Transcript Distribution Companies – Where the Network Meets the Load Merlin Raab Renewable & Energy Efficiency Sr.

Distribution Companies –
Where the Network Meets the Load
Merlin Raab
Renewable & Energy Efficiency Sr. Consultant
Wisconsin Public Service Corporation
October 02, 2012
Agenda
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Overview of Distribution Company
Distribution in the Value Chain
Responsibilities of Distribution Company
A Typical Day
Challenges
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Distribution Companies – Where the Network Meets the Load
Electric Distribution Utility-1990
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Distribution Companies – Where the Network Meets the Load
Electric Distribution Utility-2012
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Distribution Companies – Where the Network Meets the Load
Physical Characteristics
• Electric distribution company begins at the
substation where the electricity is “stepped
down” to distribution voltage
• Lines feed out from the substation (typically in
the range of 7,200 to 25,000 volts)
• At customer locations, electricity is “stepped
down” again to a usable voltage – 120/240
volts for residential customers
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Distribution Companies – Where the Network Meets the Load
The System Itself
• System has to be designed and constructed to:
– Ensure proper voltage levels
– Ensure equipment such as lines and transformers do not
overheat when peak flow occurs (hot summer day)
– Withstand the elements – weather, lightning, etc.
– Handle additional load such as new customers’ load or
existing customers adding load
• To do this, engineers develop computer models of the
distribution system to conduct load flow analysis
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Distribution Companies – Where the Network Meets the Load
Distribution System Modeling / Analysis
Output from load flow analysis is used for:
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Determining system efficiencies – present and future
Determining if equipment overload conditions exist
Determining high-loss line sections
System deficiencies during emergency switching or
temporary load transfers
Over-current protection plans
Feasibility of large load additions
Proper capacitor placement
Long-range planning – timing of substation reinforcements
Distribution Companies – Where the Network Meets the Load
Distribution System Modeling / Analysis
Increased emphasis on off-peak electricity usage
will change the shape of our typical load curve
and our computer model
– Electric vehicles charging during off-peak hours
– Customers shifting other appliance loads to
off-peak hours
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Distribution Companies – Where the Network Meets the Load
Load Cycle of Substation Transformer
- Usually repeats every 24 hours
- Load fluctuates throughout the day
- Usually one peak period in the day
150%
Equipment Rating
100%
50%
Actual Load
12 PM
8
6 AM
NOON
6 PM
Distribution Companies – Where the Network Meets the Load
12 PM
Distribution in the Value Chain
• Supply produced at central plant or distributed
resources
• Central station supply is dispatched to the “Grid” and
then into one of three grids: ERCOT, WECC, and
Eastern Interconnection
• Transmission lines transmit energy to the market
• The market matches supply offers and load bids
• Control operators oversee transfer of energy to load
serving distribution companies
• Energy is “stepped down” to a distribution area and
then further “stepped down” to a customer site
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Distribution Companies – Where the Network Meets the Load
NERC Interconnections
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Distribution Companies – Where the Network Meets the Load
NERC Regions and Balancing Authorities
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Distribution Companies – Where the Network Meets the Load
MISO Market in General
• Central bid/offer/settlement
MW
Schedules/Dispatch
MW Schedules
Bids
Offers
Generation
Generation
Generation
Generation
Generation
Generation
Generation
Generation
Distribution
Distribution
Distribution
Energy
Distribution
Distribution
Distribution
MISO Market
Energy
Dollars
Dollars
Prices
6,009 Generators
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Distribution
Distribution Companies – Where the Network Meets the Load
264 Load Zones
Responsibilities of Distribution
Company – “Obligation to Serve”
• Retail Functions
• Meter to Cash
• Customer/Government
Relations
• Construction/maintenance
• Reliability
• Engineering studies
• Line clearance
• Storm restoration
• Power continuity/quality
• Safety
• Public
• Employee
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• Economic Delivery
• Dispatch decisions
• “Cost per”
• Compliance
• PSC quality standards
• NERC reliability (Local
Balancing Authority)
• FERC
• OSHA
• Environmental and
Corporate Stewardship
• Environmental principles
• Hazardous waste/site runoff management
• Community outreach
Distribution Companies – Where the Network Meets the Load
A Typical Day in 1990
• Monitor system to ensure adequate amount of
generation to serve load; contract for additional
generation if needed
• Voluntary compliance with NERC & regional
reliability standards
• Build new and maintain distribution system
• Minimal number of customer-owned generators
putting power back to the grid
• Respond to power outages that are received via
phone from customers
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Distribution Companies – Where the Network Meets the Load
A Typical Day in 1990 (continued)
• Customers who experience outage remain without power
until line electricians travel to the site to address cause
• Customer’s receive information on restoration times from
radio & TV
• Send out meter readers who bring back reads for use by
customer billing
• Customers generally not concerned with the timing of use
of electricity
• Appliances, such as dishwashers and refrigerators, run at
will
• The number of customers behind on their bill is small and
demographically homogeneous
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Distribution Companies – Where the Network Meets the Load
A Typical Day in 2012
• Monitor system real-time and purchase power on the
MISO market to match load requirements or institute
demand control
• Limited customer-owned renewable generation putting
power onto the system requiring the distribution
company to adapt systems to handle it
• Systems used to proactively determine location of
outages and dispatch repair crews
• Customers receive restoration information via social
media
• Limited use of automated switches installed on
distribution system isolate faulted sections of line and
automatically restore power to a large portion of
customers without power
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Distribution Companies – Where the Network Meets the Load
A Typical Day in 2012 (continued)
• Mandatory compliance with NERC & regional
reliability standards with threat of financial
penalties
• Meters read from a central location
automatically through communications network.
Customers have access to unbilled energy
consumption via web-portal
• Distribution system modernization technology
/smart meters allow customers to make full
advantage of time sensitive rates?
• The number of customers behind on their bill
growing and demographically diverse
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Distribution Companies – Where the Network Meets the Load
Prices to Devices
Figure 1. Dynamic Energy Management Infrastructure for a Commercial Building
Source: EPRI
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Distribution Companies – Where the Network Meets the Load
Challenges
Increased number of renewable source
generators on the distribution system & possibly
micro-grids
• Changes load flow analysis (computer model) due to
electricity flowing back to the system
• Requires modifications to equipment on those
circuits, such as over-current protection equipment
and conductors
• Requires modifications to operating procedures for
safety
• Net-metering: Who pays for maintaining the system?
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Distribution Companies – Where the Network Meets the Load
Challenges
•Distribution companies will need to make significant
investments in equipment to accommodate increased
DG and increased off-peak usage
•Limited “Smart System” benefits to rural customers
•Regulatory Uncertainty regarding “Smart system
investments”
•Who bears the risks?
•Opt out vs. Opt. in pricing options
•Security & privacy issues
•EMF concerns
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Distribution Companies – Where the Network Meets the Load
Challenges
• Customer
• Keep costs down (low rates) amid cost pressure
• Help understand rate vs. bill – energy optimization
• Shareholder
• Maintain attractive, risk-adjusted return
• Employee
• Graying of industry / training / retention /
cost reduction
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Distribution Companies – Where the Network Meets the Load
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Distribution Companies – Where the Network Meets the Load