Every housing society has a common area electricity bill. In most mid-sized societies in Maharashtra, this bill — covering lifts, corridor lighting, pump rooms, security systems, and parking area lighting — runs to ₹60,000–₹1 lakh per month or more. For the 120 units at Greenview Residency in Baner, Pune, that bill had become the single biggest frustration for the management committee.
This is the full story of how that society went from a ₹7.4 lakh annual common area electricity bill to a ₹1.6 lakh bill — a 78% reduction — through a 40 kW rooftop solar installation planned, designed, and delivered by FGPS Solar.
Project Background: The Problem
Greenview Residency is a 120-unit residential complex spread across four towers in Baner, a rapidly growing suburb of Pune. Like most societies of its size, it has a significant common infrastructure load: four passenger lifts (15 kW combined), a booster pump system (7.5 kW), underground sump pump, overhead tank pumps (5 kW), corridor and stairwell lighting across 4 floors × 4 towers, security cabin, gate automation, and CCTV systems.
The society's average monthly common area electricity bill from MSEDCL (Maharashtra State Electricity Distribution Company) had climbed from ₹42,000 in 2020 to ₹62,000 per month by 2023, driven by both increased consumption and Pune's steadily rising commercial tariff rates. Annual maintenance charges had increased three times in four years, and resident dissatisfaction was growing.
The management committee chairman, Mr. Sanjay Kulkarni, raised the solar option at an Annual General Meeting in March 2023. The proposal received unanimous support from the 120 flat owners, and FGPS Solar was invited for a site assessment in April 2023.
Site Assessment and System Design
Our survey team spent a day on site, conducting:
- Roof area measurement across all four towers (combined usable area: 4,800 sq ft after accounting for water tanks, staircases, and parapet set-backs)
- Shade analysis using Helioscope software with Pune's actual solar irradiation data (GPS: 18.56°N)
- Structural inspection of all four roof slabs (all confirmed as RCC, built 2016, structurally sound)
- Electricity meter and switchboard review to design the grid tie-in configuration
- 12-month electricity consumption data analysis provided by the committee
Based on the analysis, a 40 kW on-grid system was specified as optimal — sized to cover approximately 90% of annual common area consumption, with net metering to credit any surplus generation back to the society's MSEDCL meter.
- Total capacity: 40 kW (40,000 Wp)
- Panels: 96 × 415W monocrystalline PERC panels (Tier 1, BIS-approved)
- Inverters: 2 × 20 kW three-phase string inverters with remote monitoring
- Mounting: Aluminium rail + ballast system on 3 of 4 rooftops (Tower 3 roof excluded due to water tank shadow coverage)
- Net metering: Bi-directional meter installed at society's main incomer
- Annual generation estimate: 55,000–58,000 units/year (Pune: 5.0 peak sun hours/day)
- Monitoring: Cloud-based inverter monitoring accessible by committee members via mobile app
Installation Timeline
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1Day 1–2
Material delivery and rooftop staging
All panels, inverters, mounting hardware, and cabling delivered and staged. Coordination with society security for crane access through the main gate was completed the previous week to minimise resident disruption.
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2Day 3–6
Mounting structure installation
Aluminium rail mounting systems installed on Towers 1, 2, and 4. Ballast blocks positioned and levelled. Our structural team verified placement against the load distribution plan — no drilling into the RCC slab required.
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3Day 7–10
Panel installation and DC wiring
96 panels installed across three rooftops. DC combiner boxes mounted and all string wiring completed. Panels grouped into 4 strings of 24 panels each, feeding into the two 20 kW inverters.
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4Day 11–12
AC wiring, inverter installation, and earthing
Inverters mounted in the ground-floor electrical room. AC cabling run from inverter output to the main distribution board. Earthing system installed as per IS 3043. All cable tray work completed.
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5Day 13–14
Commissioning, net metering, and handover
MSEDCL inspection completed (coordinated by FGPS Solar). Bi-directional net meter installed. System energised and full generation confirmed. Committee members given a live walkthrough of the monitoring app. All documentation (as-built drawings, warranties, O&M manual) handed over.
Challenges Encountered and Solutions
Challenge 1: Limited Roof Access on Tower 3
Tower 3's rooftop had two large overhead water storage tanks positioned near the south face of the roof, creating a shadow path that eliminated viable panel placement for roughly 40% of the roof area. Rather than compromise system performance by placing panels in the shadow zone, we excluded Tower 3 entirely from panel placement and distributed the full 96-panel array across Towers 1, 2, and 4, which had cleaner shadow profiles.
Challenge 2: MSEDCL Net Metering Delay
The net metering application was submitted alongside the system installation, but MSEDCL's processing time extended beyond the expected 30-day window, delaying the bi-directional meter installation by 3 weeks. During this period, the system operated in a limited mode with the inverter's anti-islanding protection active. FGPS Solar's regulatory team followed up directly with the MSEDCL divisional office to expedite the process — a step that most societies are not aware they can take through their EPC partner.
Challenge 3: Resident Concerns About Roof Waterproofing
Several flat owners in Tower 1 raised concerns that drilling or heavy loads on the roof might compromise the existing waterproofing membrane. This was addressed by using an exclusively ballast-mounted system — no drilling into the slab — and commissioning an independent assessment from a civil engineer, whose report was circulated to all concerned residents before installation proceeded. Zero waterproofing issues have been reported in the 12 months since installation.
Financial Results: 12 Months Post-Installation
The annual maintenance charge per flat, which had been increased three times between 2019 and 2023, was held flat in 2024 — the first year in five where it did not increase. The committee estimates that each flat effectively saves ₹4,866 per year in maintenance charges compared to the trajectory without solar.
Resident Testimonials
"I was sceptical at first — I thought this was another committee idea that would cost us money and deliver nothing. But the numbers are real. I can see the generation on the app every morning. Our maintenance charge didn't go up this year for the first time since 2019. That's the proof."
"The FGPS team was incredibly professional. They explained everything to us — from the shade analysis to the MSEDCL process — in plain language. The installation was fast and they left the rooftops clean. The monitoring app is a bonus — I actually enjoy checking the daily generation figures."
Lessons Learned
This project yielded several insights that we now apply to every housing society installation:
- Start with actual consumption data, not estimates. Analysing 12 months of MSEDCL bills (not just the latest one) gave us a much more accurate system sizing. Peak summer months in Pune (March–May) are the highest consumption months due to pump loads; the system was sized to address these peaks.
- Exclude poor roof zones rather than compromising performance. Using three rooftops instead of four delivered better annual yield than distributing panels across all four with some in shadow. Per-panel output averaged 15% above projections partly because of this decision.
- Involve residents early in the process. The waterproofing concern on Tower 1 could have derailed the project. Getting an independent civil engineer's report proactively, and sharing it before concerns escalated into AGM disputes, was the right approach.
- Net metering coordination requires active follow-up. Leaving DISCOM applications to the standard queue adds weeks. Our regulatory team's direct coordination saved approximately 3–4 weeks in this case.
- Remote monitoring builds ongoing trust. Societies that can see their generation in real time — and share it with residents — report higher overall satisfaction and significantly fewer post-installation queries. The investment in good monitoring infrastructure pays dividends in resident relations.
Greenview Residency is now one of several FGPS Solar-powered societies in Baner and Aundh. Word-of-mouth referrals from this project have led to five additional society consultations in the same postal code — a testament to the power of visible, measurable results in a tight-knit residential community.
