Post on 12-May-2015
description
A New Market Structure for Integrating Stochastic Renewable Generation in a Transmission Grid
Stephen Lee
Senior Technical Executive
Power Delivery & Utilization, EPRI
slee@epri.com
November 2008
2© 2008 Electric Power Research Institute, Inc. All rights reserved.
Outline
• Mandatory penetration of wind power may not be economical
• High penetration of wind power will create higher risk of blackouts
• How to prevent these problems? A New Market Structure
• Port of Entry + Storage
• Virtual Service Aggregator Balancing Authority
• CO2 Charge and Public Benefit Funds
• Conclusions
3© 2008 Electric Power Research Institute, Inc. All rights reserved.
United States Renewable Mandates
Solar water heating (SWH) eligible
4© 2008 Electric Power Research Institute, Inc. All rights reserved.
Mandatory penetration of wind power may not be economical
• Utilities are forced to buy whatever amount of wind energy produced under the mandate
• No cost penalty is placed on wind power for backup capacity, load following, operating reserve, frequency regulation
• Transmission companies have no incentive to build new transmission to integrate wind power
• Storage plants are considered power plants and are not profitable to build
• Transmission companies have no incentive to build storage plants
5© 2008 Electric Power Research Institute, Inc. All rights reserved.
Existing 765 kV
New 765 kV
AC-DC-AC Link
Our Nation’s Future Requires an EHV Interstate Transmission System.
6© 2008 Electric Power Research Institute, Inc. All rights reserved.
High penetration of wind power will create higher risk of blackouts
• Raw wind power entering the grid at many entry points will create widely varying power flows across the grid
• Extensive system frequency excursions and unusual flow patterns will create more blackouts
Source: California ISO
Tehachapi Wind Generation in April – 2005
0
100
200
300
400
500
600
700
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
Hour
MW
Average
Each Day is a different color.
Day 29
Day 5 Day 26
Day 9
Could you predict the energy production for this wind park either day-ahead or 5 hours in advance?
8© 2008 Electric Power Research Institute, Inc. All rights reserved.
Impacts on Spinning Reserves and Ramping Requirements
• E. ON Netz operates German transmission network
– 7+ GW installed wind capacity
– 21+ GW peak system load
Source: E. ON Netz 2004 Wind Report
Source: E. ON Netz 2005 Wind Report
Dec. 24, 2004 – aggregate wind power falls from 2004 max 6,024MW to <2,000MW in 10 hrs (avg. 7 MW/min).
Nov. 19, 2004 – aggregate wind power drops 3,640 MW in 6 hrs (10 MW/min.)
9© 2008 Electric Power Research Institute, Inc. All rights reserved.
Load Following, Operating Reserve, Unloadable Generation
Installed Wind Capacity
Need Operating Reserve
Need Unloadable Generation
Need Unloadable Generation
Need Operating Reserve
0 Time
? MW/hr
10© 2008 Electric Power Research Institute, Inc. All rights reserved.
Methods of Coping with Wind Uncertainty
• Short-Term– Better wind forecasting– Carry more operating/spinning
reserve and unloadable generation to handle up and down ramps of wind output
– Rapid coordination with demand response and energy storage
• Long-Term– Build more energy storage, e.g.,
Compressed Air Energy Storage (CAES)
– Controllable demand response– Holistic planning of transmission,
generation and demand
0
50
100
150
200
250
300
350
Sep06 1
2:0
0
Sep06 1
4:2
4
Sep06 1
6:4
8
Sep06 1
9:1
2
Sep06 2
1:3
6
Sep07 0
0:0
0
Sep07 0
2:2
4
1-min MW
fcst 1
fcst 2
fcst 3
Potential wind curtailment
CAES
11© 2008 Electric Power Research Institute, Inc. All rights reserved.
Large Scale Renewable Integration in Free Market and Mandate Environment
Grid Operations & Planning(Visualization, tools, monitoring, reliability assessment methods)
Balancing Resources
(Energy Storage, Demand Response, Fast
Acting CT, Hydro etc.)
Transmission Technologies
(Adv. Conductors, HVDC for wind, Advanced
FACTS)
Grid Interface Technologies
(Interface, Control, Ride Through Technologies)
Reliably and Cost Effectively Integrate High Penetration of Intermittent Generation with the Grid
12© 2008 Electric Power Research Institute, Inc. All rights reserved.
Port of Entry for Large Scale Renewables
• Restrict large scale renewables to connect to the grid only through ports of entry
• Provide large scale energy storage at ports of entry
• Dispatch storage to maintain steady power flow into the grid
• This reduces transmission investment
End-uses & DR
Distribution SystemTransmission System
Energy Storage
Power Plants
Renewable Plants
13© 2008 Electric Power Research Institute, Inc. All rights reserved.
Potential Role of the Virtual Service Aggregator Balancing Authority
TraditionalPower Plants
TraditionalPower Plants
RenewableResources
RenewableResources
EnergyStorage
EnergyStorage
TransmissionGrid
TransmissionGrid
Real RegionalControl Center
Real RegionalControl Center
VirtualService
Aggregator
Σ
VirtualService
Aggregator
Σ
End Usesand
DistributedResources
End Usesand
DistributedResources
FinancialSettlement ofNet Difference
Power Flow
FinancialTransaction
• Owns or contract for:
• Portfolio of renewablesstorage, or traditionalpower plants
• Portfolio of customerswith distributed resources
• SCADA and Area Control
14© 2008 Electric Power Research Institute, Inc. All rights reserved.
Virtual Service Aggregator Balancing Authority
• Direct measurements and control of
– All generation and storage sources in its portfolio
– All customer demand in its portfolio
– All distributed generation or storage in its portfolio
• Maintenance energy balance like a Control Area
• Area Control Error charged by the ISO/RTO
• Separate SCADA and control system
• Integrated with the main EMS of ISO/RTO
15© 2008 Electric Power Research Institute, Inc. All rights reserved.
UDi-ism (Unity in Diversity)
• Diversity means the exercise of an individual’s right of free choices.
• Unity in Diversity means creating unity while preserving diversity, or allowing diversity to achieve unity
• Hypothesis –
– Align an individual’s selfish incentive more with the socially optimal objective
– Then the creative energy of individuals would achieve the social objective.
“An Effective Pricing and Financial Method to Significantly Reduce CO2Emissions from Electricity Production – An Application of the Third WayEconomic System of Unity-in-Diversity”, IEEE PowerCon 2006, Chongqing
16© 2008 Electric Power Research Institute, Inc. All rights reserved.
CO2 Price Sensitivity of Electric Generation Market Shares with Oil Price at 60 $/bbl, Coal Price at 4 $/MBTU and
Wind/Solar w Storage at 5000 $/kW
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
$-
$5
$10
$
15
$20
$
25
$30
$
35
$40
$
45
$50
$
55
$60
$
65
$70
$
75
$80
CO2 Cost ($/ton)
Mar
ket
Sh
are
Wind/Solar w Storage
CT
IGCC
Comb Cycle
COAL
Nuclear
17© 2008 Electric Power Research Institute, Inc. All rights reserved.
18© 2008 Electric Power Research Institute, Inc. All rights reserved.
Flow of Money for Cap and Trade System
Green Power Plant Non-compliant Power Plant
Exchange
$
Allowance Certificates
$
Electricity ConsumersElectricity
$$
Electricity
Green Power Plant Non-compliant Power Plant
Exchange
$
Allowance Certificates
$
Electricity ConsumersElectricity
$$
Electricity
Another potential financial bubble
19© 2008 Electric Power Research Institute, Inc. All rights reserved.
Flow of Money for UDI-ism CO2 Charge
Green Power Plant Non-compliant Power Plant
Trustee ofCO2 Charge
0 or Low $ High $
Electricity ConsumersElectricity
$$
Accountable to International Agreements
Electricity
Rebate incentives and Electricity subsidies
Green Power Plant Non-compliant Power Plant
Trustee ofCO2 Charge
0 or Low $ High $
Electricity ConsumersElectricity
$$
Accountable to International Agreements
Electricity
Rebate incentives and Electricity subsidies
20© 2008 Electric Power Research Institute, Inc. All rights reserved.
How Is It Different from a Carbon Tax?
• Global CO2 emissions would drop from today’s 13,000 million tons per year to less about 4,000 million tons, when the optimal generation mix is finally achieved for the CO2 cost of $30/ton
• The CO2 charge would be based on scientific or market value for the social cost of CO2 - not a fixed or static tax rate
• Revenue from the CO2 charge goes into a Public Benefit Fund.
– Managed by independent trustees
– Can assist low income electricity customers
– Can be used to clean up environment
– Can be treated as an investment account in the name of the electricity customers, which grows in value
– Money may become a social safety net for unemployment and retirement
21© 2008 Electric Power Research Institute, Inc. All rights reserved.
Conclusions
• Free market capitalistic countries
– May not allow the restriction of a Port of Entry
– Will likely allow virtual service aggregator
– May not force virtual service aggregator to be balancing authority
– Will likely adopt Cap and Trade
• Would a more economical and more reliable power system result from:
– Ports of Entry
– Virtual Service Aggregator Balancing Authority
– CO2 charge with Public Benefits Funds
22© 2008 Electric Power Research Institute, Inc. All rights reserved.
Industry Demonstration 2008-2012: CAES
CT Module
Exhaust
Air
Compressor
Combustion Turbine
Motor
• Storage
Air
Intercoolers Recuperator
Fuel
Expander
Storage
Heat RateEnergy Ratio
38100.70
Constant Output Pressure Regulation Valve
Demonstration and Validate Performance of Advanced Design Underground and Above Ground CAES Plant
23© 2008 Electric Power Research Institute, Inc. All rights reserved.
Underground and Above Ground CAES
Underground CAES
– Assess and Demonstrate Porous Rock/Aquifer Storage
– Plant Size: Above 300 MW
Above-Ground CAES
– Assess Economic Feasibility of Pipe- and/or Vessel-Based Above- Ground Air Storage
– Assess corrosion impact of cycling temperature and pressure
– Plant Size: 10-20 MW with 2-3 hours of storage
Demonstrate advanced design and assess its performance for under- and above-ground CAES