EXHIBIT (a)(5)(i)

                           Offer to Purchase for Cash
                 Any and All Outstanding Shares of Common Stock
                                       of
                            HIGH PLAINS CORPORATION
                                       at
                             $5.6358 Net Per Share
                                       by
                      ASA ENVIRONMENT & ENERGY HOLDING AG,
                     an indirect wholly owned subsidiary of
                                 ABENGOA, S.A.

         THE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT 12:00 MIDNIGHT,
               NEW YORK CITY TIME, ON MONDAY, DECEMBER 17, 2001,
                         UNLESS THE OFFER IS EXTENDED.

                                                               November 16, 2001

To Brokers, Dealers, Commercial Banks,
Trust Companies and Nominees:

   We have been engaged to act as Dealer Manager in connection with the tender
offer by ASA Environment & Energy Holding AG, a company organized under the
laws of Switzerland (the "Purchaser"), which is an indirect wholly owned
subsidiary of Abengoa, S.A., a company organized under the laws of Spain, to
purchase any and all outstanding shares of the common stock, par value $.10 per
share (the "Shares"), of High Plains Corporation, a Kansas corporation (the
"Company"), at a price of $5.6358 per Share, net to the seller in cash, less
any required withholding of taxes and without the payment of interest, upon the
terms and conditions set forth in the Offer to Purchase and in the related
Letter of Transmittal (which, together with any amendments or supplements
thereto, collectively constitute the "Offer"). Please furnish copies of the
enclosed materials to those of your clients for whom you hold Shares registered
in your name or in the name of your nominee.

   The Offer is conditioned upon, among other things, (i) there being validly
tendered and not withdrawn on the expiration date of the Offer a number of
Shares equal to or greater than 81% of the total Shares then issued and
outstanding, and (ii) the satisfaction of certain other terms and conditions.

   For your information and for forwarding to your clients, we are enclosing
the following documents:

  (1) The Offer to Purchase, dated November 16, 2001;

  (2) Letter of Transmittal to tender Shares for your use and for the
      information of your clients (originally signed facsimile copies of the
      Letter of Transmittal may be used to tender Shares);

  (3) The Notice of Guaranteed Delivery for Shares to be used to accept the
      Offer if certificates for Shares are not immediately available or if
      the procedure for book-entry transfer cannot be completed on a timely
      basis or if time will not permit certificates for Shares and all
      required documents to reach the American Stock Transfer & Trust
      Company, N.A. (the "Depositary") prior to the Expiration Date (as
      defined in the Offer to Purchase) of the Offer;

  (4) Letter which may be sent to your clients for whose accounts you hold
      Shares registered in your name (or in the name of your nominee), with
      space provided for obtaining such clients' instructions with regard to
      the Offer;

  (5) The Letter to Stockholders of the Company from Mr. Gary R. Smith,
      President and Chief Executive Officer of the Company, accompanied by
      the Company's Solicitation/ Recommendation Statement on Schedule 14D-9;

  (6) Guidelines of the Internal Revenue Service for certification of
      Taxpayer Identification Number on Substitute Form W-9; and

  (7) Return envelope addressed to the Depositary.


   YOUR PROMPT ACTION IS REQUESTED. WE URGE YOU TO CONTACT YOUR CLIENTS
PROMPTLY. PLEASE NOTE THAT THE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT 12:00
MIDNIGHT, NEW YORK CITY TIME, ON MONDAY, DECEMBER 17, 2001, UNLESS THE OFFER IS
EXTENDED.

   In order for Shares to be validly tendered pursuant to the Offer, (i) a duly
executed and properly completed Letter of Transmittal (or an originally signed
facsimile copy thereof) together with any required signature guarantees, or an
"agent's message" (as defined in the Offer to Purchase) in connection with a
book-entry delivery of Shares, and other documents required by the Letter of
Transmittal must be received by the Depositary on or prior to the Expiration
Date, and (ii) either certificates representing tendered Shares along with the
Letter of Transmittal (or an originally signed facsimile copy thereof) must be
received by the Depositary, or such Shares must be tendered by book-entry
transfer into the Depositary's account maintained at the "book-entry transfer
facility" (as described in the Offer to Purchase), and Book-Entry Confirmation
must be received by the Depositary, all in accordance with the instructions set
forth in the Letter of Transmittal and the Offer to Purchase.

   If holders of Shares wish to tender, but it is impractical for them to
forward their certificates for Shares, or if the procedure for book-entry
transfer cannot be completed on a timely basis, or if time will not permit all
required documents to reach the Depositary prior to the Expiration Date of the
Offer, a tender may be effected by following the guaranteed delivery procedures
set forth in Section 2 of the Offer to Purchase.

   The Purchaser will not pay any commissions or fees to any broker, dealer or
other person (other than the Information Agent and the Dealer Manager, as
described in the Offer to Purchase) for soliciting tenders of Shares pursuant
to the Offer. The Purchaser will, however, upon request, reimburse you for
customary clerical and mailing expenses incurred by you in forwarding any of
the enclosed materials to your clients. The Purchaser will pay or cause to be
paid any stock transfer taxes payable on the transfer of Shares to it, except
as otherwise provided in Instruction 6 of the Letter of Transmittal.

   Any inquiries you may have with respect to the Offer should be addressed to
the Information Agent or the Dealer Manager at their respective addresses and
telephone numbers set forth on the back cover of the Offer to Purchase.

   Additional copies of the enclosed materials may be obtained from the
Information Agent, at the address and telephone number set forth on the back
cover of the Offer to Purchase.

                                          Very truly yours,

                                          Banc of America Securities LLC
                                          as Dealer Manager
                                          9 West 57th Street
                                          New York, NY 10019
                                          Call: (212) 583-8537

   NOTHING CONTAINED HEREIN OR IN THE ENCLOSED DOCUMENTS SHALL CONSTITUTE YOU
OR ANY OTHER PERSON THE AGENT OF ABENGOA, THE PURCHASER, THE COMPANY, THE
DEALER MANAGER, THE INFORMATION AGENT OR THE DEPOSITARY, OR ANY AFFILIATE OF
ANY OF THE FOREGOING, OR AUTHORIZE YOU OR ANY OTHER PERSON TO MAKE STATEMENTS
OR USE ANY MATERIAL ON THEIR BEHALF WITH RESPECT TO THE OFFER, OTHER THAN THE
MATERIAL ENCLOSED HEREWITH AND THE STATEMENTS SPECIFICALLY SET FORTH IN SUCH
MATERIAL.

Enclosures