For decades, system operators defined Resource Adequacy (RA) as the generation capacity needed to guarantee meeting the peak demand plus a reserve margin. This capacity centric approach has influenced capacity procurement, utility planning, and regulatory assessment. However, the rapid expansion of variable renewable energy (RE), the decentralised generators, and the rising frequency of climate-induced disruptions demand a fundamental rethinking of what constitutes an “adequate” power system. 

Fundamentally, RA is about reliability-the assurance that power reaches the consumers when and where needed. But, conventional generation-centric RA models are inadequate when generation depends on weather, and the path from source to load becomes more complex and/or vulnerable. Today, ensuring RA necessitates a comprehensive, network-centric approach – encompassing generation, transmission, distribution infrastructure and system-wide resilience. 

Why the Old Paradigm Struggles? 

Traditional RA planning relies on metrics like loss of load expectation (LOLE) and planning reserve margin (PRM) to assess the generation adequacy against the projected peak demand. These deterministic measures worked when fossil fuel generators provided relatively consistent and predictable output. However, these measures can mislead in systems with high integration of wind and solar power. 

Variable RE sources generate electricity inconsistently based on weather conditions, which are difficult to forecast accurately. Simply counting installed RE megawatts provides little insight into whether it enhances reliability during critical periods. Effective load carrying capacity (ELCC), a probabilistic metric measuring a resource’s contribution is one technique which is used to assess the firm capacity offered by variable generators, however, even this method falls short if network constraints or system resilience are disregarded. 

Importance of Network Adequacy 

As the share of renewables increases robust, flexible, and well-coordinated transmission becomes exponentially important. Many renewable resources are located far from urban load centers, such as solar in deserts, wind on remote plains necessitating long-distance transmission. Without adequate transmission infrastructure, the RE generation may need to be curtailed, making them less effective during times of high demand. 

In Rajasthan, with over 23GW of solar capacity, transmission overloads have caused up to 48% curtailment during peak hours – resulting in losses of more than ₹2.26 billion since April 2025. Despite India targeting ₹91.2 billion in interstate transmission capacity additions by 2032, the pace lags renewable deployment.[1]  

Distribution networks, too, face new pressures from rooftop solar, electric vehicles (EV), and other distributed energy resources (DER). This is transforming the local grids into bidirectional systems. Distribution adequacy, the local grid’s ability to handle variable, bidirectional flows, becomes essential for consumer-level reliability. 

Bengaluru and tier-2 cities in Karnataka frequently face load shedding – despite the state claiming to be ‘power-surplus’. Similarly, in Rajasthan, high solar output in the middle of the day has had to be curtailed because transmission lines to demand centres such as Delhi and Haryana reached their capacity limits.[2] [3]