Up to code for decarbonization

11021_Residential buil_opt


Buildings consume about one-third of the total electricity consumption in India, according to 2021 energy statistics by India’s Ministry of Statistics and Program Implementation. And this share is set to grow. Energy consumption in buildings is accelerating along with India’s urbanization rates, coupled with improvements in the wider standard of living. In fact, the International Energy Agency (IEA) puts India at the top of the list for increasing energy consumption in buildings, which is expected to grow by 2.7% a year through 2040 – more than twice the global average.

“Greenhouse gas emissions related to this overwhelming electricity consumption will greatly be determined by the share of renewable energy in the future,” says Sumedha Malaviya, manager of the energy program at WRI India. “These numbers could either become a problem or an opportunity for us to prevent lock-in of inefficient building stock by fast-tracking implementation of building efficiency policies and programs.”

India’s Bureau of Energy Efficiency (BEE) has taken up the mandate to bring about an improvement in the energy efficiency of buildings. The Energy Conservation Building Code (ECBC) and Eco Niwas Samhita developed by BEE set the minimum requirements for energy efficient design and construction of commercial and residential buildings, respectively.

RE integration

Both the ECBC and ENS apply only to new buildings. The ECBC is applicable to all buildings or complexes that have a connected load in excess of 100 kW, or a contract demand of 120 kVA or more and are used for commercial purposes. As per the code, all buildings must have provisions for the installation of renewable energy systems on rooftops or elsewhere on site.

Under the ECBC, the dedicated renewable energy generating zone is to be the equivalent to at least 25% of the roof area or area required for the generation of energy equivalent to 1% of total peak demand, or the connected load of the building – whichever is less. There are extra provisions on minimum electricity needs being met from renewable energy (not necessarily solar) for ECBC+ and super ECBC buildings.

For the renovation and retrofitting of existing buildings, changes in electricity regulations become important. The draft electricity (Rights of Consumers) amendment rules, 2021, defined a “prosumer” as a party that produces solar energy and also consumes electricity generated by power companies through the grid. It proposes the replacement of diesel gensets in buildings with cleaner technologies such as solar and storage to improve air quality in cities.

The rules also permit net metering for loads up to 500 kW. But, as the implementation is left to state regulators, these amendments are likely to have uneven outcomes across India.


The “Emerging Technology Trends in the C&I Rooftop Solar Market in India” report by the Institute for Energy Economics and Financial Analysis (IEEFA) and JMK Research highlights the opportunity for rooftop PV and storage systems to replace diesel gensets. It finds that India has more than 90 GW of behind-the-meter diesel generators, mainly used as power backup to cope with frequent power outages. However, for storage to become mainstream, costs must come down.

“While RE costs have come down and are likely to go down further, battery costs are high. In a time span of two to three years, with the increase in battery manufacturing and with battery prices estimated to reach $100/kWh by 2023, the market for integrated rooftop solar and battery storage systems would shift forward from the present cusp phase,” wrote Vibhuti Garg, energy economist, lead India, IEEFA, and Jyoti Gulia, JMK Research founder, in their report.

Apart from costs, there are regulatory hurdles. “Much of the existing regulatory framework does not explicitly address the interaction of power systems with storage. There is a lack of clarity about the functional classification of energy storage, as it is both a generator and a consumer of electricity. As such, under the current net metering provisions, the export of power from BESS to the grid is not permitted,” added Garg. “Changes to the existing regulatory framework are required to identify what energy storage is, and to add this definition to the Electricity Act, 2003.”

As for the design aspect, the climate-proofing of solar systems, with or without storage, needs to be a part of the planning and commissioning of these systems in buildings, whether in cities or rural areas. A 2021 WRI report, “Powering Development in Climate Vulnerable Areas: The Role of Decentralized Solar Solutions in India,” examined how decentralized solar solutions in climate-vulnerable regions must be effectively tailored to local conditions.

“Energy systems must be designed to meet context-specific electricity demand, based on local geography, the availability of supportive infrastructure, and end-use requirements. For example, planning for the design, installation, and maintenance of a decentralized solar energy system in a flood-prone school is very different from that in a lightning-prone mainland school, even if both schools fall under the same government program,” states the WRI report.

Scope for improvement

At the policy level, clarity and enforcement are key to the success of the new measures. “Unless ECBC compliance is properly ascertained, the provisions for installation of renewable energy systems may not be met in practice. For example, a builder may just designate the roof area for RE generation in the application but may not install,” said Sumedha Malaviya. “In one of our studies in Kochi where we have developed a zero-carbon buildings roadmap for the city, the RE requirements of ECBC were found to insufficient for a building to become zero-carbon building.” Another hurdle is the flexibility given to the state governments to mandate the ECBC implementation. There is a need to make ECBC implementation mandatory, just like environment clearance.

The Eco Niwas Samhita for residential buildings does not have mandatory provisions to install renewable energy systems apart from a mere dedicated renewable energy generating zone. Also, unlike the ECBC, where the renewable energy generation zone is obligatory to achieve building code compliance, here it is voluntary.

“For new buildings, the opportunity to integrate solar lies in the implementation of ECBC/ENS or the introduction of solar generation mandates in building bye-laws. But for this to be successful, enforcement is key. Building rules enforcement machinery needs to be strong,” concluded Malaviya.

This content is protected by copyright and may not be reused. If you want to cooperate with us and would like to reuse some of our content, please contact: editors@pv-magazine.com.