Optimal Break-Even Distance for Design of Microgrids

Transcription

1 Optimal Break-Even Distance for Design of Microgrids Omar Hafez and Kankar Bhattacharya Department of Electrical & Computer Engineering University of Waterloo, Waterloo, Ontario, Canada, N2L 3G1 10/30/2012 1

2 Outline o Introduction o Research Motivation o Objectives o Case study o Results o Conclusions 10/30/2012 2

3 Introduction Microgrids with renewable energy resources are becoming attractive options to meet electricity demand in remote locations, because of: Long distance between the nearest grid and rural system High cost of transmission line expansion High oil prices Desire to reduce CO 2 emissions Improve power quality 10/30/2012 3

4 The Microgrid Microgrids are interconnection of DGs With dispatchable generators (gas turbines, fuel cells) Non-dispatchable generators (wind and solar PV) Integrated with electrical and thermal energy storage To meet customers local needs Operate as a single system and small-scale Provide both power and heat 10/30/2012 4

5 Motivation Cost of energy from conventional sources is typically lower than that from renewable energy sources However a supply-mix of renewables and diesel can reduce overall cost of energy in a microgrid There is a need to examine energy supply options in microgrids and determine the optimal supply mix So that maximum benefits can be obtained from the design To determine the optimal break-even distance for a microgrid for isolated versus grid-connected mode of operation 10/30/2012 5

6 Objectives Optimal design of microgrids considering various renewable energy technology options With realistic inputs on their physical, operating and economic characteristics Determine the break-even distance for connection of the microgrid with the main grid Compare that with the cost of an isolated microgrid 10/30/2012 6

7 Microgrid Using HOMER Hybrid Optimization Model for Electric Renewable 10/30/2012 7

8 Test Case: Microgrid Components - Wind turbines - Solar PV array - Battery bank - Micro-Hydro turbines - Diesel generator - Dump load - Boiler - AC/DC converter 10/30/2012 8

9 Renewable Energy Resources Solar radiation profile Wind speed profile 10/30/2012 9

10 Case Studies: Microgrid Configurations Case-1: Diesel Dependent Microgrid Case-2: Renewable Based Microgrid Wind, solar PV, battery, micro-hydro, converter Case-3: Diesel-Renewable Mixed Microgrid Diesel, wind, solar PV, battery, micro-hydro, converter Case-4: Solar only Microgrid Solar PV, battery, converter Case-5: Wind only Microgrid Wind, battery, converter 10/30/

11 Optimal Plan Configurations Case-1: Diesel Dependent Microgrid Case-2: Renewable Based Microgrid 10/30/

12 Optimal Plan Configurations contd. Case-3: Diesel-Renewable Mixed Microgrid Case-4: Solar only Microgrid 10/30/

13 Optimal Plan Configurations contd. Case-5: Wind only Microgrid 10/30/

14 Comparing cost components & breakeven distance Items Case-1 Case-2 Case-3 Case-4 Case-5 Net Present Cost, M$ Levelized cost of energy, $/kwh Operating Cost, M$/year Break-even distance, km , /30/

15 Comparing Production Production, MWh/yr Component Case-1 Case-2 Case-3 Case-4 Case-5 1,825 1, Diesel Generator (100%) (46%) ,800.8 Solar PV (9%) (100%) 5, , ,924.8 Wind 0 0 (89%) (49%) (100%) Micro-Hydro (2%) (5%) Boiler Renewable Energy 100% 53.8% 99.6% 100% Contribution 0% Total 2, , , , , /30/

16 Comparing consumption Consumption, MWh/yr Electrical Load Energy Served Thermal Load Energy Served Excess Energy to dump load 1,825 1, ,825 1, , , ,925 9,917.3 Unmet Energy /30/

17 Emission Comparison Emissions, ton/yr Pollutant Case-1 Case-2 Case-3 Case-4 Case-5 Carbon dioxide Carbon monoxide Unburned hydrocarbons Particulate matter Sulfur dioxide Nitrogen oxides /30/

18 Effect of Distance from Grid: Optimal Break-even Distance Case-1: Diesel Dependent Microgrid Case-2: Renewable Based Microgrid 10/30/

19 Effect of Distance from Grid contd. Case-3: Diesel-Renewable Mixed Microgrid Case-4: Solar only Microgrid 10/30/

20 Effect of Distance from Grid contd. Case-5: Wind only Microgrid 10/30/

21 Concluding Remarks The diesel-renewable mixed microgrid (Case-3) has the lowest NPC which results in the shortest breakeven distance of 359 kms The break-even grid extension distance plays a significant role in microgrid design The microgrid located beyond its break-even distance local generation is the economical and optimal option HOMER is found to be an useful tool for microgrid planning and design 10/30/

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