Open Access
The rule that lets a factory buy power from someone other than its local DISCOM
Imagine being legally required to buy groceries only from one specific shop in your neighbourhood, regardless of whether a better priced option exists two streets away. That was effectively the position most large power consumers were in before Open Access, forced to buy exclusively from their local DISCOM regardless of price.
Open Access is the regulatory right that allows a sufficiently large consumer, typically above a certain minimum load threshold, to purchase electricity directly from a generator or trader of its choice, bypassing its local DISCOM for the actual power supply, while still paying the DISCOM regulated charges to use its wires for transmission and distribution. This has become an important channel for large industrial and commercial buyers seeking either cheaper power or specifically renewable power.
Open Access is the mechanism that makes corporate renewable power procurement genuinely possible in India, letting a factory in one state sign a direct deal with a solar or wind generator elsewhere, rather than depending entirely on whatever mix its local DISCOM happens to supply.
Related concepts
Merchant Power
What happens when a power plant sells electricity without a fixed buyer
REC: Renewable Energy Certificates
How a coal heavy company still gets to claim it uses green power
PPA: Power Purchase Agreement
The contract that makes a power plant bankable in the first place