July 24, 2008

Plaintree Systems Inc Announces the Award of a Second Phase of a Large Mining Stockpile Cover Contract in British Columbia, Canada

OTTAWA, July 24 /PRNewswire-FirstCall/ -- Plaintree Systems Inc. (the "Company" or "Plaintree") today announced that its steel division, Triodetic (http://www.triodetic.com/), has been awarded the second phase of a contract for the engineering, supply and supervision of installation of two industrial mining dome enclosures in British Columbia, Canada, from one of the world's largest mining companies. The first phase of the contract, awarded to Triodetic on October 3, 2007, was for one dome with a value of $2,100,000 CND that is now nearing on-site completion.

The second phase of the contract is for engineering, supply and supervision of installation of 2 domes, having a value in excess of $5ÃӚ“šÃƒÆ’“šÃƒ“š millionÃӚ“šÃƒÆ’“šÃƒ“š CND. Plaintree expects that the first of the two additional domes to be delivered in the 2008 calendar year and the second dome to be delivered early during the 2009 calendar year.

"Triodetic has over 40 years of experience as a major supplier of industrial mining enclosures and this contract is an excellent example of Triodetic's capabilities" said Plaintree CEO David Watson. "The domes are each 105 meters (345 feet) in diameter and are installed on working stockpiles. Each one of these domes can accommodate a Boeing 787 Dreamliner - the world's largest aircraft. It is projects like this that help us maintain the Triodetic name as the "go to people" for large difficult mining structures". David Watson also stated that: "This contract is an excellent example of the value creation to Plaintree's shareholders that will now be achieved as a result of the Triodetic and Hypernetics acquisitions earlier this year".

   About Plaintree Systems   -----------------------   

Ottawa-based, Plaintree Systems Inc. (http://www.plaintree.com/), founded in 1988 has three divisions. The first provides management services and specializes in developing optical wireless communications equipment for the local area, wide area, voice, Internet and security networks. The second, Hypernetics, manufactures avionic components for many of the largest aerospace OEM's. The third, Triodetic, is a design/build manufacturer of steel, aluminum and stainless steel specialty structures.

Plaintree is publicly quoted in the U.S. on the OTC BB (PTEEF.OB), with 12,522,143 common shares (post-consolidation) and 18,325 class A preferred shares outstanding.

This press release may include statements that are forward-looking and based on current expectations. The actual results of the company may differ materially from current expectations. The business of the company is subject to many risks and uncertainties, including changes in markets for the company's products, delays in product development and introduction to manufacturing and intense competition. For a more detailed discussion of the risks and uncertainties related to the company's business, please refer to documents filed by the company on SEDAR (http://www.sedar.com/) including the Company's proxy circular dated January 21, 2008 in relation to its annual and special meeting of shareholders held on March 18, 2008 and with the U.S. Securities and Exchange Commission, including the Company's Form 20-F dated September 28, 2007.

Plaintree Systems Inc.

CONTACT: Lynn Saunders, (613) 623-3434 ext 3002