April 10, 2006

EXHIBIT I

PRIVATE AND CONFIDENTIAL

April 10, 2006

Plug Power Inc.
000 Xxxxxx-Xxxxxx Xxxx
Xxxxxx, Xxx Xxxx 00000
Attention: President

Re: Disclosure Letter in connection with that certain Stock Purchase Agreement (the “Agreement”), dated as of April 10, 2006, by and between Plug Power Inc. (the “Company”) and Smart Hydrogen Inc. (“Buyer”)

     Pursuant to Section 5.12 of the Agreement, Xxxxx makes the following disclosures to the Company as of the date hereof:

	1.		Buyer is controlled by Xxxxxxxx and Xxxxxxx, each of which owns 49.995% of the total outstanding equity and voting interests of Buyer.
	2.		Xxxxxxxx is wholly-owned and controlled by Norilsk Nickel and other wholly-owned and controlled subsidiaries of Norilsk Nickel. Xxxxxxx Xxxxxx is controlled by Xxxxxxxx X. Xxxxxxx and Xxxxxxx X. Xxxxxxxxx (collectively, the “Interros Principals”), each of whom owns, as of the date of this letter, 27.39% (either directly or indirectly through one or more entities beneficially wholly-owned and controlled by such Person) of the total outstanding equity and voting interests of Norilsk Nickel. As of the Closing Date, Xx. Xxxxxxx and Xx. Xxxxxxxxx will collectively own in excess to 50% of the outstanding equity and voting interests of Norilsk Nickel.
	3.		Interros is controlled by Xx. Xxxxxxx and Xx. Xxxxxxxxx, each of which owns 49.9967% (either directly or indirectly through one or more entities beneficially wholly owned and controlled by such Person) of the total outstanding equity and voting interests of Interros.
	4.		Xxxxxxx is controlled by Xx. Xxxxxxx and Xx. Xxxxxxxxx, each of which owns 49.9967% (either directly or indirectly through one or more entities beneficially wholly owned and controlled by such Person) of the total outstanding equity and voting interests of Xxxxxxx.

     Capitalized terms used herein and not otherwise defined shall have the meanings assigned to such terms in the Agreement. This letter constitutes the “Buyer Disclosure Letter” within the meaning of the Agreement. This letter and all of the information contained herein constitutes “Information” within the meaning of the Buyer NDA. The letter is being provided to the Company in connection with the Transaction and may not be relied upon by any other Person for any other purpose whatsoever.

[REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]

		Very truly yours,
		SMART HYDROGEN INC.
		By:		/s/ Xxxxxx Xxxxxxxxxx
				Xxxxxx Xxxxxxxxxx
				Director

ACKNOWLEDGED AND ACCEPTED:

PLUG POWER INC.

By:		/s/ Xxxxx Xxxxxxxx
Name:		Xxxxx Xxxxxxxx
Title:		CEO and President

Date: April 10, 2006

[Signature page to Smart Hydrogen Disclosure Letter]