WIEG Board Meeting

Alliant Energy New Generation Plan

Kim ZuhlkeFebruary 8, 2007

Nelson Dewey

Nelson Dewey Units 1 and 2

Nelson Dewey Units 1, 2 and Proposed Unit 3

Nelson Dewey #3

2003 WPL and WPS enter into joint study on technology and sites.

More than 100 sites considered.

Existing facilities and green field.

Four sites emerged as top candidates.

Early 2004, WP&L decides to focus on Columbia and Nelson Dewey.

Columbia: Our First Look

Big site – ease of construction.

Synergies with existing facilities.

Very good transportation, water and air.

Can build to an economy of scale – 600+ MW’s.

Transmission ~ $20m.

Community is receptive.

Nelson Dewey: Our First Look

Very good water and air.

Barge for transportation.

Small site.

Transmission ~ $20m.

Community and the region is enthusiastic and supportive.

Two 100 MW units at Cassville today (Nelson Dewey #1 and #2) Updating emissions technology has synergies with building Nelson

Dewey #3 An opportunity for life extension of Units #1 and #2

Unit #3 Technology New circulating fluidized bed (CFB) technology (proven @ 300 MW’s) Fuel flexibility (pet coke, coal, biomass)

Add rail transportation to the site Existing rail corridor provides opportunity New benefits to Nelson Dewey #1 and #2

Nelson Dewey: A Closer Look

The Bottom Line:

The pieces align to make this the best option for customers.

River is a significant advantage in construction Materials and labor

Great local support Economic benefits to Cassville & Grant County

Transmission Low cost upgrades Enhanced river crossing Greatly improves Wisconsin import capacity

Nelson Dewey: A Closer Look

Wempletown-Paddock

Base Imports Into Wisconsin (ATC)

1,913 MW

345 kVMajor Pathways

Eau Claire- Arpin

Arrowhead-Weston

Wempletown-Rockdale

Zion-Pleasant Prairie

Zion-Arcadia

161 kVLore-

Turkey RiverBase Line

Import

3000

600

1200

1800

2400

Increase Import Columbia 3

Columbia 3

Base LineImport

3000

600

1200

1800

2400

Columbia 3

1969 MW56 MW IncreaseEau Claire- Arpin

Arrowhead-Weston

Wempletown-Rockdale

Wempletown-Paddock

Zion-Pleasant Prairie

Zion-Arcadia

345 kVMajor Pathways

Lore-Turkey River

161 kV

Import Increase: COL 3 vs. NED 3

NelsonDewey 3

2,538 MW625 MW Increase

Eau Claire- Arpin

Arrowhead-Weston

Wempletown-Rockdale

Wempletown-Paddock

Zion-Pleasant Prairie

Zion-Arcadia

345 kVMajor Pathways

161 kV

Lore-Turkey River

Base LineImport

NED 3

3000

600

1200

1800

2400

Transmission Value: COL 3 vs. NED 3

Eau Claire- Arpin

Arrowhead-Weston

Wempletown-Rockdale

Wempletown-Paddock

Zion-Pleasant Prairie

Zion-Arcadia

345 kVMajor Pathways

161 kV

Lore-Turkey River

PaddockRockdale Base Line

Import

NED 3

Base LineImport

3000

600

1200

1800

2400

Columbia 3

Columbia 3

NelsonDewey 3

$26.9M Annual

Decrease

1/1 2/1 3/1 4/1 5/1 6/1 7/1 8/1 9/1 10/1 11/1 12/1 1/1 2/1 3/1 4/1 5/1

12/1/06 5/31/08

SubmitCPCN

Establish Final EPCCost

EPC NoticeTo Proceed

Select EPCContractor

CPCN Approval

Reserve Production SlotsOn Major Equipment

Start Construction

CPCN Deemed Complete

Final Air PermitsIssued

Major Milestones - Nelson Dewey #3

WPL = 10% RPS = 300 MW of Wind

80–100 MW’s in Wisconsin – Cedar Ridge – Ratebase

Forward – PPA

200 MW’s in Iowa or Minnesota – sites under option

Project Overview

WPL to build, own & operate a 68MW - 98MW Wind Farm.

41 Wind Turbines; 1.65MW - 2.5 MW each

Located near Eden, WI Rate based asset Commercial Operation Date:

12/31/2008 Net Capacity Factor = 34% East access to transmission Excellent local support

Project Site