Typically, two procurement models are used: third-party PPAs and captive or group captive models.
Third-Party PPAs - In this model, a third-party investor or Solar developer invests in an Open Access project and sells the power to corporates via a PPA, eliminating upfront investment and Operation & Maintenance (O&M) responsibilities is at the developers end. However, the corporate buyer is liable to pay the Open Access charges incurred from the wheeling of power from the generated site to the buyer’s location.
Captive / Group Captive Model - In the captive model, the corporate buyer makes an upfront capital investment in the Open Access project. The buyer owns, operates, and maintains the power generating asset. Open access charges are also applicable but unpredictable charges, such as the cross-subsidy surcharge and additional surcharge, are waived off. In addition, the buyer (i.e., the owner of the power generating asset) is also eligible to claim tax benefits through accelerated depreciation. Another variant of the captive model is the group captive model, wherein the Open Access project is developed for collective usage by many corporate buyers. The model is considered group captive if at least one of the corporate buyers holds a minimum of 26% of equity in the project and consumes at least 51% of the power generated.