Exhibit 23

Consent of Independent Registered Public Accounting Firm

We consent to the incorporation by reference in the Registration Statement (Form S-8 No. 333-136443) pertaining to the Big Ridge, Inc. 401(k) Profit Sharing Plan and Trust of our report dated June 17, 2011, with respect to the financial statements and schedule of Big Ridge, Inc. 401(k) Profit Sharing Plan and Trust included in this Annual Report (Form 11-K) for the year ended December 31, 2010, filed with the Securities and Exchange Commission.

/s/ Ernst & Young LLP  

St. Louis, Missouri
June 17, 2011