Distributed Energy Resources and Smart Grids

Small-scale, near the consumer, not at a central power station

A Distributed Energy Resource (DER) is any electricity generation or storage device located at or near where the electricity is actually used, rather than at a large, centralised power plant far away feeding power one-way down transmission lines to consumers. Rooftop solar panels, battery storage systems, biomass-based generators, and fuel cells are all genuine examples of DERs, since each one generates or stores power right at the point of consumption rather than requiring long-distance transmission from a central station.

The consequence worth understanding is structural, not just technical: a grid built around a small number of large, central plants sending power one way outward is a fundamentally different system to manage than one where power can also flow inward, from thousands of small rooftop installations back into the grid. This is the central problem a smart grid is built to solve.

Net metering: how a rooftop owner becomes a small power producer

Net metering is the mechanism that makes rooftop solar genuinely useful to both the owner and the grid, not just to the owner. A consumer with rooftop solar generates their own electricity for their own use, and any surplus they do not consume is fed back into the grid, effectively turning that consumer into a small power producer. India's Electricity (Rights of Consumers) Rules, 2020 provide for net metering up to 500 kilowatts or the consumer's own sanctioned electrical load, whichever is lower, and all State and Union Territory electricity regulatory commissions have notified their own net or gross metering regulations to implement this at the state level.

Smart grids: the infrastructure that makes two-way power flow manageable

India's National Smart Grid Mission, under the Ministry of Power, is the programme built to modernise the grid for exactly this two-way reality, focused on advanced metering infrastructure and broader grid modernisation, with integrating rooftop solar and monitoring distribution transformers as explicit priorities.

Smart meters are the foundational sensor layer underneath this modernisation. Unlike a traditional meter, which only records total consumption for periodic billing, a smart meter reports data close to continuously, letting a utility see demand patterns, detect outages far faster, and safely manage the variable, sometimes unpredictable output flowing in from thousands of distributed rooftop and battery sources simultaneously, none of which a traditional one-way metering system was ever designed to handle.

Quick revision points

• A Distributed Energy Resource (DER): generation or storage located near the point of consumption, not at a large central plant. Genuine examples: rooftop solar, battery storage, biomass generators, fuel cells.
• DERs turn a traditionally one-way grid (central plant to consumer) into a two-way system, which is the core problem smart grid technology exists to manage.
• Net metering: lets a rooftop solar owner feed surplus power back to the grid, becoming a small producer. India's Electricity (Rights of Consumers) Rules, 2020: net metering up to 500 kW or the sanctioned load, whichever is lower. All States/UTs have notified their own regulations.
• National Smart Grid Mission (Ministry of Power): focused on advanced metering infrastructure and grid modernisation, with rooftop solar integration and distribution transformer monitoring as explicit priorities.
• Smart meters: report near-continuously rather than only for periodic billing, letting utilities manage variable, two-way power flow from many small distributed sources, something a traditional one-way metering system cannot do.