Rooftop solar typically meets only a slice of an industrial load — the roof runs out long before the demand does. Open access is how you buy the rest: power generated at a plant somewhere else and wheeled to your meter over the state network. It is also where most of the administrative work in Indian solar actually lives.
What open access is
The Electricity Act 2003 gave large consumers the right to buy power from someone other than their local distribution company and have it delivered over the existing network. You pay the generator for the power and the network owner for carriage. Nothing physical changes at your site — the same wires, the same meter, a different supplier behind them.
Green Energy Open Access rules have progressively lowered the entry threshold, and in many states the route now opens from 100 kW of contracted demand rather than the 1 MW that applied for years. The threshold, the charges and the approval path are all state-specific.
The three ways to structure it
You simply buy power from a generator under a PPA. Simplest to sign; carries the full charge stack including cross-subsidy surcharge.
You own the generating asset outright and consume its output. No cross-subsidy surcharge, but the capital is yours.
You take at least 26% equity in the generating company and consume at least 51% of its annual output. Surcharge relief without funding the whole plant.
Group captive is the structure most C&I buyers end up in, because it removes the surcharges that otherwise erode the saving while keeping the capital requirement modest. The catch is that both tests are applied every year, not once at signing — and consumption drifts as shifts change and lines are added or shut.
What the charges actually are
The tariff you agree with the generator is not the landed cost. On top of it sit transmission charges, wheeling charges, losses in kind, a state cess, and — depending on structure — cross-subsidy surcharge and additional surcharge. Banking charges apply where banking is available.
Any comparison that shows you a per-unit generation tariff against your current bill is not a comparison. The number that matters is landed cost at your meter, after every charge, against your current effective tariff for the same units.
The approval chain
This is the part that determines whether a project happens on schedule or at all, and it runs through several bodies:
- Eligibility — confirm the connected-load threshold and the applicable state policy
- Connectivity — apply to the transmission or distribution utility for a connection point
- Open access approval — short, medium or long term, at state or central level depending on where the generator sits
- Structure — incorporate the SPV and put the shareholding in place if group captive
- Metering — ABT-compliant meters at both ends, tested and sealed
- Scheduling registration — register with the load despatch centre for day-ahead scheduling
- Commercial go-live — energisation, then monthly settlement against scheduled versus actual
Two of these — land with clean title, and a connectivity slot — take longer than building the plant. They are the reason projects slip by quarters rather than weeks, and they are the reason we do both in-house rather than through a consultant.
After it is energised
Open access is not a set-and-forget arrangement. Someone has to schedule day-ahead, manage deviation settlement, handle banking drawdown inside the state's window, reconcile the DISCOM invoice, and monetise surplus. Savings leak here quietly and continuously if nobody owns it.
Open access is state-regulated and the position changes with each commission order. Eligibility, charges and banking rules are confirmed against the applicable SERC order before we quote. This is a general explainer, not advice on a specific connection.