AbstractsPhysics

Onpeak Market Dispatchable Energy From Megawatt Scale Fuel Cells And Stored Digester Methane

by Stefan Minott




Institution: Cornell University
Department:
Year: 2014
Keywords: anaerobic digester methane ; renewable energy fuel cells ; spot market smart grid
Record ID: 2042988
Full text PDF: http://hdl.handle.net/1813/37182


Abstract

This dissertation shows that pure methane storage and megawatt scale fuel cell systems operated by a spot market dispatcher can provide revenue streams that are double to quadruple the revenue that would be collected from net metered biogas generation. When configured as recommended, these systems can provide up to 38 to 59% of the theoretical revenue from a spot market for the generator company (Genco) that dispatches the stored energy. It describes the implementation of the OnPeak Time Generation and Storage (OpTiGaS) System that achieves this level of performance. This system is based on: • Computer executable simulations of biogas digester companies and an onpeak fuel cell dispatching Genco, working together to maximize biogas revenue on the electricity spot market; • A unique method of scheduling onpeak megawatt scale electricity to the wholesale power grid using purified methane that is stored in gas holders; • Interpretation of spot market data to minimize the risk of low and negative revenue times. There are up to 2,950 dairy farms in NY that could potentially benefit from digester gas generation if they are properly configured to use OpTiGaS. Fortyone of these are large enough to operate stand-alone with their own Genco. For comparable outcomes, the rest can employ clustering agreements and codigestion of food waste streams to achieve similar revenue streams. The analysis demonstrated several beneficial combinations: • clustering digester sites by pipelines to make more than 1 MW fuel cell power plants if methane supply from one digester site is insufficient; • scheduling one or two spot electric blocks totaling 8 hours/day only on spot market days for selling power to the grid, and; • tuning gas holder size and generator size to make methane gas refilling steady each month without running empty. Revenue from a cluster of three 600 milking cow farms and a 1.05 MW Fuel cell was up to $20,400 per month. Revenue from one 1,700 milking cow farm and 1.1 MW fuel cell was $21,141/month. The addition of manure to certain food wastes, such as used cooking oil and pasta, was shown to transform a 600 cow biogas production to look like a 1,700 cow facility's biogas production. For a large food processing plant, equipped with an 18 MW grid fuel cell and 2.56 MW onsite fuel cell, revenue was projected to be $2.6 million/year for combined onsite energy savings and grid power sales.