# Exhibit 10.1

# ALLIANT ENERGY CORPORATION
2002 EQUITY INCENTIVE PLAN 
NONQUALIFIED STOCK OPTION AGREEMENT

THIS
AGREEMENT, made and entered into as of [Date], by and between Alliant Energy
Corporation, a Wisconsin corporation (the Company), and [Name of
Employee], (the Optionee).

# W I T N E S S E T H:

WHEREAS,
the Company has adopted the Alliant Energy Corporation 2002 Equity Incentive Plan (the
Plan), the terms of which, to the extent not stated herein, are specifically
incorporated by reference in this Agreement (defined terms used herein which are not
otherwise defined shall have the meaning set forth in the Plan);

WHEREAS,
one of the purposes of the Plan is to permit the grant of various equity-based incentive
awards, including options to purchase shares of the Companys Common Stock, $.01 par
value (the Common Stock), to certain Key Employees of the Company and its
Affiliates;

WHEREAS,
the Optionee is now employed by the Company or an Affiliate of the Company in a key
capacity and has exhibited judgment, initiative and efforts which have contributed
materially to the successful performance of the Company or its Affiliates; and

WHEREAS,
the Company desires the Optionee to remain as an employee of the Company or its
Affiliates, and wishes to provide the Optionee with the opportunity to secure or increase
his or her stock ownership in the Company in order to develop even a stronger incentive to
put forth maximum effort for the continued success and growth of the Company.

NOW,
THEREFORE, in consideration of the premises and of the covenants and agreements herein
set forth, the parties hereby mutually covenant and agree as follows:

1.  Grant of Option. Subject to the terms and conditions
          of the Plan and this Agreement, the Company grants to the Optionee an option
          (the Option) to purchase from the Company all or any part of the
          aggregate amount of [Number of Shares] shares of Common Stock (the
          Optioned Shares). The Option is intended to constitute a
          nonqualified stock option and shall not be treated as an incentive stock option
          within the meaning of Section 422 of the Internal Revenue Code of 1986, as
          amended.

2.  Option Price. The price to be paid for the Optioned
          Shares shall be [Price Per Share]per share, which has been determined by
          the Compensation and Personnel Committee of the Board of Directors of the
          Company (together with any successor committee that may administer the Plan, the
          Committee) to be not less than 100% of the fair market value of a
          share of such stock on the date of grant of the Option (determined based on the
          average of the high and low sales prices for the Common Stock, as reported on
          the New York Stock Exchange on the date of grant).

3.  Exercisability and Termination of Option. Except as
          provided herein, the Option may be exercised only while the Optionee is an
          employee of the Company or an Affiliate of the Company and only if the Optionee
          has been continuously affiliated with the Company or any of its Affiliates since
          the date of grant of the Option. The Option may be exercised by the Optionee in
          whole or in part from time to time, during the period beginning [Date],
          and ending [Date] (the Expiration Date).

|                         | Cumulative Percentage of Shares Subject to
|------------------------ | ------------------------------------------
|                         | Option Which May be Purchased (which      
|                         | number of shares shall be rounded         
|Period                   | down to the nearest whole number)         
|                         |                                           
|Prior to [Date]          | [Percentage]                              
|                         |                                           
|[Date]to [Date]          | [Percentage]                              
|                         |                                           
|[Date]to [Date]          | [Percentage]                              
|                         |                                           
|[Date]to Expiration Date | [Percentage]                              
|                        

4.  Manner of Exercise and Payment. Subject to the
          provisions of Paragraph 3 hereof, the Option may be exercised only by
          written notice to the Company, served upon the Corporate Secretary of the
          Company at its office at 4902 North Biltmore Lane, Madison, Wisconsin
          53718-2132, specifying the number of shares in respect to which the Option is
          being exercised. Subject to the provisions of this Agreement, the notice of
          exercise must be accompanied by full payment of the option price of the shares
          being purchased (i) in cash or by certified check or bank draft;
          (ii) by tendering previously acquired shares of Common Stock (valued at
          their fair market value as determined in the manner provided below);
          or (iii) by any combination of the means of payment set forth in
          subparagraphs (i) and (ii). For purposes of this Paragraph 4, the
          fair market value of a share of Common Stock shall be equal to the
          average of the high and low sales prices for the Common Stock, as reported on
          the New York Stock Exchange on the trading date next preceding the date of
          exercise, or, if no trading occurred on the trading date next preceding the
          exercise date, then the fair market value per share of Common Stock
          shall be determined with reference to the next preceding date on which the
          Common Stock was traded. For purposes of subparagraphs (ii) and (iii) above, the
          term previously acquired shares of Common Stock shall only include
          Common Stock owned by the Optionee prior to the exercise of the Option and shall
          not include shares of Common Stock which are being acquired pursuant to the
          exercise of the Option. No shares shall be issued until full payment therefor
          has been made.

5.  Nontransferability of the Option. The Option shall
          not be assignable, alienable, saleable or transferable by the Optionee other
          than by will or the laws of descent and distribution; provided,
          however, that the Optionee shall be entitled, in the manner provided in
          Paragraph 9 hereof, to designate a beneficiary to exercise his or her
          rights, and to receive any shares of Common Stock issuable, with respect to the
          Option upon the death of the Optionee. The Option may be exercised during the
          lifetime of the Optionee only by the Optionee or, if permitted by applicable
          law, the Optionees guardian or legal representative.

6.  Exercisability After Termination of Employment.

| | (a)       Death or Disability; Retirement. In the event the
               Optionee dies while he or she is an employee of the Company or any Affiliate or
               if his or her employment is terminated by reason of his or her disability, as
               defined in the Alliant Energy Cash Balance Pension Plan, the Option shall
               immediately vest one hundred percent (100%) and, to the extent not theretofore
               exercised, may be exercised in full as follows: (i) by the legal representative
               of the Optionee (who for purposes of this Agreement may be the Optionees
               beneficiary as designated pursuant to Paragraph 9) at any time within
               twelve months after the date of the Optionees death while an employee of
               the Company or any Affiliate; or (ii) by the Optionee or his or her legal
               representative or guardian at any time within twelve months after the
               termination of the Optionees employment by reason of disability, but in
               either case in no event later than the Expiration Date. In the event the
               Optionees employment is terminated by reason of his or her retirement
               after satisfying the minimum requirements for eligibility to receive an
               Early Retirement Benefit under the Alliant Energy Cash Balance
               Pension Plan (Retirement), the Option shall immediately vest one
               hundred percent (100%) and, to the extent not theretofore exercised, may be
               exercised in full by the Optionee or by his or her legal representative or
               guardian at any time within three years after termination of the Optionees
               employment by reason of Retirement, but in no event later than the Expiration
               Date. In the event the Optionees employment is terminated by reason of his
               or her Retirement or by reason of his or her disability, as defined in the
               Alliant Energy Cash Balance Pension Plan, and within the subsequent exercise
               period the Optionee dies, the Option, to the extent not theretofore exercised,
               may be exercised in full by the Optionees legal representative or guardian
               at any time within the longer of one year following death or the remainder of
               the expiration period triggered by the termination of employment, but in no
               event later than the Expiration Date.
| | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (b)        For Cause. If the employment of the Optionee is terminated
               by the Company or any Affiliate for Cause, the Option, to the extent not
               theretofore exercised, shall immediately be forfeited to the Company and no
               additional exercise period shall be allowed, regardless of the vested status of
               the Option. For purposes of this Agreement Cause means the admission
               by or the conviction of the Optionee of an act of fraud, embezzlement, theft or
               other criminal act constituting a felony under U.S. laws involving moral
               turpitude. The Board of Directors of the Company (the Board), by
               majority vote, shall make the determination of whether Cause exists.
| | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (c)       Other. In the event that the Optionee is discharged
               or leaves the employ of the Company or its Affiliates for any reason (other than
               the death, disability or Retirement of the Optionee as contemplated by Paragraph
               6(a) above or for Cause as contemplated by Paragraph 6(b) above), the Option, to
               the extent not theretofore exercised but then permitted (as of the date of
               termination) under the percentage limitations of Paragraph 3 hereof, may be
               exercised by the Optionee or by his or her legal representative or guardian at
               any time within three months after the date of termination of employment upon
               the tender to the Company, in cash or its equivalent, of the full purchase
               price, but in no event later than the Expiration Date.
| | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

7.  Change in Control.

| | (a)        Immediately Exercisable. If a Change in
               Control occurs, all outstanding Options under this Agreement shall vest
               and become immediately exercisable.
| | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (b)        Definition. For purposes of this Agreement,
               Change in Control means the occurrence of any one of the events set
               forth in the following paragraphs:
| | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (i)       
               any Person (other than (A) the Company or any subsidiary of the Company (each a
               Subsidiary), (B) a trustee or other fiduciary holding securities
               under any employee benefit plan of the Company or any Subsidiary, (C) an
               underwriter temporarily holding securities pursuant to an offering of such
               securities or (D) a corporation owned, directly or indirectly, by the
               shareowners of the Company in substantially the same proportions as their
               ownership of stock in the Company (Excluded Persons)) is or becomes
               the beneficial owner, directly or indirectly, of securities of the Company (not
               including in the securities beneficially owned by such Person any securities
               acquired directly from the Company or its Affiliates after [Date],
               pursuant to express authorization by the Board that refers to this exception)
               representing 20% or more of either the then outstanding shares of Common Stock
               or the combined voting power of the Companys then outstanding voting
               securities; or
| | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (ii)       
               the following individuals cease for any reason to constitute a majority of the
               number of directors of the Company then serving: (A) individuals who, on
               [Date], constituted the Board and (B) any new director (other than a
               director whose initial assumption of office is in connection with an actual or
               threatened proxy or consent solicitation for purpose of opposing a solicitation
               by the Company relating to the election of directors of the Company), whose
               appointment or election by the Board or nomination for election by the
               Companys shareowners was approved by a vote of at least two-thirds (2/3)
               of the directors then still in office who either were directors on
               [Date], or whose appointment, election or nomination for election was
               previously so approved (collectively the Continuing Directors);
               provided, however, that individuals who are
               appointed to the Board pursuant to or in accordance with the terms of an
               agreement relating to a merger, consolidation, or share exchange involving the
               Company (or any Subsidiary) shall not be Continuing Directors for purposes of
               this Agreement until after such individuals are first nominated for election by
               a vote of at least two-thirds (2/3) of the then Continuing Directors and are
               thereafter elected as directors by the shareowners of the Company at a meeting
               of shareowners held following consummation of such merger, consolidation or
               share exchange; and, provided further, that in the
               event the failure of any such Persons appointed to the Board to be Continuing
               Directors results in a Change in Control, the subsequent qualification of such
               Persons as Continuing Directors shall not alter the fact that a Change in
               Control occurred; or
| | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (iii)       
               the Company after [Date] consummates a merger, consolidation or share
               exchange with any other corporation or issues voting securities in connection
               with a merger, consolidation or share exchange involving the Company (or any
               Subsidiary), other than (A) a merger, consolidation or share exchange which
               results in the voting securities of the Company outstanding immediately prior to
               such merger, consolidation or share exchange continuing to represent (either by
               remaining outstanding or by being converted into voting securities of the
               surviving entity or any parent thereof) at least 50% of the combined voting
               power of the voting securities of the Company or such surviving entity or any
               parent thereof outstanding immediately after such merger, consolidation or share
               exchange, or (B) a merger, consolidation or share exchange effected to implement
               a recapitalization of the Company (or similar transaction) in which no Person
               (other than an Excluded Person) is or becomes the beneficial owner, directly or
               indirectly, of securities of the Company (not including in the securities
               beneficially owned by such Person any securities acquired directly from the
               Company or its Affiliates after [Date], pursuant to express authorization
               by the Board that refers to this exception) representing 20% or more of either
               the then outstanding shares of Common Stock or the combined voting power of the
               Companys then outstanding voting securities; or
| | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (iv)       
               the shareowners of the Company approve a plan of complete liquidation or
               dissolution of the Company or the Company effects a sale or disposition of all
               or substantially all of its assets (in one transaction or a series of related
               transactions within any period of 24 consecutive months), other than a sale or
               disposition by the Company of all or substantially all of the Companys
               assets to an entity at least 75% of the combined voting power of the voting
               securities of which are owned by Persons in substantially the same proportions
               as their ownership of the Company immediately prior to such sale.
| | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Notwithstanding
the foregoing, no Change in Control shall be deemed to have occurred if there
is consummated any transaction or series of integrated transactions immediately following
which the record holders of the shares of Common Stock immediately prior to such
transaction or series of transactions continue to own, directly or indirectly, in the same
proportions as their ownership in the Company, an entity that owns all or substantially
all of the assets or voting securities of the Company immediately following such
transaction or series of transactions.

8.  Tax Withholding. The Company may deduct and withhold
          from any cash otherwise payable to the Optionee (whether payable as salary,
          bonus or other compensation) such amount as may be required for the purpose of
          satisfying the Companys obligation to withhold Federal, state or local
          taxes. Further, in the event the amount so withheld is insufficient for such
          purpose, the Company may require that the Optionee pay to the Company upon its
          demand or otherwise make arrangements satisfactory to the Company for payment of
          such amount as may be requested by the Company in order to satisfy its
          obligation to withhold any such taxes.

The Optionee shall be permitted to satisfy the Companys tax withholding requirements by
making a written election (in accordance with such rules and regulations and in such form
as the Committee may determine) to have the Company withhold shares of Common Stock
otherwise issuable to the Optionee (the Withholding Election) having a fair
market value (as defined in a manner similar to Paragraph 4) on the date income is
recognized (the Tax Date) pursuant to the exercise of the Option equal to the
minimum amount required to be withheld. If the number of shares of Common Stock withheld
to satisfy withholding tax requirements shall include a fractional share, the number of
shares withheld shall be reduced to the next lower whole number and the Optionee shall
deliver cash in lieu of such fractional share, or otherwise make arrangements satisfactory
to the Company for payment of such amount. A Withholding Election must be received by the
Corporate Secretary of the Company on or prior to the Tax Date.

9.  Designation of Beneficiary.

| | (a)       
               The person whose name appears on the signature page hereof after the caption
               Beneficiary or any successor designated by the Optionee in
               accordance herewith (the person who is the Optionees beneficiary at the
               time of his or her death is herein referred to as the Beneficiary)
               shall be entitled to exercise the Option, to the extent it is exercisable, after
               the death of the Optionee. The Optionee may from time to time revoke or change
               his or her beneficiary without the consent of any prior beneficiary by filing a
               new designation with the Committee. The last such designation received by the
               Committee shall be controlling; provided, however, that no
               designation, or change or revocation thereof, shall be effective unless received
               by the Committee prior to the Optionees death, and in no event shall any
               designation be effective as of a date prior to such receipt.
| | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

| | (b)       
               If no such Beneficiary designation is in effect at the time of the
               Optionees death, or if no designated Beneficiary survives the Optionee or
               if such designation conflicts with law, the Optionees estate acting
               through his or her legal representative shall be entitled to exercise the
               Option, to the extent it is exercisable after the death of the Optionee. If the
               Committee is in doubt as to the right of any person to exercise the Option, the
               Company may refuse to recognize such exercise, without liability for any
               interest or dividends on the Optioned Shares, until the Committee determines the
               person entitled to exercise the Option, or the Company may apply to any court of
               appropriate jurisdiction and such application shall be a complete discharge of
               the liability of the Company therefor.
| | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

10. Transfer Restriction. The shares of Common Stock to
          be acquired upon exercise of the Option may not be sold or offered for sale
          except pursuant to an effective registration statement under the Securities Act
          of 1933, as amended, or in a transaction which, in the opinion of counsel for
          the Company, is exempt from the registration provisions of said Act.

11. Status of Optionee. The Optionee shall not be
          deemed for any purposes to be a shareowner of the Company with respect to any of
          the Optioned Shares except to the extent that the Option shall have been
          exercised with respect thereto, the shares shall have been fully paid, and a
          stock certificate issued therefor. Neither the Plan nor the Option shall confer
          upon the Optionee any right to continue in the employ of the Company or any of
          its Affiliates, nor to interfere in any way with the right of the Company to
          terminate the employment of the Optionee at any time.

12. Powers of the Company Not Affected. The existence
          of the Option shall not affect in any way the right or power of the Company or
          its shareowners to make or authorize any or all adjustments, recapitalizations,
          reorganizations or other changes in the Companys capital structure or its
          business, or any merger or consolidation of the Company, or any issuance of
          bonds, debentures, preferred or prior preference stock senior to or affecting
          the Common Stock or the rights thereof, or dissolution or liquidation of the
          Company, or any sale or transfer of all or any part of the Companys assets
          or business or any other corporate act or proceeding, whether of a similar
          character or otherwise.

13. Interpretation by Committee. As a condition of the
          granting of the Option, the Optionee agrees, for himself or herself and his or
          her legal representatives or guardians, that this Agreement shall be interpreted
          by the Committee and that any interpretation by the Committee of the terms of
          this Agreement and any determination made by the Committee pursuant to this
          Agreement shall be final, binding and conclusive.

14. Miscellaneous.

| | (a)       
               This Agreement shall be governed and construed in accordance with the internal
               laws of the State of Wisconsin applicable to contracts made and to be performed
               therein between residents thereof.
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| | (b)       
               This Agreement may not be amended or modified except by the written consent of
               the parties hereto.
| | -------------------------------------------------------------------------------------------------------------------------------------------

| | (c)       
               The captions of this Agreement are inserted for convenience of reference only
               and shall not be taken into account in construing this Agreement.
| | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

IN
WITNESS WHEREOF, the Company has caused this instrument to be executed by its duly
authorized officers and its corporate seal to be hereunto affixed, and the Optionee has
hereunto affixed his or her hand and seal as of the day and year first above written.

| | ALLIANT ENERGY CORPORATION                         
| | ---------------------------------------------------
| |                                                    
| |                                                    
| | By:______________________________________________  
| | Name:____________________________________________  
| | Title:_____________________________________________
| |                                                    
| |                                                    
| | OPTIONEE                                           
| |                                                    
| |                                                    
| | _________________________________________________  
| | Name: [Name of Employee]                           
| | SSN:                                               
| |                                                    
| |                                                    
| | Beneficiary:_______________________________________
| | Address:__________________________________________ 
| | ______________________________________________     
| | SSN or TIN:_______________________________________