Clean energy

Focuses on India’s transition to renewable energy sources like solar, wind, and hydro, aiming to reduce carbon emissions and promote sustainable power generation.

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26 Mar 2026

Delhi’s winter air emergency is predictable: the haze returns, the AQI spikes, and advisories urge people to limit exposure. What the city cannot predict is whether the institutions tasked with prevention will act early enough. RTI documents cited by Newslaundry suggest the Union Ministry of Environment, Forest and Climate Change (MoEFCC) held only three meetings focused on Delhi’s air pollution through most of 2025—on September 16, October 10 and November 11. That schedule meant the first dedicated meeting came only weeks before peak winter pollution, despite the crisis following a year-after-year pattern. Decisions on paper, delays in the fieldThe September 16 meeting produced 19 decisions. But later minutes, as reported by Newslaundry, show that several core measures were still incomplete even as winter approached. Industrial emissions monitoring was a case in point. Officials discussed installing Online Continuous Emission Monitoring Systems (OCEMS) across 2,433 polluting industries, with procedures to be finalised in September and a monitoring mechanism expected by October 2. Yet by the November 11 meeting, only 179 installations—about 7 percent—were recorded as completed. The remaining units were pushed to a December 31, 2025 deadline, and the RTI material cited in the story does not clearly state whether that deadline was ultimately met. On emission standards, the timeline also slid. A key IIT Kanpur study on industrial emissions was expected by October 15, with revised industrial norms to be notified by October 31. The October 10 minutes instead recorded that reports for several sectors were still pending. Even by November 11, the norms were not finalised; the Central Pollution Control Board was asked to constitute another expert committee and draft action points by November 25. The RTI responses described by Newslaundry do not clarify what followed after that date. The minutes also show familiar ground-level contributors—road dust and construction dust—cycling through discussion without firm closure. In September, the ministry decided to convene officials across departments to address pothole-related dust, but the October minutes reportedly did not mention road repairs. By November, the Delhi government was asked for a report on pothole repair work. Construction and demolition waste saw repeated discussion too: in September, Delhi was told to prepare an integrated waste management plan without a deadline; in October, CAQM was asked to hold another meeting; and in November, municipal commissioners were instructed to prepare a “comprehensive plan” and submit it to CAQM before implementation. Stubble burning was mentioned in all three meetings, with plans to engage Punjab and Haryana. But the RTI responses, as presented in the report, offer no clear confirmation of whether such engagements happened or translated into measurable action. Filtered air for the fewIf the RTI minutes portray slow decision-making, a separate RTI reply highlights something faster and more concrete: protection for the ministry itself. Newslaundry reports that six air purifiers costing Rs 2.65 lakh were installed across MoEFCC offices. Five were purchased in February 2025, during the previous winter’s pollution peak, and five of the six were installed in the office of Minister of State for Environment Kirtivardhan Singh. The contrast lands in a city where winter AQI often crosses 400—levels the report describes as hazardous and linked to severe respiratory and cardiovascular harms. The story cites the World Health Organization estimate that air pollution causes 7 million premature deaths globally each year, and references India-wide estimates exceeding 1.7 million annually—figures the Modi government disputes. Independent assessments continue to underline how widespread the exposure remains. A Centre for Research on Energy and Clean Air analysis—based on CPCB monitoring data available till December 30, 2025—found most NCR cities breached India’s annual PM2.5 standards in 2025, with Delhi emerging as the most polluted major metro. The Delhi government points to improvement, with environment minister Manjinder Singh Sirsa calling 2025 the capital’s cleanest year in eight years; at the time of publication, Delhi’s average AQI was still in the “poor” category. Newslaundry says it sent detailed questions to MoEFCC, CPCB, CAQM and the Delhi government, and would update the story if responses arrive. Courtesy: Newslaundry.  ...Read more

26 Mar 2026

The Winter of AwakeningIn the grand, often chaotic narrative of Indian urbanization, the transition from late 2025 into the early months of 2026 marked a subtle yet profound inflection point. For decades, the story of the Indian city was one of unbridled expansion—a tale written in concrete, steel, and glass, often at the expense of the very environment that sustained it. The skyline was a graph of economic ambition, rising vertically with little regard for the thermal or ecological consequences on the ground. Green architecture, where it existed, was frequently relegated to a checklist for certification or a luxury add-on for the elite—a "vertical garden" in a corporate lobby or a solar panel on a gated community roof, serving more as a badge of prestige than a functional imperative.However, the winter of 2025 brought a different kind of quiet to the four great sentinels of India’s urban landscape: Kolkata, Chennai, Mumbai, and Delhi. Between December’s brittle cold and February’s uncertain warmth, these cities began to breathe differently. They were not merely expanding outward or upward; they were rethinking how buildings live, consume, and coexist with their inhabitants. The impetus was no longer just aesthetic or regulatory; it was existential. The harsh lessons of recent heatwaves, the choking reality of smog, and the erratic behavior of the monsoon had transformed green architecture from a niche experiment into a survival strategy.The prevailing sentiment across the Indian construction sector in 2025 was one of anxiety. The urban heat island effect had turned dense neighbourhoods into thermal traps, and water scarcity had become a chronic operational risk for large developments. The response from the architectural community, as observed over the last three months, was a pivot from "green washing"—superficial applications of sustainability—to "defensive design". This shift is characterized by a move away from the universal glass box, a remnant of Western modernism ill-suited to the tropics, toward forms that respect the local climatology. It is a negotiation between old wisdom and new technology.The data supports this transition. The Indian Green Building Council (IGBC) noted that green buildings in India are now saving approximately 199.3 billion litres of water annually—equivalent to 14% of Mumbai's yearly water supply—and reducing carbon emissions by 53.1 million tonnes a year. These are not abstract figures; they represent a fundamental operational shift in how cities function. The narrative of the last three months confirms that the future of Indian cities will not be decided by how fast they grow, but by how wisely they breathe.Kolkata: The Restoration of Breath and HeritageTo understand the green revolution in Kolkata, one must turn away from the gleaming glass towers of the IT corridors and look instead toward the crumbling, charismatic lanes of the north. In neighbourhoods like Shyambazar, a quiet "architectural correction" unfolded over the last few months. For decades, the aspiration of the middle class was to seal their homes—to replace slatted windows with sliding glass, to enclose balconies for extra square footage, and to rely entirely on split air conditioners to battle the stifling humidity. But as energy costs soared and the urban heat island effect intensified, a reversal began.In the winter of 2025, a century-old residential block near Shyambazar underwent a renovation that stunned observers—not for what was added, but for what was removed. Architects and conservationists, rather than demolishing the structure, chose to reopen high ventilators, shaded verandas, and internal courtyards that had been sealed over the last forty years. "We didn't invent anything new," remarked a conservation architect involved in the project. "We simply removed the mistakes of the last 40 years". This sentiment captures the essence of Kolkata's green shift: it is a reclamation of memory. The city remembered that its colonial and pre-colonial wisdom—high ceilings for thermal buoyancy, louvers for cross-ventilation, and thick walls for thermal mass—was far superior to the thin-skinned concrete boxes that replaced them.A critical component of this "correction" is the revival of lime plaster. Modern construction in India has been dominated by cement, a material that is robust but impermeable. Cement traps heat and moisture, creating a "greenhouse effect" within interiors that necessitates air conditioning. Lime, by contrast, is breathable. Research conducted in similar climatic zones in India, such as Ahmedabad, provides the scientific validation for Kolkata's intuitive return to tradition. Lime plaster possesses a significantly lower thermal conductivity (approximately 0.16 W/m-K) compared to cement plaster (1.58 W/m-K). This physical property means that lime resists the transfer of solar heat into the building envelope much more effectively than cement.Furthermore, lime acts as a natural humidity regulator. It has a high moisture buffering capacity, meaning it can adsorb excess moisture from the air during humid periods and release it when the air is dry. Studies indicate that lime-plastered buildings maintain lower indoor relative humidity levels by 6% to 10% compared to cement-plastered spaces. In a city like Kolkata, where humidity is the primary antagonist to thermal comfort, this regulation is vital. It reduces the "stuffiness" of indoor air and prevents the formation of mold, a common scourge in the humid tropics. The energy implications are profound. By reducing the internal heat load and moderating humidity, lime plaster reduces the reliance on mechanical cooling. Data suggests that lime-plastered spaces can be 3–5°C cooler than their cement counterparts, providing approximately 536 more hours of thermal comfort annually without the use of electricity. This is passive cooling in its most elemental form.While North Kolkata looks backward to move forward, the satellite townships of New Town and Rajarhat act as the city's laboratory for modern green urbanism. Here, the definition of "green" shifts from passive restoration to active technological intervention. New Town, declared a "Solar City" and "Smart Green City" by the government, represents the organized, state-driven face of sustainability. In the last three months, corporate offices and IT campuses in these areas have normalized features that were once considered experimental. Green roofs that reduce indoor temperatures by 3–4°C and sensor-based lighting systems responding to daylight availability have become standard tender language.The scale of intervention in New Town is district-wide. The authorities have implemented a 500 KW grid-connected canal-top solar power plant, utilizing the water bodies to cool the panels and increase efficiency while conserving land. Other initiatives include the installation of "Tall Tree Nurseries" to ensure a steady supply of mature trees for urban planting, and the creation of "green verges" along major arterials to act as dust buffers. The integration of technology is seamless; floating solar power plants on canals generate energy while reducing evaporation, a dual benefit that speaks to the "Smart City" ethos.Kolkata's adaptive reuse wave finds a strong resonance with European movements, particularly in cities like Copenhagen and Rome, though the drivers differ. Just as Kolkata is repurposing its heritage, Copenhagen transformed the Jaegersborg Water Tower into student housing, integrating biophilic elements such as crystal protrusions to harvest natural light. Similarly, the concept of adaptive reuse is embedded in Rome's DNA, where ancient ruins like the Teatro Marcello serve as foundations for modern life. However, a key divergence remains. In Europe, adaptive reuse often centers on aesthetic preservation and circular economy principles. In Kolkata, the primary driver is climatic survival. The reopening of a veranda in Shyambazar is not just about restoring a look; it is about restoring an airflow pattern that makes the house habitable without a generator during a power cut. It is, as the local architect noted, "repairing the relationship between buildings and the breeze from the Hooghly".Chennai: The Thermodynamics of SurvivalIf Kolkata’s narrative is one of nostalgia and repair, Chennai’s is one of defensive warfare. The enemy is heat—relentless, radiating, and lethal. The last three months have served as a stark reminder to the city that concrete traps heat, and in a rapidly warming world, design is a matter of survival. The heatwaves of 2024 left an indelible mark on the city's psyche, shifting the priorities of homebuyers and developers alike. In residential neighbourhoods from Perumbakkam to Velachery, the conversation has shifted dramatically. Post-2024, buyers are no longer just asking about square footage or tile finishes; they are asking, "How hot does the house get at 2 pm in May?". This consumer pressure has forced a return to passive cooling architecture, a discipline that had been largely forgotten during the era of cheap electricity and ubiquitous air conditioning.The architectural response has been a retreat from the "glass box". New developments are minimizing East-West orientation to reduce solar heat gain. Builders are employing double-roof systems with air gaps, a technique where a secondary roof shields the primary slab, allowing air to circulate and carry away radiant heat before it penetrates the interior. Deep-set windows with shading fins are replacing flush facades, creating pockets of shadow that cool the air before it enters the building.The most significant and scalable development in Chennai's green architecture landscape in 2025 has been the Cool Roof Initiative. What began as a pilot project has now scaled into a city-wide movement, endorsed by global bodies like the UNEP. The concept is deceptively simple: coating terraces with white high-albedo paint, china mosaic tiles, or specialized reflective membranes. However, the impact is profound. Studies associated with the initiative demonstrate that cool roofs can lower indoor temperatures by 2–6°C in concrete homes and by as much as 13°C in dwellings with metal (tin) roofs. For low-income residents in areas like Pulianthope, this temperature drop is not just a matter of comfort; it is a health intervention that prevents heat stroke and reduces the reliance on fans, thereby lowering electricity bills. The initiative draws technical inspiration from historical Madras terrace roofing found in heritage structures like the Chepauk Palace, which used layers of lime mortar and clay tiles to naturally regulate heat. Modern cool roofs are the high-tech successors to this tradition. The program has also integrated a social sustainability component, training women’s collectives and youth groups to apply these coatings, thereby generating local employment.Green architecture in Chennai is inextricably linked to water security. The city’s history of oscillation between devastating floods and acute droughts has made Net Zero Water buildings a priority. The Radiance Regalia project stands as a testament to this new standard, becoming Tamil Nadu's first residential project to achieve both IGBC Net Zero Water and Green Homes Gold certification. The project integrates a suite of water management technologies, including dual plumbing lines for greywater recycling and advanced rainwater harvesting systems designed to handle intense rainfall bursts. Permeable paving replaces concrete pavers, allowing water to seep into the ground, reducing urban flooding and increasing groundwater recharge.Chennai's strategies share a kinship with Mediterranean cooling techniques, though the execution differs due to humidity. Seville, Spain, has experimented with reviving the ancient Persian Qanat system—underground tunnels that use water and air to cool public spaces naturally. The CartujaQanat project reduces ambient temperatures by up to 10°C using these natural techniques. While Chennai hasn't dug tunnels, its use of courtyard-based planning in new public health centers mirrors the Qanat's principle of creating cool microclimates through evaporative cooling and shading. Research comparing Chennai to Mediterranean cities like Barcelona shows that cool roofs are universally effective. However, the challenge in Chennai is greater due to humidity. A cool roof reflects radiation but does not remove moisture. Therefore, Chennai's architecture must pair reflective surfaces with ventilation—high ceilings and cross-ventilation—to remove the humid air, a nuance less critical in the dry heat of Spain.Mumbai: Verticality, Density, and the Green PremiumMumbai builds vertically because it has no choice. Constrained by the Arabian Sea on three sides and a burgeoning population within, the city’s only trajectory is up. However, the narrative of 2025/2026 is a shift from "how high" to "how responsible". The city is attempting to inject nature and efficiency into its verticality, driven by a pragmatic realization that sustainable buildings are cheaper to run. The completion of Mumbai Metro Line 3 (Aqua Line) in late 2025 has been a catalyst for this shift. This fully underground corridor connects the southern tip of Colaba to the western suburbs of Aarey, linking key business districts like Bandra Kurla Complex (BKC) and MIDC. The metro is not just a transport project; it is a green spine. It has enabled a form of "green mobility" that complements green architecture. Transit-Oriented Development (TOD) around these stations is prioritizing walkability and reducing the parking footprint of new commercial towers, a major departure from the car-centric planning of the past.In the commercial hubs of Lower Parel and BKC, "green" is now a line item on the balance sheet. December 2025 marked the completion of multiple green-certified towers where the focus was on operational savings. Common areas in these towers are increasingly powered by renewable energy sources, while motion-sensor ventilation in parking levels and smart HVAC systems reduce energy loads. High-performance facades feature advanced glazing and shading devices to reduce heat ingress while maximizing daylight. One project manager noted that electricity bills dropped before full occupancy, turning finance teams—typically sceptical of the "green premium"—into advocates for sustainability. This underscores a key Mumbai trait: sustainability here is transactional. It succeeds because it saves money.A persistent aspiration in Mumbai has been the "Vertical Forest," inspired by Milan’s iconic Bosco Verticale. However, the reality of implementing this in a tropical, monsoon-heavy city is complex and fraught with challenges. Milan’s Bosco Verticale hosts 800 trees and 4,500 shrubs, effectively lowering surface temperatures by up to 30°C and indoor temperatures by 2-3°C. It is a triumph of engineering and botany. However, the maintenance is centralized and costly, estimated at $1,800 per month per unit for the gardens alone. Research indicates that in tropical climates, vertical gardens face specific challenges. High humidity can lead to fungal growth, while the intense heat of the non-monsoon months requires significant irrigation. Modular pot systems often suffer from clogging and technical failures.Instead of full-scale forests on balconies, Mumbai is opting for more pragmatic solutions: Green Walls on podiums and Terrace Gardens. Retrofitting housing societies with organic waste composting units and installing solar panels for common utilities is the more common "green" approach. It is less photogenic than Milan’s towers but more functional and financially sustainable for the average cooperative housing society.Mumbai is also in the midst of a massive redevelopment boom. Old chawls and dilapidated buildings are giving way to modern high-rises. This presents both a risk and an opportunity. The demolition generates massive waste, but the new construction offers a chance to integrate the Circular Economy. Forward-thinking developers are adopting "Zero Waste" construction methodologies, using recycled aggregates from demolished structures for non-structural applications like paving and filling. The use of fly ash bricks and AAC blocks, which utilize industrial waste, is becoming standard. While supply chain fragmentation remains a hurdle for a fully circular ecosystem, the shift is undeniable.Mumbai’s attempt to create green pockets amidst extreme density invites comparison to Barcelona’s Superblocks (Superilles). Barcelona systematically reclaimed streets from cars to create pedestrian-friendly green public spaces, reducing pollution by 30%. Mumbai lacks the regular grid structure of Barcelona to create perfect superblocks. However, the concept of "pedestrianizing" areas around new Metro stations (like BKC) and creating "green corridors" mimics this intent. The challenge is the sheer density; reclaiming even a meter of road space in Mumbai is a political and logistical battle. Yet, the integration of green mobility with green architecture offers a path toward a similar outcome: a city that prioritizes people over cars.Delhi: Designing in the Shadow of SmogIn Delhi, the winter smog is not just a weather event; it is a structural determinant. The architecture of the capital has been forced to evolve into a filtration system. The narrative of the last few months is one of buildings becoming "air filters". New and renovated structures, particularly schools and hospitals, are incorporating advanced filtration technologies directly into the building envelope. Startups like UBreathe have piloted plant-based air purification systems in Delhi-NCR schools and municipal offices. These systems use "Breathing Roots" technology to amplify the natural phytoremediation of plants by up to 500 times. A pilot in a Gurugram municipal office reported a 40% reduction in indoor PM2.5 levels.Architects face the contradiction of needing ventilation while blocking pollution. Solutions include double-skin façades and filtered air intakes that allow buildings to "breathe" without inhaling the toxic particulate matter. The Delhi government’s response to pollution has shifted from temporary bans to structural mandates. The "Anti-Smog Gun" mandate for high-rise buildings and construction sites is a crude but visible example of this. While experts debate their efficacy as a long-term solution, their presence signals a securitization of the environment—architecture is now an active combatant against the air. Furthermore, the Air Pollution Mitigation Plan 2025 has introduced stricter regulations, including the installation of indoor air quality monitoring systems in public buildings. This transparency is driving demand for better-designed buildings.Delhi’s struggle with environmental management finds a constructive counterpoint in Bangkok. Bangkok faces flooding and heat, and it responded with the Chulalongkorn Centenary Park, a "sponge" park designed to tilt and collect runoff, holding a million gallons of water. It is active infrastructure disguised as a park. Delhi is adopting similar "nature-based solutions" for dust and heat. The massive tree plantation drives and the creation of "city forests" (biodiversity parks) are Delhi’s version of the sponge city—designed to trap dust and cool the air. Tokyo has mandated green roofs since 2001 to combat the urban heat island. Delhi is moving in this direction, with bodies like the NDMC incentivizing rooftop greening to combat the thermal inversion that traps smog over the city.The primary driver for green architecture in Delhi has shifted from Energy (saving electricity) to Health (saving lungs). Parents demand schools with air purification; office goers choose buildings with "indoor air quality monitoring" screens in the lobby. Green architecture here is a public health intervention.Global Convergences: A Comparative Architectural CritiqueThe evolution of green architecture in India does not happen in isolation. It is a dialogue with global trends, adapted to the specific constraints of the Indian context. Bangkok’s Benjakitti Forest Park and Chulalongkorn Park have set the gold standard for Asian megacities, functioning as active infrastructure that manages floods and filters water through wetlands. Indian cities are adopting this in fragments, with Mumbai’s flood-resilient basements and Chennai’s recharge wells serving as micro-sponges. However, India lacks a grand, central "Sponge Park" on the scale of Bangkok, though the opportunity lies in transforming Delhi’s Yamuna floodplains or Kolkata’s East Kolkata Wetlands into formally designed resilience landscapes.Milan’s Bosco Verticale proved that trees can live in the sky. In India, this concept often gets diluted to "potted plants on balconies" due to cost. However, the impact of Green Walls (vertical gardens) on microclimates is measurable. In Mumbai and Delhi, they are serving as dust screens and sound barriers, though the challenge remains maintenance; without the automated, sensor-driven irrigation of Milan, Indian vertical gardens often turn into brown walls in summer. Globally, cool roofs are a standard energy-saving measure. Chennai has turned this into a community movement, providing immediate human relief for the non-AC population. This is a critical distinction: in the West, green architecture saves carbon; in India, it saves lives.Green architecture is living architecture, and it requires care. The research on vertical gardens in tropical climates highlights a "constant maintenance difficulty," driven by the high cost of irrigation systems, pruning, and structural waterproofing. The solution lies in developing native plant palettes that are drought-resistant, moving away from exotic ornamental species to robust local flora that can survive an Indian summer with minimal water.The "take-make-waste" model is ending, and the Circular Economy is becoming central to real estate. Urban Mining—recovering materials from demolished buildings for new construction—is gaining traction in Mumbai’s redevelopment sector. While circular construction requires higher initial investment, lifecycle cost analyses validate the economic advantages through operational efficiencies and reduced waste management costs. There is a growing realization that "green" commands a premium. Green-certified buildings in Mumbai and Bangalore attract higher rentals and better quality tenants. This economic incentive is driving developers to adopt IGBC and LEED standards not just for the environment, but for the bottom line. By 2026, the myth of the "green premium" was collapsing. While green buildings demanded higher upfront investment, lifecycle costs told a different story. Reduced energy consumption, lower water dependence, and healthier indoor environments translated into tangible financial returns.Future Horizons: The Smart, Biophilic City of 2030As we look toward the rest of 2026 and beyond, several trends are crystallizing that will define the next decade of Indian architecture. The future is digital. By 2026, "Smart Homes" in Indian metros will move beyond voice assistants to fully integrated Energy Management Systems. AI algorithms will optimize HVAC usage based on occupancy and weather patterns, shifting from passive sustainability to active, data-driven efficiency. Homes will "learn" the thermal habits of their occupants and adjust accordingly to minimize waste.The concept of Biophilia—the innate human connection to nature—is moving from interior design to urban planning. Trends include "breathing" facades, indoor forests in corporate campuses, and the integration of biodiversity corridors in city master plans. The goal is to blur the boundary between the "built" and the "natural". The role of government policy will be decisive. Linking green compliance to FSI (Floor Space Index) incentives—allowing developers to build more if they build green—is a powerful tool. Maharashtra and West Bengal already offer such incentives, and their broader enforcement could tip the scale. The adoption of rigorous energy codes like the ECBC (Energy Conservation Building Code) for residential buildings will ensure that the "green" label is backed by verifiable performance.The Resilient SentinelThe story of green architecture in India’s metros in late 2025 and early 2026 is not one of uniform aesthetic or singular technology. It is a mosaic of local responses to global crises. Kolkata has looked backward to move forward, finding solace in the breathable lime plaster of its ancestors. Chennai has painted itself white to reflect the sun’s fury. Mumbai has engineered its way upward, attempting to balance density with efficiency. Delhi has turned its buildings into lungs to survive the smog. These cities are no longer building "green" for the sake of a plaque on the wall. They are building for survival. The "green building" has evolved into the "resilient building".These sentinels are awake, and they are turning green not out of vanity, but out of necessity. It is reactive, born from heat, flood, and smog. It is pragmatic, valuing electricity savings and thermal comfort over visual gimmicks. It is indigenous, rediscovering local materials and passive wisdom. Together, they tell a single, powerful story: the future of Indian cities will not be decided by how fast they grow, but by how wisely they breathe. In that adaptation lies not just sustainability, but dignity, health, and survival. The cities are learning again. And for the first time   ...Read more