1. Page 1 Landfill Gas to Energy Clark Wiedetz General Manager Alternative Energy 678-427-0150 Program Overview Division: Energy & Environmental Solutions Date: December 12, 2007

2. Page 2 Executive Summary The landfill gas (lfg) project marketplace is expanding at record- level proportions. The Landfill Gas Methane Outreach Program (LMOP) estimates that 50 projects will become operational in the next 24 months. The price of fuel has increased 300% in the last 4 years, thus exceeding the cost to convert lfg into a usable form of utility Increased environmental regulations for landfills are being mandated Lfg has been designated as a renewable energy source by the Federal Government and in 24 States with Renewable Portfolio Standards, thus making lfg projects eligible for a number of incentives and tax credits.

3. For internal use only / Copyright © Siemens AG 2006. All rights reserved.

4. Page 4 Landfill Gas  Is about 50% CH 4 (Methane)  Is about 50% CO 2  Contains other trace gases & elements  Is naturally created by the decomposition of garbage  Has a very high greenhouse effect  Has a heating content of about 1/4 that of natural gas Methane creates roughly 20 times the greenhouse effect of CO 2 … unless you burn it!

5. Page 5 How can we use these fuels? Direct Use Project  Gas is piped to a boiler, where it is combusted to make heat or steam. Electric Generation Project  Gas is piped to a nearby electric generator, where it is combusted to make electricity. Pipeline Injection Project  CO content is minimized. Gas is compressed, then injected into a natural gas pipeline.

6. For internal use only / Copyright © Siemens AG 2006. All rights reserved. Direct Use

7. Page 7 Three Rivers SWA/ Kimberly-Clark “Landfill gas to be used for diapers” from Waste News  Installed collection system and flare  Conditioned, if necessary, to remove challenging trace gases  Compression system  17 miles of pipe  Boiler retrofit to accept and combust landfill gas  $10MM project  Carbon credits help project economics

8. Page 8 Customer Deal Structure Example (Three Rivers SWA)

9. Page 9 Electric Generation Project

10. Page 10 Electric Generation For an Electric Generation Project, the gas is also  Collected, compressed and conditioned, if necessary.  Used as fuel for reciprocating engines, fuel cells, microturbines  Larger projects can send renewable power to utilities (thus fulfilling RPS requirements)  Renewable energy credits (RECs) and possibly Production Tax Credits (PTCs) help project economics

11. Page 11 Landfill Gas Project Developers Siemens DTE Biomass Fortistar Ameresco Energy Services Group Waste Management

12. Page 12 Questions?