Approximate AD Plant Cost Estimates
The following is an extract taken from the Remade Scotland Report; An Introduction to the Digestion of Organic Wastes; Fabian Monnet, November 2003. (Available on the Remade Scotland web site.)
All cost are assumed to be based on 2003 prices. (To adjust these costs to 2009 prices some have used 4% allowance per annum until mid-2008 giving a very rough idea. To assume that due to the recession in 2008 costs ceased to rise, or fell for a year, would be reasonable, however, all readers must make their own assessments, and apply the available published inflation indices year by year.)
Although it is difficult to provide accurate costs, and we accept no liability whatsoever for correctness of these prices, it is possible to give an indication of the range of costs for an AD plant in relation to the type of waste treated and capacity, as provided in the above report, as follows:
• For an on-farm digester, the capital cost is likely to be between £100,000 and £200,000 for a capacity of about 3,000 tons/year. The operating costs should be around £2,000 (without labour).
• For larger plants, treating waste from several farms, capital costs vary from £500,000 for a capacity of 10,000 tons/year to £5,000,000 for a capacity of
200,000 tons/year. Operating costs are likely to be in a range between
£31,000 and £530,000. (Pre-sorting/materials recovery/pre-treatment costs - if appropriate are not included.)
• For AD plants, treating the organic fraction of source-segregated MSW, capital costs vary from £3,000,000 for a capacity of 5,000 tons/year to
£12,700,000 for a capacity of 100,000 tons/year. Operating costs are ranging from £127,000 to £953,000.
Energy Output
It is possible to calculate roughly the biogas production and thus the electricity and heat production of an AD plant in relation to the composition of the feedstock (for more detailed information, please see appendix 1 of the above report).
However, please note carefully that such calculations are based on average values and they do not take the process parameters into account (type of digesters, temperature of digestion etc).
Figures given below should be regarded as indicative values only.
For instance, a large centralized AD plant processing 100,000 tpa of cow slurry, which represents approximately 8,000 cows, would be expected to produce very approximately:
• 3,110 MWh/y or 31.1 kWh/tonne of electricity
• 5,710 MWh/y or 57.1 kWh/tonne of heat
Considering a selling price of 4.5p/ kWh (2003 rates), the total income for a year for the electricity would be £140,000. The heat could be used for the process (digester heating, sterilization) and for many other applications and thus may provide additional income streams.
For further information about selling electricity, see for example the Scottish Renewables internet site [www.scottishrenewables.com] where they have a report devoted to financing renewable energy projects.
The selling price for electricity is not fixed and depends on the price (feed-in tariff) agreement between the producer and the power supplier. The electricity company will require a high %age up-time (reliability) for the AD Plant to be willing to pay their highest rate, and the length of the contract to which you are willing to commit is also very important when setting the price you will obtain.
Now you have read page this go to the Financial and Contractual Biogas Funding and UK Government Procurement page.
Return to the AD Finance Articles Contents page.
Return to the Articles Contents page.
|
