Path-Q Solar
Can solar savings be estimated when my electricity bills vary widely from month to month?
Answer
Yes. Use a full year of consumption, preserve the monthly pattern, and model solar production month by month rather than relying on an average monthly bill. Large variation often reflects heating, cooling, occupancy, or rate effects that should be identified separately.
Key points
- Annual kilowatt-hours are needed for overall sizing, while monthly data helps estimate grid purchases and exports.
- Separate usage variation from price variation when bills change.
- Extreme or abnormal months should be documented rather than automatically treated as normal.
- Future changes in seasonal loads should be modeled as scenarios.
What it depends on
- Monthly consumption rather than bill dollars alone
- Cause of seasonal variation
- Monthly solar production
- Electricity pricing and export treatment
- Future heating, cooling, or occupancy changes
Risks and trade-offs
- Using bill totals without usage data can confuse rate changes with energy use.
- A single unusual year can distort the system size.
- Average annual estimates can hide winter shortfalls or summer excess.
Information you may need
- At least 12 months of usage and bills
- Rate and billing-period details
- Heating, cooling, and occupancy patterns
- Planned changes to major loads
Your next step
What to do next
Create a monthly consumption table and compare it with month-by-month production and savings estimates from the proposed system.
Path-Q
Find the right next step
Answer a few questions and we’ll narrow your options.
Loading…
SQ00931