Last updated: July 2026 · By Sri Ishaan Solar

Solar Leasing, RESCO & PPA Models for Telangana Businesses: Zero Upfront Cost Solar Explained

Not every business wants to buy a solar plant outright. If your factory, school, or shop would rather pay for solar power the way it pays for grid power — with nothing spent on equipment — there's a whole financing category built for exactly that: RESCO and PPA models. Here's how they actually work, what they typically cost, and how they stack up against owning the system yourself.

A quick note before we start

Most of the solar content you'll find online — including other guides on this site — covers ownership financing: you buy the solar system, either with cash or a bank/NBFC loan, and you own the asset from day one. That's the CAPEX (capital expenditure) route, and it's what most residential and a large share of commercial customers in Telangana use today.

This guide is about the other route: models where a third-party company owns the solar plant on your roof and you simply buy the electricity it produces, at an agreed rate, for a fixed number of years. This is broadly called the OPEX (operating expenditure) approach, and the two terms you'll hear most are RESCO and PPA. It's a genuinely different financial structure, not just a different loan product, so it's worth understanding on its own terms before you decide which way to go for your business.

What is a RESCO, exactly?

RESCO stands for Renewable Energy Service Company. It's a third-party developer or investor that puts up the capital for a solar installation, owns the equipment on its own balance sheet, and takes on the job of designing, installing, and running the plant for its entire operating life. You, the business, don't buy anything — you host the plant on your rooftop or open land and consume the power it generates.

The commercial relationship between you and the RESCO is governed by a Power Purchase Agreement (PPA) — a long-term contract that fixes the rate you'll pay per unit (kWh) of solar electricity, for a defined number of years. Structurally, many of these arrangements follow a BOOT pattern — Build, Own, Operate, Transfer — where the RESCO builds and owns the plant, operates it through the PPA term, and then transfers ownership to the customer (often for a nominal or pre-agreed price) once the contract ends.

In short: CAPEX means you buy the machine. RESCO/PPA means you buy the output.

How the zero-upfront-cost math actually works

Under a genuine RESCO/PPA structure, the developer funds 100% of the capital cost — panels, inverters, mounting structure, wiring, metering, and installation labour. There is no equipment purchase for the customer to finance, so there's no EMI, no down payment, and no loan on your books. That's the "zero upfront cost" pitch, and it's largely accurate for the equipment itself.

What's usually still the customer's responsibility, even in a RESCO deal:

• A structurally sound, shadow-free roof or land parcel, and any roof reinforcement it needs
• Site access and basic civil work coordination during installation
• Any statutory approvals tied to your premises (electrical inspectorate NOCs, building permissions, etc., depending on plant size)
• A minimum consumption commitment — most PPAs specify a "must-take" quantity of solar units per month or year

Instead of an EMI to a bank, you pay the RESCO for the units consumed, at the PPA rate, on a monthly billing cycle — much like your existing electricity bill from the DISCOM, except one line item now comes from the solar developer instead of TGSPDCL.

What does the PPA rate typically look like?

Published industry ranges for rooftop RESCO/OPEX tariffs in India generally fall between roughly ₹3.50 and ₹5.50 per unit, though the exact number in any specific deal depends on plant size, roof condition, PPA tenure, and the developer's cost of capital. Telangana's HT commercial and industrial retail tariffs, by comparison, run meaningfully higher once you add fixed/demand charges, fuel cost adjustment, and electricity duty on top of the base energy charge — which is the entire basis of the savings pitch behind RESCO solar.

PPA tenure: how long are you locked in?

Commercial and industrial rooftop PPAs commonly run 10 to 20 years, with some structured for as long as 25 years to track the panel's full productive life. There's a direct trade-off between tenure and rate: a shorter PPA (say 10-12 years) usually comes with a higher per-unit rate, because the developer has less time to recover its investment. A longer PPA (18-25 years) typically unlocks a lower rate, but ties your business to that agreement — and that counterparty — for a much longer stretch.

Before signing anything, it's worth thinking through questions like: What happens if your business relocates or the unit closes down mid-contract? Is there an exit clause, and at what cost? What happens if the developer itself is acquired or wound up? These aren't hypothetical — they're the kind of clauses a commercial or legal advisor should review in any PPA before signature.

Ownership, maintenance, and what happens at the end of the term

Because the RESCO owns the asset throughout the PPA, it also carries full responsibility for operations and maintenance — panel cleaning, inverter servicing, monitoring, insurance, and performance guarantees are all the developer's job, not yours. If output drops because of a fault, that's the RESCO's problem to fix, not an expense you absorb.

At the end of the PPA term, arrangements vary by contract, but two patterns are common in the Indian market:

• Transfer at end of term: under a BOOT structure, ownership passes to the customer once the PPA period is complete, sometimes for a nominal residual value.
• Earlier buyout option: many OPEX contracts also allow the customer to buy out the plant part-way through — commonly discussed in the 5-10 year range — at a price defined in the contract, if the business wants to convert to full ownership sooner.

Whichever pattern your contract uses, get the buyout formula and the end-of-term transfer terms written into the PPA itself — not left as a verbal understanding.

RESCO/PPA vs. buying your own system (CAPEX): side by side

Which businesses tend to prefer RESCO/PPA?

The trade-off is fairly intuitive once you see the table above. RESCO/PPA tends to suit businesses that:

• Want to move fast on cost savings without touching capital budgets or bank credit lines
• Prefer to keep solar as an operating expense rather than adding a depreciating fixed asset to the balance sheet
• Don't want the operational burden of managing their own O&M contract
• Are less certain about occupying the same premises for the full 15-25 year horizon and want that risk sitting with the developer's contract terms rather than a bank loan tied to them personally

Ownership (CAPEX/EMI) tends to suit businesses that:

• Can access reasonably priced business loan or working capital financing
• Want to capture accelerated depreciation and the full long-run savings once the loan is repaid
• Plan to stay in the same premises for the long haul
• Want direct control over the asset — choice of components, monitoring, and any future capacity expansion

Questions worth asking any RESCO/PPA provider

If you're evaluating a RESCO/PPA offer for your factory, shop, or commercial building in Telangana, these are the questions to get answered in writing before signing:

• What is the fixed PPA rate per unit, and does it escalate over the term (some PPAs build in a small annual escalation)?
• What is the minimum "must-take" consumption, and what happens if your actual usage falls below it?
• Who bears the cost of insurance, and what happens in case of damage (storm, fire, theft)?
• What performance guarantee is offered — is there a penalty if the plant underperforms its promised generation?
• What's the exit clause if you want to terminate early, relocate, or shut the unit down?
• Is there a defined buyout price at any point during the term, and how is it calculated?
• What happens to the plant and the PPA if the developer company is sold, merged, or wound up?

These are commercial and legal questions as much as technical ones — it's worth having your CA or company counsel review the PPA draft alongside the technical proposal.

Where Sri Ishaan Solar fits into this decision

To be clear about our own role here: Sri Ishaan Solar is a rooftop solar installer based in Bandlaguda, Hyderabad, working with homes and businesses — factories, schools, shops, and commercial buildings — across Telangana since 2017. We are not a RESCO or a financing company, and this guide is meant to explain the market landscape, not to advertise a RESCO/PPA product of our own.

What we can help with, regardless of which financing route you're leaning toward: an honest site assessment (roof condition, shading, sanctioned load), a realistic generation and savings estimate, and a design and installation that performs to spec. If you're comparing an ownership (EMI) quote against a RESCO/PPA offer from a developer, we're happy to sanity-check the technical side of either proposal so you're deciding on facts specific to your roof, not brochure numbers.