Ashish Gulagi, Manish Ram and Christian Breyer Lappeenranta University of Technology, Finland

Transcription

1 THE ROLE OF TRANSMISSION GRID AND SOLAR WIND COMPLEMENTARITY IN MITIGATING THE MONSOON EFFECT IN A FULLY SUSTAINABLE ELECTRICITY SYSTEM FOR INDIA & ROLE OF BATTERIES DISCHARGE TO POWER-TO-GAS FOR A LEAST COST ENERGY SYSTEM Ashish Gulagi, Manish Ram and Christian Breyer Lappeenranta University of Technology, Finland Neo-Carbon Energy 9th Researcher s Seminar Lappeenranta, December 11-13, 2017

2 Agenda Part 1 The Role of Transmission Grid and Solar Wind Complementarity in Mitigating the Monsoon Effect in a Fully Sustainable Electricity System for India Part 2 Role of batteries discharge to power-to-gas for a least cost energy system 2

3 Agenda Part 1 Motivation Methodology and Data Results Summary 3

4 Motivation A major transition is taking place in the power sector in India to keep up with the COP21 pledge and this is evident from increased investments in the renewable energy sector India has an abundant solar potential with clear sunny days with average radiation varying from 1460 kwh/(m 2 a) to 2555 kwh/(m 2 a) and to utilize this potential, the government has taken various initiatives while, the cost has by fallen by 73% since 2010 The wind energy potential is concentrated in some parts of India with better wind conditions, mainly during the monsoon months Large-scale deployment of variable solar and wind resources in future would require various flexibility options such as different storage technologies, transmission grids and sector integration to balance not only the diurnal but also seasonal variation The monsoon season is characterized by decrease in solar radiation and increase in wind and hydropower availability, which alone will not be sufficient to satisfy demand on an hourly basis in a fully sustainable energy system A combination of wind and hydropower balancing, storage technologies and transmission grids are needed to overcome the monsoon obstacle 4

5 Agenda Part 1 Motivation Methodology and Data Results Summary 5

6 Methodology Overview Energy transition pathway from 2015 fossil-based system to a 100% RE based power system by 2050 Transition in 5-year time steps No new nuclear or fossil-based thermal power plants installed after 2015; An exception for gas-fired plants since they can be shifted to renewable-based fuels Least cost RE power plant mix replaces phased out fossil power plants Energy system modelled to meet increasing electricity demand for each time step Research Objective: To find a least cost energy transition pathway for India and the demand for storage technologies for this transition Total Electricity Consumption (TWh) Aggregated load profile for India for 2050 Estimated electricity consumption of India from 2015 to 2050

7 Methodology Full system Renewable energy sources PV rooftop PV ground-mounted PV single-axis tracking Wind onshore Hydro run-of-river Hydro dam Geothermal energy CSP Waste-to-energy Biogas Biomass Electricity transmission node-internal AC transmission interconnected by HVDC lines Storage options Batteries Pumped hydro storage Adiabatic compressed air storage Thermal energy storage, Power-to-Heat Gas storage based on Power-to-Gas Water electrolysis Methanation CO 2 from air 7 Energy Demand Electricity Non-energetic industrial gas Water desalination Gas storage

8 Scenarios assumptions India is divided into 10 regions according to the regional grids which are furthur subdivided and the sub-regions are interconnected by HVDC power lines. Key data 1.7 billion population in million km 2 ~5952 TWh electricity demand (2050) ~196 b m 3 /a water desalination demand (2050) ~844 TWh non-energetic industrial gas demand (2050) 8

9 Scenarios assumptions Full load hours Region PV fixedtilted FLH PV single-axis FLH CSP FLH Wind FLH India East India Central East India West India Central West India North India North West India Uttar Pradesh India South India Central South India North East FLH computed on the basis of the spatially resolved data: 0%-10% best areas %-20% best areas %-30% best areas %-40% best areas %-50% best areas 0.1 Data: Based on NASA (Stackhouse P.W., Whitlock C.H., (eds.), SSE release 6.0) reprocessed by DLR (Stetter D., Dissertation, Stuttgart) 9

10 Scenarios assumptions Generation profile PV generation profile Aggregated feed-in profile computed using earlier presented weighed average rule. Wind generation profile Aggregated feed-in profile computed using earlier presented weighed average rule. Key insights Almost constant solar resource all year around In the monsoon months wind overcomes solar resource unavailability Wind energy complements solar in period of low solar radiation 10

11 Agenda Part 1 Motivation Methodology and Data Results Summary 11

12 Results Electricity generation from solar PV and wind in India in 2050 Key insights The total annual electricity generation from solar PV and wind is 6000 TWh and 415 TWh respectively, contributing to almost 92% of total electricity generation in 2050 Solar PV generation is highest in the months of March, April and May (summer months). Wind generation is highest in the months of June, July, August and September The lowest generation from solar is observed in the month of July 12

13 Results Resource Utilization Key insights The monsoon months produce 62% of the total wind energy generated in India The regions IN-West, Central West, Central South and South produce more than 95% of the total wind energy generated The total power generated by solar decreases by 14% in the monsoon months The total power generated by hydro, 48% is generated in the monsoon months 13

14 Results Complementarity of solar and wind IN-Central West IN-South Key insights Dispatch for the regions of India Central West and India South in a monsoon week. The region of Central West, most affected by monsoon a decrease in solar PV output is compensated by increase in wind generation. When solar is available, wind generation decreases as observed at the end of the week. The Southern region, least affected by monsoon, solar PV output is constant with export of excess electricty to the neighbouring regions. 14

15 Results Role of storage technologies Key insights The relative utilisation of storage technologies was 30% in the monsoon period in comparison to 37% in non-monsoon The contribution of batteries to the power output decreases in the monsoon period However, increase in output of stored gas to produce electricity increases in the monsoon period by 10% in comparison to non-monsoon period 15

16 Results Role of Transmission Grid Import and Export Key insights The monsoon period shows as overall increase in the imports with net electricity utilized from the grid was 6.2% in comparison to 4.9% in the non-monsoon period. The regions of Central West, West, East and Central South are the largest importers of electricity in the monsoon season. Regions which are least affected by monsoon, support other regions by exporting electricity such as the North West and Southern regions. Grid utilization increases considerably in the monsoon period in some regions where PV is a major electricity generation source. 16

17 Results Role of Transmission Grid Regional analysis Key insights The Western region of India is most affected by monsoon with electricity from solar decreases by almost 19%. The North-Western region is mostly desert and least affected by monsoon. Regions which are least affected by monsoon, support other regions by exporting electricity such as India-North West. Grid utilization increases considerably in the monsoon period in some regions where PV is a major electricity generation source. Same can be observed for regions of Central-South and South (least affected). 17

18 Agenda Part 1 Motivation Methodology and Data Results Summary 18

19 Summary A fully renewable energy system is possible for India and the proposed system can effectively handle the monsoon period. The reduced power generation from solar PV can be effectively managed by increase in power generation from wind and hydro. The decrease in battery output is managed by increase in power-to-gas storage via CCGT plants. The transmission grids help utilize the resources available in other regions which are not affected by monsoon. The results confirm that a fully renewable electricity system can be run smoothly even in the monsoon season without utilizing fossil-based backup power. 19

20 Agenda Part 1 The Role of Transmission Grid and Solar Wind Complementarity in Mitigating the Monsoon Effect in a Fully Sustainable Electricity System for India Part 2 Role of batteries discharge to power-to-gas for a least cost energy system 20 Role of batteries discharge to power-to-gas for a least cost energy system

21 Energy flow from Batteries-to-PtG Key insights The discharge from the batteries is used for charging of the gas storage. For the year 2050, the discharge is 211 TWh. 21 Role of batteries discharge to power-to-gas for a least cost energy system

22 Energy flow from Batteries-to-PtG - Analysis Key insights The peak demand for India is observed in the months of September and October (festival months). Significant amount of electricity is stored in batteries due to excellent solar availability and lower demand. The night time demand is lower than the energy stored in the batteries as a consequence, batteries start discharging electricity to the electrolyser units to produce gas to be stored. The discharging from the batteries and charging of the gas storage starts from the year 2040, when the share of renewables is around 98%. This is also the period when gas storage is utilised by the system. 22 Role of batteries discharge to power-to-gas for a least cost energy system

23 Energy flow from Batteries-to-PtG - Analysis Key insights The discharging from the batteries and charging of the gas storage starts from the year 2040, when the share of renewables is around 98%. This is also the period when gas storage is utilised by the system. A gradual increase in the battery discharge to PtG charging can be observed from the year 2040 onwards. This electricity transferred is about 3.4% of the total electricity demand for India. Since the contribution reaches a level of more than 3% of total demand, this effect cannot be ignored, but represents an option more for the overall cost optimization of the system. 23 Role of batteries discharge to power-to-gas for a least cost energy system

24 Energy flow from Batteries-to-PtG - Summary The synchronised discharging of batteries in the night time and charging of PtG, in the early summer and summer months, reduces the possibility of curtailment on the following day. If the batteries were not fully discharged the next day, the generated primary energy would have to be curtailed due to limited total capacities of batteries and electrolyser units of power-to-gas storage. Installation of additional battery capacity would be required to store the excess energy if the batteries are not fully discharged. Thus the observed synchronised battery discharge to PtG charging process is part of a least cost solution. 24 Role of batteries discharge to power-to-gas for a least cost energy system

25 Thank you for your attention! NEO-CARBON Energy project is one of the Tekes strategy research openings and the project is carried out in cooperation with Technical Research Centre of Finland VTT Ltd, Lappeenranta University of Technology (LUT) and University of Turku, Finland Futures Research Centre.

26 FURTHER INFORMATION Wind_Complementarity_with_Optimal_Storage_and_Transmission_in_Mitigati ng_the_monsoon_effect_in_achieving_a_fully_sustainable_electricity_syste m_for_india NEO-CARBON Energy project is one of the Tekes strategy research openings and the project is carried out in cooperation with Technical Research Centre of Finland VTT Ltd, Lappeenranta University of Technology (LUT) and University of Turku, Finland Futures Research Centre.