MERC Proposes New Rooftop Renewable Rules With Mandatory ESS And 70% Grid Capacity Cap In Maharashtra

The Maharashtra Electricity Regulatory Commission (MERC) has released its Draft Grid Interactive Rooftop Renewable Energy Generating Systems Regulations, 2026, proposing an updated framework for rooftop solar and other grid-connected renewable energy systems across Maharashtra. The draft regulations have been prepared under Sections 86(1)(e) and 181 of the Electricity Act, 2003.

The proposed framework covers Net Metering, Net Billing, Group Net Metering, Gross Metering and Virtual Net Metering arrangements. It also includes grid-connected systems operating behind the meter without exporting electricity to the grid. Eligible consumers can install systems up to their contracted demand or sanctioned load, while behind-the-meter systems can be installed without a contract demand limit if they do not inject power into the grid.

Consumers would also be permitted to change their metering arrangement twice during the validity of their connection agreement through the distribution licensee’s online portal.

A major feature of the draft is the proposed mandatory Energy Storage System (ESS) requirement. New grid-interactive rooftop and behind-the-meter systems above 100 kW would have to incorporate storage. The requirement would be equivalent to 50% of installed capacity with a two-hour duration or 25% of installed capacity with a four-hour duration. A minimum storage requirement of 1 kWh per kW of installed capacity would apply until 2030, increasing to 2 kWh per kW thereafter.

The draft also proposes limits on rooftop renewable capacity connected to individual distribution transformers or feeders. The cumulative connected capacity would generally be restricted to 70% of the rated capacity of the concerned transformer or feeder. Distribution licensees could permit higher capacity after carrying out detailed load studies.

Technical safeguards would include automatic anti-islanding and synchronization systems to prevent electricity injection during grid outages. Inverters would also be required to provide harmonic filtering and daily generation data sharing in accordance with applicable national standards. Unannounced behind-the-meter installations above 1 kW would attract additional fixed charges at twice the applicable default rate.

The proposed banking framework would vary according to the prosumer’s contracted renewable capacity. Systems up to 3 kW would receive annual banking without time-slot restrictions or banking charges, while systems between 3 kW and 10 kW would follow monthly settlement. Larger systems would use monthly settlement across multiple time slots and would be subject to fixed and variable banking and standby charges.

For systems above 5 MW, banking would be limited to 10% of consumption per slot, with the framework moving toward 15-minute scheduling and withdrawal of banking services after three years.

Connection applications and fee payments would be processed electronically. Connection agreements would remain valid for 20 years, while existing systems would continue under their existing regulations until expiry, capacity enhancement or voluntary migration.