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                                                                    Exhibit 10.1



                THIRD AMENDMENT TO CREDIT AND SECURITY AGREEMENT

         This Amendment, dated as of April 4, 2003, is made by and between
SOUTHERN FLOW COMPANIES, INC., a Delaware corporation (the "Borrower"), and
WELLS FARGO BUSINESS CREDIT, INC., a Minnesota corporation (the "Lender").

                                    RECITALS

         The Borrower and the Lender are parties to a Credit and Security
Agreement dated as of September 24, 2001, as amended by (i) the First Amendment
to Credit and Security Agreement dated as of November 19, 2002 and (ii) the
Second Amendment to Credit and Security Agreement and Waiver of Defaults dated
as of March 26, 2003 (as so amended, the "Credit Agreement"). Capitalized terms
used in these recitals have the meanings given to them in the Credit Agreement
unless otherwise specified.

         The Borrower has requested that certain amendments be made to the
Credit Agreement, which the Lender is willing to make pursuant to the terms and
conditions set forth herein.

         NOW, THEREFORE, in consideration of the premises and of the mutual
covenants and agreements herein contained, it is agreed as follows:

         1. Defined Terms. Capitalized terms used in this Amendment which are
defined in the Credit Agreement shall have the same meanings as defined therein,
unless otherwise defined herein. In addition, Section 1.1 of the Credit
Agreement is amended by adding or amending, as the case may be, the following
definitions:

         "Borrowing Base" means at any time the lesser of:

         (a) the Maximum Line; or

         (b) subject to change from time to time in the Lender's sole
discretion, the sum of:

                  (i)      85% of Eligible Accounts,

                  (ii)     the lesser of (A) 20% of Eligible Inventory or (B)
                           $200,000, plus

                  (iii)    the Overadvance.

       "Overadvance" means (i) from the date of this Amendment until August 1,
2003, $200,000 and (ii) from August 2, 2003 and thereafter, zero.


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         2. No Other Changes. Except as explicitly amended by this Amendment,
all of the terms and conditions of the Credit Agreement shall remain in full
force and effect and shall apply to any advance or letter of credit thereunder.

         3. Accommodation Fee. The Borrower shall pay the Lender as of the date
hereof a fully earned, non-refundable fee in the amount of $10,000 in
consideration of the Lender's execution and delivery of this Amendment.

         4. Conditions Precedent. This Amendment shall be effective when the
Lender shall have received an executed original hereof, together with each of
the following, each in substance and form acceptable to the Lender in its sole
discretion:

                  (a) The Acknowledgment and Agreement of Guarantors set forth
         at the end of this Amendment, duly executed by each Guarantor.
                  (b) Payment of the fee described in Paragraph 3.
                  (c) Such other matters as the Lender may require.

         5. Representations and Warranties. The Borrower hereby represents and
warrants to the Lender as follows:

                  (a) The Borrower has all requisite power and authority to
         execute this Amendment and to perform all of its obligations
         thereunder, and this Amendment has been duly executed and delivered by
         the Borrower and constitute the legal, valid and binding obligations of
         the Borrower, enforceable in accordance with their terms.

                  (b) The execution, delivery and performance by the Borrower of
         this Amendment has been duly authorized by all necessary corporate
         action and does not (i) require any authorization, consent or approval
         by any governmental department, commission, board, bureau, agency or
         instrumentality, domestic or foreign, (ii) violate any provision of any
         law, rule or regulation or of any order, writ, injunction or decree
         presently in effect, having applicability to the Borrower, or the
         articles of incorporation or by-laws of the Borrower, or (iii) result
         in a breach of or constitute a default under any indenture or loan or
         credit agreement or any other agreement, lease or instrument to which
         the Borrower is a party or by which it or its properties may be bound
         or affected.

                  (c ) All of the representations and warranties contained in
         Article V of the Credit Agreement are correct on and as of the date
         hereof as though made on and as of such date, except to the extent that
         such representations and warranties relate solely to an earlier date.

         6. References. All references in the Credit Agreement to "this
Agreement" shall be deemed to refer to the Credit Agreement as amended hereby;
and any and all references in the Security Documents to the Credit Agreement
shall be deemed to refer to the Credit Agreement as amended hereby.

         7. No Other Waiver. The execution of this Amendment and any documents
related hereto shall not be deemed to be a waiver of any Default or Event of
Default under the Credit Agreement



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or breach, default or event of default under any Security Document or other
document held by the Lender, whether or not known to the Lender and whether or
not existing on the date of this Amendment.

         8. Release. The Borrower and each Guarantor by signing the
Acknowledgment and Agreement of Guarantors set forth below, each hereby
absolutely and unconditionally releases and forever discharges the Lender, and
any and all participants, parent corporations, subsidiary corporations,
affiliated corporations, insurers, indemnitors, successors and assigns thereof,
together with all of the present and former directors, officers, agents and
employees of any of the foregoing, from any and all claims, demands or causes of
action of any kind, nature or description, whether arising in law or equity or
upon contract or tort or under any state or federal law or otherwise, which the
Borrower or such Guarantor has had, now has or has made claim to have against
any such person for or by reason of any act, omission, matter, cause or thing
whatsoever arising from the beginning of time to and including the date of this
Amendment, whether such claims, demands and causes of action are matured or
unmatured or known or unknown.

         9. Costs and Expenses. The Borrower hereby reaffirms its agreement
under the Credit Agreement to pay or reimburse the Lender on demand for all
costs and expenses incurred by the Lender in connection with the Loan Documents,
including without limitation all reasonable fees and disbursements of legal
counsel. Without limiting the generality of the foregoing, the Borrower
specifically agrees to pay all fees and disbursements of counsel to the Lender
for the services performed by such counsel in connection with the preparation of
this Amendment and the documents and instruments incidental hereto. The Borrower
hereby agrees that the Lender may, at any time or from time to time in its sole
discretion and without further authorization by the Borrower, make a loan to the
Borrower under the Credit Agreement, or apply the proceeds of any loan, for the
purpose of paying any such fees, disbursements, costs and expenses and the fee
required under Paragraph 3 hereof.

         10. Miscellaneous. This Amendment and the Acknowledgment and Agreement
of Guarantors may be executed in any number of counterparts, each of which when
so executed and delivered shall be deemed an original and all of which
counterparts, taken together, shall constitute one and the same instrument.


         IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be
duly executed as of the date first written above.

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WELLS FARGO BUSINESS CREDIT, INC.           SOUTHERN FLOW COMPANIES, INC.



By:      /s/ Patti Scudder                  By:      /s/ A. Bradley Gabbard
         --------------------------                  ----------------------
Name:    Patti Scudder                      Name:    A. Bradley Gabbard
Its:     Commercial Banking Officer         Its:     Chief Financial Officer


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                   ACKNOWLEDGMENT AND AGREEMENT OF GUARANTORS

         The undersigned, each a guarantor of the indebtedness of Southern Flow
Companies, Inc. (the "Borrower") to Wells Fargo Business Credit, Inc. (the
"Lender") pursuant to a separate Guaranty dated as of September 24, 2001 (the
"Guaranty"), each hereby (i) acknowledges receipt of the foregoing Amendment;
(ii) consents to the terms (including without limitation the release set forth
in Paragraph 8 of the Amendment) and execution thereof; (iii) reaffirms its
obligations to the Lender pursuant to the terms of its Guaranty; and (iv)
acknowledges that the Lender may amend, restate, extend, renew or otherwise
modify the Credit Agreement and any indebtedness or agreement of the Borrower,
or enter into any agreement or extend additional or other credit accommodations,
without notifying or obtaining the consent of the undersigned and without
impairing the liability of the undersigned under its Guaranty for all of the
Borrower's present and future indebtedness to the Lender.

                                    METRETEK, INCORPORATED



                                    By:      /s/ A. Bradley Gabbard
                                             --------------------------------
                                    Name:    A. Bradley Gabbard
                                    Its:     Chief Financial Officer


                                    METRETEK TECHNOLOGIES, INC.



                                    By:      /s/ A. Bradley Gabbard
                                             --------------------------------
                                    Name:    A. Bradley Gabbard
                                    Its:     Executive Vice President

                                    POWERSECURE, INC.



                                    By:      /s/ A. Bradley Gabbard
                                             --------------------------------
                                    Name:    A. Bradley Gabbard
                                    Its:     Chief Financial Officer



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