Shareholder Update Issued for U. S. Sustainable Energy Corporation

NATCHEZ, MS -- U.S. Sustainable Energy (PINKSHEETS: USSE) President & CEO, John H. Rivera, issued today the following letter and update to the shareholders of USSEC.

Dear Shareholders,

Our first operating period has seen exceptional positive movement, internal achievements, and company milestones being met as we lay the foundation for our highly anticipated market entrance. The new Natchez bioenergy facility, completion of the first full-sized reactor, process advancements for lower-cost energy production, our expanding and highly talented management team, valued strategic partnerships, global brand visibility -- we’ve come a long way since presenting the technology at our international demonstration in Vidalia towards the end of last year.

With the last four months bearing witness to more than 6,000 queries for our technology, it has provided a needed framework to better identify and gauge USSEC’s value proposition against our original assumptions. The market has been very clear: Our biofuel and energy processes represent a fundamental change in technological capability to do more than just talk about reducing dependence on petroleum and harmful gas emissions. The application of our green energy models are giving legislators, municipalities and utility companies the ability to plan for genuine change -- without compromise from cost or efficiency barriers as typical transition-based obstacles.

This has expectedly put a tremendous amount of responsibility onto our shoulders, as our first production contracts will set clear precedence and a new bar for what is possible within the green energy field. The value proposition of our biofuel yield alone, when combined with large-scale power facilities, redefines everything that academia has past known regarding the feasibility of green power. Subsequently our technology can be matched with the planning of progressive leaders, allowing states and nations to become early adopters of fully renewable energy to meet the inevitable movement towards federally mandated compliance markets for environmental reasons.

Through this process our management team has a clear and important obligation to shareholders: to ensure that the associated value we place on the price of our biofuel, energy reduction processes, fuel and additive byproducts, and ultimately the price per kilowatt of every green energy unit offered matches our role as an emerging leader with the capability to reduce foreign oil dependency and improve our environment.

Our actions should very well determine future subsidies and initiatives offered to accelerate area-based green energy conversions. Even small undertakings of applying our biomass resources and technology to energy production are considerably larger than external achievements of the past, allowing us to quickly open and create new accessible markets for the free trading and application of green energy investments.

A Recap of Our First Days

-- U.S. Sustainable Energy established its base of operation in December
2006 within our first bioenergy facility in Natchez, Mississippi, a 35 acre
/ 447,800 sq. foot operations center with railcar infrastructure and
waterfront loading docks. From this location we’ve undertaken the final
research and process configurations needed to proceed with development of
our first 200 green fuel reactors -- for an initial production goal of 1.2
million gallons of USSEC biofuel daily.

-- Including our biofuel demonstration held in October 2006, U.S.
Sustainable has entertained and hosted more than 1500 guests, including
company shareholders, media and journalists, power companies, officials,
universities, and a host of academia working to apply USSEC’s discoveries
worldwide. Our team has facilitated nearly 300 successful biofuel
demonstrations showcasing process refinements, unique fuel properties, and
our application to diesel and gasoline engines without the need for motor
modifications.

-- February 2007 saw the formal launch of Sustainable Power Corp.
(PINKSHEETS: SSTP), a USSEC-related company appointed as the official
International Green Power Provider for U.S. Sustainable. The company is
focused on all aspects of power generation and facility management -
ranging from feasibility studies, project financing, and site design, to
full scale implementation and turnkey plant construction. Sustainable Power
started its operations by receiving interest for more than 60,000 Megawatts
(60 Gigawatts) of green power plant facilities in February alone, a clear
testament to the worldwide demand for USSEC’s energy processes and the
focus on creating clean power from renewable energy.

-- USSEC has met with various members of congress, including high
profiled meetings with Governors, Senators, Green Energy Lobbyists, the
USDA, and a long list of distinguished organizations (Harvard, National
Science Foundation, Bank of America, Sovereign, etc.). Our activities have
ensured that the USSEC biofuel discovery, our energy processes, and the
capabilities of Sustainable Power Corp. are positioned to support state and
federally mandated green power initiatives, paving the way for a future
filled with green energy plants that offer a superior value proposition to
any other alternative energy source available.

-- U.S. Sustainable Energy reached a definitive agreement to acquire 900
million shares of Diversified Ethanol, Inc., and United Ethanol Group, Inc.
Utilizing USSEC energy processes and existing technologies within United
Ethanol Group, the company will be able to provide turnkey plant solutions
that generate ethanol at a significant cost reduction over any alternative
production process in the market. This year alone the company has received
plant requests totaling more than 15 million gallons of ethanol production
daily, and final plant configurations with pricing are being completed for
release later this month.

-- Sustainable Power Corp. and U.S. Sustainable Energy have begun the
process for providing turnkey engineering, project analysis, and
construction costs for more than 6,000 Megawatts of green energy power
plant facilities. To date nearly three dozen formal quotes or starting cost
projections have been created, including power projects domestically within
Massachusetts, Pennsylvania, Maryland, New Hampshire, Connecticut, New
Jersey, New York, Mississippi, and Louisiana. On an international level,
engineering presentations are being drafted or have been submitted for
formal proposal requests in nearly two dozen countries, including Italy,
India, Pakistan, China, The Americas, and The Netherlands.

U.S. Sustainable Energy Corp. will continue with our commitment to attract and recruit the very best in talent, experience, and innovation, providing a management team capable of achieving extraordinary results from opportunities presented. We see ourselves already positioned as a future leader in the emerging green fuel and clean energy sectors, with opportunities to extend our energy reduction processes to help numerous bioenergy companies gain better access to the market. We believe confidently that USSEC can help pave the way for dozens of innovative organizations and solution providers in the future, adding viable profit centers to our base and future umbrella, along with direct and lateral benefits to our highly valued shareholder base.
We look eagerly forward to sharing all of the upsides associated with 2007 and beyond.

Yours respectfully,

John H. Rivera
Chairman and Chief Executive Officer
U.S. Sustainable Energy Corp.
About U.S. Sustainable Energy Corp.
U.S. Sustainable Energy offers a revolutionary new energy process that creates three times more fuel per feedstock unit than any other biofuel process. The company has engineered the first bio-renewable fuel able to serve as a replacement to diesel, with none of the negative traits associated with competitive green fuels. The USSEC biofuel is furthermore created at a nominal cost as the byproduct of producing organic fertilizer from recycled waste products, a discovery made during research into agricultural biomass now known as the “Rivera Process.” The technology offers a solution to foreign oil dependence, significant reduction to the cost of electricity and ethanol production, and the eventual reversal of greenhouse gas emissions.

Management and current operations are focused on leveraging the superior performance and low cost of the fertilizer, biogas and biofuel within bundled plant operations, turnkey energy contracts, ethanol production, and other critical applications that rely on energy as a major cost component. For more information please visit www.ussec.us.

Forward-Looking Statements

Investors are cautioned that certain statements contained in this document as well as some statements in periodic press release and some oral statements are “Forward-Looking Statements” within the meaning of the Private Securities Litigation Reform Act of 1995 (the “Act”). Forward-Looking statements include statements which are predictive in nature, which depend upon or refer to future events or conditions, which include words such as “believes,” “anticipates,” “intends,” “plans,” “expects,” and similar expressions. In addition, any statements concerning future financial performance (including future revenues, earnings or growth rates), ongoing business strategies or prospects, and possible future actions, which may be provided by management, are also forward-looking statements as defined by the Act. Forward-Looking statements involve known and unknown risks, uncertainties, and other factors which may cause the actual results, performance or achievements of the Company to materially differ from any future results, performance or achievements expressed or implied by such forward-looking statements and to vary significantly from reporting period to reporting period. Although management believes that the assumptions will, in fact, prove to be correct or that actual future results will not be different from the expectations expressed in this report. These statements are not guarantees of future performance and the Company has no specific intention to update these statements.