Your society's electricity bill, rewritten by its terrace.
Rooftop solar for Mumbai housing societies, designed, approved, installed and maintained by us. Own the plant, or pay per unit.
Today: ₹1,50,000 With solar, about ₹22,600
with a 105 kW plant on your terrace
Common areas: lifts, pumps, lighting, clubhouse, EV chargers. Shown if the society owns the plant, which needs about 10,500 sq ft of shadow-free terrace. Before time-of-day rules and shading, which your proposal applies.
How we worked it out.
Every figure on this page comes from three numbers: your bill, your rate per unit and your terrace. Change any of them and the whole statement updates.
| Per month | Today | With solar |
|---|---|---|
| Units used1 | 11,538 | 11,538 |
| Solar plant on your terrace2 | none | 105 kW |
| Units the plant generates2 | none | 11,813 |
| Units bought from the grid | 11,538 | 0 |
| Energy charges at ₹13/unit | ₹1,50,000 | ₹0 |
| Grid support charge on solar units3 | none | ₹22,615 |
| Amount payable | ₹1,50,000 | ₹22,600 |
| Saving a month | ₹1,27,400 |
- Units used = your bill divided by your average rate.
- Plant sized to your units at about 1,350 units per kW a year (unshaded Mumbai rooftop), rounded to 5 kW and capped by terrace area if you enter it.
- ₹1.96 per solar unit on LT connections above 10 kW (₹1.42 on HT).
- Not modelled here: time-of-day slot matching (above 10 kW, solar units made 9am to 5pm offset only same-slot use), shading, tariff category and battery-storage rules for larger plants, which are under review. Your proposal models these from 12 months of bills and meter data.
- Indicative, as of Oct 2026. Subject to site survey and DISCOM rules.
Own it, or pay per unit.
Same panels, same engineering, same team. What changes is who pays upfront, and when the plant becomes the society's.
| Compare | Own it (CAPEX)About ₹38.3 lakh after subsidy for your plant. Pays back in about 2.5 years, before time-of-day rules. |
Pay per unit (RESCO)₹0 upfront. Save about ₹38,000 to 60,000 a month from the first month. |
|---|---|---|
| Upfront cost | One-time investment | Nothing, or a small security deposit |
| Every month you pay | Nothing for the solar units | An agreed rate for each unit generated |
| Who owns the plant | The society, from day one | The investor, during the agreement |
| Maintenance | First year included, then optional AMC | On us for the whole tenure |
| Government subsidy | The society claims it; we file it | Built into the per-unit rate |
| After the tenure | Already the society's | Transfers to the society at nil or nominal valueNo renewal. No removal. |
| Best for | The largest 25-year saving and an asset on the books | Savings now, with no capital and no hassle |
Longer RESCO tenure, 10 to 15 years
Save 25 to 40% on every solar unit during the agreement, then the plant is the society's for the rest of its life.
Shorter RESCO tenure, 3 to 7 years
Save 0 to 15% during the agreement, then own it sooner and keep the full saving for longer.
A non-refundable security deposit may apply; it trades off against the per-unit rate and tenure. Levies that change after signing pass through. RESCO financing is structured with Clarte Financial Advisory, a CA-led advisory firm.
We file the subsidy. The society gets it.
Less: PM Surya Ghar subsidy
₹18,000 per kW for group housing societies and RWAs, on solar that powers common facilities, up to 500 kW (at most ₹90 lakh). Shown for your 105 kW plant, if the society owns it.
−₹18.9 lakh at ₹18,000/kW
What we handle
- The PM Surya Ghar portal application, from registration to the subsidy claim.
- DCR (made-in-India cell) panel certificates, which both the subsidy and net metering require.
- Net metering and inspection with Tata Power, Adani Electricity or MSEDCL.
| 1 kW on a home | ₹30,000 |
|---|---|
| 2 kW | ₹60,000 |
| 3 kW and above | ₹78,000 |
As per PM Surya Ghar: Muft Bijli Yojana, as of Oct 2026. Subject to scheme terms, DCR modules and capacity limits.
Order to switch-on in 3 to 4 months.
The site survey and proposal come first, and are free. After the order, one team takes it through approvals to switch-on and maintains it for 25 years. We chase the DISCOM for you.
- Site surveyRoof, shading, meters and 12 months of bills.
- DesignTerrace layout, single-line diagram, generation model, CAPEX and RESCO options.
- ApprovalsDISCOM net metering, electrical inspector, subsidy filing.
- InstallWind-rated structure, modules, inverters, earthing.
- CommissionTesting and grid synchronisation.
- HandoverNet meter, as-built drawings, warranties, training.
- Operations & maintenanceRemote monitoring, module cleaning and upkeep.
Built for high-rise wind.
Mumbai rooftops are high, salty and windy. We make our own mounting structures, rated for 150 km/h wind, so we control the part that has to last the longest.
Founding team with 60+ years combined in renewables, engineering and execution, and exposure to 100 GW+ of installed and planned solar.
| Item | Specification | Warranty |
|---|---|---|
| On the roof | ||
| Modules | N-type TOPCon bifacial, DCR-certified, 615 to 630 Wp | 12 yrs product, 30 yrs performance |
| Mounting structure | Punarbhu-made, rated for 150 km/h wind, SS304 fasteners, aluminium clamps | 5 to 10 yrs |
| Cleaning line | Built-in sprinkler line for the modules | 2 yrs |
| In the electrical room | ||
| Inverters | 3-phase string, 98% efficiency, IP65, remote monitoring over Wi-Fi or GPRS | 5 to 10 yrs (maker) |
| Cables, boards, protection | DC and AC cables, distribution boards with Type II surge protection, ESE lightning arrestor, earthing | 2 yrs |
| Our work | ||
| Workmanship | Installation and commissioning | 1 yr |
| Electrical O&M | Monitoring and upkeep after handover | 1 yr (CAPEX), whole tenure (RESCO) |
Taking it to your AGM? We'll come with you.
Solar is a society decision. We present to the managing committee, answer members' questions, and leave a proposal built for a vote.
Ask for a committee presentation- Terrace layout drawing with the module count
- Consumption and generation model, meter by meter
- CAPEX and three RESCO options, side by side
- Savings during and after the RESCO tenure
- Scope list: what we do, what the society does
Questions members ask.
Will it damage our terrace or waterproofing?
We survey the slab first and design the structure to the roof. Waterproofing and any roof strengthening stay with the society. If waterproofing needs redoing, we'll say so before installation so it is done once.
What happens to the plant when a RESCO tenure ends?
It transfers to the society at nil or a pre-agreed nominal value. From then on, every unit it generates saves the society the full grid rate for the rest of the plant's life.
Do we need batteries?
Most society plants are on-grid with net metering: surplus goes to the grid and is credited. Rules on battery storage for larger plants are under review in Maharashtra. We check the current position for your plant and include storage in the proposal if it is required.
What are time-of-day billing and grid support charges?
Above 10 kW, solar units made between 9am and 5pm offset only consumption in that same slot, and the DISCOM charges about ₹1.96 per solar unit on LT connections (₹1.42 on HT). The quick estimate on this page includes the grid support charge; your proposal also models the time slots from your meter data.
DCR or non-DCR panels?
Net metering and the subsidy both need DCR (made-in-India cell) panels. Non-DCR is 15 to 20% cheaper but only suits captive plants that never export. We price both so the committee can choose.
What does the society have to arrange?
Busbar extension, an internet connection for monitoring, statutory fees, roof strengthening or waterproofing if needed, and clearing vegetation. Everything else, from design to net metering, is on us.
Send this estimate
Your estimate, ready to send
Indicative, if the society owns the plant. Before time-of-day rules and a site survey.
- Monthly bill today
- ₹1,50,000
- Solar plant
- 105 kW
- Payable if the society owns it, about
- ₹22,600
- Subsidy (CAPEX)
- ₹18.9 lakh