EXHIBIT 23

Consent of Independent Registered Public Accounting Firm

We hereby consent to the incorporation by reference in the Registration Statements on Form S-3 (Nos. 333-204422, 333-213628, and 333-48587), and Form S-8 (Nos. 333-202184, 333-204436, 333-56094, 333-72768, 333-81183, 333-89356, 333-101472, 333-110662, 333-146170, 333-165640, and 333-172464) of FirstEnergy Corp. of our report dated February 21, 2017, relating to the financial statements, financial statement schedule, and the effectiveness of internal control over financial reporting, which appears in this Form 10-K.

/s/ PricewaterhouseCoopers LLP

Cleveland, Ohio

February 21, 2017

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