RESCO

Key Takeaways

• RESCO = solar OPEX-model provider in India.
• Owns plant; customer pays per kWh.
• Major segment of C&I solar market.
• Common term: “RESCO PPA” = OPEX solar deal.
• Differentiated from EPC (which builds for an owner).

How the RESCO Model Works

A RESCO installs, finances, and operates a rooftop or ground-mount solar plant on a customer’s premises at no upfront capital cost to the customer. The RESCO holds title to the equipment, carries the O&M obligation for the PPA term (typically 15-25 years), and bills the customer only for the electricity actually generated, at a fixed or escalating per-unit rate that is set below the prevailing DISCOM tariff. Because the asset sits on the RESCO’s own balance sheet rather than the customer’s, a C&I buyer gets the savings of a captive solar plant without the capital outlay, the depreciation accounting, or the long-term O&M responsibility — all of which stay with the RESCO.

This is the structural opposite of the CAPEX route, where the customer buys the plant outright through an EPC contract and owns every rupee of the savings (and every rupee of the maintenance risk) from day one. For a factory or commercial building deciding between the two, the trade-off is usually IRR and balance-sheet impact versus long-term savings: CAPEX ownership produces a higher effective return over the plant’s life, while a RESCO PPA converts that same benefit into a predictable, off-balance-sheet operating expense.

Worked Example

Consider a mid-sized textile unit with a monthly grid bill built on a DISCOM commercial tariff. Under a RESCO arrangement, the RESCO funds and installs a rooftop system sized to the unit’s daytime load, retains ownership, and signs a PPA that charges the factory a fixed per-kWh rate for solar units consumed — set meaningfully below the grid tariff so the customer sees an immediate reduction in its electricity cost with zero capital deployed. The RESCO recovers its investment over the PPA tenure through that per-unit billing, while remaining responsible for insurance, inverter and module upkeep, and performance guarantees for the life of the contract.

Related Reading

For teams comparing ownership models, OPEX Model (Solar) and CAPEX Model (Solar) lay out the balance-sheet and IRR mechanics that make a RESCO PPA attractive to some buyers and not others, and Heaven Designs’ Heaven Green Energy team works directly with RESCOs and C&I asset owners on the EPC side of these deals. Readers evaluating which model fits a specific project should also see the CFO’s decision framework for CAPEX, OPEX, and RESCO, which breaks down IRR, NPV, and balance-sheet treatment across all three structures, and Solar PPA vs CAPEX vs OPEX for Indian C&I buyers for a side-by-side comparison of tariff and risk-transfer outcomes. For the mechanics of the tariff and savings math behind a typical Opex/RESCO deal, the Solar Opex Model Explained guide covers how PPAs are structured and what EPCs need to engineer around. Once a RESCO plant is designed, it still needs to clear the same electrical inspection and commissioning steps as any other project — see Electrical CEIG Drawings for what that approval requires.