Net Metering Calculator
Estimate your monthly solar bill under time-of-use net metering. Enter your production, usage, peak/off-peak rates, and connection fee to see exactly what you owe or earn back.
About this calculator
Net metering credits solar-panel owners for excess electricity sent to the grid. With time-of-use (TOU) pricing, the value of that electricity depends on when it is produced and consumed. This calculator splits both production and usage into peak and off-peak portions using the percentage of energy generated during peak hours. The net bill formula is: Bill = [(monthlyProduction × peakPct × peakRate) + (monthlyProduction × (1 − peakPct) × offPeakRate)] − [(monthlyUsage × peakPct × peakRate) + (monthlyUsage × (1 − peakPct) × offPeakRate)] + connectionFee. A negative result means your utility owes you a credit; a positive result is what you pay. Understanding TOU net metering helps solar owners shift loads or size battery storage to maximize savings.
How to use
Suppose your panels produce 600 kWh/month and you use 500 kWh. Your peak rate is $0.28/kWh, off-peak is $0.12/kWh, 60% of production occurs during peak hours, and the connection fee is $10. Peak credit = 600 × 0.60 × $0.28 = $100.80. Off-peak credit = 600 × 0.40 × $0.12 = $28.80. Peak charge = 500 × 0.60 × $0.28 = $84.00. Off-peak charge = 500 × 0.40 × $0.12 = $24.00. Net bill = ($100.80 + $28.80) − ($84.00 + $24.00) + $10 = $21.60 credit returned to you after the connection fee.
Frequently asked questions
How does time-of-use net metering differ from standard net metering?
Standard net metering credits all exported solar energy at a single flat retail rate regardless of when it is produced. Time-of-use (TOU) net metering assigns different credit rates depending on whether the electricity flows during high-demand peak hours or lower-demand off-peak hours. This means solar energy exported during afternoon peak periods may be worth significantly more than energy exported at night or on weekends. Homeowners with TOU rates can maximize savings by shifting appliance use to off-peak windows or adding battery storage to dispatch power during peak hours.
What is a good percentage of solar production during peak hours?
For a typical south-facing rooftop system in the continental US, roughly 50–70% of daily production occurs during utility-defined peak windows, which often run from late morning through early evening. The exact share depends on your panel orientation, local peak-hour definition, season, and latitude. West-facing panels can push peak-hour production above 70% since they capture more afternoon sun. Checking your inverter's hourly production data against your utility's TOU schedule is the most accurate way to determine your personal peak-production percentage.
Why is there still a monthly connection fee even when solar covers all my usage?
Utilities charge a fixed monthly connection or service fee to recover the cost of maintaining the grid infrastructure — poles, wires, meters, and billing systems — regardless of how much electricity flows through them. This fee applies even if your solar system produces more than you consume, because you still rely on the grid as a backup and for net-metering credit transfers. Connection fees typically range from $5 to $25 per month and are separate from energy charges. Some utilities are lobbying to increase these fees for solar customers, so it is worth monitoring your tariff schedule annually.