Hi! My project is getting hot water from the central combined heat and power plant in the campus, but it's NOT getting the electricity from it. It's getting power from the public utility. Can I still get credit from the CHP? The LEED guide only describes projects that use the power from the CHP but I cannot find reference for my situation. The thermal efficiency is below 30% so it's killing all my saving.
Thanks!
Tyler Thumma
7GroupLEEDuser Expert
61 thumbs up
April 5, 2024 - 11:48 am
Yes, if you are accounting for the fuel input of the CHP you should also be including the electricity generation.
Moses Chong
Mechanical EngineerWSP
1 thumbs up
April 5, 2024 - 2:50 pm
Thanks for your reply! Do I simply add the energy to the baseline as process loads? I'm trying to understand the users' manual. It read to me I can add the excess electricity to the baseline as process load, and the gas that used to generate that electricity as process load. So in my situation, because I'm adding all of the gas as process load to the baseline, and all the electrcity generated from the CHP as process load to the baseline as well. Am I reading it correctly?
Tyler Thumma
7GroupLEEDuser Expert
61 thumbs up
April 8, 2024 - 8:45 am
CHP electricity generation and fuel input are only accounted for in the Baseline in a situation where the Proposed building's allocation of CHP-generated electricity exceeds its modeled electricity consumption (Scenario B in the Reference Guide), which is typically not the case. Most projects have less CHP-generated electricty than their total electricity consumption (Scenario A), in which case no adjustments are made to the Baseline.
Moses Chong
Mechanical EngineerWSP
1 thumbs up
April 8, 2024 - 1:32 pm
But the project is not using the electricity from the CHP at all, so the CHP generated electricity exceeds the proposed building's allocation (which is zero). The CHP generated electricity is used only in other buildings of the campus. It's weird I know.
Tyler Thumma
7GroupLEEDuser Expert
61 thumbs up
April 9, 2024 - 8:19 am
I understand the project is not using electricity from the CHP. I am referring to are the CHP_ELECBLDG calculated according to the formula below from the reference guide (simple systems used for reference), which will either be less than (Scenario A) or greater than (Scenario B) the building's modeled electricity.
CHP_ELECBLDG(simple systems) = (XHEAT x BLDGHEAT) x CHP_ELECTOTAL
where
CHP_ELECBLDG(simple systems) = CHP electricity generation allocated to building
XHEAT = fraction of CHP plant's total production of waste heat applied to the DES directly
BLDGHEAT = fraction of total district heat provided to building
CHP_ELECTOTAL = total CHP electricity generated at DES plant