The Petroleum and Natural Gas Regulatory Board (PNGRB) has floated draft guidelines for blending up to 5 per cent hydrogen with natural gas supplied to domestic piped natural gas (D-PNG) consumers through city gas distribution networks, marking a regulatory step towards using existing gas infrastructure for hydrogen delivery.
The draft guidelines set minimum requirements for the commercial supply of hydrogen-natural gas mix, or HNG, in small deployment areas served through a single injection point. These areas must be hydraulically defined and confined to domestic consumers, according to the proposal reported by The Hindu BusinessLine.
PNGRB has clarified that 5 per cent hydrogen by volume would be the maximum commercial concentration permitted under the draft framework, rather than the routine operating level. The normal operating setpoint would have to be lower and sufficient to prevent hydrogen injection from exceeding the permitted concentration during peak or minimum demand, start-up, shutdown and system disturbances.
The proposed framework places measurement and verification at the centre of the blending process. PNGRB defines the “Maximum Commercial Blend Limit” as 5 per cent hydrogen by volume, demonstrated through measurement and verification arrangements approved for the relevant area. This means that any commercial deployment would have to operate within an approved and monitored zone rather than across an unrestricted gas network.
The move is relevant to India’s city gas distribution system, which supplies piped natural gas to households through local networks. By focusing the draft guidelines on domestic consumers and limited deployment areas, the regulator has outlined a controlled approach to testing hydrogen-natural gas blends before any wider application is considered. The draft, however, does not establish a nationwide rollout of hydrogen-blended gas.
The proposal follows PNGRB’s earlier work on transporting green hydrogen through natural gas transmission lines. In March 2024, the regulator said it was examining ways to move green hydrogen through existing gas transmission infrastructure and was considering gas transmission lines as a first choice for its transportation. Hydrogen can serve as an energy carrier for multiple applications, including the integration of renewable energy and transport.
For households connected to city gas networks, the immediate significance of the draft lies in the operating controls it would require from gas distributors. The regulator’s emphasis on lower routine setpoints, approved areas and monitoring arrangements indicates that commercial supply would depend on maintaining the blend within defined technical limits under changing demand and operating conditions.
The draft guidelines therefore link hydrogen deployment to the existing institutional structure of city gas distribution rather than proposing a separate household delivery network. Their implementation would depend on the final regulatory framework and the approval of specific commercial deployment areas. PNGRB has floated the guidelines as a draft and has not, in the supplied material, announced a general start date for household supply of hydrogen-blended gas.
