<PAGE>
Exhibit 5
Hale and Dorr LLP
One Freedom Square
11951 Freedom Drive, Suite 1400
Reston, VA 20190
(703) 654-7000/Fax (703) 654-7100
September 29, 2000
Proton Energy Systems, Inc.
50 Inwood Road,
Rocky Hill, CT 06067
Re: Registration Statement on Form S-8
----------------------------------
Ladies and Gentlemen:
This opinion is furnished to you in connection with a Registration
Statement on Form S-8 (the "Registration Statement") to be filed with the
Securities and Exchange Commission (the "Commission") under the Securities Act
of 1933, as amended (the "Securities Act"), for the registration of an aggregate
of 7,901,689 shares of Common Stock, $.01 par value per share (the "Shares"), of
Proton Energy Systems, Inc., a Delaware corporation (the "Company"), issuable
pursuant to the Company's 1996 Stock Option Plan, 2000 Stock Incentive Plan and
the 2000 Employee Stock Purchase Plan (collectively, the "Plans").
We have examined the Certificate of Incorporation and the By-Laws of the
Company, each as amended and restated to date, and originals, or copies
certified to our satisfaction, of all pertinent records of the meetings of the
directors and stockholders of the Company, the Registration Statement and such
other documents relating to the Company as we have deemed material for the
purposes of this opinion.
In examination of the foregoing documents, we have assumed the genuineness
of all signatures, the authenticity of all documents submitted to us as
originals, the conformity to original documents of all documents submitted to us
as copies, the authenticity of the originals of such latter documents and the
legal competence of all signatories to such documents.
We assume that the appropriate action will be taken, prior to the offer and
sale of the Shares in accordance with the Plans, to register and qualify the
Shares for sale under all applicable state securities or "blue sky" laws.
We express no opinion herein as to the laws of any state or jurisdiction
other than the state laws of the Commonwealth of Massachusetts, the Delaware
General Corporation Law statute and the federal laws of the United States of
America.
Based upon and subject to the foregoing, we are of the opinion that the
Shares have been duly authorized for issuance and the Shares, when issued and
paid for in accordance with the terms of the Plans, will be validly issued,
fully paid and nonassessable.
<PAGE>
It is understood that this opinion is to be used only in connection with
the offer and sale of the Shares while the Registration Statement is in effect.
Please note that we are opining only as to the matters expressly set forth
herein, and no opinion should be inferred as to any other matters.
We hereby consent to the filing of this opinion with the Commission as an
exhibit to the Registration Statement in accordance with the requirements of
Item 601(b)(5) of Regulation S-K under the Securities Act. In giving such
consent, we do not hereby admit that we are in the category of persons whose
consent is required under Section 7 of the Securities Act or the rules and
regulations of the Commission.
Very truly yours,
/s/ Hale and Dorr LLP
HALE AND DORR LLP
