Understanding Parasitic Load Percentage
How we calculate. Parasitic % = station service energy ÷ gross generation × 100. The form uses the same arithmetic as the worked examples on this page. See our methodology and accuracy policy.
Real-world scenario: A typical Parasitic Load Percentage case uses auxiliary / station service (mwh) 3000 and gross generation (mwh) 100000. Enter the same figures below to reproduce the worked path.
What is Parasitic Load Percentage?
A plant netting KPI. Distinct from T&D loss % (network delivery) and battery RTE (storage in/out).
- Gross = generation before station service
- Aux = house load / parasitic for the unit
- Same period
The Formula
Worked Example
Common Use Cases
- Plant heat balances: house load share
- Net vs gross reviews: parasitic drag
- Outage planning: aux while offline (label separately)
Pro Tips
- Don’t mix T&D losses into plant aux
- Label gross vs net MWh on CF pages
- Freeze which auxiliaries are in scope
Limitations: Parasitic Load Percentage results are educational energy and utilities planning aids—not engineering, grid-operations, or investment advice. Confirm definitions with your ISO/RTO, plant, and regulatory reporting standards.
FAQ
Same as T&D loss %?
No. T&D loss is network injected vs delivered. Parasitic load is plant auxiliary energy vs gross generation.
What if gross generation is 0?
Parasitic % is undefined—enter positive gross generation (or use a dedicated offline-aux metric).
Authoritative References
For power system and plant performance concepts, consult: