Current and near-term GHG emissions factors from electricity production for New York State and New York City

This paper reports estimates of average GHG emissions factors for New York State and marginal GHG emissions factors for interventions in New York City. A multi-regional unit commitment model was developed to simulate the behavior of the grid. The parameters defining the system operation were gathered from several publicly available data sources including historical hourly electricity production and fuel consumption from over one hundred power plants. Factors were estimated for a baseline year of 2011 and subsequently for the year 2025 considering planned power plant additions and retirements. Future scenarios are also developed considering different wind turbine installation growth rates and policies affecting the cost of generation from coal power plants. The work finds marginal GHG emissions factors for New York City could reduce between 30 and 36% from 540 kg CO2e/MWh in 2011 for all future scenarios considered. Average GHG emissions factors for New York State could reduce 9 to 39% from 215 kg CO2e/MWh depending on the wind growth rate and price burden on coal power plants

Combined heat and power's potential to meet New York City's sustainability goals

Combined Heat and Power (CHP) has been proven as a mature technology that can benefit both building owners and utility operators. As the economic and environmental benefits of CHP in urban centers gain recognition, regulations and policies have evolved to encourage their deployment. However, the question remains whether these policies are sufficient in helping to achieve the larger sustainability goals, such as the New York City-specific goal of incorporating 800 MW of distributed generation. In this paper, the current regulatory and policy environment for CHP is discussed. Then, an engineering analysis estimating the potential for CHP in NYC at the individual building and microgrid scale, considered a city block, is performed. This analysis indicates that over 800 MW of individual building CHP systems would qualify for the current incentives but many systems would need to undergo more cumbersome air permitting processes reducing the viable capacity to 360 MW. In addition microgrid CHP systems with multiple owners could contribute to meeting the goal even after considering air permits; however, these systems may incorporate many residential customers. The regulatory framework for microgrids with multiple owners and especially residential customers is particularly uncertain therefore additional policies would be needed to facilitate their development

Examination of the optimal operation of building scale combined heat and power systems under disparate climate and GHG emissions rates

This work aims to elucidate notions concerning the ideal operation and greenhouse gas (GHG) emissions benefits of combined heat and power (CHP) systems by investigating how various metrics change as a function of the GHG emissions from the underlying electricity source, building use type and climate. Additionally, a new term entitled \CHP Attributable" reductions is introduced to quantify the benefits from the simultaneous use of thermal and electric energy, removing benefits achieved solely from fuel switching and generating electricity more efficiently. The GHG emission benefits from implementing internal combustion engine, microturbines, and phosphoric acid (PA) fuel cell based CHP systems were evaluated through an optimization approach considering energy demands of prototypical hospital, office, and residential buildings in varied climates. To explore the effect of electric GHG emissions rates, the ideal CHP systems were determined under three scenarios: \High" GHG emissions rates, \Low" GHG emissions rates, and \Current" GHG emissions rate for a specific location. The analysis finds that PA fuel cells achieve the highest GHG emission reductions in most cases considered, though there are exceptions. Common heuristics, such as electric load following and thermal load following, are the optimal operating strategy under specific conditions. The optimal CHP capacity and operating hours both vary as a function of building type, climate and GHG emissions rates from grid electricity. GHG emissions reductions can be as high as 49% considering a PA fuel cell for a prototypical hospital in Boulder, Colorado however, the \CHP attributable reductions are less than 10%