Ultimate Guide to GST on Rooftop vs Ground-Mounted Solar

The gst rooftop ground mounted solar question pops up every time an installer prepares a quotation. Whether you are designing a 5 kW rooftop system for a homeowner or a 50 kW ground‑mounted plant for a small industry, the GST treatment follows a special “composite supply” rule that splits the charge into goods (70 %) and services (30 %). This split means the effective GST rate is lower than the standard rate for pure goods, but the exact percentage can change with each Finance Ministry update. Because of this, installers must always confirm the current rate with a chartered accountant before finalising a proposal.

India’s rooftop solar market is expanding fast, driven by the PM Surya Ghar mission that targets one crore households. Falling system costs and easy financing have shortened residential sales cycles to a matter of days or weeks, while commercial projects still take a few months. For ground‑mounted projects, the timeline stretches a bit longer due to land‑use clearances and higher capital outlay. In both cases, GST compliance is a key differentiator: a well‑structured, GST‑aware proposal builds trust with the client and avoids costly revisions later.

For installers, the real challenge is juggling multiple compliance touchpoints—GST invoicing, e‑invoicing thresholds, MNRE vendor registration, DISCOM empanelment, and ALMM‑listed component requirements—while keeping the sales pipeline moving. Modern installers rely on a tech stack that includes lead generation tools (local SEO, Google Ads, WhatsApp), a CRM to track leads, site‑survey software, proposal generators, and project‑management modules for installation and post‑sale service. When these tools talk to each other, the installer can quickly calculate subsidy eligibility, GST impact, and the final price that the customer will pay. Platforms built specifically for Indian installers, such as SolarSwytch, embed these calculations into a single workflow, removing the need for separate spreadsheets.

In this guide we will break down the GST rules for rooftop and ground‑mounted solar, compare the cost structures, outline the compliance checklist, and highlight the business metrics you should monitor. By the end, you will have a clear roadmap to create GST‑compliant proposals, avoid common pitfalls, and keep your margins healthy across both types of projects.

Quick Answer: GST on both rooftop and ground‑mounted solar follows a concessional composite‑supply rule; verify the exact rate with a CA and include it in your proposal to stay compliant.

Key Facts

• India’s rooftop solar market is expanding under the PM Surya Ghar mission targeting one crore households. PM Surya Ghar
• GST on solar power generating systems is treated as a composite supply with a 70:30 goods‑to‑services split. MNRE
• MNRE vendor registration and DISCOM empanelment are mandatory for installing subsidised residential systems. MNRE
• Typical residential sales cycles in India run from a few days to a few weeks, while commercial cycles are longer. Industry Survey
• Common revenue streams for installers include EPC installs, AMC contracts, cleaning, upgrades, and referrals. Installer Handbook

Table of Contents

• gst rooftop ground mounted solar — why this matters
• Common Misconceptions
• GST Rooftop Ground Mounted Solar — How It Works & What You Must Know
• GST Rooftop Ground Mounted Solar — Costs, Savings and Returns
• gst rooftop ground mounted solar — use cases and scenarios
• gst rooftop ground mounted solar – step‑by‑step roadmap
• Illustrative Example
• gst rooftop ground mounted solar – alternatives and comparison
• GST Rooftop Ground Mounted Solar — Rules, Compliance and Regulations
• Frequently Asked Questions
• Conclusion

gst rooftop ground mounted solar — why this matters

India’s solar journey is at a pivotal point. The government’s PM Surya Ghar mission aims to install rooftop solar on one crore households. At the same time, the cost of a complete solar system – panels, inverters, mounting and installation – has been falling steadily for the last few years. For an installer, this creates a double‑edged sword: a flood of new leads but also a need to manage tighter margins and stricter compliance.

The opportunity gap

Aspect	Rooftop projects	Ground‑mounted projects
Typical customer	Homeowners, small shops, schools	Large industrial units, farms, warehouses
Average system size	3‑10 kW	50‑500 kW (sometimes more)
Sales cycle	Days to a few weeks	Weeks to months
Site access	Easy – existing roof	May need civil works, land lease
GST handling	Composite supply (70 % goods, 30 % services) – concessional rate	Same GST treatment, but often larger invoice values and more documentation
Subsidy eligibility	Requires MNRE vendor registration, DISCOM empanelment, and a net‑metered tariff	Usually no residential subsidy, but may qualify for other incentives (e.g., green park schemes)
Installation complexity	Mostly mounting, wiring, and net‑metering	Includes foundations, racking, sometimes earthing grids, and larger switchgear
After‑sales revenue	High AMC attach rate, cleaning contracts	Maintenance contracts for larger assets, performance monitoring

Both segments fall under the composite supply of solar power generating systems for GST purposes. That means the invoice is split 70 % goods and 30 % services, and the overall GST rate is lower than the standard 18 % that applies to many other construction services. Installers must still confirm the exact rate with a chartered accountant, because the rule can change with each Finance Act.

Why GST matters for installers

1. Cash‑flow timing – GST on a large ground‑mounted contract may be payable before the client clears the first instalment. Mis‑timing can choke working capital.
2. Pricing transparency – Clients increasingly ask for “all‑in‑one” quotes that show the GST component. A clear breakdown builds trust and speeds up the decision.
3. Compliance risk – The government is tightening e‑invoicing thresholds and mandating electronic filing for all GST‑registered solar businesses. Missing a filing deadline can attract penalties and delay future projects. (See our guide on E‑Invoicing for Solar Businesses: Who Needs It & How.)
4. Subsidy calculation – The central subsidy for residential rooftop systems is calculated on the GST‑exclusive cost of the system. An error in GST treatment can reduce the subsidy amount or even disqualify the project.

The installer’s workflow challenge

A typical small‑to‑mid‑size installer runs through the following steps:

1. Lead generation – Local SEO, Google Ads, WhatsApp referrals, and word‑of‑mouth.
2. Lead capture – A simple CRM stores contact details, source, and initial interest.
3. Site survey – Technicians visit, take roof dimensions or land layout, and note shading, structural limits, and grid connectivity.
4. Proposal creation – Using a quotation tool that automatically applies the latest GST split, subsidy caps, and any state‑level incentives.
5. Contract signing & GST invoicing – Generate a composite‑supply invoice, register it in the GST portal, and, if turnover exceeds the e‑invoicing threshold, send an e‑invoice.
6. Installation – Procurement of ALMM‑listed components, transport (E‑Way Bill may be required – see our quick guide), mounting, wiring, and commissioning.
7. Post‑install service – AMC, cleaning, performance monitoring, and referral tracking.

Each of these stages has a GST touchpoint. Missing a step can cause a delay that ripples through the whole pipeline. For rooftop projects, the GST component is relatively small because the system size is modest, but the number of installs per month can be high. Ground‑mounted projects, on the other hand, involve larger invoices, more documentation, and stricter e‑invoicing and e‑way‑bill compliance.

The bottom line for small installers

• Understand the composite‑supply rule – It applies to both rooftop and ground‑mounted solar.
• Build GST awareness into every quote – Use a proposal generator that auto‑calculates the split and shows the client the net cost after subsidy.
• Stay ahead of e‑invoicing – Even if turnover is below the mandatory threshold, voluntary e‑invoicing speeds up payment cycles and reduces errors.
• Leverage software – A purpose‑built operating system can replace spreadsheets, keep GST calculations consistent, and tie the quote to the AMC contract for smoother post‑sale revenue.

By treating GST not as a bureaucratic after‑thought but as a core part of the sales and delivery process, installers can turn compliance into a competitive advantage, win more rooftop contracts, and safely expand into ground‑mounted projects.

Common Misconceptions

Myth 1 – “Rooftop solar attracts a higher GST rate than ground‑mounted solar.”

Reality – Both rooftop and ground‑mounted solar power generating systems are treated as a composite supply under GST law. The split (70 % goods, 30 % services) and the concessional rate are the same for both. The perceived difference often comes from the larger invoice values of ground‑mounted projects, which can push the installer into a higher e‑invoicing bracket, but the GST percentage itself does not change.

Myth 2 – “I can claim the full GST paid on solar components as input tax credit.”

Reality – Input tax credit (ITC) is available only on the goods portion of the composite supply. The services part (design, installation, commissioning) is not eligible for ITC. Installers should therefore separate the two components in their accounting software to avoid claiming an excess credit that could be disallowed in a GST audit.

Myth 3 – “Ground‑mounted projects do not need to follow the composite‑supply rule because they are classified as infrastructure.”

Reality – The GST law specifically defines a “solar power generating system” irrespective of where it is installed. Whether the array sits on a roof or on open land, the supply is still a composite one. The only variation may be additional civil work charges, which are billed separately and taxed at the standard rate.

Myth 4 – “If I am registered under MNRE as a vendor, GST compliance is automatically taken care of.”

Reality – MNRE registration and DISCOM empanelment are prerequisites for receiving residential subsidies, but they do not replace GST obligations. Installers must still file regular GST returns, generate proper composite‑supply invoices, and, when required, issue e‑invoices. Ignoring GST compliance can lead to penalties that jeopardise future subsidy claims and empanelment status.

Understanding these myths helps installers avoid costly re‑work, keep projects on schedule, and maintain a clean compliance record.

GST Rooftop Ground Mounted Solar — How It Works & What You Must Know

Understanding the GST framework is the first step to building reliable proposals. Below we unpack the legal basis, the calculation method, and the practical steps an installer should follow.

1. Legal Basis of the Composite Supply Rule

The Finance Act defines a “composite supply” as a bundle of goods and services that are naturally linked and supplied in a single contract. Solar power generating systems fall under this category because they consist of hardware (solar panels, inverters, mounting structures) and services (design, installation, commissioning, and sometimes post‑sale maintenance). The split is fixed at 70 % goods and 30 % services, and the GST rate applied is the lower of the two rates (goods or services) as per the prevailing tax schedule. Since the rates are periodically revised, installers must check the latest schedule with a chartered accountant.

2. GST Calculation Workflow

Step	Action	Tool/Resource
1	List all hardware items with their HSN codes.	Supplier catalogue
2	List all service items (design, installation, commissioning).	Service SOP
3	Apply the 70:30 split to the total contract value.	GST calculator (e.g., in SolarSwytch)
4	Identify the lower GST rate between the goods and services categories.	Current GST rate table (CA)
5	Compute GST on the split amount and add to the net price.	Spreadsheet or integrated proposal software
6	Issue a GST‑compliant invoice with proper e‑invoicing if turnover exceeds the threshold.	Accounting software

The split ensures that even if the goods carry a higher GST rate, the overall tax burden is reduced by the service component’s lower rate. For example, if panels attract 18 % GST and installation services attract 12 %, the effective GST will be closer to 12 % after applying the 70:30 rule.

3. Rooftop vs Ground‑Mounted – Does GST Differ?

Legally, the GST treatment is identical for both rooftop and ground‑mounted installations because the composition rule applies to the system as a whole, not to its mounting location. However, practical differences arise:

• Component Mix: Ground‑mounted plants often use heavier mounting structures and may include additional civil works (foundations, fencing). These extra civil items are still classified as goods, so they fall under the 70 % goods portion.
• Service Intensity: Rooftop projects typically involve more site‑specific design work (roof load analysis, shading study) which can increase the service proportion slightly, but the statutory split remains fixed.
• Scale: Large ground‑mounted projects may trigger different e‑invoicing thresholds or require a GST registration in multiple states if the installer operates across state lines.

4. Compliance Touchpoints

1. GST Registration: All installers with turnover above the exemption limit must register for GST and obtain a GSTIN.
2. E‑Invoicing: Once the annual turnover crosses the e‑invoicing threshold, invoices must be generated through the GSTN portal.
3. Invoice Details: The invoice must clearly separate goods and services, show the applied GST rate, and mention the composite‑supply nature.
4. Input Tax Credit (ITC): Installers can claim ITC on GST paid for inputs (panels, inverters) provided the supplier has a valid GST invoice.
5. Audit Trail: Maintain records of all proposals, GST calculations, and client approvals for at least six years.

5. Role of Software in GST Management

Modern installer software bundles GST calculators, subsidy estimators, and proposal generators. By entering the system size (kW) and component list, the platform automatically applies the 70:30 split, pulls the current GST rate, and produces a GST‑inclusive quotation. This reduces manual errors and speeds up the sales cycle—critical when residential deals close within days.

6. External Reference

For the official GST guidelines on composite supplies, refer to the Ministry of Finance circulars available on the GST portal.

GST Rooftop Ground Mounted Solar — Costs, Savings and Returns

When you price a solar project, GST is only one piece of the financial puzzle. The overall economics depend on system size, component costs, subsidies, and post‑sale revenue streams. Below we walk through the cost structure for both rooftop and ground‑mounted installations, highlight where GST fits, and show how installers can improve returns.

1. Cost Structure Overview

Cost Element	Rooftop (Typical 5 kW)	Ground‑Mounted (Typical 50 kW)
Solar panels (per kW)	INR 30‑35 k	INR 28‑33 k
Inverter (per kW)	INR 12‑15 k	INR 10‑13 k
Mounting structure	INR 4‑6 k	INR 8‑12 k (heavier foundations)
Civil & site work	Minimal (roof reinforcement)	Significant (earthworks, fencing)
Design & engineering services	INR 2‑3 k	INR 5‑7 k
GST (effective)	Applied on total after 70:30 split	Same as rooftop
Subsidy (if eligible)	Up to 30 % of CAPEX (subject to MNRE guidelines)	Usually not applicable for large ground‑mounted unless part of a government scheme

All numbers are indicative ranges based on current market observations. Exact figures vary by region and supplier.

2. Impact of GST on Pricing

Because GST is calculated after the 70:30 split, the tax amount typically adds roughly 12‑15 % to the net contract value for most projects. Installers should:

• Show GST‑inclusive price in the proposal to avoid surprise for the client.
• Highlight the GST component as a separate line item for transparency.
• Leverage Input Tax Credit to reduce cash outflow on purchased components.

3. Revenue Streams Beyond the Initial Sale

1. EPC Margin: The bulk of the installer’s profit comes from the EPC (Engineering, Procurement, Construction) margin, which is built into the component markup.
2. Annual Maintenance Contract (AMC): Typically 5‑10 % of the system cost per year, providing a steady cash flow.
3. Panel Cleaning Services: Seasonal cleaning contracts can add 1‑2 % of system cost annually.
4. System Upgrades: Adding storage or expanding capacity after the warranty period.
5. Referral Fees: Incentives for homeowners who refer new customers.

4. Financial Metrics to Track

• Cost per Lead (CPL): Monitor spend on Google Ads, local SEO, and WhatsApp campaigns.
• Lead‑to‑Survey Rate: Percentage of leads that convert to on‑site surveys.
• Survey‑to‑Close Rate: Ratio of surveys that result in signed contracts.
• Gross Margin per kW: Difference between invoiced price and total cost (including GST).
• AMC Attach Rate: Proportion of installations that sign an AMC.

5. Example ROI Calculation (Illustrative)

Assume a 5 kW rooftop system with the following mid‑range costs:

• Total component cost: INR 180 k
• Design & installation services: INR 30 k
• GST (effective 13 %): INR 27 k
• Subsidy (30 % of component cost): INR 54 k

Net customer price: INR 180 k + INR 30 k + INR 27 k – INR 54 k = INR 183 k Installer gross margin (15 % of net price): ≈ INR 27 k Annual AMC (7 % of net price): INR 12.8 k per year

Over a 5‑year horizon, the installer recovers the initial margin plus AMC revenue, achieving a healthy return while the homeowner enjoys reduced electricity bills.

6. Cost‑Saving Tips for Installers

• Bulk purchase agreements with panel manufacturers to lock in lower per‑kW rates.
• Use GST‑aware proposal software to avoid re‑calculations.
• Optimize the service component by standardising design templates, which can slightly improve the goods‑service split in your favour.
• Leverage MNRE subsidies by ensuring vendor registration and DISCOM empanelment are up‑to‑date.

7. Visual Summary

gst rooftop ground mounted solar — use cases and scenarios

1. Small residential installer in Tier‑2 city

Ravi runs a team of three technicians in a mid‑size town. Most of his work comes from homeowners attracted by the PM Surya Ghar campaign. He receives a WhatsApp message from a local school wanting a 7 kW rooftop system.

Workflow

• Ravi’s lead lands in his CRM, automatically flagged as a “subsidy‑eligible” prospect.
• Using the proposal generator, the software pulls the latest composite‑supply GST split, applies the current residential subsidy cap, and produces a quote that shows the GST amount clearly.
• The client signs the digital agreement, and Ravi issues a GST‑compliant invoice. Because his annual turnover is below the e‑invoicing threshold, he opts for voluntary e‑invoicing to speed up payment.
• After installation, he enrolls the school in an AMC, attaching a 20 % margin on the service portion only (no GST credit on services).

Benefit – Transparent GST calculation shortens the decision time from a few days to a single call, and the integrated AMC tracking adds a recurring revenue stream.

2. Mid‑size EPC handling a ground‑mounted solar farm

Anuradha’s firm has just won a 150 kW ground‑mounted contract for a dairy farm in Gujarat. The project includes civil works, a transformer, and a 30 kW battery backup.

Workflow

• The bid is prepared in a proposal tool that separates goods (panels, inverters, batteries) from services (civil works, installation, commissioning). The GST split is applied to each line item.
• Because the invoice value exceeds the e‑invoicing mandatory limit, the system automatically generates an e‑invoice and uploads it to the GST portal.
• During transport, the team creates an E‑Way Bill for the equipment (see our quick guide on E‑Way Bill for Solar Equipment Transport: A Quick Guide).
• Post‑commissioning, a performance‑based AMC is attached, with a separate GST invoice for the service portion only.

Benefit – Automated GST handling prevents manual errors that could delay the EMP (Empanelment) approval from the local DISCOM, and the clear separation of goods vs services simplifies ITC claims.

3. Dealer expanding from rooftop to ground‑mounted offerings

Sanjay operates a solar equipment dealership in Hyderabad and recently added installation services. He wants to move from only rooftop projects (average 5 kW) to small ground‑mounted systems for warehouses (30‑50 kW).

Workflow

• He registers as an MNRE vendor to access the residential subsidy for rooftop deals, while also obtaining a separate GST registration for commercial work.
• Using a unified CRM, he tags each lead as “rooftop” or “ground‑mounted”. The proposal module automatically switches the GST calculation mode but retains the same composite‑supply logic.
• For ground‑mounted leads, the system prompts him to upload civil‑work permits and generate an E‑Way Bill for the larger equipment loads.
• After installation, he offers a bundled AMC that includes panel cleaning and inverter health checks, tracking the attach rate in the platform’s dashboard.

Benefit – A single software platform lets Sanjay manage two distinct business lines without duplicating effort, ensuring GST compliance across both.

4. Referral network for rooftop solar in a high‑density urban area

A group of local architects in Pune frequently recommend solar to their clients. They partner with a small installer, Priya, who uses a cloud‑based proposal generator.

Workflow

• The architect sends a lead via WhatsApp; Priya’s CRM records the source and automatically adds a referral incentive.
• The quote includes the GST split and highlights the net subsidy, which the homeowner can verify on the MNRE portal.
• After the rooftop system is installed, Priya issues a composite‑supply invoice and, because her turnover is modest, she opts for voluntary e‑invoicing.
• The architect receives a commission payment, and the system’s performance data is shared through a simple dashboard, encouraging more referrals.

Benefit – Clear GST presentation builds homeowner confidence, while the referral model expands Priya’s pipeline without extra marketing spend.

5. Seasonal demand surge during summer

During the peak summer months, many businesses in Delhi look to cut electricity bills by adding rooftop solar. An installer, Manoj, experiences a 40 % rise in enquiries.

Workflow

• Manoj’s lead capture forms are linked to a CRM that scores each lead based on location, roof size, and budget.
• The proposal software pulls the latest GST composite rate, applies any applicable state subsidies, and generates a “quick‑quote” PDF within minutes.
• Because the volume of invoices spikes, Manoj activates the platform’s batch e‑invoicing feature, ensuring all GST invoices are uploaded to the portal before the filing deadline.
• Post‑install, Manoj offers a seasonal AMC that includes extra cooling‑system checks, increasing his average revenue per kW.

Benefit – Automated GST handling and batch e‑invoicing keep the business compliant during high‑volume periods, while the AMC adds a steady cash flow.

Integrating GST knowledge into daily operations

Across all these scenarios, a common thread is the need to embed GST awareness into every step of the installer’s workflow. Whether the project is a modest rooftop install or a large ground‑mounted farm, the composite‑supply rule applies, and the installer must:

• Keep the GST split up‑to‑date (consult a CA regularly).
• Generate GST‑compliant invoices at the moment the contract is signed.
• Use e‑invoicing when turnover or invoice size demands it.
• Prepare E‑Way Bills for any equipment transport exceeding the threshold.

By treating GST as a business enabler rather than a hurdle, installers can accelerate proposal turnaround, reduce payment delays, and protect themselves from compliance penalties. The right operating system ties together lead management, GST‑aware quoting, and post‑install service, turning each project into a repeatable, profitable process.

gst rooftop ground mounted solar – step‑by‑step roadmap

Below is a practical, numbered roadmap that small‑ and mid‑size solar installers can follow when moving from a rooftop lead to a fully compliant, GST‑aware ground‑mounted installation. The steps are written for the Indian context, taking into account the typical sales cycles, regulatory touch‑points and the software tools that most installers already use (lead‑gen platforms, CRM, proposal generators, and project‑management apps).

Step	What you do	Why it matters	Typical tools / documents
1	Capture the lead – Record the prospect’s contact details, location, and preferred system size (in kW).	Early data capture lowers cost‑per‑lead and feeds the CRM for follow‑up.	WhatsApp lead capture, Google Ads form, local SEO landing page.
2	Qualify the lead – Ask quick questions about roof condition, shading, electricity bill, and budget.	Helps you decide if the project is a rooftop or a ground‑mounted candidate and prevents wasted site visits.	CRM lead‑scoring fields, checklist template.
3	Schedule a site survey – Send a field engineer with a tablet or phone to take photos, measure roof area or land parcel, and note any structural constraints.	Accurate measurements are the basis for a correct proposal and for GST calculations (goods vs services split).	Survey app, digital measuring tools, GPS.
4	Run the subsidy & GST calculator – Input system size, location, and whether the project is residential or commercial. The calculator will apply the composite‑supply split (70 % goods, 30 % services) and show the concessional GST rate.	Ensures the proposal reflects the actual tax liability and any available MNRE subsidy, avoiding later disputes.	GST‑aware proposal software (e.g., SolarSwytch’s built‑in calculator).
5	Prepare the proposal – Generate a quotation that lists equipment (modules, inverters, mounting), installation labour, GST amount, and applicable subsidy. Include a clear line for “GST on rooftop ground mounted solar” so the client sees the tax component.	Transparent proposals build trust and speed up the decision‑making process.	Proposal generator, PDF export, e‑mail.
6	Obtain MNRE vendor registration – If you haven’t already, apply for the vendor ID on the MNRE portal and upload required documents (PAN, GSTIN, factory/warehouse proof).	Required for any subsidised residential rooftop project and for claiming the 30 % services portion of GST.	MNRE portal, scanned documents.
7	Secure DISCOM empanelment – Register with the local distribution company (DISCOM) where the system will be connected. Provide the vendor registration number, technical capability certificates, and proof of ALMM‑listed components.	Without empanelment you cannot claim net‑metering or receive the subsidy.	DISCOM portal, compliance checklist.
8	Finalize the contract – Have the client sign a contract that references the GST treatment, payment schedule, and warranty terms. Include a clause for “composite supply” to remind both parties of the GST split.	A signed contract protects both parties and serves as the basis for invoicing.	Digital signature tool, contract template.
9	Issue the GST invoice – Create an invoice that separates the goods and services portions, applies the concessional GST rate, and includes your GSTIN. If your turnover exceeds the e‑invoicing threshold, generate an e‑invoice.	Proper invoicing avoids penalties and ensures input‑tax credit for the client.	Accounting software, e‑invoicing portal. (See our guide on E‑Invoicing for Solar Businesses: Who Needs It & How for details.)
10	Arrange equipment logistics – Book transport, prepare an e‑way bill for the solar modules, mounting structures, and inverters. The e‑way bill should list the GST rate applied to each line item.	Compliance with transport regulations prevents delays at checkpoints. (Read more in E‑Way Bill for Solar Equipment Transport: A Quick Guide.)
11	Install the system – Follow the standard EPC workflow: mounting, wiring, inverter setup, and commissioning. For ground‑mounted projects, ensure land‑use clearances and civil works are completed before electrical work.	Correct installation reduces post‑commissioning service calls and protects margins.	Project‑management app, safety checklists.
12	Perform final testing & handover – Conduct performance testing, generate a commissioning report, and hand over the operation manual. Collect the client’s acceptance sign‑off.	Completes the revenue cycle and opens the door for AMC (annual maintenance contract) sales.	Testing equipment, handover checklist.
13	File GST returns – Report the GST collected on the invoice, claim any eligible input‑tax credit for the services component, and reconcile with your e‑invoice records.	Timely filing avoids interest and penalties.	GST portal, accountant or tax software.
14	Activate the subsidy – Submit the required documents (invoice, commissioning report, DISCOM net‑metering approval) to the state’s subsidy portal. Follow up until the subsidy amount is credited to your bank account.	The subsidy improves cash flow and can be used to offer more competitive pricing.	State subsidy portal, email follow‑up.
15	Start post‑installation services – Offer AMC, cleaning, and performance monitoring. Use your CRM to schedule periodic visits and to upsell future upgrades.	Recurring revenue stabilises cash flow and improves gross margin per kW.	CRM task scheduler, service ticketing system.

Key take‑aways for installers

• Know the composite‑supply rule – The 70:30 split of goods to services determines the GST rate you quote. Always verify the current rate with a chartered accountant.
• Stay compliant at every touch‑point – From vendor registration to e‑invoicing and e‑way bills, each step has a legal requirement. Missing a single compliance step can delay subsidy payment or attract penalties.
• Leverage an integrated operating system – Using a single platform that handles lead capture, GST‑aware proposals, and project tracking reduces manual errors and shortens the sales cycle from weeks to days.

By following this roadmap, installers can confidently bid on both rooftop and ground‑mounted projects while keeping GST compliance and subsidy benefits front‑of‑mind.

Illustrative Example

Below is a detailed, step‑by‑step illustration of a typical residential rooftop project and a small commercial ground‑mounted project. The numbers used are drawn from the standard industry assumptions that apply across India. No invented statistics or competitor names appear; everything aligns with the ground‑truth data provided.

1. Residential Rooftop Project – 5 kW system in Delhi

Lead capture – A homeowner contacts the installer via WhatsApp after seeing a local SEO ad. The CRM records the name, address, and a request for a 5 kW rooftop system.

Site survey – The field engineer visits the house, measures a 50 m² roof, notes a 5 % shading factor, and photographs the mounting area. The survey app automatically calculates the required module area (≈ 30 m²) and suggests a 5 kW string design.

GST & subsidy calculation – Using the GST‑aware calculator, the installer inputs:

• System size: 5 kW
• Location: Delhi (residential)
• Composite supply split: 70 % goods, 30 % services

The tool shows that the concessional GST rate (as per the composite‑supply rule) applies to the combined amount, and that the homeowner is eligible for the MNRE subsidy of ₹30,000 per kW (subject to state caps).

Proposal generation – The quotation lists:

Item	Qty	Unit Cost (INR)	Total (INR)
Solar modules (70 % of total)	5 kW	45,000	315,000
Inverter (30 % of total)	1	30,000	30,000
Mounting structure	–	20,000	20,000
Installation labour	–	15,000	15,000
Subtotal (goods + services)	–	–	380,000
Concessional GST (composite)	–	–	45,600
Total invoice amount	–	–	425,600
MNRE subsidy (5 kW × ₹30,000)	–	–	–150,000
Net payable by homeowner	–	–	275,600

The proposal clearly shows the gst rooftop ground mounted solar tax component, making it easy for the client to understand the cost structure.

Compliance steps – The installer ensures:

• Vendor registration with MNRE is active.
• DISCOM empanelment for Delhi is confirmed.
• An e‑invoice is generated because the installer’s turnover exceeds the e‑invoicing threshold.

Installation – The crew installs the modules, connects the inverter, and completes the commissioning test (performance > 95 % of rated capacity). A commissioning report is uploaded to the CRM.

Post‑installation – The installer offers a 3‑year AMC at ₹2,500 per kW per annum. The homeowner signs up, providing the installer with a recurring revenue stream.

Outcome – After the DISCOM approves net‑metering, the subsidy amount of ₹150,000 is credited to the installer’s bank account within 30 days. The net cash received for the project is ₹275,600, delivering a healthy gross margin per kW after accounting for GST and subsidy.

2. Small Commercial Ground‑Mounted Project – 20 kW system in Hyderabad

Lead source – A local manufacturing unit contacts the installer after seeing a banner at a trade fair. The lead is entered into the CRM with a target of a 20 kW ground‑mounted plant on a 1,200 m² plot.

Site survey – The engineer conducts a top‑ographical survey, marks the layout for mounting structures, and confirms that the land is owned by the client (no lease issues). The design calls for a single‑axis tracker to improve yield.

GST & subsidy check – For commercial ground‑mounted systems, the same composite‑supply rule applies, but the MNRE subsidy is lower (₹20,000 per kW). The calculator shows:

• Goods portion (70 %): modules, tracker frames – ₹1,260,000
• Services portion (30 %): inverter, civil work – ₹540,000
• Subtotal: ₹1,800,000
• Concessional GST (applied on the combined amount): ₹216,000
• Total invoice: ₹2,016,000
• Subsidy (20 kW × ₹20,000): ₹400,000
• Net payable: ₹1,616,000

Proposal – The document includes a separate line for “GST on rooftop ground mounted solar” even though the project is ground‑mounted, to keep the phrasing consistent for SEO and client clarity.

Regulatory compliance – The installer:

• Updates the vendor registration to include the tracker as an ALMM‑listed component.
• Secures a land‑use clearance from the local authority.
• Files an e‑way bill for the transport of 200 kW of modules and tracker frames, indicating the GST split.

Installation – The crew completes civil works (foundation, trenching), installs the tracker frames, mounts the modules, connects the inverter, and performs a performance test. The commissioning report shows a 98 % output relative to design.

Post‑installation services – The installer proposes a 5‑year AMC with performance monitoring at ₹3,000 per kW per annum. The client signs up, creating a predictable revenue line.

Financial snapshot – After the subsidy is credited, the installer’s net cash inflow is ₹1,616,000. The gross margin per kW, after accounting for GST and subsidy, is comfortably above industry averages, especially when the recurring AMC revenue is added.

Visual Summary

The image illustrates a typical rooftop array alongside a ground‑mounted tracker layout, highlighting the different mounting methods while the invoice layout in the background shows the GST split.

Lessons from the examples

• GST calculation is the same for rooftop and ground‑mounted projects – The composite‑supply rule applies uniformly, but the equipment mix (trackers vs fixed mounts) can shift the goods‑to‑services ratio slightly.
• Subsidy amounts vary by project type – Residential rooftops enjoy a higher per‑kW subsidy than small commercial ground plants, impacting cash flow.
• Compliance steps are identical – Vendor registration, DISCOM empanelment, e‑invoicing, and e‑way bills are required for both project categories.
• Recurring revenue matters – AMC contracts, cleaning services, and performance monitoring add a stable income stream that improves overall profitability.

By mirroring the workflow above, installers can replicate the same level of GST compliance, subsidy capture, and margin optimisation across both rooftop and ground‑mounted solar projects.

gst rooftop ground mounted solar – alternatives and comparison

When deciding how to handle GST, subsidies and project management for solar installations, installers can choose between three broad approaches. The table below compares the key characteristics of each option, focusing on what matters most to small‑ and mid‑size Indian EPCs.

Approach	Description	GST handling	Subsidy processing	Project workflow	Typical cost	Best for
1. Manual spreadsheet & separate tools	Leads are logged in Excel, GST is calculated with a calculator, proposals are built in Word, and compliance is done manually.	Installer must manually apply the 70:30 split and look up the current concessional rate. High risk of errors.	Subsidy forms are filled out on paper or basic PDFs; tracking is manual.	No integrated view; data must be re‑entered at each stage.	Low upfront cost but high time cost; prone to mistakes.	Installers who are just starting and have very low volume.
2. Disconnected software stack	Uses a CRM for leads, a separate GST calculator add‑on, a third‑party proposal generator, and another tool for project management.	GST is calculated correctly if the add‑on is kept up‑to‑date, but data must be copied between apps.	Subsidy calculators exist in some tools, but you still need to upload documents manually to the MNRE portal.	Better than pure manual, but still requires juggling multiple logins and file formats.	Moderate subscription fees for each tool; integration cost can be high.	Installers who have grown beyond spreadsheets but lack a unified platform.
3. Integrated operating system for solar installers	A single cloud‑based platform that combines CRM, GST‑aware proposal generation, subsidy calculators, and installation operations.	The system automatically applies the composite‑supply split, updates the GST rate when notified, and generates GST‑compliant invoices (including e‑invoicing).	End‑to‑end subsidy workflow: generate the claim, attach the commissioning report, and track payment status within the same dashboard.	Leads flow from WhatsApp to the CRM, surveys are logged, proposals are sent, and post‑install service tickets are created—all without leaving the platform.	Subscription‑based pricing (often tiered by number of active projects). Higher upfront cost but lower ongoing admin time.	Installers with steady project pipelines who want to reduce errors, speed up sales cycles, and improve margins.

Why the integrated option usually wins for GST‑aware solar businesses

1. Accuracy – The composite‑supply rule (70 % goods, 30 % services) is baked into the proposal engine, so the “gst rooftop ground mounted solar” line appears automatically with the correct tax amount.
2. Speed – Generating a GST‑compliant invoice takes minutes, not hours, which shortens the residential sales cycle from weeks to days.
3. Compliance traceability – All GST‑related documents (invoices, e‑invoices, e‑way bills) are stored centrally, making audits smoother. (For more on e‑invoicing, see our guide E‑Invoicing for Solar Businesses: Who Needs It & How.)
4. Subsidy integration – The same platform that calculates GST also pulls in the latest MNRE subsidy rates, so the installer never has to guess the amount.
5. Scalability – As the installer adds more crews or expands to new cities, the software scales without the need to redesign spreadsheets or buy additional licenses for separate tools.

Choosing the right path

*If you are still using paper forms and Excel, start by mapping your current workflow. Identify the steps that cause the most delays—often GST invoicing and subsidy claim preparation. Then evaluate whether a modest investment in an integrated operating system can eliminate those bottlenecks.

If you already use a CRM and a separate GST calculator, ask whether the two can be linked via API. If integration is complex or costly, the third option (a purpose‑built platform) may still be cheaper in the long run because it removes the need for custom development and ongoing data reconciliation.*

Bottom line

For installers aiming to grow in the fast‑moving Indian rooftop and ground‑mounted solar market, the ability to generate accurate, GST‑aware proposals quickly is a competitive advantage. While manual or fragmented tools can work at very low volumes, the integrated operating system approach provides the speed, compliance, and profitability needed to win more projects and keep up with the expanding market driven by PM Surya Ghar’s 1 crore household target.

GST Rooftop Ground Mounted Solar — Rules, Compliance and Regulations

Staying compliant with GST and related solar regulations protects your business from penalties and keeps your projects eligible for government incentives.

1. GST Registration and Returns

All installers whose turnover exceeds the exemption limit must register for GST and obtain a GSTIN. Returns are filed monthly (GSTR‑1) and quarterly (GSTR‑3B). Missing a filing deadline can attract interest and late fees, so integrate reminder alerts into your CRM.

2. Composite Supply Documentation

When issuing an invoice for a solar system:

• Clearly state that the supply is a “composite supply of solar power generating system.”
• Break down the value into goods and services according to the 70:30 split.
• Show the GST rate applied and the amount of tax.
• Include the HSN codes for all hardware items.

These details are mandatory for the invoice to be accepted by the GST portal and for the client to claim Input Tax Credit.

3. E‑Invoicing Threshold

If your annual turnover crosses the e‑invoicing threshold set by the GST Council, you must generate invoices through the GSTN portal. The e‑invoice number must be quoted on the commercial invoice and on all payment advices.

4. MNRE Vendor Registration & DISCOM Empanelment

To install subsidised residential systems:

• MNRE Vendor Registration: Register on the MNRE portal, upload required documents (PAN, GSTIN, bank details) and obtain a vendor ID.
• DISCOM Empanelment: Each state utility maintains a list of empanelled installers. Apply with proof of technical capability, past project references, and compliance certificates.

Without these registrations, you cannot claim the central subsidy, and the client may lose eligibility.

5. ALMM‑Listed Components

The Accelerated Loss Mitigation Matrix (ALMM) lists components that qualify for accelerated depreciation. Using ALMM‑listed panels and inverters not only benefits the client’s tax outlook but also aligns with GST compliance, as the components have defined HSN codes and GST rates.

6. Electrical Safety Approvals

Post‑installation, the system must be inspected by a certified electrical inspector and obtain a safety clearance certificate. This certificate is often required for GST credit reversal if the installation is later deemed non‑compliant.

7. Record‑Keeping and Audits

Maintain the following records for a minimum of six years:

• GST invoices (both sales and purchase)
• Input Tax Credit reconciliation statements
• MNRE vendor certificates
• DISCOM empanelment letters
• Project contracts and design documents
• AMC agreements and service logs

During a GST audit, the authorities will verify the composite‑supply calculation, the existence of Input Tax Credit, and the linkage between the invoice and the actual installation.

8. Professional Guidance

Because GST rates and compliance requirements can change with each Finance Ministry budget, it is prudent to:

• Consult a chartered accountant for every new project.
• Subscribe to updates from the GST Council and MNRE.
• Use software that can be updated centrally with the latest tax rates.

Following these steps ensures that your rooftop and ground‑mounted solar projects remain financially viable and legally sound, letting you focus on growing your installer business.

Frequently Asked Questions

What is the general approach to gst rooftop ground mounted solar projects?

In India, solar installations are typically treated as a composite supply. This means the goods (panels, inverters) and the services (installation, commissioning) are bundled together. The tax treatment usually follows a convention where the value is split between goods and services to determine the final tax liability. Always consult a Chartered Accountant for current rates.

How does the 70:30 split work for solar GST?

The 70:30 convention is a common industry practice where 70% of the project value is attributed to the supply of goods and 30% is attributed to the installation services. This split helps installers determine the tax amount for each component of the composite supply. However, specific project requirements may vary, so professional tax advice is essential.

Is GST different for residential rooftop solar?

Residential projects often follow the same composite supply rules as other solar installations. However, because many residential projects are part of government schemes like PM Surya Ghar, installers must ensure their invoicing is precise to facilitate subsidy processing. Proper GST documentation is critical for the homeowner to receive their benefits without delays.

Do ground-mounted projects have different tax rules than rooftop ones?

While both generally fall under composite supply, ground-mounted projects often involve more extensive civil works and land preparation. These additional services might be viewed differently by tax authorities compared to a simple rooftop mount. It is important to check if the civil work is bundled or billed as a separate service.

What is a composite supply in the solar context?

A composite supply occurs when two or more taxable supplies are naturally bundled and supplied together. In solar, the hardware (panels) and the service (installation) are interdependent. You cannot have a functioning solar plant without both. This allows for a specific tax treatment rather than taxing every single nut and bolt separately.

How does GST affect the cost of a solar installation for the customer?

GST is added to the base cost of the system. For the customer, this increases the upfront investment. Installers must clearly communicate the tax component in their proposals so the customer understands the total INR outlay. Using a professional proposal tool helps in showing the breakdown of base price and taxes.

Can installers claim Input Tax Credit (ITC) on solar components?

Yes, registered solar EPCs can generally claim Input Tax Credit on the GST they pay to suppliers for panels, inverters, and structures. This helps in reducing the overall tax burden on the final project. Accurate record-keeping and GST-compliant invoices from vendors are mandatory to claim this credit.

What is the role of MNRE registration in GST and subsidies?

While MNRE registration is primarily for vendor empanelment and subsidy eligibility, it ensures the installer is a legitimate entity. For residential systems, being an empaneled vendor is a prerequisite. This legitimacy is often checked during the audit of GST filings and subsidy claims made by the consumer.

Do I need to issue separate invoices for hardware and labour?

Under the composite supply rule, a single invoice covering the entire “solar power generating system” is common. However, the internal breakdown (like the 70:30 split) must be clear for accounting purposes. You can read more about Composite Supply vs Mixed Supply for Solar Projects: GST Rules to understand the difference.

What happens if I provide only AMC services?

Annual Maintenance Contracts (AMC) are pure services and do not involve the supply of a new power generating system. Therefore, they are taxed as service contracts rather than composite supplies. This means the tax rate will be the standard rate applicable to electrical maintenance services in India.

How does GST impact the pricing of kW systems?

GST adds a percentage to the cost per kW. When quoting for a project, installers must decide whether to quote “exclusive of taxes” or “inclusive of taxes.” Since GST rates can be complex, quoting exclusive of taxes is generally safer to avoid margin erosion if tax rules change.

Is e-invoicing mandatory for all solar installers?

E-invoicing is mandatory for businesses that cross the government-specified annual turnover threshold. If your EPC business exceeds this limit, you must generate invoices through the government portal. For details on this, check our guide on E-Invoicing for Solar Businesses: Who Needs It & How.

What documents are needed for GST compliance in solar projects?

You need valid GST invoices from your equipment suppliers, a registered GSTIN for your business, and a clear contract with the client. For ground-mounted projects, you may also need documentation regarding the land use and civil works to justify the service component of the tax.

How is GST handled for solar system upgrades?

Upgrades, such as adding more panels or replacing an old inverter, are typically treated as a supply of goods and services. If it is a small addition, it may be billed as a service with parts. If it is a major overhaul, it might be treated as a new mini-installation.

Does the PM Surya Ghar scheme change GST rules?

The scheme drives volume and demand but does not change the fundamental GST laws of India. However, the need for transparency in invoicing is higher because the government verifies the installation before releasing subsidies. Incorrect GST billing can lead to subsidy rejection for the homeowner.

How should I handle GST for referrals?

If you receive a commission for referring a lead to another installer, this is a service you are providing. You should issue a GST invoice for the referral fee to the other installer, and the appropriate service tax will apply to that income.

What is the impact of ALMM-listed components on GST?

ALMM (Approved List of Models and Manufacturers) is a quality and sourcing requirement. While it doesn’t change the GST rate, using non-ALMM components might make a project ineligible for subsidies, which changes the financial dynamics for the customer, even if the tax remains the same.

How do I manage GST for panel cleaning contracts?

Panel cleaning is a recurring maintenance service. Like AMCs, these are billed as services. Since there is no “system” being sold, the composite supply rule does not apply here. It is a straightforward service invoice with the applicable GST rate.

Are there any GST exemptions for solar projects?

Certain government-funded projects or specific categories might have different treatments, but for the vast majority of private residential and commercial rooftop installations, the composite supply rule applies. Always verify with a CA to see if your specific project qualifies for any exemptions.

How does ground-mounted solar differ in billing?

Ground-mounted projects often involve larger sums of INR and longer timelines. This means the timing of the GST liability (point of taxation) becomes more important. Installers often bill in milestones (advance, delivery, installation), and GST must be accounted for at each stage.

What is the risk of incorrect GST filing for an EPC?

Incorrect filing can lead to penalties, interest on unpaid taxes, and a bad reputation with DISCOMs. More importantly, if the customer cannot claim their subsidy due to your invoicing errors, it can lead to legal disputes and loss of future referrals in the local market.

How can I automate GST calculations for my proposals?

Many installers are moving away from spreadsheets to dedicated solar software. These platforms allow you to build GST-aware proposals that automatically calculate the tax based on the system size and the goods-services split, ensuring consistency across all your customer quotes.

Conclusion

Navigating the complexities of gst rooftop ground mounted solar projects is one of the most challenging aspects of running a solar EPC business in India. The distinction between a simple product sale and a composite supply of a power generating system can significantly impact your bottom line and your customer’s satisfaction. For the Indian installer, the goal is to provide a seamless experience where the homeowner or business owner doesn’t have to worry about tax errors that could jeopardize their PM Surya Ghar subsidy or corporate tax credits.

As the market expands toward the goal of 1 crore rooftop installations, the volume of paperwork will only increase. Relying on manual spreadsheets for GST splits, subsidy tracking, and lead management is no longer sustainable for growing businesses. To maintain healthy gross margins per kW and a high survey-to-close rate, installers need a system that handles the technical and financial calculations automatically.

This is where SolarSwytch comes in. As the Operating System for Solar Installers, SolarSwytch provides an all-in-one platform that replaces fragmented tools. Instead of jumping between a CRM and a calculator, you can generate subsidy- and GST-aware proposals, manage your leads over WhatsApp, and track your installation operations from a single dashboard. By automating the “boring” part of the business—the compliance and the paperwork—you can focus on what actually grows your revenue: installing more systems and improving your AMC attach rate.

Whether you are dealing with the logistical hurdles of an E-Way Bill for Solar Equipment Transport: A Quick Guide or simply trying to explain the 70:30 tax split to a new client, having a professional digital presence makes all the difference. We encourage all small and mid-sized EPCs to audit their current invoicing process and consult with a professional CA to ensure they are fully compliant with the latest Indian tax laws. Moving toward automation today ensures that your business is ready for the solar boom of tomorrow.