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                            December 20, 2021

       Paul Middleton
       Chief Financial Officer
       Plug Power, Inc.
       968 Albany Shaker Road
       Latham, NY 12110

                                                        Re: Plug Power, Inc.
                                                            Form 10-K for the
Fiscal Year Ended December 31, 2020
                                                            Filed May 14, 2021
                                                            File No. 001-34392

       Dear Mr. Middleton:

              We have reviewed your November 16, 2021 response to our comment
letter and have the
       following comments. In some of our comments, we may ask you to provide
us with information
       so we may better understand your disclosure.

              Please respond to these comments within ten business days by
providing the requested
       information or advise us as soon as possible when you will respond. If
you do not believe our
       comments apply to your facts and circumstances, please tell us why in
your response.

             After reviewing your response to these comments, we may have
additional
       comments. Unless we note otherwise, our references to prior comments are
to comments in our
       October 19, 2021 letter.

       Form 10-K for the Fiscal Year Ended December 31, 2020

       Restatement Background, page 3

   1.                                                   We note your responses
to prior comments 2 and 4 and reissue our comments. We
                                                        continue to believe the
information provided in response to these comments is material
                                                        and necessary for your
Form 10-K to be complete. Please amend your filing to provide
                                                        the information
requested in prior comments 2 and 4.
   2.                                                   We have reviewed your
response to comment 3. We note that the ITC is reflected in both
                                                        the equipment and the
future service revenue. Please provide us with a specific and
                                                        comprehensive analysis
of your determination of whether the ITC is a separate
                                                        performance obligation
and how amounts have been allocated to revenue related to the
                                                        ITC. Reference ASC
606-10-25-19 through 22 and ASC 606-10-32-28 or the applicable
                                                        guidance you followed.
 Paul Middleton
Plug Power, Inc.
December 20, 2021
Page 2
Critical Accounting Estimates
Impairment of Long-Lived Assets and PPA Executory Contract Considerations, page
61

3.       We have reviewed your response to comment 5 and have the following
comments:

                We note that the response references    required uptimes.
Please clarify what is
              meant by this term and provide additional details regarding the
products and/or
              services specified in the PPA arrangements and how the contracts
are structured. For
              example, clarify if the PPAs include a specified number of fuel
cells and related
              hydrogen infrastructure that will be provided to the customer.
Also, clarify the nature
              of the customer in each PPA, including whether the customer is at
the corporate level
              or at the individual location.

                Provide additional details regarding your substantive
substitution conclusion. In this
              regard, we note that the response focuses on moving additional
fuel cells to a
              particular customer site but it is unclear how the substitution
provisions work.
              Additionally, tell us whether fuel cells are moved from one
customer location to
              another location for that same customer or whether fuel cells are
moved between two
              distinct customers. Finally, provide additional explanation
regarding how
              you concluded that customers benefit economically from the
substitution as the
              response seems to focus on moving additional fuel cells to a
particular location.

       You may contact Andrew Blume, Staff Accountant, at (202) 551-3254 or
Mark Rakip,
Staff Accountant, at (202) 551-3573 with any questions.



FirstName LastNamePaul Middleton                               Sincerely,
Comapany NamePlug Power, Inc.
                                                               Division of
Corporation Finance
December 20, 2021 Page 2                                       Office of
Manufacturing
FirstName LastName