower cost and truly sustainable recycling routes.