Treasure Valley Electrical Plan

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Treasure Valley

Electrical Plan

Community Advisory

Committee

January 25, 2006 January 25, 2006

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Agenda

10 a.m. Welcome

10:10 a.m. Follow up DSM discussion 10:30 a.m. TVEP – CAC process update 10:40 a.m. Transmission Presentation

Overview & Reliability 11:40 a.m. Lunch

12:10 p.m. Small group discussion –

Transmission in the Treasure Valley

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Recap of Previous Meetings

¾August 24 – Toured Facilities

 Fossil Gulch Wind Park

 Bennett Mountain Power Plant  Boise Bench Substation (drive by)

¾September 22 – Toured Facilities

(makeup session)

 Bennett Mountain Power Plant  Caldwell Substation

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Recap of Previous Meetings

¾September 28

 Overview of Idaho Power System

 Discussed base load vs peaking power plants  Integrated Resource Plan

 Brief discussion of Treasure Valley power

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Recap of Previous Meetings

¾October 26

 Discussed generation in the Treasure Valley  Discussed Treasure Valley distribution

buildout

 Breakout discussion about pros and cons of

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Recap of Previous Meetings

¾November 30

 Regional Planning Updates

• Communities in Motion

• Blueprint for Good Growth

 Demand Side Management presentation  Demand Side Management breakout

sessions

• Barriers to DSM

• What would it take to exceed expected results? • How could Idaho Power encourage community

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Future Treasure Valley

Electrical Projections

2030 Buildout Population 873,561 2,400,000 Electrical Demand (MW) 2,620 7,200 DSM Potential (20-30% of new load) 230 1600

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Population & Demand Projections

¾Buildout population determined using 3

different methods.

 The first method was described in October

• Used land based GIS approach based on

availability of land, proximity to transportation etc.

• Assigned 3 density zones

 Urban  Suburban  Rural

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Population & Demand Projections

¾The second method used zoning as

determined by using comprehensive

plans of the various cities.

 Some cities don’t have comp plans.

• Made assumptions based on nearby cities

 For each zone, assigned a loading (kW) per

square mile based on the type of zoning.

 Added up load for each zoning type.

 For areas outside of city areas of impact,

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Population & Demand Projections

¾ The third method ignored everything other

than residential zoning with the assumption that all residences will be in areas zoned

residential.

 Assumed areas will fill in accordance with their

zoning. I.e. R-4 will have 4 residences per acre, etc.

 Idaho Power estimates there are about 2.5 people

per customer

 Subtracted out land for golf courses, parks, etc.

¾ All three methods result in between 7,000 and

7,200 MW of load.

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Substation Types

¾Source Substation – Act as the receiving

point for energy produced at distant

generation.

 Typically 230 kV and higher

 Can be co-located with other types of

substations

 Send out power at 230 kV to Hub Substations  Currently there are 2 Source Substations in

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Substation Types

¾Hub Substations – Convert 230 kV

(typically) to 138 kV for transmission to

Distribution Substations.

 Each Hub Substation can have 2 or more 138

kV loops fed from them

• 3 to 5 distribution substations per loop

 Currently there are 3 Hub Substations in the

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Substation Types

¾Distribution Substation – Convert the 138

kV transmission from the loops fed by

the Hub Substations to 13.8 or 34.5 kV for

delivery to its end use

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Transmission Loop Configuration

¾ Three-Four

230 kV lines into the Hub Substation ¾ Two 138 kV loops (Four Lines) ¾ Three to Five Distribution Stations on a loop 138 kV 230 kV

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Treasure Valley 138kV Transmission Layout

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Transmission

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Idaho Power Voltage Levels

¾ Extra-high voltage Transmission

 230,000; 345,000; 500,000 volts

 Used for transmitting electrical energy

over great distance.

 Higher voltage lines are more efficient

than lower voltage lines.

• Higher voltage line results in fewer losses

than a lower voltage line.

• Idaho Power loses between 2 and 3 percent

of its energy due to line losses on the extra-high voltage transmission system.

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¾230 kV corner

structure.

 Similar in diameter

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¾230 kV

transmission on

Eagle Road

 Note the transmission line is in road right-of-way.

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138 kV and 230 kV lines running down

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Idaho Power Voltage Levels

¾ Sub-transmission lines

 69,000; 138,000; 161,000 volts  Used for transmitting energy

between substations that are close to one another

• Up to ~ 100 miles

 Will typically not carry as

much energy as extra-high voltage lines.

138 kV

13.8 kV Underbuild

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Idaho Power Voltage Levels

¾Distribution Lines

 13,800; 34,500 volts  Used for transmitting

energy to its end use.

• Commercial facilities • Small factories

• Small transformer

outside a group of houses.

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Transmission Line Capacity

¾ There are many factors that go into

determining how much power a given

transmission line can carry. For general purposes, we can say:

 500 kV line can carry ~ 1,000 to 1,500 MW  345 kV line can carry ~ 700 to 1,000 MW  230 kV line can carry ~ 300 to 500 MW

¾ All the above lines will normally be operated in

parallel (electrically alongside) with another line of equal size or a set of lower voltage lines.

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Transmission Reliability

¾Idaho Power must be able to reliably

serve its customers under all normal

operating conditions and under expected

abnormal operating conditions (events

that are statistically likely to occur fairly

often)

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Transmission Reliability

¾ Idaho Power voluntarily complies with WECC

reliability standards.

 By agreement, WECC can impose financial

penalties on Idaho Power for reliability violations

¾ Idaho Power must periodically submit reports

to the WECC on varying reliability topics.

¾ IPUC has some oversight authority

 Can force Idaho Power to improve its system if

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Transmission Reliability

¾ Transmission system must be able to survive

the single worst contingency (abnormal condition) on the system.

 No one event on a major transmission line can

disrupt the system, making it unable to supply all the end users.

 Certain transmission lines are not loaded to their

full capacity – they hold some in reserve.

 Additional capacity is held in reserve so that energy

can be imported from surrounding utilities should Idaho Power lose generation.

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Transmission Reliability

¾Idaho Power must also adhere to what’s

known as an “n-1” criterion.

 For multiple transmission lines delivering

power to the same point, if one of the lines goes out of service, the remaining lines must be able to carry both the load they were

carrying before the event, plus the load carried by the line that is out of service.

• This is true even if the line with the highest

capacity is the one that goes out of service.

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N

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Transmission Reliability

¾Not all transmission has backup

 Many times, a single lower voltage line will

be the only transmission serving an area so that if the line goes out of service, the

customers being served by that line lose power.

• Typical of smaller demand areas such as in

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Transmission Reliability

¾Not everyone sees the same level of

reliability.

 It would be prohibitively expensive to ensure

all customers had the same reliability.

 Customers located in urban areas generally

have the ability to receive power from more than one feeder.

 More remote customers have only one feeder

serving their area.

 In mountainous areas, snow and wind will

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Transmission Right of Way

¾ The width of right-of-way corridor required

for a transmission line is set by the National Electrical Safety Code.

 Takes into account blowout

• How far the wire can be expected to swing during a high

wind on a hot day.

• Can’t come close to structures or trees because of wind.

¾ If a tower is made taller, sometimes it will

require less ROW width.

¾ Single pole structures also require less ROW

width than do lattice structures.

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Transmission Right of Way

¾500 kV

 Single circuit – 150 feet

 Two circuits in same ROW – 300 feet

• Separate pole lines

 Single circuit along road ROW – 70 feet

• If the road ROW has landscaping and burming,

this can decrease the need for additional

transmission ROW since the transmission can overhang

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Transmission Right of Way

¾345 kV

 Single circuit – 130 feet

 Two circuits in same ROW – 300 feet  Single circuit along road ROW – 60 ft

• If the road ROW has landscaping and burming,

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Transmission Right of Way

¾230 kV

 Double circuit (same tower) – 80 feet

• Normally we will run double circuits for 230 kV

 Double circuit along road Row – 40 feet

• If the road ROW has landscaping and berming,

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¾230 kV

transmission on

Eagle Road

 Note the transmission line is in road right-of-way.

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Increasing Capacity of Existing

Lines

¾ The capacity of existing transmission lines can

sometimes be increased

 Increase wire size

• If structurally able

 Increase voltage

• If electrical clearances are great enough • If ROW is available

¾ If the line was already serving an end-load, that

load still must be served

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Small Group Discussion

¾What are important issues to consider

when locating transmission lines in the

Treasure Valley? (What are the “most”

important?)

¾Where would you like to see transmission

lines enter the Treasure Valley?

¾Explore the possible corridors that

transmission lines could use to cross the

Treasure Valley

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A Buildout Scenario

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Midpoint GEN Existing Existing 2004 2004 Mt. Home Brownlee Ontario Boise Bench Caldwell Locust

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46 Midpoint GEN Nampa 230 Nampa 230 Mt. Home Ontario Boise Bench Caldwell Nampa Brownlee

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Midpoint GEN Happy Happy Valley 230 Valley 230 Mt. Home Ontario Boise Bench Caldwell Nampa Brownlee Happy Valley

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48 Midpoint GEN Middleton Middleton Mt. Home Ontario Boise Bench Caldwell Middleton Nampa Brownlee

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Midpoint GEN Pearl to Pearl to Middleton Middleton Mt. Home Ontario Boise Bench Caldwell Middleton Pearl Switching Station Brownlee

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50 Midpoint GEN Pearl to Pearl to Locust Locust Mt. Home Ontario Boise Bench Caldwell Pearl Locust Brownlee

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Midpoint GEN Pearl to Pearl to Happy Happy Valley Valley Mt. Home Ontario Boise Bench Caldwell Happy Valley Pearl Brownlee

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52 Midpoint GEN Mora 230 Mora 230 Mt. Home Ontario Boise Bench Caldwell Mora Brownlee

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Midpoint GEN MORA to MORA to Mt Home Mt Home Mt. Home Ontario Boise Bench Caldwell Mora Brownlee

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54 Midpoint GEN MORA to MORA to Cloverdale Cloverdale Sub Sub Mt. Home Ontario Boise Bench Caldwell GEN Mora Cloverdale Brownlee

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Midpoint GEN Cloverdale Cloverdale Tap Tap Mt. Home Ontario Boise Bench Caldwell GEN Cloverdale Mora Brownlee

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56 Midpoint GEN Dry Creek Dry Creek Mt. Home Ontario Boise Bench Caldwell GEN Dry Creek Brownlee

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Midpoint GEN Nampa to Nampa to Cloverdale Cloverdale Mt. Home Ontario Boise Bench Caldwell GEN Cloverdale Nampa Brownlee

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58 Midpoint GEN Midpoint to Midpoint to Southwest Southwest Treasure Valley Treasure Valley Mt. Home Ontario Boise Bench Caldwell GEN Midpoint Brownlee Southwest TV PacifiCorp

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Midpoint GEN Southwest Southwest Treasure Valley to Treasure Valley to Western Canyon Western Canyon County County Mt. Home Ontario Boise Bench Caldwell GEN Midpoint Brownlee Southwest TV PacifiCorp

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60 Midpoint GEN Southwest Southwest Treasure Valley to Treasure Valley to Northwest Northwest Mt. Home Ontario Boise Bench Caldwell GEN Midpoint Northwest Brownlee Southwest TV PacifiCorp

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Midpoint

GEN

Convert

Convert Bowmont Bowmont Sub to 230 Sub to 230 Mt. Home Ontario Boise Bench Caldwell GEN Midpoint Northwest Brownlee Southwest TV PacifiCorp

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62 Midpoint GEN Treasure Valley Treasure Valley Build

Build--OutOut

Mt. Home Ontario Boise Bench Caldwell GEN Midpoint Southwest TV PacifiCorp Northwest Brownlee