Complementing WTE A Proposal to Implement Recycling and Remediate the GT Landfill Complementing WTE A Proposal to Implement Recycling and Remediate the GT Landfill Complementing WTE A Proposal to Implement Recycling and Remediate the GT Landfill Complementing WTE A Proposal to Implement Recycling and Remediate the GT Landfill Complementing WTE A Proposal to Implement Recycling and Remediate the GT Landfill Complementing WTE A Proposal to Implement Recycling and Remediate the GT Landfill New Concepts in Waste Disposal By: Walling Whittaker, MSc

Presentation Outline A brief look at the GTLF – Issues and challenges Innovation in Landfilling - Energy from Wastes – Solar Landfill – Sustainable Landfill Potential for energy recovery at the GTLF

Addressing the Problem Closing and Capping GTLF

Engineered Containment Groundwater Lining System Waste Leachate Rainfall Leakage Gas Cover System

Demerits of Mining the Existing Landfill According to GBB, it will take 19 years to mine the landfill and reduce it to grade During this period there will be a continuous release of landfill gas and odors over George Town Continuous risk of Explosions, Sparks causing fires Workers will be continuously exposed to hazardous materials injury and loss of life

A Typical Landfill Cap

Is A Renewable Energy Cap the Remedy? Need for topsoil and vegetation is eliminated. In areas where water is limited this saves money in O&M phase of project. Need for additional fill material (and associated heavy equipment and manpower) is eliminated while the remedy is equally protective. A Solar Cap provides a protective barrier while generating energy to run equipment or produce revenue

Solar Energy Landfill Caps An Innovative Alternative to Traditional Landfill Capping

Advantages of Solar Energy Landfill Cap Transforms a liability into a revenue Potential to reduce post-closure care costs Sale of renewable power Carbon cap and trade credits Innovative end-use for closed landfill Positive public image

Solar Energy Landfill Caps A great way to protect the environment and provide clean, renewable energy Landfill Design Benefits: – Promotes positive drainage – Minimizes infiltration – Reduced maintenance – Accommodates settlement – Produces high quality stormwater runoff

Two Types of Solar Caps Flexible solar panelsRigid panels Low power production efficiency ca. 6% Higher power production efficiency > 13% LightHeavier (steel frame, glass) Flexible, unbreakableStiff frame Works well with diffuse light Less efficient with diffuse light Works well with temperatures above 40°C Less efficient with temperatures above 40°C

Rigid Panels

Flexible Panels

Placement of Rigid Panels

Project Opportunities for Flexible Solar Caps: Closed or ‘inactive’ landfills Sites located near transmission lines Sites adjacent to large electricity load/demand

Existing Solar Landfill Projects Malagrotta, Italy: 998 kW from PV in landfill cap Brockton, Massachusetts 460 kW “Brightfield” with ground mounted panels Nellis Air Force Base, Nevada 15 MW from tracking panels on old landfill Republic Services, San Antonio, TX – solar demonstration project to incorporate PV membranes in landfill cap FPL’s 250 kW solar panel array on closed Bee Ridge Landfill in Sarasota, FL New Jersey Meadowlands Comm. Proposal for 5 MW solar project on Erie Landfill FLS Energy to build and operate 1 MW PV array on closed landfill in North Carolina Epuron PV array adjacent to G.R.O.W. Landfill owned by Waste Management in Bucks Co. PA

Solar Integrated Technologies, Malagrotta Italy 1 Megawatt Landfill Application. Flexible Panel

Tessman Rd. Landfill, Houston Tx Winner of the 2010 SWANA Gold Excellence Award for Landfill Secondary Use

Hickory Ridge Landfill Atlanta, Georgia 48 acres 7,000+ solar panels to produce over 1 MW of renewable energy over a 10-acre south slope Construction completed in July 2011 If this can be done in other countries…why not in Cayman?

A Solar Farm at GTLF Solar radiation in Cayman reaches 6.6 Kwh/m2/day, from March to September Can be designed using either flexible panels or rigid panels, ground mounted at 15 degrees angle. With the price of energy averaging US$0.37/Kwh Has the potential to produce 2.2Mw electricity

A Solar Farm at GTLF A small section ( 10 acres ) of the GTLF could accommodate 9,300 rigid panels of 235 watts, each. Based on climate data (10 years average), it has a potential capacity of 2.18 Mwp, on just 40,950 square meters of the site. Enough electricity to power about 300 homes

A Solar Farm at GTLF Total Investment: US$ 6.1 MM Installed Capacity :2.18Mwp Average production/yr:3.9MMKwh Project life:25 yrs Pay Back Years - 8 Internal Rate of Return - 18% NPV - US$8.9MM (6%)

Sustainable Landfills

What is a Sustainable Landfill? An engineered landfill in which the cells are designed to operate as ‘bioreactors’ so that they can be reused again and again Create conditions for waste degrading organisms to thrive Most typically performed by increasing moisture content – Leachate recirculation – Air Injection A large scale composting operation

Gas Production Bioreactor Landfill Conventional Landfill

The Sustainable Landfill Landfill Cover Leachate Air Leachate Collection System

Economic Benefits of Sustainable Landfills Reduces the need to build new landfills Enhanced gas production Recovered space Reduced env. impact Reduced post-closure care

Existing Projects 10 field-scale demonstration projects in the US and Canada – Waste solids decomposition – Nitrogen cycling and management – Liquid distribution – Gas production modelling – Liquid waste bioassay development – Methane oxidation and emissions measurement 8 patents issued 6 applications pending Existing projects in Florida

New River Regional Landfill Lined Landfill Manages waste from several North Florida Counties (approximately 800 tons per day)

Gas Extraction Wells

Gas is converted to “green” energy

Landfill Engineering is Becoming Innovative

Clay and plastic lining to prevent leaks; pipes collect leachate from bottom of landfill Groundwater Leachate monitoring well Groundwater monitoring well Leachate pumped up to storage tank for safe disposal Leachate storage tank Leachate treatment system Pipes collect explosive methane for use as fuel to generate electricity Electricity generator building When landfill is full, layers of soil and clay seal in trash Methane storage and compressor building Methane gas recovery well Compacted solid waste Leachate pipes Probes to detect methane leaks Topsoil Garbage Clay Sand Garbage Subsoil Synthetic liner Sand Clay Sand Better Engineered Landfills

Questions