Posts Tagged ‘CHP’

Back in July, 2011, Elizabeth Keokosky wrote a posting for this blog titled: “RPS in New York State” in which she explained the RPS. I recently received from the Public Service Commission (PSC) staff an updated New York State Renewable Portfolio Standard Biomass Power Guide, September 2011. It contains the clearest definition to date of the category in which grass finds itself: “Sustainable yield wood (woody or herbaceous) – woody or herbaceous crops grown specifically for the purpose of being consumed as an energy feedstock (energy crop). Some examples include willow, poplar, sycamore, and ash species (woody), and Miscanthus, hemp, and grasses (herbaceous). “
We have talked about the various potential users of grass energy and have generally characterized them into three groups: (1) large commercial/institutional (combined heat-and-power operations (CHP); (2) smaller commercial/institutional (example: school districts); (3) residential. Significant utilization of grass biomass for fuel is initially likely to require large-scale consumers in the first and second categories. The residential market will be the most challenging to develop. This posting will focus on the first category and its relationship to the Renewable Portfolio Standard (RPS) in New York State. The RPS deals with electrical energy and not heat per se because the PSC has authority over electricity issues (as well as gas, steam, telecommunications and water utilities) but not the use of biomass for heat-only applications. Elizabeth noted in her posting that the heating sector is controlled only by the market, yet it represents a significant component of our fossil fuel use. Although it could be helpful if the PSC was given policy-making authority over biomass heating under a revised RPS, for now the potential markets under the RPS remain CHP projects.
The RPS classifies biomass fuels into unadulterated and adulterated. Both are eligible fuel types but have differing processing and use requirements. The Guide states: “Unadulterated biomass may be used with any of the accepted feedstock conversion and power generation technologies to generate eligible renewable generation under the RPS program.” Grass is an example of an unadulterated fuel. Adulterated biomass includes such things as paper, paperboard boxes, plywood, particle board, textiles, yard waste, leather, offal, food processing residues and mixed adulterated and unadulterated wood wastes. If grass is combusted alone or in combination with other unadulterated fuels, the electrical energy so produced is designated 100% renewable or “green” power. If grass is combusted with adulterated fuels, then things get more complicated. Basically what has to happen is that there must be: “….. separate feed and measurement systems for each fuel stream plus regular sampling and analysis of fuels to ensure that the reported eligible generation is based on an accurate measurement of heat input for each fuel stream to the boiler or other conversion system.” For example, if 15% of the heat input to the boiler/generator is from grass, then 15% of the electrical energy is renewable or green power.

Another feature of the RPS is that grass and wood are not held to the same standard with respect to sustainable harvesting. Wood can take several forms, but here I will concentrate on wood commercially harvested from forests or “waste” wood harvested as part of timber stand improvement. These two classes of woody biomass require a Forest Management Plan that is reviewed and approved by NYSERDA and the PSC. Alternatively, the biomass producer can use one of the following already-approved certifications: Forest Stewardship Council (FSC), Sustainable Forestry Initiative (SFI), American Tree Farm System (ATFS) or New York State Real Property Tax Law 480A Program. Grass, on the other hand, requires no such certification because it falls in the “sustainable yield wood (woody or herbaceous)” category. This is of course not to say that grass should not be managed for sustainability, but merely to emphasize that there is no pre-approval cost associated with a plan approval.

The take-home message is that under the RPS there are currently no significant regulatory constraints on the use of grass fuel for biomass-fueled CHP applications. We need to see some demonstrations of this use to establish the economics and then a scale-up of production. This will create jobs and help New York State reduce its reliance on non-renewable sources of (electrical) energy. Once production capacity has been created, grass fuel can then be attractive for heat-only applications.


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