Executive Summary The world today is witnessing several kinds of technological disruptions in different sectors. One of the likely disruption in power sector can be replacement of thermal based generation with Renewable energy generation complimented with energy storage technology. This has been possible with the downward trend of cost of solar panels and newer technology options like battery energy storage systems. In fact, the reduction in cost projections is very aggressive for Battery Energy Storage technology to render them financially viable in near future. In this context, planning for optimal generation capacity mix gains tremendous importance so as the future generation capacity mix is cost effective as well as environmental friendly, a horizon of 10-12 years is sufficient to gear up the systems and policies in the right direction to achieve the optimal generation mix. Keeping this in perspective, the study year of 2029- 30 has been considered.

Introduction Electricity is one of the key enablers for achieving socio-economic development of the country. The economic growth leads to growth in demand of power. Generation capacity augmentation is the most vital component amongst various modes adopted for meeting the ever-increasing demand of power to achieve the targeted growth rate.

Objective of the Study To find out the optimal generation capacity mix to meet the projected peak electricity demand and electrical energy requirement in the year 2029-30 considering possible/feasible technology options, intermittency associated with Renewable energy sources and constraints if any, etc.

Why 2029-30? To achieve the target of RE installed capacity of 175 GW by 2022, India has taken several policy initiatives for encouraging investment in RE Generation sources. National Electricity Plan has also laid its emphasis on RE integration and detailed studies have been carried out in NEP for the year 2021-2022 to analyze the power scenario with 175 GW of RE capacity in the Grid. Further, NEP has also given a perspective scenario for 2026-27 assuming 100 GW of capacity addition from RE during the period 2022-27 in view of the consistency in policy push for RE.India is working towards low carbon emission path while meeting its developmental goals. In this regard, India is aiming to have 40 % of the total installed capacity by the year 2030 based on non-fossil fuel sources as submitted in Intended Nationally Determined Contributions (INDCs). This phase of transition warrants a detailed study of the power scenario in the year 2030.

Generation Expansion Planning Tool The optimal generation mix study for the year 2029-30 has been carried out using the state of the art computer Generation Expansion planning model namely ORDENA. The model performs generation expansion planning, production costing and has the capability of modelling renewable energy sources using Mixed Integer Programming. The model minimises the cost of energy generation including the capital investments required for meeting peak electricity demand and electrical energy requirement by carrying out numerous iterations for selecting the most optimal generation capacity mix considering all financial parameters and satisfying technical/operational constraints. It optimizes the cost of transportation of fuel and emissions from power plants. The software has the capability to carry out hourly/sub hourly economic generation dispatch considering all the technical constraints associated with various generation technologies.

The schematic diagram of the software is given as Exhibit 1.

Present Installed Capacity Total Installed Capacity of the country as on 30.09.2019 was 363.4 GW, which comprise of 45.4 GW from Hydro, 228.6 GW from Thermal, 82.6 GW from R.E.S and 6.8 GW from Nuclear. The detailed sector and fuel wise breakup of the total installed capacity as on 30.09.2019 and energy contribution from different sources during 2018-19 is given in Table 1 and Exhibit 2 respectively.

Table 1
INSTALLED CAPACITY AS ON 30.09.2019

Generation Capacity mix of the country Generation capacity mix of the country has undergone significant changes since the time of independence with increased electricity demand in the country. Share of hydro capacity which was about 26% by the end of 10th plan period (i.e.2006-07) has come down to about 13% presently.Exhibit 3 and Exhibit 4 depicts the capacity and generation mix historically. It can be seen that share of hydro in installed capacity has reduced in recent years though the share of renewable energy has increased. However, in view of increasing share of variable renewable sources (Wind and Solar) in the system, hydro power plants with storage are the best option to address the intermittency of renewables as they have capabilities of fast ramping-up and ramping -down.

Present Load Profile of the country The country’s load profile indicates that peak load is generally observed during morning hours and evening hours. However, the evening peaks are higher than the morning peaks. The All India peak load is observed generally in the month of September/October (load curve of the year 2014-15, 2015- 16 and 2016-17). The load curve of the country varies significantly during different seasons and the same is shown in Exhibit 5.

Energy Storage Systems

The next phase of energy transition driven by the large-scale deployment of variable renewable energy sources (VRES) like solar and wind power can be fully realized by key technologies of Energy Storage. The grid integration challenges of the intermittent generation sources ensuring quality of supply on real time basis along with the capability to store excess electricity over different time horizons (minutes, days, weeks) can be achieved by the electricity storage systems.

The likely installed capacity by the end of the year 2029-30 is given in Table 5 and Exhibit 8.

RE generation dispatch and absorption is shown in the Exhibit 12. The RE absorption on the peak day is likely to be around 99.74%.

Maximum VRE (Wind + Solar) Generation day – 3rd July, 2029 The system has to be resilient on the day when the maximum generation from RE (wind + solar) is likely to be available. The maximum generation from RE is likely to occur in the month of July, typically 3rd of July.

Daily Variation in Demand and VRE Absorption The Exhibit 27 given below depicts the variation of daily demand and daily VRE generation (solar and wind only) along with the percentage of daily demand met from renewable sources (solar and wind). It may be seen that demand met by VRE generation on few days is as high as 50%.

Projected Coal Requirement in 2029-30 The Gross Generation from coal power plant is estimated to be 1358 BU for the year 2029-30. The coal requirement for the year 2029-30 has been worked out to be about 892 Million Tonnes considering specific coal consumption of 0.65kg/kWh + 1% transportation loss.

Conclusions The long term study results for the period 2022-23 to 2029-30 is the least cost generation mix and most economical solution for meeting the peak electricity demand and electrical energy requirement of each year till 2029- 30 as projected by 19th EPS. The capacity mix honours all the technical constraints associated with various technologies. Grid scale Battery energy storage systems(BESS) along with Pumped Storage systems has been considered for estimating the optimal results keeping in view the challenge of RE integration due to its inherent nature of being variable and intermittent and to fulfil the demand at every instance of time.

Likely installed capacity by 2021-22 as per Mid-Term Review of NEP (Base Capacity considered):

Under construction, Planned and Candidate plants considered in the study for the period 2022-23 to 2029-30:

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