India has ambitious renewable energy targets, a portion of which must be met through rooftop solar in residential buildings. Major Indian cities are seeing a trend towards gated apartment buildings (or apartment complexes). In these buildings, apartment residents share common areas that provide communal amenities. As such, the energy used in common areas is the aggregate use from all residents for the services.

This working paper co-authored by WRI India and TIDE describes the findings from examining demand aggregation potential in ten apartment complexes in Bengaluru. We define demand aggregation as the act of grouping together multiple residents in an apartment complex as a single consumer of the services provided in a common area. The study found that there was significant potential to save energy in common services in apartment buildings and use solar energy to meet most needs. Apartment Owners Associations (AOAs) that manage common services can be the anchors for implementing these clean energy measures in apartment complexes.

Key Findings

  • Water pumping assets account for the largest share of total connected load in most apartment complexes. The total connected common area electricity load for the 10 apartment complexes was four megawatts (excluding fire hydrant pumps). At an aggregate level, pumping assets alone accounted for 45 percent of the common area connected load of the 10 apartment complexes containing a total of 4,169 apartments. In six apartment complexes, pumping loads were more than 40 percent of the total common area connected load; and in others, pumping loads accounted for 15 to 28 percent of the total connected load
  • In most apartment complexes, RTS can meet the entire annual electricity demand for common services. Calculations based on available roof area showed that RTS could potentially meet all energy needs of the common areas for eight apartment complexes. For two other apartment complexes, due to roof space constraints, RTS could meet 25 to 50 percent of the common area energy needs. We also found that, despite solar water heaters being mandatory for apartment complexes as per BBMP bylaws of 2003, none of the apartment complexes had them.
  • There is a potential to devise and implement low-carbon pathways for reducing aggregate energy demand from the common services of apartment complexes. Clean energy options comprising both EE and RTS measures, either individually or in combination, can be introduced in common areas of existing apartment complexes.
  • The energy savings potential technically possible in the 10 apartment complexes varies based on several factors: the age of the building; its size and the size of the common areas; total occupancy; and the age, quality, efficiency, and maintenance of the equipment are the major factors that affect energy savings potential. To illustrate the variance range, in one of the apartment complexes, measures to save energy in water pumping and lighting could technically save 20 percent of electricity consumed in common areas. In some of the other complexes, lesser energy savings of up to 5 percent were possible.
  • Surrendering excess sanctioned load (or contracted power) can save apartments money. In seven apartment complexes, the sanctioned load allocated on some utility meters was more than the maximum demand recorded. This reveals a potential opportunity for apartment complexes to surrender the excess sanctioned load, which can lead to significant savings on their electricity bills.
  • Surveyed AOAs lacked strong motivation to invest in EE and RTS measures. As individual AOAs are the single entity managing common facilities in each complex, it is critical to secure their willingness to implement clean energy projects and interventions. When we interviewed AOA Management Committee (MC) members, we found that although the common area electricity bill is a concern to several AOAs, there are other budgetary items at a higher priority (such as water supply or waste management). In the state of Karnataka, subsidized domestic tariffs are levied on common area services that use electricity in Karnataka; hence, the incentive to invest in EE is low.3 Consequently, EE and RTS technology measures are not prioritized. Other barriers expressed by the AOA MC focused on the higher up-front investment required, reluctance to seek approvals from multiple decision-makers for changing the technologies used on site, and lack of access to publicly available and objective information on clean energy interventions. Interestingly, respondents view RTS as green or environmentally friendly, and MC members from six AOAs, expressed willingness to install RTS, despite technical constraints.
  • Data on energy use for common services is often not maintained or catalogued. In all apartment complexes we studied, basic information on monthly or annual electricity bills was incomplete. Most AOAs were unaware of the number and the types of appliances, equipment, and other common area electrical assets owned or used by the complex and of the maintenance practices needed to operate these assets at effective functioning levels. Annual Maintenance Contracts (AMCs) are common for elevators but less common for diesel generators and completely absent for pumping systems. For the water pumping systems, maintenance is ad-hoc and effected when necessary through informal practices like motor rewinding that further degrade pump performance.

Executive Summary

  • Buildings and construction sector are one of the largest sources of carbon emissions, and residential buildings alone account for 22 percent of global energy use and 17 percent of energy-related carbon dioxide emissions (IEA and UNEP 2018). Cities cannot take serious action on climate without prioritizing residential buildings. The combination of energy efficiency (EE) measures and on- or offsite renewable energy (RE) is a powerful tool for tackling building-related emissions.
  • In India, the information technology hub of Bengaluru has experienced rapid inward migration from highly skilled Indian professionals. Apartment buildings are quickly emerging as housing choices in this land-constrained city. To meet the service expectations of people and to offer increasingly attractive housing options, developers are providing water, power, safety, and exclusive access to premium amenities through private gated residential apartment complexes. There are significant energy-consumption implications built into the provision and maintenance of these common area facilities by apartment complexes.
  • The apartment owners associations (AOA), as a single collective group of residents in each complex, makes decisions on the management of common area facilities. Engaging with AOAs alone may ensure efficiency in services and on-site rooftop solar (RTS) wherever feasible, to meet energy needs. We consider apartment complexes as natural aggregators of energy demand and AOAs as potential partners to accelerate clean energy interventions in apartment complexes.
  • We engaged with 10 apartment complexes in Bengaluru to assess their common area energy use to identify potential EE measures and the feasibility of RTS in the complexes. Post-assessment, we were able to recommend implementation of clean energy interventions to the complexes
  • While apartment complexes showed an interest in undertaking the recommended interventions, we found that there were institutional, management, and policy barriers to the adoption of these interventions
  • Using demand aggregation as a mechanism to promote clean energy pathways for residential apartment complexes will necessitate finding methods to overcome these barriers.

Thumbnail image credit: Design for Health