Building technology
is what we sell.
Policy change is
what we make.
Protostar's impact extends beyond individual buildings. We have shaped national green building standards, rewritten solar energy regulations for millions of apartment residents, and catalysed a systemic shift in how India thinks about distributed solar energy.
Two systemic impacts that changed India's energy landscape
“Protostar submitted that when multiple consumers wish to participate under Virtual Net Metering... Protostar has suggested hardware-based approach. It has proposed to consider allowing the energy settlement at a common net meter for the entire building. The distribution of electricity can then be allocated to each apartment via Energy Allocation Devices (EAD) / Smart Power Distribution Unit (SPDU). This approach will simplify the billing process for the Distribution Licensee and ensures fair distribution of solar generated power.”
— MERC (Grid Interactive Rooftop REGS) Second Amendment Regulations, 2024 · SOR
Why hardware beats digital billing
One meter. Full stop.
Under VNM, every flat needs its own virtual accounting trail: ratios, adjustments, monthly reconciliations. With SPDU, the building has one net meter connection. The DISCOM bills it like any other prosumer. The hardware handles everything inside the building.
Physical power, not billing credit
VNM credits residents' bills after the fact, based on ratios that may or may not reflect actual consumption. SPDU distributes real solar power to each flat in real time. Residents receive actual energy, not a month-end accounting entry they have to trust.
Transparent and resident-controlled
Each flat knows exactly how much solar it consumed, live, through the Nova platform. There is no intermediary, no DISCOM billing calculation, and no shared-ratio dispute. The allocation is deterministic and hardware-enforced.
Grid-Connected Micro-Grid — the regulatory hook
MERC's Second Amendment introduced the Grid-Connected Micro-Grid concept alongside VNM. This is precisely the framework that legitimises an SPDU-based building solar system: RE generation, internal distribution hardware, and a single grid connection, recognised as a legal installation.
Rewriting the
rules for
rooftop solar
MERC's Virtual Net Metering (VNM) framework is a digital billing adjustment allowing apartment residents to share rooftop solar. It was always going to happen. The regulator had been moving in this direction for years. But digital billing fixes create their own problems: DISCOMs must manage complex per-flat accounting, shared-ratio adjustments, and monthly reconciliation across thousands of meters. Errors are inevitable. To this day, VNM is not operationally live in Maharashtra.
Protostar's submission to MERC argued for a fundamentally different approach: solve it in hardware, not in billing software. The SPDU allocates physical solar power to each flat in real time. The DISCOM sees just one net meter, familiar and exactly what it already knows how to bill. No virtual accounting. No shared-ratio tracking. No new IT infrastructure.
MERC's Statement of Reasons acknowledges Protostar's submission by name and introduces the Grid-Connected Micro-Grid concept alongside VNM. This is the regulatory hook that legitimises the SPDU architecture at building level.
Reshaping India's
green building
standard
Water heating is one of the largest single electricity loads in any residential building. Conventional electric geysers are among the most energy-wasteful appliances in Indian homes. Heat pump water heaters consume just one-third the electricity for the same output, yet they were absent from India's mainstream green building certification criteria.
Rahul Rajan, founder of Protostar Technologies, engaged in extended technical discussions with the IGBC Green Homes Core Committee — the body responsible for shaping India's national residential green building rating system. The committee was initially unfamiliar with heat pump technology at scale in residential buildings. Through persistent, detailed advocacy grounded in real installation data, the committee came to understand the efficiency gains and incorporated heat pumps into IGBC Green Homes Rating System Version 3.0 under the Energy Efficiency category.
This codified heat pumps as a recognised, creditable green technology for multi-dwelling residential units across India, creating a framework that now incentivises developers, architects and housing societies to adopt energy-efficient water heating at scale.
IGBC Green Homes v3 · Energy Efficiency
EE Credit 2 — Alternate Water Heating Systems
3 credit points available · applicable to all multi-dwelling residential projects · incentivises heat pump water heaters as a superior alternative to conventional electric geysers
The scale this unlocked
Source: IGBC Green Homes Rating System Ver 3.0 · September 2019
Cascading effects
Heat pump technology now creditable under India's largest residential green building rating system
Developers across India incentivised to specify heat pump water heaters to earn IGBC credits
Building-level electricity demand for water heating reduced by up to 67% vs. conventional geysers
Standard now applied across multi-dwelling units, apartment complexes, gated communities and residential resorts nationwide
Rahul Rajan · Advocate to IGBC Green Homes Core Committee
From rooftop to
national grid
Every SPDU deployment creates value at three distinct levels simultaneously. Our 2023 impact report calls it a “multifold climate contribution in a single action.”
Benefit to Societies
Passive cooling
Full rooftop solar coverage blocks direct sunlight from reaching the terrace slab, eliminating the building's biggest source of heat gain. Air-conditioning load drops for every flat below, and so do the bills.
Waterproofing extension
Solar panels shield the waterproofing membrane from thermal expansion cycles and monsoon impact. Buildings see fewer leaks, lower maintenance costs and a substantially longer roof lifespan.
Usable rooftop space
The shaded space created under elevated panels becomes a functional recreational area for residents. Its intrinsic value often exceeds the capital cost of the entire solar system.
40–100% energy coverage
Most residential buildings (except narrow high-rises) have sufficient rooftop area to meet 40% to 100% of their total electricity requirements through rooftop solar, delivered fairly to every unit via the SPDU.
Benefit to DISCOMs
Deferred infrastructure investment
Every unit consumed within the building is a unit the DISCOM never has to generate, transmit, or step down. As EV charging and cooling loads drive rising residential demand, buildings with SPDU reduce peak draw on local distribution transformers. DISCOMs can defer costly network upgrades worth crores per substation.
Reduced transmission losses
Power generated at the point of consumption eliminates long-distance transmission and transformer losses entirely. Every unit generated on a rooftop is a unit that never travels the grid.
EV charging support
India's EV revolution is straining an already overloaded grid. Residential rooftop solar provides clean daytime generation precisely when EV charging peaks, allowing DISCOMs to meet rising demand without new peaker plant capacity.
Decentralised grid stability
A dense network of rooftop micro-generators provides distributed redundancy with no single point of failure. Reduced congestion and lower susceptibility to demand shocks make the grid inherently more resilient.
Benefit to the Nation
Energy security
India is the world's third-largest energy consumer. Distributed rooftop solar creates a decentralised grid with no single point of failure, reducing dependence on international energy imports that can be disrupted by geopolitical events.
Farmland preservation
Unlike utility-scale solar farms that consume and degrade fertile agricultural land, rooftop solar utilises existing dead space in cities. Urban rooftops visible in satellite imagery represent an enormous untapped generation opportunity.
Air quality & health
India recorded over 2.3 million premature deaths attributable to ambient and household air pollution in 2019 alone. Displacing coal-based grid electricity with clean rooftop solar is among the highest-leverage public health interventions available.
National energy targets
India's share of global primary energy consumption is projected to grow from 6.1% to 9.8% by 2050. Rooftop solar on residential buildings, enabled by SPDU, is a scalable and bankable path to meeting this demand with clean energy.
Distributing
the Power of
the Sun
Our full-length impact literature explores the three-tier benefits of SPDU technology in depth: passive cooling and waterproofing extension at society level, DISCOM grid relief, and national energy security and farmland preservation. Includes primary research citations and quantitative analysis.
Multifold climate contribution in a single action
Benefit to Societies: passive cooling, waterproofing, space
Benefit to DISCOMs: deferred capex, reduced losses, EV support
Benefit to the Nation: energy security, farmland, air quality
22 peer-reviewed references and citations
Add your building
to the story
Every new deployment compounds the impact: on carbon, on policy precedent, and on what's possible. Partner with Protostar to bring net-positive energy to your next project.