What Is Digital Solar or Solar Biscuit? A Simple Guide for Indian Homes and Businesses

Rooftop solar can cut your dependence on grid electricity and lower your electricity bills up to 90% or more. But what if you live in a rented home, stay in an apartment without access to the terrace, or have a roof that receives too little sunlight?

This is where Digital Solar, sometimes called a solar biscuit model, offers another way to participate in solar energy without installing panels on your property. Instead of buying a rooftop solar system, digital solar panel technology lets you reserve a small portion of capacity from a solar project located elsewhere.

• The electricity generated by that reserved capacity earns you credits that can be used to offset eligible electricity bills.
• There is no panel installation at your home, and the amount you pay depends on the solar capacity you reserve and the terms of the project.

However, digital solar is an alternative for people who cannot install rooftop solar, rather than a replacement for it. If you own a home with enough shadow-free roof space, rooftop solar gives you a stronger long-term proposition because you own the solar system installed on your property and generate electricity directly at your premises. Digital solar becomes useful when those conditions are not fulfilled.

In this guide, we’ll break down what digital solar means, how digital solar biscuit pricing works, and whether it’s worth it for your situation. We’ll also clear up a common mix-up: digital solar is sometimes confused with a digital solar controller, which is an entirely different thing. It is a physical device used in off-grid solar setups, not an online solar-sharing platform.

What Is Digital Solar?

Digital solar is a model where you don’t buy or install a physical solar panel. Instead, you reserve a small tokenized share of a solar plant that’s built and maintained somewhere else, usually on a warehouse, factory, or commercial rooftop. The power your share generates is converted into energy credits, which are then applied to your regular electricity bill.

The idea grew out of a personal problem: living in a cramped Bengaluru studio apartment, the founders of Digital Solar realized there simply wasn’t enough usable rooftop space to install solar panels. So, they built a platform that lets anyone go solar remotely instead.

Digital solar generates energy credits to offset power bills rather than linking a panel directly to a home meter, making it especially useful for tenants and apartment dwellers.

Who Is Digital Solar Designed For?

Digital solar was built primarily for people who want to support solar generation but don’t have the eligibility fulfilled to get the panel installed for themselves on their own property. That typically includes:

• Renters and tenants who don’t own their property and can’t make structural changes to a roof.
• Apartment and flat residents in multi-unit buildings where individual rooftop access usually isn’t possible.
• People in temporary or transitional housing, who may move before a rooftop system would pay for itself.
• Housing societies awaiting rooftop approval, who want to start participating in solar generation while shared-roof arrangements are worked out.
• Environmentally conscious individuals who simply want a low-effort way to add solar capacity to the grid without managing a physical installation.

If you fall into any of these groups, digital solar is worth exploring. If you own your home or building and have workable roof space, it’s worth weighing a rooftop system alongside it, see which option is right for you below.

What Is a Solar Biscuit?

A solar biscuit is simply the unit of measurement used in digital solar. It’s a small, fixed-capacity slice of a larger solar plant that you reserve online. When you or your household consumes electricity, your reserved biscuits earn you returns in the form of power dividends, commonly called credits.

Think of it like buying a small, specific portion of a solar farm rather than the whole system; similar in spirit to fractional investing, except what you get back is electricity savings rather than cash dividends.

Rooftop Solar Vs. Digital Solar

Digital solar and rooftop solar both cut electricity bills, but they work differently. Rooftop solar means owning physical panels on your own roof for maximum long-term savings and asset value. Digital solar lets you reserve a share of an off-site plant remotely, a practical alternative when roof space, ownership, or upfront budget aren’t options.

How Digital Solar / Solar Biscuits Actually Work?

The process generally follows four steps:

1. Reserve your biscuits: You choose how much solar capacity you need from an active project to offset your monthly power bill.
2. Generation is tracked automatically: Your account monitors and stores the credits generated by your reserved capacity every day.
3. Link your electricity provider: You add your billing details, choosing from the power providers available on the platform, so credits can be matched to your actual bill.
4. Pay only the balance: You use the accumulated credits to pay your bill, and only pay any remaining balance if your usage exceeds the credits generated. Unused credits don’t expire and roll over to later months.

On the host side, the model works through a PPA or RESCO arrangement. The solar developer finances, installs, and operates the system, while the host purchases the electricity generated at a pre-agreed tariff that can be lower than the prevailing grid tariff. According to industry estimates, the property hosting the solar system uses the power it produces and pays a fixed rate that runs 30-40% below standard utility rates. Once the project term ends, ownership of the plant transfers to the host at little to no extra cost.

What is the Solar Biscuit Price in India in 2026?

Digital Solar pricing in 2026 is based on the capacity you reserve and the terms of the specific project you join, not a fixed per-biscuit rate. Earlier coverage cited a flat ~Rs. 600 for a 10 W biscuit; current SundayGrids project data works out to ~ Rs. 44 per watt, making a 10 W biscuit roughly Rs. 440 as an indicative reference point.

Earlier versions of the Digital Solar model priced a 10 W solar biscuit at ~ Rs. 600, but current pricing is generally based on the amount of solar capacity you reserve and the terms of the individual solar project.

As a current reference point, Digital Solar capacity can work out to ~ Rs. 44 per watt, which would make a 10 W solar biscuit equivalent to ~ Rs. 440. However, this should be treated as an indicative figure rather than a standard market price. The actual reservation cost can vary based on the project, reserved capacity, project tenure, electricity credit rate, taxes, and applicable platform or handling charges.

Solar Biscuits Price Snapshot (Year – 2026)

Source: SundayGrids Bloc 2 Leo project page. Pricing varies by project, capacity reserved, tenure, and credit rate: confirm live figures on the platform before purchase.

Why is Rooftop Solar Better than Solar Biscuits in 2026?

Rooftop solar remains the stronger long-term choice for anyone with access to their own roof. Unlike digital solar, which only offers a financial and energy-credit arrangement, rooftop solar gives you a physical asset that directly powers your home and builds real, lasting value:

• You own real, physical hardware: A rooftop system is a tangible asset on your property, not a reserved share in someone else’s plant.
• Direct power, not just credits: Rooftop solar physically powers your home from your own panels. Digital solar only offsets your bill through credits while your electricity still comes from the regular grid.
• Greater long-term savings: Owning your system means capturing the full value of the energy it generates, without ongoing dependence on a third-party platform’s terms or rates.
• Professionally installed and supported: Backed by site surveys, approvals, and warranty-backed maintenance, built for durability over decades.
• Adds real capacity you control: Every rooftop installation contributes directly to India’s renewable push, tracked by the Ministry of New and Renewable Energy, without relying on a platform intermediary.

Digital solar can make sense in specific situations – for tenants, apartment dwellers, or those with shaded or unavailable roof space, where installing physical panels isn’t possible. But for anyone with a viable roof, rooftop solar offers ownership, direct savings, and control that a credit-based arrangement can’t match.

How Much Digital Solar Do You Need?

Sizing your reservation comes down to your average monthly electricity bill; the higher your bill, the more biscuits (or capacity) you’ll want to reserve to meaningfully offset it. Here are some indicative numbers:

Disclaimer: These are indicative price ranges, not fixed formulas – actual output depends on sunlight availability at the host site, seasonal variation, and the specific project you reserve into. Most platforms let you increase your reservation later if your usage grows, so it’s fine to start conservatively and scale up.

What Is an Energy Credit?

An energy credit is the actual “currency” that digital solar pays you. Every unit of electricity your reserved biscuits generate is converted into a credit and deposited into your platform wallet: not paid out as cash. These credits aren’t a fixed monthly payout; the amount varies slightly month to month based on real solar generation (sunlight hours, weather, seasonal changes), similar to how a rooftop system’s output naturally fluctuates.

You then apply these accumulated credits against your linked electricity bill. If your credits cover the full bill, you pay nothing that cycle; if they fall short, you simply pay the remaining balance to your regular power provider as usual.

Do Digital Solar Credits Expire?

No, unused energy credits typically don’t expire and roll over to future billing cycles instead of being forfeited. That said, credit generation is tied to the term of the specific project you’re reserved into (commonly around 15 years), so once that project term ends, no new credits will be generated unless you move your reservation to a new one. It’s worth checking the exact rollover and end-of-term policy in your service agreement, since terms can vary by project.

Can You Use Credits for Multiple Electricity Bills?

Credits are generated into your personal wallet and applied against the specific electricity connection you register on the platform. If you want to offset more than one bill, say, a home and a small office, you’d typically need to add each connection separately and allocate reserved capacity across them, rather than one pool of credits automatically splitting across unrelated accounts. If this matters to you, it’s worth confirming directly with the platform whether multi-account or multi-property credit allocation is supported for your specific setup.

Digital Solar vs Digital Solar Charge Controller – Don’t Mix These Up

Search results for digital solar sometimes surface a completely different product: digital solar charge controllers. These are physical devices, not investment platforms. So, it’s worth knowing the difference.

A solar digital charge controller sits between a solar panel and a battery, regulating how the panel charges the battery so it doesn’t overcharge or get damaged.

There are two common types:

• PWM (Pulse Width Modulation) controllers: PWM solar panel charge controllers are simpler and the more affordable option. They connect the solar array directly to the battery bank, and during charging the array’s output voltage is pulled down close to the battery’s voltage.
• MPPT (Maximum Power Point Tracking) Digital solar charge controllers: The MPPT solar charge controllers are the more advanced options. They use microprocessor-controlled algorithms to track changing panel output in real time, converting higher panel voltage into the exact current the battery needs rather than wasting the difference as heat. This can boost energy harvest by roughly 5-30% compared to PWM, depending on climate.

Who Owns the Solar Panels in Digital Solar?

The physical solar panels are owned and maintained by the project developer (the digital solar platform) or transferred to the property host under a RESCO (Renewable Energy Service Company)-style arrangement, not by the individual biscuit holder. The site that physically hosts the plant (a warehouse or commercial rooftop, for example) hosts the equipment and benefits from discounted power in exchange, while the platform handles installation, monitoring, and upkeep for the entire project term.

Do You Own the Solar Panel When You Buy a Solar Biscuit?

Not in the traditional sense of holding a title to physical hardware. When you buy or reserve a solar biscuit, you are not buying a physical piece of the solar plant. Instead, you get a tokenised right to the energy produced by that portion of the plant for the duration of the service agreement. This is intentional: it’s what lets you “go solar” without ever touching a roof, a wire, or an inverter. The trade-off is that your stake exists as a digital reservation governed by contract terms, not as a deed to hardware.

What Is a Digital Solar Service Agreement (DSSA)?

A Digital Solar Service Agreement (DSSA) is the contract every user is given when they sign up for a digital solar platform. It typically spells out:

• The validity period and terms of your capacity reservation
• How credits are calculated, assured, and paid out
• Panel performance assumptions (for example, a standard ~2% annual efficiency degradation in the first year and ~0.5% annual efficiency degradation every year afterwards.
• Refund and early-exit terms if you need to leave a project before its term ends
• Liability, indemnification, and dispute-resolution clauses (commonly arbitration under Indian law)
• Restrictions on assigning or transferring your reservation to someone else

It works much like a power purchase agreement (PPA) for someone who does not own or host the physical solar plant. Before making a reservation, it is important to read the agreement carefully, especially the refund and exit clauses.

What Happens to the Solar Panels After the Project Ends?

Digital solar projects run for a fixed term, typically around 15-20 years, matching the operational lifespan of a solar PV system. Once the agreement ends, ownership of the physical solar plant transfers to the host, typically at little or no additional cost. The host has already provided the roof or land for the project throughout the agreement period. For biscuit holders, credits from that specific solar project stop when the agreement ends. To continue saving through digital solar, they would need to reserve capacity in a new project, if the platform offers a renewal or rollover option.

Which Option Is Right for You?

Digital solar and solar biscuits are more suited for a specific situation: when you genuinely have no roof to work with. That mainly means you:

• Live in a rented flat or apartment where you don’t control the roof
• Are part of a building or society where individual rooftop installations aren’t currently possible
• Want to start supporting solar generation right away while a rooftop option isn’t on the table

But if you do own your home or building and have a decent, shadow-free roof, going the traditional route with a rooftop solar installer is often the stronger long-term choice. You own the asset outright, and savings tend to be much larger over time since the electricity is generated and consumed right at your meter.

At SolarSquare, we handle rooftop solar end-to-end. Including site assessment, custom system design, solar panel installation, subsidy paperwork, financing, and multi-year maintenance, so you don’t have to manage any of it yourself. Get a free rooftop assessment, and we’ll show you exactly what savings and payback period would look like for a rooftop solar system in your city.

Frequently Asked Questions

Is a solar biscuit the same as buying a solar panel?

No. You’re reserving a share of an existing plant’s output, not purchasing or installing physical equipment. There’s nothing to mount on your property.

Do I need my electricity provider’s (DISCOM) approval to use digital solar?

Generally no. Utilities that are already listed and enabled on the platform can have credits added to your bill without any extra permission or changes to your building’s power meter. Check the provider’s site for your specific DISCOM (Distribution Company).

Which cities or states in India offer digital solar?

Availability depends on where projects are actively hosted and which power providers are integrated. Coverage has historically included cities like Bengaluru and Mumbai, with more locations added over time. Confirm current coverage before reserving.

Do solar biscuit credits expire?

No, unused credits typically carry over and can be used in future billing months rather than being lost.

Is digital solar a safe or legitimate way to invest in solar energy?

Digital solar is a bill-offset and green-energy participation model, not a stock-market-style investment with guaranteed monetary returns. Returns come as electricity credits tied to actual solar generation. As with any financial commitment, review the platform’s terms, host agreements, and payout structure before reserving the solar biscuits.

Can you exit digital solar before the project ends?

Yes, most platforms allow you to exit a reservation early; for example, if you move to a location the service doesn’t cover. In that case, you may be eligible for a refund based on how long you have held the reservation. The refund amount would include gains calculated at a rate similar to what your solar credits would have earned. Exact refund terms and any conditions are set out in the platform’s service agreement, so it’s worth reviewing before you commit.

What are the limitations of digital solar?

There are a few trade-offs to consider. You don’t own a physical asset at the end of the term, and your credits can vary each month based on actual power generation. You also depend on the platform and host site continuing to operate as expected, and your reservation may only work with specific power providers and locations rather than everywhere. Since the panels sit off-site, you’re also relying on the provider’s monitoring and reporting rather than being able to inspect the system yourself.

Is digital solar worth it in India?

It depends on your situation. For renters, apartment residents, or anyone without a usable roof, digital solar is a genuinely practical way to lower electricity bills and support solar generation without any installation. For homeowners with roof access, however, a full rooftop system generally delivers greater long-term savings and results in owning a physical, long-lasting asset rather than a time-limited reservation.