What if going solar did not mean buying the entire rooftop system upfront? That is the simple promise behind the opex model solar structure. India’s grid-connected rooftop solar capacity reached 25.73 GW as on 31 March 2026, while MNRE’s rooftop solar programme continues to target 40,000 MW. As rooftop solar adoption grows, financing models that reduce upfront investment are becoming important for businesses that want clean energy without locking capital into asset ownership.
For businesses, the question is no longer just whether solar makes sense. It is also about how easily it can be adopted. This blog explains how the OPEX solar model works and when it becomes a practical choice for businesses looking at clean energy without heavy capital spending.
The OPEX solar model in India is typically structured through a Power Purchase Agreement (PPA). In this model, a third-party developer installs, owns, and manages the system, while the business pays only for the electricity consumed at a pre-agreed tariff. This ensures predictable energy costs, improves cash flow visibility, and allows businesses to focus on core operations without technical involvement.
In practice, this means -
This is why OPEX is often referred to as a “pay-as-you-go” solar model, making adoption easier for businesses that prioritize liquidity and operational simplicity.
OPEX solar model powers savings without asset ownership
In a typical solar opex model, the customer and the developer sign a Power Purchase Agreement. This agreement defines the solar tariff, contract period, billing structure, system responsibilities, and performance expectations.
Here’s how the process usually works -
1. Rooftop assessment and feasibility check
2. System design and solar generation estimate
3. PPA discussion and tariff finalization
4. Installation of rooftop solar panels
5. Grid connection and required approvals
6. Monthly billing for solar power consumed
Since the developer owns and manages the plant, the customer does not have to handle maintenance, repairs, or performance monitoring. The business simply consumes solar electricity and pays the agreed tariff, making the opex model solar rooftop structure especially useful for commercial buildings, institutions, factories, and MSMEs with steady daytime power demand.
The opex model solar rooftop option makes sense when a business wants to adopt solar but does not want to use internal capital for asset ownership.
It can be useful for -
1. Businesses with limited capex budgets
2. Commercial buildings with high daytime usage, where renewable power procurement can reduce grid tariff exposure by 20% to 30%
3. MSMEs looking for lower investment pressure
4. Institutions with long-term rooftop availability
5. Companies with sustainability targets
6. Businesses that prefer developer-led solar maintanence
The broader solar adoption environment also supports this shift. According to PIB (Press Information Bureau), India’s solar energy installed capacity increased from 2.82 GW in March 2014 to 150.26 GW in March 2026, highlighting the scale at which solar is becoming part of India’s energy transition. For businesses, this makes it important to evaluate adoption models such as OPEX or PPA-led solar that can support a clean energy transition without a heavy upfront capital commitment.
However, the model should be evaluated carefully. The business should review tariff escalation, PPA tenure, roof access terms, minimum consumption clauses, termination conditions, and long-term savings.
Understanding the OPEX solar model is useful, but its real advantage lies in easier adoption. Tata Power Solaroof offers an OPEX / PPA route where businesses can switch to rooftop solar through a pay-for-power structure instead of buying the system up front. This helps reduce initial investment pressure while keeping capital free for core business priorities.
Here’s how Tata Power supports businesses with the OPEX solar model -
Lower upfront investment pressure
Businesses can explore rooftop solar through an OPEX or PPA-led structure, reducing the need to bear the entire system cost at the beginning
Pay-for-power structure
Instead of owning the system outright, businesses pay for the solar electricity generated, making solar adoption easier to plan as an operating expense.
Long-term financing flexibility
Tata Power Solar’s non-residential OPEX financing information mentions tenure options of 5 to 25 years, helping businesses align solar adoption with longer-term energy planning
Operations and maintenance support
Under the OPEX structure, plant maintenance and insurance support are handled by the provider, reducing the operational responsibility for the customer
Suitable for commercial and industrial users
The model is relevant for businesses, institutions, and industrial users that want rooftop solar benefits without taking on full asset ownership from day one
Structured solar adoption journey
By combining financing, implementation, and service support, the OPEX route helps businesses move to solar in a more planned and practical way
Businesses can explore rooftop solar through an OPEX or PPA-led structure, reducing the need to bear the entire system cost at the beginning
Tata Power’s Meri Roof Meri Takat initiative also shows the business value of rooftop solar in practice. For instance, Vithani Textiles, a Gujarat-based textile business, saved over ₹48 lakh every year after going solar, while MU Plus Pvt. Ltd., a Srirampur-based manufacturing plant, reduced its monthly manufacturing bills by around ₹4 lakh.
While these are broader rooftop solar examples, they reinforce why businesses with steady power demand often evaluate models such as OPEX/PPA to access solar benefits without heavy upfront capital commitment.
Curiosity has its rewards
The opex solar model is a practical route for businesses that want solar power without turning it into a large upfront capital purchase. It gives customers access to clean energy, lower investment pressure, and developer-led maintenance. At the same time, it needs careful review of tariffs, tenure, ownership terms, and long-term savings. For businesses comparing CAPEX, OPEX, loans, or EMI-led solar financing, the smarter approach is to assess electricity usage, rooftop potential, and cash-flow priorities first. With the right partner, solar can move from a cost decision to a long-term business advantage.
The frequently asked questions section is a reliable source for unlocking answers to some of the most crucial inquiries. Please refer to this section for any queries you may have.
CAPEX means the customer buys and owns the rooftop solar system. OPEX means the system is owned by a third-party developer, while the customer purchases the electricity generated. In CAPEX, the customer bears the system cost and receives ownership benefits. In OPEX or RESCO, the developer handles ownership, operations, and maintenance, while the customer pays a monthly tariff under a PPA.
Yes, the OPEX solar model can work well for businesses that want solar power without a high upfront investment. It is especially useful when a company has steady electricity usage, suitable rooftop space, and long-term site availability. However, businesses should review the PPA carefully, including tariff, tenure, escalation, minimum usage clauses, and exit terms, before choosing the model.
Businesses should avoid the OPEX solar model if they want full asset ownership, faster payback, or complete control over system design and lifecycle gains. It may also not suit users with uncertain long-term rooftop access, low daytime consumption, or concerns around long PPA tenures, since OPEX structures can run for 5 to 25 years.
RESCO stands for Renewable Energy Service Company. In rooftop solar, the RESCO developer finances, installs, operates, and maintains the solar power plant. The customer uses the generated electricity and pays a pre-decided monthly tariff. This model is closely linked to the solar opex model because the customer treats solar as an operating expense rather than buying the system.
No, in most OPEX or RESCO solar arrangements, the customer does not maintain the solar plant. The responsibility for operations and maintenance usually remains with the developer for the system's life or the agreement period. This is one of the key reasons businesses choose the solar OPEX model, because they can consume solar power without directly managing technical maintenance, repairs, performance checks, and system upkeep
A solar PPA, or Power Purchase Agreement, is the contract that defines how a customer buys solar electricity from a developer. It covers key details such as the agreed tariff, contract tenure, billing terms, system responsibilities, and performance expectations. In the OPEX solar model, the PPA becomes especially important because the customer does not own the system but pays for the power generated
The OPEX solar model and solar loans serve different needs. A solar loan helps a business buy and own the system, while OPEX allows solar adoption without full asset ownership. OPEX may suit businesses that want lower upfront investment and provider-led maintenance. A loan may suit businesses that want ownership and long-term asset value. Tata Power Solar’s business financing information lists both CAPEX and OPEX options for non-residential solar projects
1. Grid Connected Rooftop Solar Programme – MNRE
2. Physical Achievements – MNRE (Renewable energy)
3. Affordable solar financing in India for homes & businesses
4. MNRE Knowledge Centre: Rooftop Solar
5. Solar That Shines Power, Style & Savings!
6. OPEX vs CAPEX solar model: What is best for your company today and over the next decade
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