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Community Wood Energy  technologies, project development and resources.

 


Community Wood Energy

Wood fuels are unique among renewable energy sources in that they offer flexibility in storage, transportation and utilization upon demand.  Community wood energy is the use of wood fuels for heating and powering public buildings, business and homes.  Community-scale wood energy is energy generated where it is utilized, with local resources supplied by members of the community.  Community-scale wood energy is about people knowing where their energy comes from.

Wood fuels, also called biomass, are arguably mankind’s oldest source of energy.  Biomass is defined in the Virginia Code as “organic material available on a renewable or recurring basis”.   Specifically, woody biomass is defined as:

  • Forest-related materials, including mill residues, logging residues, forest thinnings, slash, brush, low-commercial value materials or undesirable species, and woody material harvested for the purpose of forest fire fuel reduction or forest health and watershed improvement,
  • Solid woody waste materials, including landscape trimmings, waste pallets, crates and manufacturing, construction, and demolition wood wastes, excluding pressure-treated, chemically treated or painted wood wastes and wood contaminated with plastic;,
  • Crops and trees planted for the purpose of being used to produce energy.

    Biomass wood chips

The concept of a Community Wood Energy Program was codified in the 2008 Farm Bill and was continued in the 2014 Farm Bill.  The promotion of institutional wood energy has expanded in a number of states through Fuels-for-Schools programs (Vermont, Pennsylvania, Missouri, and Montana) and the U.S. Forest Service’s Statewide Wood Energy Teams.  Additional information and resources for community-scale woody biomass energy is available through the US Forest Services’ Wood Education and Resource Center, Vermont’s Biomass Energy Resource Center (BERC), and advocacy organizations such as the Alliance for Green Heat and the Biomass Thermal Energy Council.

 

Social, environmental and economic impacts of using wood for fuel

There are many benefits to using locally grown and sustainably harvested wood fuels over conventional fossil fuels.  The principal reason for using wood is economic – levelized energy costs of wood fuels in Virginia are 4 to 6 times less expensive than fuel oil, propane or electricity, and have been consistently so for several decades!  Even better, energy dollars spent on locally produced wood fuels stay and circulate in the local economy supporting jobs in the community.

For a quick overview of the many benefits see BERC’s Benefits of Using Woodchip Heating for Schools and Communities fact sheet.   For concern about what comes out of the smoke stack see their Air Emissions from Modern Wood Energy Systems and their Carbon Dioxide and Biomass Energy factsheets.  More in-depth examination of the benefits that can accrue from switching to wood fuels can be found in Dovetail Partner’s Community-Based Bioenergy and District Heating.

Modern Wood Energy Technology

Like the wood stoves of old, most modern wood energy systems are based on combustion technology.  Unlike the old wood stoves, modern woody biomass systems are clean, efficient and can be fully automated.  Woody biomass fuels are typically delivered by truck into a storage bin and then augured directly into the boiler, keeping the boiler room free of dust and dirt.  Smaller-scale systems can be completely automated, providing institutions lower cost, hassle-free heat with virtually no change in labor requirements.

Fuel Delivery with Automated Hopper

Wood fuels come in a variety of forms and qualities, presenting users a number of factors to consider.  Woody biomass systems can be engineered to handle multiple fuel types, which offers flexibility and insurance if an opportunity fuel becomes available or the preferred fuel is temporarily not, however the trade-off is increased capital costs.  Cleaner (no bark, soil or leaves) and dryer fuels have a greater recoverable energy content and with lower emissions and ash production, however, handling and processing increases the delivered price.  Also, the more processed the fuel, the more uniform the shape and size, making handling easier.  For an introduction to wood boiler systems, clear descriptions and specifications of wood chip fuels and a detailed look at institutional and commercial-scale wood chips systems, see:

Wood Boiler

Wood pellet systems and fuels

Residential heating

Examples of Wood Energy from Virginia and beyond

Longwood University Plant

Supply, availability and sustainability

Surveying the supply and determining availability of woody biomass fuels is an essential component of the project feasibility study.  Availability includes both the economic cost of extracting, transporting, processing and delivery of the material as well as the social willingness of the community to supply.  Once a delivered price has been determined the United States Forest Service Forest Products Laboratory Fuel Value Calculator can be used to compare prices.

Smaller wood energy users will most likely contract with a fuel supplier for a guaranteed supply while larger facilities may be willing to take on managing their own supply chain.  The Forest Guild and the Pinochet Institute for Conservation have produced four short videos exploring sustainable forest biomass harvesting and use from four different perspectives – the end user, forest management, conservation and environmental protection and the policy angle: Harvesting Guidelines.  Also available from the Forest Guild is Harnessing the Power of Local Wood Energy – Ensuring a sustainable supply of wood chips for your school (A community resource guide).

Project Development

Key characteristics of successful projects include an organization with a committed community member who will champion the project for energy costs savings and/or environmental benefit.  The University of Minnesota’s Community Biomass Handbook  provides guidance, case studies and tools, including their easy-to-use Wood Energy Financial App, for assisting users’ through the initial stages of project development.  The EPA’s Combined Heat and Power Partnership is a resource for larger intuitions and communities looking to reduce energy costs and the environmental impacts of their power generation.

Fuel switching from a conventional to a woody biomass fuel (or including a biomass system in a green field project) is a multi-stage processes.  Initial screening will determine if it makes economic and technical sense at the location.  Preliminary feasibility considers the organizational goals and potential barriers that will need to be overcome to determine if a woody biomass heating system is a good economic and technical fit for the location.  The feasibility stage (preliminary engineering) determines the design and operation of the system for pricing and return on investment.  Procurement is where final engineering takes place, financing is secured, any required permits are obtained and the system components are ordered, delivered, installed and commissioned.  The final stage is operation and maintenance, where cost savings are realized.  Labor for operation and maintenance of a solid fuel system can be expected to be greater than a conventional fuel system, the extent of which should be determined during the pre-feasibility stage.

VA DEQ Permitting

In 2013 Virginia approved a Permit by Rule (PBR) for small biomass combustion electricity generating facilities (less than 5 MW).  Virginia does not require an air permit for biomass combustion if the unit is less than 1,000,000 Btu per hour or if the uncontrolled emissions are below the criteria pollutant exemptions levels.  If not exempt the facility has the option of obtaining permitting though the Minor New Source Review (NSR) Program, or a Biomass Pilot Test Facility General Permit.  DEQ’s Combustion Based Energy page provides links to the legislation, and PBR Overview and a Permit Guide.

Financing

Financing for woody biomass projects exist in a variety of forms and sources.  State and federal grants and loan guarantees can help to offset the cost of a project or secure a competitive rate from a private or public bank.  Investment funds or fuel providers or energy servicing companies (ESCO’s) may be other sources of financing.  Another avenue worth exploring is what is referred to as the BOO model – a company will Build, Own, and Operate a biomass-fueled system on site and enter into a contract to sell the energy (hot water, hot air, electrons, etc.)  Depending on the situation this model can be attractive as the contracted company assumes responsibility for operation, maintenance and uninterrupted service and the user only pays for what they consume.  Similarly, a wood pellet manufacturer or similar fuel supplier might be willing to underwrite the installation of a system if they are confident they will have a long-term customer.  The Virginia Department of Agriculture and Consumer Services has compiled an extensive list of Financial Resources for Ag & Forestry Businesses in Virginia.

 

Biomass System Building Designed to Mitigate Wetland Impact