Solar for apartments in Karnataka: RWA subsidy, virtual net metering, roof rights and sizing

Three ways an apartment can go solar

Many societies combine 1 and 2: first cover the common load, which every resident pays for through maintenance, then offer a shared plant to flats that want it.

The RWA / GHS subsidy in detail

MNRE's PM Surya Ghar structure gives Group Housing Societies and Resident Welfare Associations ₹18,000 per kW for common facilities, including EV charging, up to 500 kW. The cap is calculated at 3 kW per house, and it includes any rooftop plants that individual residents in the society have already put up. So a 40-flat society has a ceiling of 120 kW, minus any individual systems.

• The applicant is the registered association or society, with its own electricity account for the common area.
• DCR (Indian-cell) panels and a vendor registered on the national portal are required, as for homes.
• Apply on pmsuryaghar.gov.in before installation, and keep the association's bank account details ready for the subsidy credit.

Virtual net metering: one plant, many flats

KERC first allowed virtual net metering (VNM) in its July 2025 tariff order. The 2026 DSPV Regulations confirm it, and all ESCOMs follow a common procedure issued by BESCOM on 12 May 2026. How it works:

• A solar plant of at least 5 kW, on the roof or elsewhere in the same ESCOM's area, exports all its generation to the grid.
• The generation is credited to each participating consumer's bill in the ratio declared in the VNM agreement, e.g. Flat 101 gets 4%, Flat 102 gets 3%.
• All participants must be in the same consumer category (domestic with domestic).
• Plant size cannot exceed the combined sanctioned load of the participants.
• Credits beyond a flat's own monthly use are bought at 75% of the generic DSPV tariff. So, as with homes, size to what the flats actually use.
• The ratio can be changed once a year, at the start of the financial year, with two months' notice.
• One participant must be the lead person who signs for everyone and deals with the ESCOM.
• Smart meters at the participants' cost, at the plant and at every participating flat.
• No open access charges if the plant and the flats are on the same transformer or 11 kV feeder, which is normally the case for a single building.

If a participating flat's connection is disconnected, its unadjusted credits lapse. Build that into the association's rules.

Approvals inside the association

The terrace is usually common property under the apartment's deed of declaration and the association's bye-laws. No single owner, and no committee on its own, should decide to fill it with panels. In our experience, the projects that go smoothly do this:

Common objections we hear: ground-floor residents who don't use the lift, residents who have already put up their own panels, and tenants who will leave. A common-area plant is the easiest sell because everyone pays maintenance; a VNM plant should be voluntary, with each flat paying for its share.

Sizing the plant

1. Common area: take 12 months of the common meter bills. Lifts, borewell and transfer pumps and STP run largely in the day, which suits solar. Divide the monthly units by about 120 for the kW needed.
2. Roof: allow about 80–100 sq ft of shadow-free area per kW. Water tanks, lift machine rooms and parapets cast shadows; elevated structures (at least 8 ft clearance) can raise panels above them.
3. Sanctioned load: net metering on the common connection is limited to its sanctioned load. A small common meter may need load enhancement.
4. Large societies on HT supply: apartments on an HT connection are billed under tariff HT-4 (₹290/kVA demand charge and 700 paise per unit in 2026-27), and common areas there are billed at the tariff of the predominant category. Solar on an HT complex above 150 kW connects at 11 kV and needs ESCOM feasibility and a PPA. See our HT connection guide.

Lifts and water supply that are independently metered for a residential complex are billed under the domestic LT-1 schedule in the 2025 tariff order, so each solar unit used there saves the same ₹5.80 plus charges as in a house.

Where apartment solar projects go wrong

• Builder still holds the common meter. If the common-area connection is in the builder's name, the association cannot apply. Get it transferred first; see our name transfer guide.
• Mixed categories in VNM. A shop or office in the complex is on a commercial tariff and cannot join a domestic VNM group. It needs its own arrangement.
• Tenants and resale. VNM shares follow the electricity connection. When a flat is sold or the tenant changes, the VNM agreement and lead person details must be updated in writing, and the share ratio can only be changed once a year with two months' notice.
• No one owns maintenance. Dusty panels on a terrace nobody visits lose output quietly. Put cleaning and an annual electrical check in the facility manager's contract.
• Fire access and safety. Leave clear walkways to tanks, lift rooms and the staircase head. Run DC cables in metal conduit, fit DC isolators near the inverter, and earth the structure properly. Our earthing checklist helps before the ESCOM inspection.
• Arrears on the common account. Under the 2026 regulations, a connection with pending dues is not eligible until they are cleared or the disputed amount is deposited.

After commissioning: running the plant as a society

A society plant outlives several committees. The projects that keep delivering are the ones where somebody owns the numbers and the paperwork from year one.

• Report savings to residents. Keep a simple monthly sheet: units generated (from the inverter or generation meter), units imported and exported on the common meter, and the common bill amount. Present it at the annual general body meeting. Residents who can see the saving stop asking why the maintenance went up.
• Keep a replacement fund. The inverter is the part most likely to need repair or replacement within the panels' life. Set aside a small amount each year from the savings rather than raising a special levy later.
• Keep the VNM register current. Maintain a list of participating flats, their share, the lead person and the date each share last changed. Update it whenever a flat is sold or a lead person moves out.
• Plan EV charging with the solar. The RWA subsidy covers common facilities including EV charging, and daytime charging in the parking area uses solar units directly. Before residents fit their own chargers, agree on the cable routes and load with the association; our guide to EV chargers at home and in apartments covers the wiring.
• Check the transformer. Adding solar, lifts and EV chargers to an older building changes the load on the transformer. If the building was supplied from its own transformer, read electricity for apartments and multi-storey buildings before a large expansion.
• Hot water is separate. Under Bengaluru's bye-law, apartments must also provide solar water heating. A common solar water heater system and a PV plant compete for the same terrace, so plan both together.

From idea to commissioning

Building a new apartment? Plan conduit routes from terrace to the meter room, space for inverters and a structure-friendly terrace layout at the design stage. Our construction electrical guide covers the wiring stages.

Questions

Sources

Rules and figures in this article were checked against these sources on 30 Sep 2026. Schemes and tariffs change, so confirm with the official office before you act.

• MNRE PM Surya Ghar CFA structure (GHS/RWA)
• KERC DSPV Regulations 2026 (VNM, GNM, metering)
• Common SOP for VNM and GNM for all ESCOMs, 12.05.2026
• KERC DSPV tariff order dated 25.08.2026
• BESCOM DSPV portal (VNM / GNM application links)
• KERC Tariff Order 2025 schedules (LT-1 lifts and water supply, HT-4 apartments), HRECS copy
• TeamLease RegTech: KERC introduces virtual / group net metering (Jul 2025)

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