1. Aspects of Smart Grid Operation
QIP STC on Computational Methods for Smart Grids
9th - 13th March, 2014
Indian Institute of Technology Guwahati, Assam, India
Dr. G. B. Shrestha
School of EEE, IIT Guwahati
13 March 2015
GB Shrestha: March 2015

2. Indian Power System Network- Grid
Two factors:
Generation Capacity
Transmission Network
Both capacities and
interconnections growing.
GB Shrestha: March 2015

3. Brief History of Electric Power Grid
Industry/Ownership Structures
Single units,
Isolated Systems,
Interconnected Networks - Grid
Regulations
Blackouts (1965),
Fuel Crisis (1973),
Financial Crises
Deregulation
PURPA (1978)
Deregulation, and Markets, etc.
Micro-Grids – Smart Grids – Why?
Tie Line Tr
Load
Line
GB Shrestha: March 2015

4. Power System Operation and Planning
Electric Energy cannot be stored.
Generation must exactly balance the load (plus losses)
2. Quality of Power Supply
The voltage profile throughout
the power system must be
maintained within an
acceptable narrow band.
The frequency must be maintained
near the rated value - etc.
Level of Reliability – must be maintained
Environmental impact is becoming increasingly more important.
The role of renewable/sustainable energy is increasing.
The operating cost must be minimized!!!
Tie Line Tr
Load
Line
GB Shrestha: March 2015

5. Load Forecast and Load Characteristics
Short term, Long Term, etc.
Load Curve
The load duration curve
Load duration curves are useful in efficient operation of power systems.
Base Demand
- lasts all 24 hrs
Peak Demand
- lasts only the
peak hour
GB Shrestha: March 2015

6. Cost Characteristics of Power Plants
Two different types of costs are involved.
Operating Cost:
The fuel cost and the operation and maintenance cost basically depends on the amount of energy produced.
For a given size of generator the cost linearly increases with the length of time used.
The general behaviors of this component of cost for steam and combustion turbine generators are shown below.
8760
Time (hours/year) $
Steam Turbine
Combustion Turbine
GB Shrestha: March 2015

7. General Cost Characteristics of Power Plants
Capital Cost:
The amount invested in the construction of the plant.
Both (i) return of capital, and
(ii) return on the capital
will involve an annual fixed cost independent of the power produced.
The general nature of this component of cost for steam and combustion turbine generators are shown below.
8760
Time (hours/year) $
Steam Turbine
Combustion Turbine
GB Shrestha: March 2015

8. Cost Characteristics of Power Plants
8760
Time (hours/year) $
Combustion Turbine
The sum of the two cost components will determine the overall cost of energy produced.
Steam Turbine T
Consideration of total costs shows that:
Steam/Coal Plant costs are lower if operated for T hrs or more.
Combustion plant costs are lower if operated for less than T hrs.
GB Shrestha: March 2015

9. Cost Characteristics of Power Plants
Such cost characteristics are called the screening curves.
These curves are used in the operation and planning of generation capacity.
A set of screening curves for various types of generators may be as shown below.
GB Shrestha: March 2015

10. Classification of Generators
Specification:
Size, voltage level, efficiency, availability, etc
Cost
Capital cost, fuel cost, etc
Type of Use
Base Load Unit
Intermediate Unit
Peaking Unit
GB Shrestha: March 2015

11. Daily Scheduling Forecast the power demand for the day.
Determine suitable spinning reserve margin. Run (start and/or shut down) the generators in the order of increasing cost.
Note that the base
units will be on all
the time, while
peaking units will
be used for during
the peak hours only.
In practice, the
failure of generators
will have to be
taken into account.
Hours
Spinning Reserve
Generation
Capacity
Demand/Capacity
GB Shrestha: March 2015

12. Challenges Facing Electric Power Industry
US Scenario
Generation capacity:
(2008)
1,022 GW
(2030)
1,400 GW
New Additions Required: 600 units of 1,000 MW plants
Chinese Scenario
Generation capacity:
Per Capita Consumption
(2006)
622 GW
< kW
(2020)
1,500 GW
1 kW
( )
2,400 GW
1.5 kW
New Additions Required: 1800 units of 1,000 MW plants
GB Shrestha: March 2015 12

13. World Electricity Generation by Fuel
Source: IEA, Key World Energy Statistics 2007
** Other includes geothermal, solar, wind, combustible renewables & waste
GB Shrestha: March 2015

14. Electricity Generation by Fuel Types for Selected Countries
Source: International Energy Agency (IEA Statistics 2005 data, available as of June 2008)
GB Shrestha: March 2015

15. Generation Mix of Indian Power System
Total installed capacity: GW
(April 2012)
Present renewable resources contribution is about 11 %
14 % of the capacity is owned by non-utilities as captive plants
GB Shrestha: March 2015

16. Challenges in Meeting Forecasted Demands
Where to put these two thousand 1,000 MW power plants in China and the United States?
Where would you find the water to run these coal or nuclear power plants?
How to deal with environmental effects?
GB Shrestha: March 2015

17. Likely Scenario
Electricity supply mix move away from fossil fuels with expanded development of wind, solar, biomass, geothermal, nuclear and energy from the oceans
Expanded focus on energy efficiency
Greater application of IT and communication technologies
Smart electric power grid
Link:
GB Shrestha: March 2015 17

18. Attributes of Smart Grids
Use of information technologies to improve electricity delivery from power plants to consumers
Consumers to interact with the grid
Integrates new and improved technologies into the operation of the grid
Information-based
Communicating
Secure
Self-healing
Reliable
Flexible
Cost-effective
Dynamically controllable
Link:
GB Shrestha: March 2015 18

19. Diverse Energy Sources
Fossil
EVs
Wind
Solar
Consumer

20. Renewable Resources Solar Energy Systems Wind Energy Systems
Mini-hydro Power Plants
Bio-Energy
Geothermal, Tidal, and
Wave Power Plants
GB Shrestha: March 2015

21. Future Prospects - How does the future look?
GB Shrestha: March 2015

22. Fastest Growing Energy Sources in the World
Global % Growth in 2009 by Energy Source
Source: Statistical Review of World Energy 2010 (bp.com) Note: Wind, PV, Geothermal – (installed capacity MW); Gas, Oil, Hydro, Coal, Nuclear
GB Shrestha: EE January 2011

23. Wind Power Highlights
Global wind capacity: 93,849 megawatts (end of 2007)
Some leading countries:
Wind turbines generate more than 1% of the global electricity.
Germany (27.8%)
Spain (15.7%)
USA (15.7%)
India (8.5%)
Denmark (4.2%)
Source: BP, 2008 and WWEA, 2008
GB Shrestha: March 2015

24. World Wind Energy - Total Installed CapacityMW
Source: BP.com, 2008
GB Shrestha: March 2015

25. Worldwide Wind Energy by Continents
Total Installed Capacity 2007 (Total: 93.9 GW)
Europe
61%
Australia Pacific
1.2%
Africa
0.4%
Asia
17%
Latin America
0.6%
North America
20%
Source: WWEA, 2008
GB Shrestha: March 2015

26. Share of Wind in Total Electricity Generation (2006)US
India
Calif. EU
Ger.
Spain
Den.
Source: BP.com, 2007
GB Shrestha: March 2015

27. Cumulative Installed Wind Turbine Capacity (MW) - China
Cumulative installed capacity (MW) at the end of 2007：6,050MW.
Source:
GB Shrestha: March 2015

28. Cumulative Installed Wind Turbine Capacity (MW)- US
Cumulative installed capacity (MW) at the end of 2007：16,818 MW.
Source: and
GB Shrestha: March 2015

29. Offshore wind turbines - Horns Rev, Denmark
80 x 2MW = 160 MW
Source: BWEA © Elsam A/S
GB Shrestha: March 2015

30. Wind Turbine Generators near Gibraltar
© Saifur Rahman
GB Shrestha: March 2015

31. Solar Power Highlights
Current solar PV capacity: 9,100 megawatts (end of 2007)
Some leading countries:
- Germany (38.6%)
- Japan (38.4%)
- USA (12.9%)
- Spain (1.6%)
Above 40% growth rate continued in 2004 and 2005, more than doubling the solar PV capacity in two years.
Source: EPIA, 2008 and BP, 2007
GB Shrestha: March 2015

32. Global Installed Solar Photovoltaics
Cumulative Capacity
9,100
6,851
5,253
3,847
2,795
Source: EPIA, 2008
GB Shrestha: March 2015

33. Cost Characteristics of Renewable Generation
Costs:.
Operating Cost:
The fuel cost practically zero (solar, wind, hydro, etc.)
Other operating costs = negligible (may not be quite so for hydro).
Capital Cost:
Usually extremely high
Desirable Economic Operating Practice:
As long as possible
GB Shrestha: March 2015

34. System Characteristics and Markets for Renewable Generation
Actual Physical Behavior:
Highly uncertain
Solar
– only during sunshine hours,
Wind
- only during windy periods, etc.
Markets
Interconnection Issues
Energy Price Issues
PPAs
GB Shrestha: March 2015

35. Cost-Competitiveness of Selected Renewable Power Technologies
Source: Renewable Energy: RD&D Priorities, OECD/IEA 2006.
GB Shrestha: March 2015

36. Thank You!
GB Shrestha: March 2015

37. Present System Performance - Singapore
SARFIx – System Average RMS (variation) Frequency Index
GB Shrestha: March 2015 37

38. Modern Coal Power Plant
GB Shrestha: March 2015 38

39. Basic Gas Turbine Brayton Cycle: Working fluid is always a gas
Most common fuel is natural gas
Typical efficiency is around 30 to 35%
GB Shrestha: March 2015

40. Combined Cycle Power Plants
Efficiencies of up to 60% can be achieved, with even higher values when the steam is used for heating
GB Shrestha: March 2015

41. Smart Nation
GB Shrestha: March 2015

42. The long time goal of transmitting power from the West to the East
North East
Xinjiang Coal ase
Xinjiang
North China
Jin,Shan,Mong Coal Base
To North and Central China
To Centre,East
North West
To Centre
Load centers
Tibet Hydro 上海
Tibet
Sichuan Hydro
East China
Chuanyu
Centre China
To Centre, East
Jinshajiang Hydro
Taiwan
South China
Source: X. Zhao, China EPRI
P42
GB Shrestha: March 2015 42