In Maharashtra, commercial and industrial solar installations exceeding sanctioned capacity thresholds (typically above 1 MW or defined DISCOM limits) operate under the Net Billing (Gross Feed-in) framework rather than traditional 1:1 Net Metering. Under Net Billing, all power generated and self-consumed on-site directly displaces retail utility tariffs, while any surplus energy exported to the utility grid is purchased by the DISCOM at the Average Power Purchase Cost (APPC) tariff and credited against your monthly bill.
Dual-tariff energy settlement for large industrial systems.
Energy imported from the grid is billed at your normal retail slab tariff (e.g. ₹9.50/unit), while energy exported to the grid is credited at the DISCOM APPC rate (typically ₹3.00 - ₹3.50/unit). Optimizing system sizing for direct self-consumption maximizes ROI.
Industrial facilities with solar plants larger than 1 MW or restricted net-metering allocations.
Displaces full retail rate (₹9.50/u) instantly
Surplus credited at lower DISCOM APPC tariff
System sized strictly to match baseline daytime load
Because exported units are compensated at lower APPC rates, engineering under Net Billing requires precision load profiling rather than maximizing panel surface area.
Baseline Daytime Sizing
Size the solar plant around your factory minimum daytime operating demand, ensuring 85%+ of generated energy is consumed directly.
BESS Arbitrage Layer
Incorporate battery energy storage (BESS) to capture surplus daytime solar energy for evening discharge rather than low-value APPC export.
Bi-Directional TOD Logging
Deploy automated 15-minute Time-of-Day telemetry meters that track import and export cycles aligned with DISCOM billing software.
| Parameter | Net Billing (Gross Feed-in) | Net Metering (1:1 Banking) | Zero-Export Installation |
|---|---|---|---|
| Capacity Limit | Above 1 MW (or DISCOM cap) | Up to 1 MW (DISCOM limits) | Unlimited (subject to load) |
| Imported Energy Rate | Standard retail slab rate | Standard retail slab rate | Standard retail slab rate |
| Exported Energy Rate | DISCOM APPC rate (~₹3.20/u) | 1:1 retail credit offset | 0 export allowed (throttled) |
| Bi-directional Meter | Required with net billing PPA | Required with net meter PPA | Standard meter + reverse relay |
| Best Sizing Strategy | Match baseline daytime load | Match annual net consumption | Match peak instantaneous load |
