Summary Presentation ENVIRONMENTAL POWER CORPORATION Underwriter – B.C. Ziegler and Company Member SIPC and FINRA NASDAQ: EPG Issuer Free Writing Prospectus Pursuant to Rule 433 under the Securities Act of 1933 Registration Statement on Form S-3: No 333-152807 Environmental Power Corporation has filed a registration statement (including a prospectus) with the SEC for the offering to which this communication relates. Before you invest, you should read the prospectus in that registration statement and other documents Environmental Power has filed with the SEC for more complete information about Environmental Power and this offering. You may get these documents for free by visiting EDGAR on the SEC Web site at www.sec.gov. Alternatively, Environmental Power and the underwriter will arrange to send you the prospectus if you request it by calling (888) 884-8339.

Environmental Power Corporation Safe Harbor Statement The Private Securities Litigation Reform Act of 1995, referred to as the PSLRA, provides a "safe harbor" for forward-looking statements. Certain statements contained in this presentation, such as statements concerning planned manure-to-energy systems, our sales pipeline, our backlog, our projected sales and financial performance, statements containing the words "may," "assumes," "forecasts," "positions," "predicts," "strategy," "will," "expects," "estimates," "anticipates," "believes," "projects," "intends," "plans," "budgets," "potential," "continue," "targets" "proposed," and variations thereof, and other statements contained in this presentation regarding matters that are not historical facts are forward-looking statements as such term is defined in the PSLRA. Because such statements involve risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. Factors that could cause actual results to differ materially include, but are not limited to: uncertainties involving development-stage companies; uncertainties regarding project financing, the lack of binding commitments and/or the need to negotiate and execute definitive agreements for the construction and financing of projects, the sale of project output, the supply of substrate and other requirements and for other matters; financing and cash flow requirements and uncertainties; inexperience with the development of multi-digester projects; risks relating to fluctuations in the price of commodity fuels like natural gas, and our inexperience with managing such risks; difficulties involved in developing and executing a business plan; difficulties and uncertainties regarding acquisitions; technological uncertainties; including those relating to competing products and technologies; risks relating to managing and integrating acquired businesses; unpredictable developments; including plant outages and repair requirements; the difficulty of estimating construction, development, repair and maintenance costs and timeframes; the uncertainties involved in estimating insurance and implied warranty recoveries, if any; the inability to predict the course or outcome of any negotiations with parties involved with our projects; uncertainties relating to general economic and industry conditions, and the amount and rate of growth in expenses; uncertainties relating to government and regulatory policies and the legal environment; uncertainties relating to the availability of tax credits, deductions, rebates and similar incentives; intellectual property issues; the competitive environment in which Environmental Power Corporation and its subsidiaries operate and other factors, including those described in the prospectus relating to the offering to which this presentation relates, well as in other filings we make with the Securities and Exchange Commission. Readers are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date that they are made. We undertake no obligation to publicly update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.

2 2 Overview • Environmental Power Corporation (“EPC”) owns and operates proven commercial scale renewable energy facilities producing a versatile methane-rich biogas from waste products consisting of agricultural livestock and other organic wastes. • EPC has a proven track record and is a leader in the biogas based renewable energy market and evolving carbon credit market. Market Drivers First Mover Status Unique Offering – Projects “Ready to Go” • Unique opportunity to provide project dedicated funds at a market coupon rate and participate in equity upside. • High and volatile energy prices, growing renewable energy demand (RPS), increasing environmental concerns (carbon emissions) and increasing regulation of agricultural waste have led to increased interest in EPC’s renewable product. Environmental Power Corporation Agenda

3 3 Environmental Power Corporation Process Overview

4 Environmental Power Corporation Advantages of Biogas 4 Versatility Income Alternative Security of Supply • Biogas can be used to displace an array of conventional fuels. • Infrastructure already exists vs. other renewables • Provides income diversification and cost savings for farmers • Reduces dependence on fossil fuels and is a domestic supply of energy • Produces energy when needed, rather than when available unlike wind & solar which are intermittent High Economic Efficiency • Does not require government subsidies • Production efficiency is significantly higher than other biofuels • Addresses farms nutrient management concerns. • Biogas process sequesters methane; 21 times the effect of carbon dioxide as a greenhouse gas • Waste products (manure and other organic wastes) are the feedstock; not dependent on food crops • Non-depleting asset utilizing waste streams Good for Environment Waste to Energy Renewable Output available 24/7

5 5 Environmental Power Corporation Confluence of Agriculture and Energy • Agriculture – Outsourcing of manure management issues – Alignment of Long-Term Interest • Reduced farm operating/capital costs • Lease payment for the site of facilities • Project profit sharing with local farmers – By-products can be used as bedding for animals and liquid fertilizer add value to farm; potential third party sales • Energy – Useful renewable energy product (Renewable Portfolio Standards, state mandates, Renewable Energy Credits, etc.) - Most projects expected to qualify for salable carbon credits Solutions that are clean, proven, cost-effective and operate at the confluence of the agricultural and energy markets: Environment Ag Energy

6 EPC produces pipeline-quality natural gas . . . with renewable attributes • EPG is essentially a renewable exploration and production natural-gas company with some key differences: - No exploration risk - No drilling risk - No dry holes - Non depleting resource Also an active participant in the evolving carbon credit market Environmental Power Corporation EPC as a Renewable E&P Play

7 7 Environmental Power Corporation Operating Facilities Five Star Facility – Elk Mound, WI Commercial Operation: Q1 2005 750kw Wild Rose Facility – La Farge, WI Commercial Operation: Q2 2005 750kw Norswiss Facility – Rice Lake, WI Commercial Operation: Q4 2005 850kw Huckabay Ridge, Texas • Largest Renewable Natural Gas (RNG ® ) facility of its kind in North America • Commercial Operation: January 14, 2008 • 635,000 MMBtu/yr RNG ® production target – Enough natural gas to heat approximately 7,000 Midwestern homes for the winter

8 Wisconsin Dairy Power Facilities • Facilities have demonstrated sustained reliability at or above expected levels Huckabay Ridge, Texas Renewable Natural Gas Facility • First large scale facility to produce pipeline-quality natural gas • Biogas production has exceeded target levels • Currently finishing substantial reconstruction of gas clean up system to correct design and equipment deficiencies • Improvements being implemented for extreme weather conditions and pressure controls • Above improvements to be completed November 2008 Environmental Power Corporation Operating Experience 8

Valuable Strategic Relationships Cargill – Provider of food, agricultural and other products and services Business Development Agreement to accelerate market penetration PG&E – Distributor of natural gas and electricity focused on renewable energy Long-term purchase and gas distribution agreements Provides off-take and pipeline access in critical markets Dairyland Power – Provider of electricity generation and transmission services Biogas offtake on three initial facilities in Wisconsin (proven platform for biogas production and electric generation) Liquid Environmental – Major US grease haulers and processors Contracted substrate supplier providing large supplies of substrate Texas Gas Service – Third largest natural gas distribution company in Texas Established agreement to purchase RNG ® from Texas projects

10 Environmental Power Corporation Executive Team Finance Accounting Treasury Human Resources IT Project Cost Control Investor Relations Public Relations Corporate Sec. Legal Ethics Risk Mgmt. Insurance E/H/S/Q Government Affairs Growth Team Bus. Dev. Mkt. Dev. Project Dev. Project Execution Strategic Alliances Carbon Strategy Operations Plant Ops. Substrate Logistics Plant Betterment Plant E/H/S Rich Kessel CEO and President EPC and Microgy, Inc. Micky Thomas Senior VP & Chief Financial Officer Dennis Haines VP & General Counsel Mike Newman VP Operations Michael Hvisdos Executive Vice President Growth Team

11 11 • Debt Financing in place – To date, $130 million of tax exempt debt financing has been raised from institutional lenders in support of construction of these projects. – Investors in the 2006 Texas bond issue purchased additional California bonds in September 2008 – Tax exempt debt financing required analysis by independent third party experts: • Economic Analysis – SJH, a leading Ag Consultant • Technical/Operations Analysis – RW Beck, a leading independent engineering consulting firm • Permits in place – All necessary permits to begin construction are in place for identified Texas, California and Nebraska projects • Secured Revenue Streams – Gas offtake agreements in place for stability of revenue streams reflecting premium, “green” attributes of our natural gas – When these projects are operational, targeted 2010, EPC expected to have an annualized revenue stream of $40 million Environmental Power Corporation Projects Ready to Go

12 Environmental Power Corporation Project Pipeline Facility Location Type Annual Energy Production Notes Mission TX RNG® 635,000 Project Debt Financing obtained; Permitted Rio Leche TX RNG® 635,000 Project Debt Financing obtained; Permitted Cnossen TX RNG® 635,000 Project Debt Financing obtained; Permitted Hanford Cluster CA RNG® 732,000 Project Debt Financing obtained; Permitted Bar 20 CA RNG® 601,000 Permitted; In Financing Riverdale Cluster CA RNG® 621,000 Project Debt Financing obtained; Permitted Cargill 1 ID RNG® 550,000 Option agreements executed Cargill 2 CO RNG® 365,000 Option agreements executed Swift-Grand Island NE Inside-the-fence 235,000 Project Debt Financing obtained; Permitted Total Announced Projects 5,009,000 MMBtu/year Additional 10,700,000 MMBtu under development Note: All amounts in MMBtu/yr sales

13 Environmental Power Corporation Project Economics Highlights • Long/Medium Term Natural Gas Sales Agreements – We use long/medium term gas sales agreements with fixed prices recognizing “green” value of our gas to provide certainty of revenue streams • Carbon Credit Revenue Opportunity – In the current US voluntary market, we see $2.00 to $7.00/metric ton depending on demand. Utility executives planning on $12 to $30/metric ton under proposed mandatory markets – market will dictate price – Typical, lagoon-based 635,000 MMBtu project is expected to produce 75,000 – 250,000 metric tons of carbon offsets per year, depending upon final protocols • Waste-Based Feed Stocks Used to Create Biogas – Manure – we typically get manure for free from the farm or industry – Substrate (organic materials) – we pay transport but may get tipping fee for partial offset • Potential By-product Value – Solids – third party discussions as a peat replacement or as an eco-friendly building product – Liquids – fertilizer without odors, seeds, pathogens and in more suitable form to meet permit requirements

14 14 • Subsidies are not assumed in project economic forecasts compared to other industries, such as ethanol, biodiesel, etc. • Long/medium term off-take RNG ® agreements recognizing premium value of RNG ® • Finance with combination of equity and debt – Cross-collateralization and revenue pooling to create portfolio diversification – Tax exempt financing: target 80% debt; 20% equity • Long-term alignment of interest with project participants • Targeted project economics provide: – Attractive returns – Further upside potential should subsidies be established similar to other renewable and clean energy sources Environmental Power Corporation Targeted Project Economics

15 Environmental Power Corporation Debt Convertible into Common Equity 15 Fixed Rate Liquid Security Senior to All Equity Dedicated Project Funding • Fixed rate debt fully registered with the SEC and unrestricted from trading • Debt has seniority in the holding company capital structure, ahead of the existing convertible preferred stock and common stock • With $130 million in project financing already raised, money raised in this offering will go directly to facility construction/operations • Contractors pre-qualified, permits obtained and site arrangements secured for the next seven projects Convertible Equity at 2008 Price • Debt convertible into common equity at a minimum conversion price achieved in summer 2008 • When construction of the seven permitted facilities is complete (anticipated to be in 2010), EPC annual revenues expected to be greater than $40 million • Likely transition to mandatory market could significantly increase EPC revenue opportunity • US dairy, cattle and hog farms can take advantage of this cost-effective environmental waste management solution Transition to Operating Company Carbon Credit Revenues Substantial Potential Market Contracts & Permits in Place

16 16 • Unique offering; projects “ready to go” that: – Have debt financing and permits in place – Have secure and stable revenue streams as gas offtake agreements are in place which reflect premium “green attributes” of our natural gas – Have multiple revenue streams – renewable natural gas, carbon credits, other by-products – Do not rely on subsidies, although we will seek parity with other renewables • Unique company: – EPC holds market leadership position with first mover status in the renewable biogas energy sector – Strong growing market for cost effective renewable and domestic energy sources – Large untapped market with announced projects and robust development pipeline • 5 million MMBtu/yr with an additional 10.7 million MMBtu/yr in development – Target project long term stable cash flow streams resulting in attractive returns – EPC can be viewed as an E&P company without exploration risks or depletion curve – Innovative, proven and scalable technology – Valuable strategic relationships – Management team with deep industry experience to execute the plan Unique opportunity to participate in the renewable energy sector Environmental Power Corporation Summary: Compelling Value Proposition Environmental Power Corporation has filed a registration statement (including a prospectus) with the SEC for the offering to which this communication relates. Before you invest, you should read the prospectus in that registration statement and other documents Environmental Power has filed with the SEC for more complete information about Environmental Power and this offering. You may get these documents for free by visiting EDGAR on the SEC Web site at www.sec.gov. Alternatively, Environmental Power and the underwriter will arrange to send you the prospectus if you request it by calling (888) 884-8339.

17 www.environmentalpower.com