Experience from Landfill Developments in New England...

Experience from Landfill Developments in New

England

Andrew Reed

Borrego Solar

www.borregosolar.com © Borrego Solar Systems, Inc. Private & Confidential

Generating Change Since 1980


EBC Rhode Island Chapter Program Renewable Energy at Closed Landfills

December 3, 2012

Andrew Reed

Director of Project Development

Borrego Solar


1. Overview of Borrego Solar

2. Considerations for landfill development

3. Long term operation and maintenance

4. Case Study: Easthampton landfill in MA

5. Conclusions and discussion

Agenda and Discussion Topics


Borrego Solar overview

Our installations meet the highest quality and reliability standards in the industry

‣ Established 1980

‣Nearly 100 employees in offices on both

coasts

‣ Leading provider of turnkey solar

photovoltaic systems

‣ Fully integrated PPA provider with nearly

$100m to deploy

‣Commercial, Government, and Utility

‣ ~10 MW of landfills completed or under

construction


‣ Additional revenue from land with limited uses

• For private and municipal sites

• Methane extraction tapers off after closure

• Low demand for other types of development

‣ Available financing

• Labeled “stable” by investors

‣ Large expanses of space

• EPA estimates over 15 million acres in US

‣ Good transmission

• Close proximity to existing grid and point of interconnection

‣ Environmental stewardship/leadership

Landfills & Brownfields

Why landfills should go solar…


‣ Buy the system

• Hire Engineering, Procurement and Construction (EPC)

Services for the installation

• Optional O&M for system operations

• Upfront cost would be paid back through power savings

• No ability for municipalities to take advantage of tax incentives

‣ Utilize third party ownership structure

• No upfront capital requirements

• PPA provider would monetize tax attributes and own, operate,

& maintain the system

• Municipality would enter into a long-term fixed contract to

hedge on electricity rates

• Net metering regulations often require on-site load

‣ Collect a lease payment

• Provider would enter into a PPA with the utility

• Provider would own, operate, and maintain the system

Financing options

Pay or be paid


‣ Only about a dozen known solar landfill projects are complete in the US

‣ Specific standards for landfill solar installations are still being developed

‣ Landfill solution considerations:

• Waste Composition – municipal solid waste; gases omitted

• Cover Materials – no cap v. cap; membrane v. membrane plus soil; vegetation

• Landfill Age – impacts settling expectations

• Construction – Slope angle, drainage, loading requirements

• Location – wetlands, conservation, species, wind speeds, marine environments

‣ Designs incorporate ground-mounted ballasted racking & fencing to minimize disturbance

Project planning

Landfill considerations


TYPICAL MAX

SLOPE 5°

DECOMPOSITION CAUSES

SETTLING


Project planning


‣ Permitting

• Landfill sites have challenging permitting hurdles

• Process can be lengthy

• Concept is new to most AHJ’s including environmental

regulators

• Proper planning is essential

• Construction oversight may be required

‣ Load on landfill

• Consider construction & long term gravity loads

• Limits based on specific landfill construction

• Easthampton = 10 psi/1440 psf

• May restrict location of inverter/transformer

Project planning

Engineering challenges


‣ Steep side grades

• Up to 5° top surfaces ok for ballast, minimal preparation

• Up to 13° side surfaces more challenging

• Flexible solution can be used on exposed caps and is best

when applied during closure process

‣ Settling

• Depends on depth, content, placement and age

• Could be 10-20’ over the life of the landfill

• Likely greater than 1' per year in first few years

• Generally reduced effect with age

• Differential settling is an issue

• Voids in fill - depressions / sinkholes

Project planning



MAINTAIN

CLEARANCE

DURING SETTLING

Project planning



‣ Drainage

• Must be maintained

• changing surface changes drainage characteristics

• Interrupted by digging or placing crushed stone

• Situation will aggravate if not remediated

‣ Interconnection

• No landfill specific issues

• Often little or no onsite load for net-metering

• Potentially long runs to three phase

• Competing for interconnection with wind power/landfill gas

to energy

Project planning



‣ Staging areas off the landfill are critical

• Space constraints

• Weight limits

‣ Low ground pressure equipment

• Cap limited to 5-10psi

• Heavy equipment is limited to Low Ground Pressure

machinery

‣ Protect the cap!!!!

• Don’t plan on digging

• Work with the land – react to how the land is reacting to

our work

• Use contractors that build landfills to work on the landfill

Project planning

Construction


‣ Current maintenance requirements of landfills

• Annual or semi-annual inspections for compliance

• Ground water monitoring/sampling

• Gas extraction and monitoring

• Cap inspection

• Vegetation management

• Man hole lock maintenance

‣ Long-term O&M

• Electrical inspection and system check

• System washing

• Mowing

• Fence maintenance

• Settlement surveys

• Erosion Inspections - storm water control

Project planning

Operations and maintenance


Case Study: Town of Easthampton

Easthampton landfill


‣ 2.3 MW array

‣ 16 acre landfill

‣ 10,000 modules

‣ 10 year PPA under 7 cents

‣ 2,828,000 kWh annually

‣ 3,606,146 lbs of CO2 offset annually

‣ Town will save $110,000 in the first year

‣ Nothing down, no operational expenses or

additional responsibility

Case Study: Town of Easthampton

Project Overview


Construction Sequencing

Construction – Site Prep



Construction - Access Roads



Construction – Drainage and Culverts



Construction - Ballasts: Pre-cast



Construction - Racks



Construction - Modules



Construction – Conduit and Wiring



Construction – Electrical Equipment


Conclusions and discussion

‣ Rhode Island has many factors that support good solar economics

‣ Not all landfills are perfect candidates for solar

‣ Consider the characteristics of your own facility

‣ What other properties might you have that could also host a system?

‣ What kind of contract fits with your goals?

‣ Be considerate of who you partner with

Is this right for me?


Andrew Reed

Phone 978-513-2607

[email protected]

1115 Westford Street, 2nd floor

Lowell, MA 01851

www.borregosolar.com

Phone (888) 898-6273

Fax (888) 843-6778

Borrego Solar Systems, Inc.

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Experience from Landfill Developments in New England...

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