posted on 2017-11-08, 14:59authored byBianca Howard, V. Modi
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%.
History
School
Architecture, Building and Civil Engineering
Published in
Applied Energy
Volume
185
Issue
Part 1
Pages
280 - 293
Citation
HOWARD, B. and MODI, V., 2017. Examination of the optimal operation of building scale combined heat and power systems under disparate climate and GHG emissions rates. Applied Energy, 185, pp. 280-293.
This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/
Acceptance date
2016-09-27
Publication date
2016-11-07
Notes
This paper was accepted for publication in the journal Applied Energy and the definitive published version is available at https://doi.org/10.1016/j.apenergy.2016.09.108