Chapter 1 Introduction
5.2 Numerical Results
5.2.1 RE Penetration and Curtailment
and reduces to 43% in 2050 as solar PV based generation increases steadily from 2017. In 2050, the contribution of coal and solar PV is about 860 TWh and 712 TWh respectively.
PV penetration in 2050 (36%) is much higher than wind (5%) due to higher cost reduction potential. Overall RE penetration (excluding hydro; in terms of percentage) increases by approximately 16 times from 2014 to 2050. The contribution of hydro is around 263 TWh (13%) in 2050, utilizing full capacity potential. Around 2% generation in 2050 comes from nuclear power plants.
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CR.LL.SR.WR.TR.
Model Case
Percentage
Year 2017
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CH.LL.SR.WR.TR. CR.LL.SR.WR.TR.
Model Case
Percentage
Year 2030
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CH.LL.SR.WR.TR. CR.LL.SH.WR.TR. CR.LL.SL.WR.TR. CR.LL.SR.WR.TR.
Model Case
Percentage
Year 2040
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CH.LL.SH.WH.TR.CH.LL.SH.WL.TR.CH.LL.SH.WR.TR.CH.LL.SL.WH.TR.CH.LL.SL.WL.TR.CH.LL.SL.WR.TR.CH.LL.SR.WH.TR.CH.LL.SR.WL.TR.CH.LL.SR.WR.TR.CR.LL.SH.WR.TR.CR.LL.SL.WR.TR.CR.LL.SR.WR.TR.
Model Case
Percentage
Year 2050
Biomass Coal
Gas HydroL
HydroS Lignite
Nuclear Solar
Wind
Figure 5.3Technology wise generation share for various CO2price, solar and wind cost scenarios in different years
Year and scenario wise variation of generation mix
Annual generation mix varies considerably in different model cases throughout the planning horizon. Figure 5.3 outlines scenario wise generation share variation of power producing technologies for 2017, 2030, 2040, and 2050. To illustrate results, two scenarios of CO2 price (CR, CH), and all the three scenarios of solar and wind cost are chosen; coal price and storage cost are set to Ref.
5.2 Numerical Results 81 In 2017, every case has a similar generation mix as expected. Hence, generation mix of only the base case is illustrated. Among fossil fuel based generators, coal has the dominant share (62%). Gas and lignite contribute 7% and 2% respectively. Wind penetration (3%) is more than solar PV (1%). Large hydro is also a significant contributor, having approximately 21% generation share. Nuclear power contribution is around 3%. In 2030, a noticeable change is observed only in coal and large hydro generation share, between the two CO2price scenarios. Hence, two cases (base and a case involving CH scenario) are chosen to outline the results. In CH cases, share of coal-based generation reduces to 45% while hydro-based generation share increases to 27%. On the other hand, for CR cases, share of coal and hydro-based generation is around 59% and 13% respectively. Total RE penetration is around 17% (8% wind, 9% solar) irrespective of CO2 price variation. Nuclear based generation increases to 6% due to completion of proposed plants in HR and RJ. Small hydro power contributes 4% of total the generation in all cases.
In 2040, all CH cases have similar generation mix; hence a single case is considered to outline their results. Total RE penetration is around 50% in these cases (solar 35%, wind 15%). The share of coal and large hydro-based generation reduce to 23% and 17%
respectively. In CR cases, variation of generation mix is primarily observed between three solar cost scenario groups. Therefore, three cases involving the three solar cost scenarios are illustrated to discuss the results. Total RE penetration for SR, SH, and SL scenarios are 30%, 25%, and 36% respectively. The share of coal-based generation varies inversely in the range of 46%-57%, according to solar cost variations. Large-scale hydro generation share goes down to 12%. Nuclear based generation share is constant at 4%, irrespective of CO2price scenarios.
In 2050, clear diversification of generation mix is observed between two CO2price cases.
Effect of wind cost on wind generation is prominent in CH cases. Variation of generation mix in CR cases is seen in the solar cost scenario groups. Therefore, for illustrating results, all model cases involving CH scenario and three CR cases representing three solar cost scenarios are considered. In CH cases, total RE penetration is around 83% (solar 57%-73%, wind 10%-25%). As in all CH cases, share of firm generation is low (around 5%), system balancing is mainly done using storage charge-discharge operation and inter-regional power exchange, which is further elaborated in following subsections. Inter-case variation of solar and wind penetration is directly linked to their cost assumptions. In CR, or no CO2price cases, coal-based generation is higher as expected. Coal supplies approximately half of total energy demand in high solar cost cases with RE contributing around 35%. In low and ref solar cost cases, PV penetration increases to around 47% and 41% respectively. Variation of wind generation share is not prominent for any CR case (4%-7%). Hydro generation share is
almost constant at 11% in all cases irrespective of CO2price, due to the full utilization of capacity potential.
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CH DL HP HR JK PB RJ UT UU Region
TWh
CH.LL.SR.WR.TR
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CH DL HP HR JK PB RJ UT UU Region
TWh
CR.LL.SR.WR.TR
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CH DL HP HR JK PB RJ UT UU Region
TWh
CR.LH.SR.WR.TR
Biomass Coal
Gas HydroL
HydroS Lignite
Nuclear Solar
Wind
Figure 5.4Region wise variation of technology activity in various RE penetration scenarios in 2050.
Regional generation mix in three RE penetrated scenarios
Due to the difference in RE resource potential, existing capacity, and demand level, generation mix of each model region varies substantially. In Figure 5.4, regional interpretation of annual generation mix is presented for 2050. Three selective model cases are chosen indicating three different RE penetration levels (base: CR.LL.SR.WR.TR, mid: CR.LH.SR.WR.TR, high: CH.LL.SR.WR.TR).
It is observed that coal-based generation is highest in UU region. In base and mid-RE cases, it produces almost 60% and 55% of total coal-based generation. Solar PV based production mainly comes from UU, RJ, HR, and PB. In base and mid-RE cases, each of these regions has almost 18%-24% contribution in total PV generation. In high-RE case, PV generation from HR drops to 12% while UU increases its contribution to 36%. It is mainly due to the increase of energy import and imposition of CO2price respectively for HR and UU. In the base case, wind-based generation is only seen in RJ; but for other two cases (high, mid), UU also contributes 14% and 10% share respectively. In RJ, the increase of wind generation is almost 2 and 2.8 times respectively in mid and high-RE cases, as compared to the base case. HP, UT, and JK are major hydro power producing regions contributing 91 TWh, 88 TWh, and 63 TWh respectively for all three RE cases. In hydro-rich states like HP, UT, and JK, hydro-based generation is constant for all three cases.
5.2 Numerical Results 83
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CH_SH_TH CH_SH_TL CH_SH_TR CH_SL_TH CH_SL_TL CH_SL_TR CH_SR_TH CH_SR_TL CH_SR_TR CR_SH_TH CR_SH_TL CR_SH_TR CR_SL_TH CR_SL_TL CR_SL_TR CR_SR_TH CR_SR_TL CR_SR_TR
Model Case
TWh
Solar Solar−Curt
A) Solar generation and curtailment in 2050, LL.WR
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CH_WH_TH CH_WH_TL CH_WH_TR CH_WL_TH CH_WL_TL CH_WL_TR CH_WR_TH CH_WR_TL CH_WR_TR CR_WH_TH CR_WH_TL CR_WH_TR CR_WL_TH CR_WL_TL CR_WL_TR CR_WR_TH CR_WR_TL CR_WR_TR
Model Case
TWh
Wind Wind−Curt
B) Wind generation and curtailment in 2050, LL.SR
Figure 5.5Annual solar and wind energy curtailment in various scenarios
RE Curtailment
Renewable energy curtailment is a major operational concern for high RE penetrated power systems. The present study captures possible solar and wind energy curtailment in all model cases. Current and subsequent subsections respectively present annual and time-slice wise interpretation of RE curtailment levels.
Figures 5.5 A) and B) outline annual solar and wind energy curtailment respectively in various scenarios for 2050. Two cases of CO2price (CH, CR) and all the three cases of solar, wind and storage cost are considered. Coal price is set to LL in all the cases. For outlining solar energy curtailment, wind cost is set to reference scenario and vice versa. For both solar and wind, curtailment is only prominent in CH cases. Maximum 3% curtailment is seen in CR cases for both solar and wind. Solar and wind curtailment varies in the range of 4%-11%
and 3%-9% respectively in CH cases. For the same cases, solar and wind penetrations are in the range of 52%-73% and 11%-28%. In CR or negligible curtailment cases, solar and wind penetration is around 24%-47% and 5%-7% respectively.
Figure 5.6 outlines year wise variation of solar and wind penetration and curtailment for two selective high solar and wind curtailment cases. Regional interpretations of curtailment for both solar and wind is also drawn. Curtailment is prominent from 2040, for both solar and wind when their penetration is around 36% and 15% respectively. UU, HR, PB, and RJ report higher solar energy curtailment. Despite high solar penetration in RJ, curtailment is considerably less. Higher energy export and storage activity are the major reasons behind this. RJ reports considerable wind energy curtailment due to its higher penetration.
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TWh
Solar Solar−Curt Solar gen and curt CH.LL.SL.WR.TH.
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CH.LL.SL.WR.TH.
TWh
HR JK PB RJ UU
Regional Solar curtailment 2050
(a)Solar generation and curtailment
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2020 2030 2040 2050 Year
TWh
Wind Wind−Curt Wind gen and curt CH.LL.SR.WH.TH.
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CH.LL.SR.WH.TH.
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RJ UU Regional Wind curtailment 2050
(b)Wind generation and curtailment Figure 5.6Yearly variation of solar and wind generation and curtailment in various regions