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        <link:definition>2105100 - Disclosure - INVENTORIES, NET</link:definition>
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        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
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        <link:definition>2410402 - Disclosure - NET LOSS PER COMMON SHARE (Earnings per Share) (Details)</link:definition>
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        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
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        <link:definition>2410403 - Disclosure - NET LOSS PER COMMON SHARE (Potentially Dilutive Securities) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
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        <link:usedOn>link:calculationLink</link:usedOn>
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        <link:definition>2108100 - Disclosure - OTHER INTANGIBLE ASSETS, NET</link:definition>
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        <link:definition>2408402 - Disclosure - OTHER INTANGIBLE ASSETS, NET (Components and Changes in Other Intangible Assets) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
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        <link:definition>2408404 - Disclosure - OTHER INTANGIBLE ASSETS, NET (Future Amortization by Fiscal Year) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
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        <link:definition>2408403 - Disclosure - OTHER INTANGIBLE ASSETS, NET (Narrative) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
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      <link:roleType id="OtherIntangibleAssetsNetTables" roleURI="http://www.oesx.com/role/OtherIntangibleAssetsNetTables">
        <link:definition>2308301 - Disclosure - OTHER INTANGIBLE ASSETS, NET (Tables)</link:definition>
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        <link:usedOn>link:calculationLink</link:usedOn>
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        <link:definition>2106100 - Disclosure - PREPAID EXPENSES AND OTHER CURRENT ASSETS</link:definition>
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        <link:definition>2406402 - Disclosure - PREPAID EXPENSES AND OTHER CURRENT ASSETS (Details)</link:definition>
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        <link:usedOn>link:presentationLink</link:usedOn>
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        <link:definition>2407403 - Disclosure - PROPERTY AND EQUIPMENT, NET (Equipment under Capital Leases) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
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        <link:definition>2407404 - Disclosure - PROPERTY AND EQUIPMENT, NET (Narrative) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
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        <link:definition>2407402 - Disclosure - PROPERTY AND EQUIPMENT, NET (Summary of Property and Equipment) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
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        <link:definition>2307301 - Disclosure - PROPERTY AND EQUIPMENT, NET (Tables)</link:definition>
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        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
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        <link:definition>2111100 - Disclosure - RELATED PARTY TRANSACTIONS</link:definition>
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        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
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        <link:definition>2411401 - Disclosure - RELATED PARTY TRANSACTIONS (Details)</link:definition>
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        <link:definition>2118100 - Disclosure - REORGANIZATION OF BUSINESS</link:definition>
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      <link:roleType id="ReorganizationOfBusinessRestructuringBySegmentDetails" roleURI="http://www.oesx.com/role/ReorganizationOfBusinessRestructuringBySegmentDetails">
        <link:definition>2418403 - Disclosure - REORGANIZATION OF BUSINESS (Restructuring by Segment) (Details)</link:definition>
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        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
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        <link:definition>2418402 - Disclosure - REORGANIZATION OF BUSINESS (Restructuring by Statement of Operations Location) (Details)</link:definition>
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        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
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        <link:usedOn>link:calculationLink</link:usedOn>
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