Table of Contents

Acknowledgments

Abstract

Introduction

Case Study Experiences with Short-rotation Plantations

Philippines Case Study

Plantation Management

Plantation Establishment, Tending and Protection

Growth, Production, and Harvest

Observations

Hawaii Case Study

Plantation Management

Growth, Production, and Harvest

Observations

Brazil Case Study

Plantation Management

Growth, Production, and Harvest

Observations

The Production of Short-rotation Woody Crops

Site Selection

Species Selection

Plantation Establishment, Tending, and Protection

Site Preparation

Seeds, Cuttings, and Nursery Operation

Spacing

Planting

Weed and Pest Control

Protection from Fires and Animals

Stand Renewal

Summary

Use of Plantation-grown Biomass for Power Generation

Harvesting, Transport, Storage, Handling and Fuel Preparation

Power Generation Options

Currently Available Technologies

Emerging Technologies

Environmental and Social Benefits/costs of Biomass Plantations

Tree Plantations and Soil/water Issues

Tree Plantations and Biodiversity

Tree Plantations and Chemical Pollution

Tree Plantations and Social Economics

Economics of Plantation-grown Fuels for Power Generation

The Costs of Producing and Harvesting Plantation Fuels

The Costs of Power Production from Plantation Fuels

Conclusions

Notes and References

List of Tables

Table 2.1. Plantation biomass annual production rates from around the world

Table 3.1. Productivity summary of machine and manual felling in short rotation, biomass plantations

Table 4.1. Example carbon offsets from short-rotation plantation energy used for power production and displacing coal

Table 5.1. Summary of the costs and productivity of plantation-grown fuel

List of Figures

Fig. 2.1. Annual production of wood and leaf biomass of natural forests across a latitudinal gradient from the Boreal Zone to the Tropics

Fig. 2.2. Biomass project decision tree

Fig. 2.3. Steps in a recommended site preparation strategy

Fig. 3.1. Process diagram: plantation-grown biomass to power generation

Fig. 3.2a and Fig. 3.2 b. A comparison of productivity and cost of harvesting systems for a large diameter (15.2 cm) and small diameter (7.6 cm) plantation stand

Fig. 4.1.a. and 4.1.b. Effects of land-cover type, precipitation, and slope on surface runoff and erosion at four tropical sites

Fig. 5.1. The effect of biomass plant scale on feedstock requirements and transport distances

Fig. 5.2. Variation in delivered feedstock costs by bioclimatic region in Northeast Brazil

Fig. 5.3. Average cost of plantation-grown feedstocks in Northeast Brazil

Fig. 5.4. The effect of fuel cost on power costs for a low-efficiency (conventional steam-turbine) technology and a high-efficiency, low-capital cost technology

Acknowledgments

This report was sponsored by the U.S. Agency for international Development (Office of Energy and Infrastructure), Winrock International, and the U.S. Department of Energy (Biofuels Systems Division). The authors want to thank Pat Layton (Scott Paper Company), Vic Phillips (University of Hawaii), Robin Graham (ORNL), and Dan Wadell (National Rural Electric Cooperative Association) for their reviews and comments.

Abstract

This report discusses the biologic, environmental, economic, and operational issues associated with growing woody crops in managed plantations. Information on plantation productivity, environmental issues and impacts, and costs is drawn from DOE's Biofuels Feedstock Development as well as commercial operations in the U.S. and elsewhere. The particular experiences from three countries -- Brazil, the Philippines, and Hawaii (U.S.) -- are discussed in considerable detail.

Introduction

Biomass accounts for nearly 15% of world energy supplies.1 In industrialized countries, biomass supplies about 3%, or 8 exajoules (EJ), of total primary energy. The dominant and fastest growing use of biomass fuels in industrialized countries is for process heat and electricity.2 In the developing countries, biomass fuel supplies about 48 EJ or 35% of total primary energy. Most of this biomass energy is used traditionally for domestic cooking and space heating. However, where there are industrial and agricultural enterprises, wood, bagasse, rice hull, and other waste products are often used to generate heat for agricultural processes such as crop drying, steam to drive small-scale industrial processes, and electricity for on-site use and sometimes for off-site power sales.

The recent interest in converting biomass to electricity comes not only from its potential as a low-cost, indigenous supply of power, but for its potential environmental and developmental benefits. For example, biomass may be a globally important mitigation option to reduce the rate of CO₂ buildup by sequestering carbon and by displacing fossil fuels. Renewably-grown biomass contributes only a very small amount of carbon to the atmosphere. Locally, plantations can lessen soil erosion, provide a means to restore degraded lands, offset emissions and local impacts from fossil-fired power generation (e.g., SO₂ and NO_x), and, perhaps, reduce demands on existing forests. In addition to the direct power and environmental benefits, biomass energy systems offer numerous other benefits, especially for developing countries. Some of these benefits include the employment of underutilized labor and the production of co- and by-products (e.g., fuelwood).

Nearly all of the experience with biomass for power generation is based on the use of waste and residue fuels (primarily wood/wood wastes and agricultural residues). The production of electric power from plantation grown wood is an emerging technology with considerable promise. However, actual commercial use of plantation-grown fuels for power generation is limited to a few isolated experiences. Wood from plantations is not an inexpensive energy feedstock, and as long as worldwide prices of coal, oil and gas are relatively low, the establishment of plantations dedicated to supplying electric power or other higher forms of energy will occur only where financial subsidies or incentives exist or where other sources of energy are not available.

In countries where biomass plantations are supplying energy on a commercial basis, such as in Brazil, the Philippines and Sweden, it can be shown that a combination of government policies and/or high conventional energy prices have stimulated the use of short-rotation plantations for energy. Brazil used tax incentives beginning in the mid-1960s to initiate a reforestation program to provide for industrial wood energy and wood product needs.3 As a consequence of the Brazilian Forestry Code with its favorable tax incentives, the planted forest area in Brazil increased from 470,000 ha to 6.5 million ha by 1993.4 With the discontinuation of the tax incentives in 1988, plantation establishment in Brazil has slowed although the commercial feasibility of using eucalyptus for energy and other products has been clearly demonstrated.5 In Sweden, where district heating with wood is relatively common, the government used direct subsidies to farmers and by 1992 over 6,000 ha of commercial willow plantations had been planted. Government support was also used to provide extension services to farmers, distribute improved plant materials and contract with regional power plants to buy the biomass and fund an extensive research and development program.6 The Dendro Thermal Power Program in the Philippines started off with a considerable amount of government support through farmer loan programs and technical assistance that resulted in nearly 18,000 ha of leucaena being planted in the early 1980s. With the demise of government support in the mid-80's, and because of inadequate planning, poor technical decisions and inexperience with biomass energy systems, the program failed. Today, very little of the planted area is supplying feedstocks for electric power.7

The commercialization of short-rotation energy plantations are more likely to occur where market opportunities coincide with suitable crop production areas (i.e., availability of local expertise on soil and crop management, and locally adapted sources of selected fast-growing plant materials). In considering the potential for commercially viable biomass energy systems, it is necessary to think beyond conversion technologies, crop yield potential and site-specific production costs. To be successful developers must be cognizant of fuel prices; energy, environmental and agricultural policies; infrastructure support; financing arrangements; conversion technology requirements; potential risks; and local environmental conditions to make informed decisions about location, crop type and management approach. Successful ventures also require regional (or local) crop development and research activities to assure the availability of selected materials that are adapted to soils and climates of the region and the availability of knowledge and techniques for crop management.

This Report focuses on the biologic, environmental, economic and operational issues to be considered by decision makers contemplating the establishment of biomass plantations to provide fuel for power generation. Although some of the policy, social, and infrastructure issues will be alluded to, they are very country specific and difficult to treat generically. To provide context, three case studies are first discussed in Chapter 1. Chapter 2 considers concepts associated with plantation management that would apply to plantations established for nearly any purpose. Chapter 3 discusses harvest and handling technologies as well as electricity conversion technologies. Chapter 4 deals with environmental issues that must be considered in the establishment and harvesting of short-rotation wood plantations as well as social and environmental benefits of locally produced energy resources. Chapter 5 integrates the sections together by discussing the economics of producing wood for energy and the implications of scaling factors.

The information on plantation growth and environmental concerns used in this Report has largely been drawn from commercial experience in the production of short-rotation forests in the U.S. and Brazil and from research data generated by the Biofuels Feedstock Development Program in the U.S. and similar programs in Sweden, U.K. and other European countries. Information on the use of wood for energy has largely been drawn from available information on biomass energy projects using wood wastes and residues.