First Solar Bill Explained Calculator
See your first 3 months of solar bills side-by-side — connection charges, export credits, NEM bank balance, and why you still got a bill.
| Line Item | Before Solar | Month 1 (Apr — partial) | Month 2 (May — full) | Month 3 (Jun — full) |
|---|---|---|---|---|
| Connection charge | $10.00 | $10.00 | $10.00 | $10.00 |
| Solar production | — | 516 kWh | 1,152 kWh | 1,257 kWh |
| Grid import charges | $140.00 | $77.76 | $11.26 | $25.92 |
| Export credits (14¢/kWh) | — | -$0.00 | -$11.26 | -$25.92 |
| NEM bank balance (rolling) | — | — | $11.26 | $37.18 |
| Net bill due | $150.00 | $87.76 | $10.00 | $10.00 |
How to Use This Calculator
Enter your pre-solar bill
Enter your average monthly electric bill before solar was installed. This establishes your baseline consumption in kWh and the savings potential for your system.
Enter system details
Enter your system size (from your installation contract or monitoring app), select your city for seasonal production data, and choose the month your system was activated — the PTO (Permission to Operate) date on your utility approval letter.
Select your net metering type
This is the most important input for post-solar bill accuracy. Check your utility's net metering policy: Full retail NEM means exported kWh credit at the same rate you pay to import. Avoided cost means exports earn only 3–5¢/kWh. No NEM means excess solar has zero monetary value.
Read the month-by-month table
The table shows all bill line items across three months — including the connection charge that never disappears, solar production, grid charges, export credits, and the NEM "bank balance" that accumulates under full retail net metering.
Anatomy of Your Post-Solar Bill
Most solar owners are surprised by their first bill. Here's every line item explained:
| Line Item | What It Means | Goes Away With Solar? |
|---|---|---|
| Customer/connection charge | Fixed monthly fee for grid access — poles, wires, meter | No — always there |
| Energy charges | Electricity you imported from the grid (kWh × rate) | Partially — solar offsets this |
| Solar export credit | kWh you sent to grid × export rate (NEM type) | N/A — appears after solar |
| NEM bank balance | Accumulated credits rolled over month to month | N/A — only with retail NEM |
| Annual true-up | Annual reconciliation of credits vs charges | N/A — replaces monthly billing |
| Delivery charges | Distribution infrastructure costs | Usually no |
| Demand charge | Commercial accounts only — peak 15-min power draw | Partially with battery |
The 3 Most Common Post-Solar Bill Confusions
"Why did I still get a bill?"
You will almost always get a bill after going solar — just a much smaller one. The connection charge ($5–$25/month depending on utility) covers your physical grid connection and never goes away regardless of solar production. Additionally, if your system doesn't fully offset 100% of consumption, you'll still pay for grid imports at night and on cloudy days.
"What's this bank balance I'm carrying?"
Under full retail NEM, when you export more than you import in a month, the excess credits don't convert to a cash payment — they roll into a "bank" on your utility account. This bank accumulates through summer (high production) and draws down in winter (high consumption). At your annual true-up date, the utility settles the final balance — often at a lower "avoided cost" rate for any remaining credit, depending on your tariff.
"Month 1 was disappointing — is my system working?"
Month 1 is almost never representative. Your system was only active for a portion of the billing period — often 15–20 days. Production is prorated. The connection charge represents a larger fraction of a shorter production period. Give it 3 full months before judging system performance. Use your monitoring app (Enphase Enlighten, SolarEdge, SMA) to verify daily production matches your installer's estimates.