Doughty Hanson Purchases 50,000 Preferred Shares of Sustainable Energy

TORONTO, ONTARIO--(Marketwire - Dec. 21, 2011) - Sustainable Energy Technology Ltd. (TSX VENTURE:STG) ("Sustainable Energy") announced today that Doughty Hanson purchased 50,000 First Preferred Shares Series 12 under a previously announced Equity Commitment Agreement for a total consideration of $500,000.

The Series 12 shares are convertible into Common Shares of Sustainable Energy at $0.10 per share or at $0.08 per share if the shareholders approve a special resolution to consolidate the common share capital on the basis of up to ten old shares for one new share with the exact consolidation basis to be determined by the Board of Directors to be in the best interests of the Company and its shareholders. The Company intends to seek such a resolution at the next Annual General Meeting of the Shareholders.

About Doughty Hanson: Doughty Hanson (www.doughtyhanson.com) is one of Europe's most successful independent private equity firms. Since 1985, Doughty Hanson has undertaken more than 118 investments with an aggregate acquisition value in excess of €28 billion. Doughty Hanson employs over 50 investment professionals of 15 nationalities, located in offices in London, San Francisco, Frankfurt, Madrid, Milan, Munich, Paris and Stockholm.

About Sustainable Energy:

Sustainable Energy (www.SustainableEnergy.com) is a Canadian solar inverter company which supplies Canada, the U.S. and Europe. The Company's patented inverter technologies are a breakthrough in power inverter design and capabilities for all forms of distributed generation and smart grid applications. The PARALEX inverter is the industry's only grid-interactive solar inverter which enables a "parallel" solar PV system architecture in higher power ratings at a cost and serviceability factor that is comparable to conventional string inverters in the market.

Forward Looking Information

The reader is advised that some of the information herein may constitute forward-looking statements within the meaning assigned by National Instruments 51-102 and other relevant securities legislation. In particular, we include: statements concerning the impact of our technology on solar PV system performance; and statements concerning demand for products; Forward-looking information is not a guarantee of future performance and involves a number of risks and uncertainties.

Many factors could cause the Company's actual results, performance or achievements, or future events or developments, to differ materially from those expressed or implied by the forward-looking information. Readers are cautioned not to place undue reliance on forward-looking information, which speaks only as of the date hereof. Readers are also directed to the Risk Factors section of the Company's current Annual Information Form which may be found on its website or at www.sedar.com The Company does not undertake any obligation to release publicly any revisions to forward-looking information contained herein to reflect events or circumstances that occur after the date hereof or to reflect the occurrence of unanticipated events, except as may be required under applicable securities laws.