Product Marketing
As of the late 1990s, 35 operating digesters produced 4MW of electricity per year in the US, and prevented the emission to the atmosphere of 124,000 metric tonnes of methane. As of 2002, there were 70 farms in the US with digesters and many more were planned or under construction. Some were swine operations, but most were dairy farms. Three facilities were centralized, serving several farms in one area. The theoretical yield is 0.35 cubic meters of methane per kg of chemical oxygen demand (COD), but the exact recoverable yield depends on environmental conditions. Farmers may expect to generate 2.3-5.5 kWh per cow per day.
In order to benefit from digester technology, the manure management strategy for a given farm must be compatible with the digester technology. The farm requires a large, confined herd of 100 or more cows, with stable year-round manure production in order to feed the digester regularly. Irregular feeding can disrupt the delicate balance of the biological processes, thereby making the system work inefficiently or causing it to fail outright. Care must be taken with feed additives like antibiotics, or cleaning chemicals as these may damage the process. It is not known how much of these substances can be tolerated.
Manure needs to be collected at one point and managed as a liquid, slurry or semi-solid. In other words, it needs to be free of large quantities of bedding, as bedding forms clumps which clog pipes and interfere with digestion. The amount of collectible manure and its total solids content must be known in advance in order to design the digester, and size the engine and generator components.
Successful projects from the early biogas building boom tended to share several primary characteristics. Most importantly, successful systems were designed and built to be compatible with farm operation. The owner realized the benefits of the technology and wanted it to work. Owners needed at least some mechanical knowledge and ability, and also ready access to knowledgeable technical support. Success was associated with a stable and profitable framework for the sale of energy, and also the exploitation of additional profitable opportunities such as the sale or on-farm use of the manure by-products. In fact, some diary farmers earn more revenue from the sale of electricity and manure by-products than on sale of milk.
Failed projects also shared many characteristics. Digesters were often built with little thought to their compatibility with the manure handling methods used by the farm, or with inappropriately sized components. Poor system design (often produced from cobbled together parts) made previous systems too expensive to maintain and repair, and farmers were given inadequate training and subsequent technical support. Owners may not have had the skills or the time to keep a marginal system operating. Financial returns on such systems were poor or non-existent.
As a result of previous errors leading too frequently to failure, the Powerbase Biopower Consortium has developed the Synergy Biopower™ Technology. Capitalizing on the successes of previous designs and recognizing the inherent weakeness of past failures has led to the development of a new modular, factory manufactured system.
The Synergy Biopower™ Technology provides the farm operator with cradle to grave support, to ensure the long-term success of the project. Our services include, in chronological order:
• Electrical supply survey, including the requirement for "islanding" and emergency backup power
• A thermal energy study for the use of excess heat, for water and building heating
• Compliance with nutrient management and environmental regulations
• Site design and budgeting
• Electrical generator licensing applications
• All necessary building permits
• Complete anaerobic digester fabrication
• Installation of skid-mounted power house
• Commissioning and training of system
• Remote monitoring for electrical metering, maintenance personnel dispatching, aggregation of carbon credits for market trading
• Supply of off-farm waste materials to increase power generation output
The strength of the Powerbase Biopower Consortium is not only our technology, but our team of after-sales support personnel. Our dispatch centre will provide daily monitoring of the digester operation and can dispatch support personnel to site before problems arise. Sommers Motor Generator Sales provides onsite maintenance support and has been working with Ontario’s farm generator and PTO since 1936. We are a team you can trust.
Power Purchase Agreements in Ontario
As financial viability can hinge on a contract to sell excess electricity, Ontario is currently in a far less advantageous position than it should be with regard to exploiting biogas technology. This position can be easily remedied by the introduction of an appropriate regulatory and financial framework, policies that are under consideration now.
The current methods of selling power to the Ontario electrical grid include:
• Net Metering
• Small Generator Licence
Legislation currently under consideration (as of February 15, 2006) will add Standard Offer Contracts (SOCs) to the regulatory mix; which are the preferred method of compensation for small-scale renewable energy producers.
Net Metering
Net metering is a simple process whereby electrical energy is produced on farm and is used primarily to offset energy consumed from the electrical grid. Any excess energy that is produced is "sold" to the grid at the same price you pay, including taxes, transmission and debt reduction charges. Over a period time, energy is traded back and forth with your local utility and at the end of a yearly term, the final electrical bill is calculated. If you have produced less energy than you have consumed, you pay the utility the amount due. If you produce more energy than you consume, the excess energy is gifted to the utility free of charge. The maximum size of net-metered facility is 500 kW, which is much larger than most farming facilities.
Although simple, net metering does not allow you to sell excess energy into the electrical grid and may restrict the operation from being financially viable. In addition, net metering causes the small-scale renewable energy operator to "sell" power into the electrical supply system at heavily subsidized tariff levels, at prices which do not reflect the overall value provided by green, distributed energy generators.
Small Generator Licence
Small-scale electrical generators may also become licensed to sell electricity into the market pool at the current spot market price. With electricity prices hovering in excess of 25 cents/kWh this may appear to be very enticing. Unfortunately, high spot market prices depend on the whims of the market, weather conditions, availability of energy supply and numerous other issues which make long-term predictions impossible. Further, spot market prices follow a well-known "double peak" meaning that energy costs rise in the early morning and again during the mid-afternoon, evenings and overnight tend to have very low prices, which may restrict viable selling opportunities.
Nevertheless, with electricity prices expected to continue to rise, this may be an excellent opportunity for operators who are prepared to trade long-term, fixed-price supply contracts for the ability to maximize gaming, by selling only during peak periods.
Standard Offer Contracts
Standard Offer Contracts are simple and transparent long-term contracts whereby producers of renewable energy are allowed access to the grid and are paid a premium price for their power – a premium determined by the technology they use and its potential production rate in the area in which it is deployed – over a period of up to twenty years. Prices are fixed politically, while quantity is determined by the market. A new report entitled "Powering Ontario Communities" fully explains the concept under consideration by the Ontario Ministry of Energy and was recently released by the Ontario Sustainable Energy Association and is available in our biogas library.
Summary
Agriculture is particularly well placed to produce and sell surplus power to the grid through investment in biogas digester technology. Doing so benefits the grid by both reducing demand and increasing supply, and converts a sunk cost for manure handling into a revenue generating opportunity for the farm operation. Biopower can be used to generate heat and power and can also substitute effectively for natural gas across a wide range of applications, which may prove to be a very considerable benefit as natural gas supply gets tighter in the coming years. Very substantial greenhouse gas reductions can be guaranteed as methane emissions are minimized and fossil-fuel based generation is offset by farm-based energy recycling.
The Powerbase Biopower Consortium is well equipped to offer a complete biogas digester technology package at a price which will allow the biogas advantage to be taken up by a much wider range of agricultural operations than would previously have been possible. It will no longer be necessary for participating farms to operate on a gigantic scale for biogas technology to be justifiable on cost grounds, particularly where additional waste streams can be incorporated into the process.
We would be pleased to discuss your energy needs and develop a site plan assessment to determine if our Synergy Biopower Technology is right for your farming application.