The following description of the Wisconsin Energy Corporation (the "Company") Employee Retirement Savings Plan (the "Plan") is provided for general information purposes only. More complete information regarding the Plan's provisions may be found in the Plan document.

General -- The Plan is a defined contribution plan covering all non-represented employees who are employed by a participating company and represented employees who are represented by a union which elected to participate in the Plan, as defined in the Plan document; and who are projected to complete at least 1,000 hours of service within one year from their hire date. The Plan is subject to the provisions of the Employee Retirement Income Security Act of 1974, as amended ("ERISA").

The plan assets are held in a trust as maintained by Fidelity Management Trust Company (the "Trustee").

Effective June 1, 2006, the Plan was amended to offer a Roth 401(k) option where contributions are made on an after-tax basis and are included in current taxable income. Upon distribution, Roth contribution earnings are tax-free. In addition, employee contribution limits increased to 75% of eligible compensation subject to the annual IRS maximum.

An auto-enrollment feature was put into effect on January 1, 2007 for all management employees hired or rehired on or after this date and those represented employees whose unions have adopted it. These employees will be enrolled automatically in the 401(k) Plan at a rate of 3% of their 401(k) eligible wages unless they make an alternate election. In addition, these 401(k) account contributions will increase automatically by 1% in each subsequent year up to 6%. If employees enroll in the 401(k) Plan, but do not designate a desired investment strategy, the Trustee will direct the employee's contributions into the age-appropriate Fidelity Freedom Fund.

Contributions -- Contributions are subject to certain limitations of the Internal Revenue Code ("IRC"). Participants are allowed to make pre-tax and post-tax contributions of up to 75% of their base wages, as defined. Participants may also contribute amounts representing distributions from other qualified defined benefit or defined contribution plans ("rollovers"). The Company matches 50% of participant contributions of up to 6% of wages as defined in the Plan. Effective January 1, 2008, the match for management employees will increase to 100% of the first 1% and 50% of the next 6% of participant contribution. This increase in Company match will also be in effect for those represented employees whose unions have adopted this change, effective as of the date specified in the contract. Company matching contributions are made to the employee stock ownership plan or the Company Common Stock Fund, as the case may be. Additionally, each

Participant Accounts -- Individual accounts are maintained for each of the Plan's participants to reflect the participant's contributions and related employer contributions, as well as the participant's share of the Plan's income and any related administrative expenses. Allocations are based on the proportion that each participant's account balance has to the total of all participants' account balances.

Vesting -- Participants are immediately vested in their contributions plus actual earnings thereon. Upon completion of one year of service or upon attainment of 59-1/2 years of age while in the service of the Company, participants become 100% vested in the Company's matching contributions. Forfeited balances of terminated participants' nonvested accounts are used to reduce future employer contributions. At December 31, 2007 and 2006, forfeited non-vested accounts totaled $21,695 and $9,142, respectively. Total forfeitures used to reduce future employer contributions were $12,148 and $1,550 in 2007 and 2006, respectively.

Investment Options -- The participants' deposits and the Company's annual contributions are paid to the Trustee who invests the deposits, as directed (in whole percentages) by the participant, within prescribed limitations, into various investment funds offered by the Trustee, which includes Company common stock. Company contributions are initially made to the employee stock ownership plan or the Company Common Stock Fund, as the case may be, but can then be transferred to other funds by the participant.

Benefit Payments -- A participant may take a distribution due under the Plan as a single lump-sum cash payment or installment payments over a period not extending beyond the life expectancy of the participant. The full value of a participant's account is automatically distributed through a lump-sum cash payment to the employee or designated beneficiary upon retirement, termination of employment or death, for account balances less than $1,000. Balances between $1,000 and $5,000 are rolled over into an IRA in the employee's name if they have not provided direction for distribution. As the Plan is primarily designed to meet long-term financial needs, employees may permanently withdraw amounts from their accounts under the terms of the Plan's financial hardship withdrawal guidelines. Additionally, participants may withdraw all or a portion of the value of their after-tax contributions; however, these withdrawals are limited to once per Plan year per participant.

Participant Loans -- Participants may borrow from their fund accounts a minimum of $1,000 up to the lesser of 50% of their account balance or $50,000, minus any outstanding loan balances over the past 12 months. Loans are repayable monthly over periods not to exceed five years. The interest rate charged on participant loans is fixed at the beginning of each loan at the then current prime rate plus 1%. The interest paid by a participant on their loan balance is credited directly to their individual account. Interest rates on participant loans ranged from 5.0% to 9.25% at December 31, 2007 and December 31, 2006, respectively.

As of December 31, 2007 and 2006, the Plan held 4,206,005 and 4,568,146 shares, respectively, of Company common stock in the Company Common Stock Fund and the employee stock ownership plan. The Company Common Stock Fund and the employee stock ownership plan are unitized and in total held 8,195,970 and 8,888,015 units as of December 31, 2007 and 2006, respectively.

The following presents individual investments that represent 5 percent or more of the Plan's net assets as of December 31, (in thousands):