I am working on a building project in the Netherlands that will utilize district heating. The District Energy System (DES) serving the building comprises five energy sources: Residual heat, Biomass, Waste-to-energy, Power plant (CHP), Gas boiler.
I downloaded the Large-Scale District Energy Calculator (2024Jul19), which supports Path 3 modeling. I have several questions regarding its use and the LEED methodology:
Questions
1. DES CO₂ Emissions Calculator Tab
In the Excel calculator:
- I assume the gas boiler (35%) falls under “Combustion Boiler.”
- The power plant (30%) is categorized as “CHP.”
- The remaining sources (35%) are “Other Recovered Waste Heat.”
Is this allocation correct based on LEED definitions?
2. Combustion Fuel Sources Table Issue
In the “Combustion Fuel Sources” tab:
- The first column lists fuel types (e.g., natural gas).
- The second column shows the percentage of the combustion boiler (35%) using natural gas.
- However, the “% of Total Fuel Input CHP” must sum to 100%, but my CHP source is not derived from combustion.
How can I resolve this if my CHP input is zero?
3. Cooling Source Requirement
My DES does not provide cooling, yet the calculator requires a 100% allocation for cooling sources.
How should I address this in the calculator when no cooling is supplied?
4. Renewable Energy and GHG Impact
My DES includes biomass and waste heat reuse, which are renewable and low-carbon sources.
5. How can I ensure their positive impact on GHG emissions is reflected in the LEED evaluation?
If these sources are not properly accounted for, the system’s efficiency may be undervalued. From my understanding:
- Path 1 and Path 2 do not account for the DES system’s efficiency. Points are based solely on the building envelope and internal systems.
- Path 3 includes the DES efficiency in the performance evaluation.
Is this correct?
Thank you for your time!