What Is Captive Open Access Solar (100% Equity Model)

For large industrial and commercial (C&I) consumers in India, rooftop space is often the biggest bottleneck to going green. You might have a monthly electricity bill of ₹50 lakhs but only enough roof space for a 100kW system. This is where Captive Open Access Solar India regulations change the game.

Commonly known as the "100% Equity" or "Captive" model, this arrangement allows businesses to own a solar plant located hundreds of kilometers away and "virtually" pipe that power to their factory or office using the existing state grid. In this comprehensive guide, we will break down how the captive model works, the legal requirements under the Electricity Rules 2005, and why it is the preferred choice for India’s largest corporations.

What is Captive Open Access Solar?

Captive Open Access is a regulatory framework that allows an electricity consumer to set up a power plant for their own use, even if the plant and the consumption point are in different locations.

In India, this is governed by the Ministry of Power under the Electricity Rules, 2005. To qualify as a "captive" user and avoid heavy penalties like the Cross-Subsidy Surcharge (CSS), your company must meet two critical criteria:

1. The Ownership Rule: The captive user(s) must hold at least 26% of the equity share capital in the special purpose vehicle (SPV) that owns the power plant.
2. The Consumption Rule: The captive user(s) must consume at least 51% of the annual aggregate electricity generated by the plant.

When a company owns 100% of the equity (the "100% Equity Model"), they are essentially their own power producer.

Why Choose Captive Over Rooftop Solar?

While rooftop solar is excellent for smaller loads, captive open access is built for scale.

The "100% Equity" Model Explained

In the 100% equity model, a business invests the full capital required to build a solar plant on a remote plot of land. They own the land (or lease it long-term), the panels, and the infrastructure. Because they own 100% of the equity, they naturally satisfy the "26% minimum" requirement.

This model offers the highest possible ROI because there is no "margin" paid to a third-party power developer. You are only paying for the wheeling and banking charges to the state utility.

Financial Comparison: Grid vs. Captive Solar (2026)

The primary driver for captive open access solar India is the massive gap between commercial grid tariffs and solar generation costs. In states like Delhi or Maharashtra, commercial tariffs can exceed ₹10/unit.

Commercial Solar Cost per kW Tiers (2026)

Landed cost for large-scale plants (excluding land and GST).

Note: These prices reflect the efficiencies of scale achieved in utility-scale ground-mounted projects used for open access.

Typical Savings Potential

If your current commercial electricity rate in Delhi is ₹9.00/unit, and your levelized cost of solar (after O&M and wheeling charges) is ₹4.50/unit, you are effectively cutting your power bill in half for the next 25 years.

How the Power Reaches Your Facility: Wheeling & Banking

Since the solar plant is off-site, you use the State Transmission Utility (STU) or DISCOM network to transport power. This involves three key costs:

1. Wheeling Charges: The "toll tax" paid to the DISCOM for using their wires.
2. Transmission & Distribution (T&D) Losses: A small percentage of electricity (usually 3–5%) "lost" during transit.
3. Banking Charges: Solar only generates during the day, but you might need power at night. Banking allows you to "store" excess day power with the grid and withdraw it later, for a fee.

One of the biggest advantages of the Captive Model is the exemption from Additional Surcharge and Cross-Subsidy Surcharge (CSS) in most states. In a Third-Party PPA model, these surcharges can be as high as ₹2–3 per unit, often making solar unviable. By owning the equity, you bypass these "taxes."

Real-World Example: A Textile Factory in North India

Let’s look at a medium-sized textile mill in an industrial hub like Noida Extension or Faridabad.

• Monthly Electricity Bill: ₹18 Lakhs
• Average Unit Cost: ₹8.50/unit
• Roof Capacity: Only 100kW (Needs 1.5MW to offset 80% of bill)
• Solution: 1.5 MW Captive Open Access Solar Plant.

Calculations:

• Annual Generation: ~22 Lakh units
• Solar Generation Cost (LCOE): ₹4.00 (includes wheeling/banking)
• Grid Cost: ₹8.50
• Savings per Unit: ₹4.50
• Annual Savings: ₹99 Lakhs
• Project Cost: ~₹5.4 Crores
• Payback Period: ~5.5 Years (excluding tax benefits like ACC Depericiation)

For businesses looking for financing, options like the SIDBI 4E Solar Loan offer rates between 8.5% and 10%, making the project cash-flow positive from Day 1.

The Role of Group Captive

What if one company isn't large enough to consume 51% of a 1MW plant? This is where Group Captive comes in.

Under the Group Captive model, multiple consumers (e.g., three different factories) come together to form an SPV.

• Collective Equity: They must collectively own 26%.
• Collective Consumption: They must collectively consume 51% in proportion to their equity.

This allows even MSMEs to enjoy the benefits of large-scale open access without huge individual land requirements.

Technical Maintenance: Ensuring 25 Years of Life

Building the plant is only half the battle. Because captive plants are remote, they are prone to soiling losses and equipment degradation.

At Bridgeway Power, we leverage our 35+ years of experience to manage over 25 MW of solar assets. Off-site plants require:

• String Monitoring: To detect a single failing panel among thousands.
• Automated Cleaning: Waterless robots or high-pressure systems to combat the 20-30% power loss caused by dust.
• Inverter Health Checks: Routine thermal imaging to prevent inverter failures.

Steps to Implement Captive Open Access Solar India

1. Feasibility Study: Analyze your 12-month load profile and local DISCOM rules.
2. Land Acquisition: Identify land near a substation with available "bay" capacity.
3. SPV Formation: Register a new company (SPV) where the consumer holds 26% or 100% equity.
4. Connectivity Approval: Get "In-principle" approval from the Transco/DISCOM.
5. Installation: Deploy High-efficiency Topcon Mono PERC panels.
6. Net Metering & Commissioning: Install ABT (Availability Based Tariff) meters for net metering.

Frequently Asked Questions

What is the minimum load required for Open Access in India?

In most Indian states, any consumer with a "Contract Demand" of 100 kW or higher is eligible for Green Energy Open Access. Previously, this limit was 1 MW, but recent Ministry of Power rules have lowered it to encourage MSMEs.

Why is captive solar cheaper than third-party solar?

In the captive model, you are both the producer and the consumer. This qualifies you for exemptions from the Cross-Subsidy Surcharge (CSS) and Additional Surcharge (AS), which typically save you ₹2 to ₹3 per unit compared to buying solar power from a third party.

Can I do captive solar for my home?

Currently, captive open access is primarily designed for Industrial and Commercial consumers. For homes, rooftop solar remains the most viable option, supported by the PM Surya Ghar Yojana.

What happens if I don't consume 51% of the power?

If your annual consumption falls below the 51% threshold, the "captive" status of the plant is revoked for that year. You will then be liable to pay the full Cross-Subsidy Surcharge and Additional Surcharge on all units consumed, significantly reducing your savings.

How much land is needed for 1 MW of captive solar?

Generally, you need about 3.5 to 4 acres of shade-free land for a 1 MW solar plant using modern high-efficiency panels.

Conclusion

Captive open access solar India is the "Gold Standard" for corporate sustainability. It provides a hedge against rising grid tariffs, offers massive tax benefits through accelerated depreciation, and allows companies to achieve 100% green energy goals even with limited roof space.

With over 35 years in the industry and 5,000+ successful installations, Bridgeway Power helps businesses navigate the complex regulatory landscape of open access — from SPV formation to grid connectivity.

Ready to see if your business qualifies for Captive Solar? Contact our Open Access Experts for a free site feasibility report or a detailed 25-year ROI projection.