India’s new power lines should be measured by the electricity they can deliver

The useful measure of a transmission project is the electricity it makes deliverable when someone needs it. India’s July parliamentary assessment cites a plan to expand the transmission network from 5.09 lakh circuit-kilometres in June 2026 to 6.48 lakh by 2032, with transformation capacity rising from 1,478 GVA to 2,345 GVA. Those are large changes in physical infrastructure. The return will depend on where the lines are built, which generation and demand they connect, and the timing of completion on both sides. Parliamentary reply, transmission adequacy · CEA, National Electricity Plan, Transmission

Why distance is a poor measure of value

Circuit-kilometres describe the length of electrical circuits. They do not indicate how much additional power can flow between two locations in a critical hour. That depends on voltage, ratings, topology, other grid elements and security limits. A short connection to a constrained substation can release more usable capacity than a long line to a site where no generation is ready. Extra transformer capacity can matter when the main line has room and the local connection cannot receive more.

Transmission can also diversify supply. A region facing an evening shortage can import from a region with spare output if there is a usable path and the supply is available at the same time. A surplus of annual renewable generation says little about the value of that path in a particular evening. A good appraisal uses hourly conditions, including maintenance and the correlated effect of weather on output and load. CEA, National Electricity Plan, Transmission · Parliamentary reply, transmission adequacy

A route buys relief from a constraint

Suppose a line makes 100 MW of otherwise constrained generation available for 500 hours a year. That is 50 GWh, or 50 million kWh. If it displaces electricity costing ₹2 more per kWh, the illustrative saving is ₹10 crore a year before losses and other effects. If the same 100 MW is usable for only 100 hours, the energy saving falls to ₹2 crore. Both designs can have the same nominal rating. The direction and duration of the constraint determine the value.

The actual comparison should also account for curtailed output, reduced outage risk and changes in losses. Some benefits are shared across states. A state may be unwilling to pay the whole cost of a route if consumers elsewhere enjoy part of the savings. Cost allocation can delay or distort a project with positive total value. Identifying who gains from added transfer capability can make a shared tariff easier to defend.

The cost of waiting and the cost of arriving early

The strongest case for building ahead of utilisation is the long lead time of a grid project. Waiting for every generator to commit can delay both investments when each depends on the other. A line delivered far ahead of its customers can leave consumers carrying its financing costs. Coordination should distinguish projects whose value holds across several generation scenarios from specialised links that depend heavily on one counterparty. Stage the latter when a credible construction commitment exists, and avoid delaying robust shared connections until the queue is visible.

Publish the constrained hours, delivered flows and project-level commissioning dates, alongside generation connection status. Report where forecast savings depended on renewable generation that has not arrived and where congestion remained after commissioning. Compare planned capital cost with the measured reduction in expensive dispatch or curtailed generation. If a line relieves a recurring bottleneck under several demand scenarios, early investment is easier to justify. If usage remains low because the last connection is missing, completion of that connection can be more valuable than another announcement of circuit length.

Construction timing should be compared with alternatives such as reconductoring an existing line or improving how a substation is operated. A smaller intervention that releases capacity sooner can be valuable even when a new route will eventually be needed. Appraisals should count the value of the years of constraint avoided.

India’s plan will earn its return in the hours when a particular line changes which generator can serve a consumer. Those hours should be visible in the public record.