United States

Department of

Agriculture

Forest Service

Southern

Research Station

Research Paper

SRS–46

Assessing the Potential for 

Biomass Energy Development 

in South Carolina

Roger C. Conner, Tim O. Adams, 

and Tony G. Johnson
The Authors:

Roger C. Conner, Research Forester, U.S. Forest Service, Southern 

Research Station, Knoxville, TN 37919; Tim O. Adams, Resource 

Development Division Director, South Carolina Forestry Commission, 

Columbia, SC 29212; and Tony G. Johnson, Resource Analyst, U.S. 

Forest Service, Southern Research Station, Knoxville, TN 37919.

October 2009

Southern Research Station

200 W.T. Weaver Blvd.

Asheville, NC 28804

Cover photo: 

Harvesting operation in Chester County, South Carolina. (photo by Mike Howell) 
Assessing the Potential for 

Biomass Energy Development in 

South Carolina

Roger C. Conner, Tim O. Adams, and Tony G. Johnson

iii

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

 Identifying Potential Sources for Biomass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

 Biomass From Unutilized Logging Residue and Residual Inventory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

 Commercial Thinning: Potential Biomass in Poletimber Trees . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

 Potential Biomass in Small-Diameter Trees: Overstocked Sapling-Seedling Stands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

 Biomass From Mill Residue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

 Biomass From Urban Wood Waste. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

 Biomass Producer Surveys: Determining Biomass Production Over a Range of Prices . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

 Logging Residue and Residual Inventory: Unutilized Biomass on Harvested Acres . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

 Potential Biomass From Commercial Thinning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

 Overstocked Stands: Potential Biomass From Precommercial Thinnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

 Mill Residue: Nearly All is Utilized for Other Products. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

 Reallocation of Mill Residues by Price Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

Urban Wood Waste: A Potential Primary Contributor to Bioenergy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

 Estimating Recoverable Logging Residue: Timber Producer Survey Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

Summary: Total Biomass Potential at Price Points. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

Discussion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

Literature Cited. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

Contents

Page

Abstract

An assessment of the potential for developing a sustainable biomass energy 

industry in South Carolina was conducted. Biomass as defined by Forest 

Inventory and Analysis is the aboveground dry weight of wood in the bole 

and limbs of live trees ≥1-inch diameter at breast height, and excludes tree 

foliage, seedlings, and understory vegetation. Several possible sources of 

biomass were analyzed: unutilized logging residue and standing residual 

inventory trees on acres with tree harvesting; commercial thinning; 

precommercial thinning on overstocked natural sapling-seedling stands; 

mill residue; and urban wood waste. A range of prices from $20 to $30 per 

ton was established by surveys sent to South Carolina’s timber producers. 

Prices reflect 2008 market conditions. The estimates of potential biomass 

distributed across these price points rose from 4.8 million tons to a total 

of 16.5 million tons annually. Nearly 7.7 million tons are currently being 

utilized. New facilities that use wood to produce energy could capitalize 

on the 8.8 million annual tons of unutilized biomass and operate without 

overly impacting existing forest industries or increasing harvest levels 

above 2006 estimates. 

Keywords: Biofuel, biomass markets, FIA, forest landowner, green tons, 

hardwood poletimber, haul distance, softwood poletimber, timberland.

Introduction

Recent price increases in fossil fuels have renewed interest 

in finding and utilizing renewable sources of raw material 

to generate energy. In South Carolina, woody biomass as 

feedstock for biofuel is one source that has been used to 

produce heat, steam, and electricity on a moderate scale for 

well over a century. Increasing the role of biomass in energy 

production can be largely accomplished by more efficient 

use of existing sources.

Sources for biomass vary, but typically include unutilized 

wood residue from both tree harvesting and mill operations, 

volume from standing forest inventory including 

nonmerchantable trees, and woody material from urban 

waste. We identify and discuss these sources and provide 

estimates of biomass potentially available to develop and 

sustainably supply a bioenergy industry in South Carolina 

without increasing harvest rates above current levels. 

Harvesting and transporting biomass in the form of logging 

residue and nonmerchantable trees is a costly undertaking 

for the State’s loggers. We determine a range of prices per 

delivered ton that would enable loggers to profitably harvest, 

process, and transport this material. We then provide 

estimates of the additional biomass that loggers could 

potentially supply with increasing price per ton.

The objectives of this study were to:

• identify potential sources of unutilized woody biomass 

in South Carolina and estimate the amount in tons 

potentially available each year

• determine the range of prices per ton needed by loggers 

to invest in equipment necessary to begin harvesting 

biomass in logging residue and residual inventory

Methods

Biomass as defined and reported by Forest Inventory and 

Analysis (FIA) is the aboveground dry weight of wood 

in the bole and limbs of live trees ≥1-inch diameter at 

breast height (d.b.h.). FIA’s estimates exclude tree foliage, 

seedlings, and understory vegetation (Conner and others 

2004). FIA’s biomass estimates are derived from equations 

developed by Clark and Saucier (1990) and Saucier and 

Clark (1985). For live trees, the dry weight estimates 

of biomass are doubled to convert to green weight. For 

harvested trees, cubic-foot removal volumes (including 

logging residue) are converted to green tons using 69.5 

pounds per cubic foot for softwoods and 75.3 pounds 

per cubic foot for hardwoods. These conversions are 

derived from the relationship between the biomass in the 

merchantable portion of the tree (1-foot stump to a 4-inch 

diameter outside bark top) and the cubic-foot volume in that 

portion. Green weight is the wood and bark per cubic foot of 

volume immediately after felling. Severed trees with limbs 

intact lose moisture content rapidly. Therefore, the pounds 

per cubic foot and thus tons per acre of logging residue can 

drop significantly in a short amount of time.

Assessing the Potential for Biomass Energy 

Development in South Carolina 

Roger C. Conner, Tim O. Adams, and Tony G. Johnson
2

Identifying Potential Sources for Biomass

This study updates a similar effort conducted in 2001 by 

the Strom Thurmond Institute at Clemson University and 

funded by the South Carolina Forestry Commission (SCFC). 

The findings from that study are provided in an internal 

report (referred to as the Harris report) available from 

SCFC.

For this study, we considered the following as possible 

sources:

• unutilized logging residue and standing residual inventory trees on acres with tree harvesting

• potential biomass from commercial thinning

• potential biomass in small-diameter trees (<5.0 inches 

d.b.h.) on overstocked natural sapling-seedling stands 

(precommercial thinning)

• biomass from mill residue

• biomass from urban wood waste 

A range of prices per ton of biomass was established from 

responses to surveys conducted by the SCFC. We then estimated the amount of biomass that would potentially become 

available from each source with changes in price per ton. 

Unless otherwise indicated, all estimates are in green tons.

Biomass From Unutilized Logging Residue and 

Residual Inventory

Estimates of biomass in logging residue and standing residuals are from timberland acres where tree cutting of any kind 

has occurred. Cutting activity ranged from final harvests 

where >50 percent of the tree stocking is removed, to 

timber stand improvement where small-diameter trees are 

removed from immature stands to improve future stocking. 

Definitions of the different types of tree harvesting identified 

by FIA are available in Conner and others (2004).

Logging residue is a component of FIA’s estimates of total 

timber removals. FIA defines timber removals as the cubicfoot volume in trees ≥5 inches d.b.h. harvested for products; whole trees or portions of trees left behind as logging 

residue; and trees removed due to land clearing or other 

changes in land use. For this study, we also include logging 

residue in nonmerchantable trees (<5 inches d.b.h.) killed 

during the harvesting operation. 

Estimates of average total removals, annual roundwood 

product output, logging residue, and other removals are 

reported here in green tons for the inventory period from 

2001 through 2005. Equivalent cubic-foot timber removals 

are available in the 2006 analytical report for South Carolina 

(Conner and others 2009). 

Potential biomass from 

logging residue. (photo 

by Tony Johnson)
3

FIA calculates the merchantable portion (bole) of logging 

residue as the volume from a 1-foot stump to a 4-inch top 

of whole trees cut and not utilized. Underutilization factors 

derived from felled-tree utilization studies are applied to 

this volume for the remainder of the merchantable portion 

of logging residue (Bentley and Johnson 2008). Factors 

derived from standing inventory data and utilization studies 

are applied to the merchantable portion of logging residue to 

calculate the nongrowing-stock portion in tops, limbs, and 

stumps.

Empirical evidence suggests that a 60-percent recovery 

rate of logging residue (volume recovered to roadside for 

chipping and transportation to mills) is realistic for harvesting operations using conventional equipment (Perlack and 

others 2005). We adjusted our estimates of available logging 

residue to reflect this plausible rate of recovery. 

Biomass in residual inventory is the volume (in weight) of 

standing trees left after tree harvesting activity. On final 

harvest acres, we estimated the biomass in all-live (includes 

rough and rotten) standing residual trees ≥1.0-inch d.b.h. 

from the 2006 inventory data (Conner and others 2009). 

On all other acres with evidence of tree cutting, we provide 

estimates of the biomass in rough and rotten trees ≥1.0 

inches d.b.h. remaining in the standing inventory. Trees left 

in streamside management zones were not included in our 

estimates of biomass.

Commercial Thinning: Potential Biomass in 

Poletimber Trees

Commercial thinning typically removes trees of poletimber 

size (5.0–8.9 inches d.b.h. for softwoods and 5.0–10.9 

inches for hardwoods) and the volume—primarily softwood—is traditionally considered pulpwood supply. The 

Harris report assumed that one-half of the net annual growth 

in poletimber growing-stock trees would be available for 

biofuel. 

Taking a more conservative approach for this study, commercial thinning would be included as a potential source 

for biofuel if (1) all-live poletimber volume had increased 

significantly based on estimates from the 2001 and 2006 

inventories, and (2) our analysis indicated that this increase 

could be sustained in the future. Meeting both requirements 

signified that there was an accessible and sustainable supply 

of volume for potential use as biofuel. If both requirements 

were met, then we follow a similar approach as the Harris 

report and assume that one-half the net annual growth in 

all-live poletimber trees would contribute to the estimates 

of potential biomass supply. Note that this is biomass that 

is yet to be harvested and should not be confused with 

acres that already have been commercially thinned (and 

the biomass included in our estimates of unutilized logging 

residue). 

Thinning operation in 25-year old loblolly pine plantation. (photo by Tony Johnson)
4

Potential Biomass in Small-Diameter Trees: 

Overstocked Sapling-Seedling Stands

Using the 2006 inventory data, we identified acres of natural 

overstocked sapling-seedling stands with no evidence of 

tree cutting. These stands are >100 percent stocked with the 

majority of the stocking in trees from 1.0 to 4.9 inches d.b.h. 

Small trees are difficult and costly for loggers to efficiently 

handle with current technology. The harvesting of biomass 

from precommercial thinnings is tempered by these high 

costs, and by the current lack of markets for small-diameter 

material. Given these constraints, we wanted our estimate of 

available biomass from precommercial thinnings to be conservative. To accomplish this, we assumed that only 1/10th

of the overstocked sapling-seedling acres would be treated 

in a given year, and the thinning would remove 75 percent 

of the biomass in live trees 1.0–5.0 inches d.b.h. 

Biomass From Mill Residue

Mill or plant residues are defined as wood material generated in the production of timber products at primary 

manufacturing plants. This material falls into three main 

categories: coarse residues (e.g., slabs, edgings, trim, veneer 

cores, and ends suitable for chipping), fine residues (e.g., 

sawdust, shavings, and veneer residue not suitable for chipping), and bark (used mainly for industrial fuel). Biomass 

from mill residue is a mix of both green and dry material. 

Estimates of timber product output (TPO) and plant residues 

were obtained from surveys sent to all major primary woodusing mills in the State (Johnson and Knight 2006, Johnson 

and others 2004, Johnson and Smith 2007). In the past, virtually all (98 percent) of the mill residue generated in South 

Carolina has been used to produce primary products such as 

paper, particleboard, or medium-density fiberboard; secondary products such as mulch and animal bedding; or used to 

supply wood-fired boilers and dry kilns. 

Biomass From Urban Wood Waste

Previous attempts to estimate urban woody biomass were 

based on the average production of wood waste per person 

for rural and urban counties. In this study, measured weights 

(primarily dry tons) of biomass being landfilled or processed 

(Department of Health and Environmental Control 2008) 

Mill residue produced from saw-log mill. (photo by Tony Johnson)
5

were used to quantify urban wood waste. Urban wood is 

a diverse category that includes five distinct sources of 

biomass: recycled wood and paper, wood grinding/composting operations, construction and demolition (C&D) landfills, 

land clearing debris (LCD) landfills, and incinerators. With 

the exception of LCD, weight estimates for biomass in 

urban wood waste are dry tons.

Biomass Producer Surveys: Determining Biomass 

Production Over a Range of Prices

A timber producer survey and a mill residue survey were 

conducted by SCFC in October 2008 to estimate the availability of several forms of biomass over a range of prices. A 

copy of the survey questions is available upon request from 

SCFC. 

The timber producer survey, sent to the 148 members of the 

South Carolina Timber Producers Association, described 

the types of biomass being assessed: logging residues (tops, 

limbs, and bark) and small-diameter and cull trees left 

standing after logging. These types of biomass are being 

underutilized presently. 

Conventional equipment needed for most mechanized 

logging operations includes a feller-buncher, one or more 

grapple skidders, a delimber, and a loader. The survey 

stressed the need for additional specialized equipment, 

such as chippers, grinders, and chip vans to recover the 

material—additions that require a significant investment by 

the timber producer. 

Producers already recovering biomass from logging operations were asked to provide specific information about their 

annual production level, their average delivered price per 

ton, their average hauling distance, and the region of the 

State where they operate.

Timber producers not currently recovering biomass during 

their logging operations were asked to estimate the price 

per ton where they would invest in the needed equipment 

to harvest logging residues or standing residuals, assuming 

a 30-mile haul distance. These timber producers were also 

asked to identify their region of operation and estimate the 

weekly production level in tons of biomass they potentially 

could recover.

A mill residue survey was distributed to South Carolina’s 

solid wood product mills. The survey requested information 

about the potential quantity of residues, the current price per 

ton received by the producing mill, and the average distance 

the biomass is hauled to current users. The types of mill 

residue covered in the survey included sawdust, shavings, 

bark, chips, and other coarse residues for both softwood and 

hardwood mills. Volume estimates for each type are from 

TPO data. The specific price requested was the price per 

ton (dry or green weight) paid for each commodity at the 

producing mill, not including freight charges. A weighted 

average sales price for each type of mill residue was 

calculated by dividing the total value (quantity X price) by 

the total volume sold. The weighted average sales price was 

assumed to be the point where the estimated volume of each 

mill residue would become available for biofuel. As with 

other biomass sources, the per ton prices for mill residue 

reflect 2008 market conditions and do not account for effects 

of competitive supply and demand conditions that could 

arise between current industry and new energy users.

Results

Logging Residue and Residual Inventory: 

Unutilized Biomass on Harvested Acres

Biomass in logging residue and standing residual inventory 

represent missed opportunities loggers could take advantage 

of should biomass markets develop. This material can 

be harvested as part of the original logging operation, 

eliminating the need for a costly second site visit. 

Table 1 provides a summary of the tree harvest activity that 

occurred on South Carolina’s timberland acres annually 

between 2001 and 2006, and estimates of the biomass in 

standing residual inventory after cutting. Final harvest was 

the predominant cutting activity occurring on 167,900 acres 

Table 1—Timberland acres with tree harvesting and the 

biomass in standing residual inventory trees after harvest, 

South Carolina, 2001 to 2006

Tree harvest activity Acres

Biomass in residual 

inventory treesa

thousand green tons 

per acre

green tons 

per year

Final harvest 167.9 10.9 1,831,585

Partial harvest 66.5 9.6 638,659

Seed-tree/shelterwood 10.1 4.5 45,903

Commercial thinning 155.6 7.5 1,166,863

Timber stand improvement 12.3 4.3 52,915

Total 412.4 3,735,925

a For final harvest acres standing residual inventory includes the biomass 

in trees ≥1.0-inch d.b.h. For all other tree harvesting standing residual 

inventory includes only rough and rotten trees ≥1.0-inch d.b.h.
6

annually, while commercial thinning occurred on 155,600 

acres each year. Total timberland area with evidence of tree 

cutting averaged roughly 412,400 acres annually.

Total biomass in standing residual inventory on all acres 

with tree cutting averaged >3.7 million tons annually. 

On final harvest acres—which includes clearcutting—

loggers left an average of 1.8 million tons of biomass per 

year in residual inventory (all standing inventory trees 

≥1.0 inch d.b.h.). This equates to 10.9 tons per acre of 

unutilized biomass on final harvest sites each year that 

could potentially supply a bioenergy industry. Estimates of 

residual biomass for all other cutting includes only rough 

and rotten trees ≥1.0 inches d.b.h. Biomass in rough and 

rotten trees on these acres averaged 1.9 million tons, or 7.8 

tons per acre, per year. 

The volume attributed to South Carolina’s TPO and logging 

residues are generated from the cutting that occurred on 

the 412,400 acres. Table 2 shows the estimate of logging 

residue as a component of timber removals. Biomass in 

logging residue averaged 7.8 million tons annually from 

2001 to 2005. Nearly 5.3 million tons were from softwoods 

while 2.5 million tons were from hardwood species. 

Averaged over all acres with evidence of cutting, nearly 

19 tons of biomass per acre were left as logging residue, 

material potentially recoverable for biofuel. 

Table 2—Annual timber removals by class, species group, 

and source, South Carolina, 2001 to 2005

Removals class

and species group

All

sources

Source

All live

removals

Other 

sourcesa

green tons

Roundwood products

Softwood 18,636,115 18,049,425 586,690

Hardwood 4,993,773 4,682,169 311,604

Total 23,629,888 22,731,594 898,294

Logging residuesb

Softwood 5,306,869 1,497,913 3,808,956

Hardwood 2,494,400 1,383,660 1,110,740

Total 7,801,269 2,881,573 4,919,696

Other removalsc

Softwood 1,585,877 1,178,665 407,212

Hardwood 2,678,848 2,133,570 545,278

Total 4,264,725 3,312,235 952,490

Total removals

Softwood 25,528,861 20,726,003 4,802,858

Hardwood 10,167,021 8,199,399 1,967,622

Total 35,695,882 28,925,402 6,770,480

a Includes stumps, tops, and limbs.

b

 The unused portion of trees cut or destroyed during logging 

operations. 

c

 The volume of trees removed from the inventory by cultural 

operations, resulting in the removal of the trees from timberland.

Pine saw-log operation in Newberry County, South Carolina. (photo by Nathan Smith)
7

Based on current FIA estimates, biomass from standing 

residuals and logging residue combined totaled 26.8 tons 

per acre on acres with tree harvesting activity. These are 

currently unutilized, sustainable sources of biomass material 

that could help develop and supply a bioenergy industry in 

the State without increasing current harvesting rates.

Potential Biomass From Commercial Thinning

Recall that for this study, commercial thinning would be 

included as a potential source for biofuel if (1) poletimber 

volume had increased significantly over time, and (2) that 

the increase could be maintained in the future. To determine 

whether these requirements were met, we analyzed the 

distribution of volume by diameter class for soft hardwood, 

hard hardwood, and southern yellow pine species groups for 

the 2001 and 2006 FIA surveys (fig. 1). The southern yellow 

pine volume includes other softwoods which contribute little 

to estimates of total pine volume in South Carolina.

From 2001 to 2006, volume in the poletimber diameter 

classes (the 6-inch and 8-inch classes) for both hardwood 

species groups remained relatively unchanged (fig. 1a and 

b). Based on FIA estimates, there is currently no excess 

volume of hardwood poletimber to contribute to biomass 

supply. The minor changes in volume indicate that growth 

and removals of hardwood poletimber are generally in 

balance. To assume that one-half of the volume and net 

growth of hardwood poletimber could be harvested for 

biomass might risk overcutting in those diameter classes 

and negatively effecting future volume trends. Therefore, 

we excluded commercial thinning of hardwoods from 

consideration as potential feedstock for bioenergy at this 

time. 

Southern yellow pine poletimber presents a much different 

case to consider. Since 2001, southern yellow pine 

poletimber volume has increased substantially (fig. 1c), 

adding to the softwood volume that has been accumulating 

for decades. This increased poletimber volume met one 

requirement for consideration as a potential source for 

biomass. Additional analysis, however, suggests that the 

increase may be short lived.

The rate of planting in South Carolina—more specifically 

the rate of planting loblolly pine—has trended downward 

since the late 1990s, and has dropped substantially since 

2001 (fig. 2). As a result, there are far fewer acres of young 

southern yellow pine stands (0–15 years old) available 

Feller buncher thinning in a 25-year old loblolly pine plantation. (photo by Tony Johnson)
8

Figure 1—All-live tree volume on timberland in South Carolina by diameter class, species 

group, and survey year.

(b) Hard hardwoods

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

6 8 10 12 14 16 18 20 21 28

Diameter class (inches)

All live volume (million cubic feet)

2006 2001

(c) Southern yellow pine

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

6 8 10 12 14 16 18 20 21 28

Diameter class (inches)

All live volume (million cubic feet)

2006 2001

(a) Soft hardwoods

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

6 8 10 12 14 16 18 20 21 28

Diameter class (inches)

All live volume (million cubic feet)

2006 2001
9

to replace older stands now ready for harvest (fig. 3). The 

current high level of softwood poletimber volume will 

diminish as these trees grow from the pulpwood diameter 

classes to higher value products. Although commercial 

thinning of softwood poletimber is currently an option, there 

is reason to doubt that this biomass source would continue to 

be available at such high levels in the long term. 

Based on our analysis, neither softwood or hardwood 

poletimber should currently be considered as a potential 

source as feedstock for bioenergy development. However, 

the criteria used to arrive at this decision should be 

reassessed as new inventory data are made available. 

Our approach considers only the biological constraints 

determining the supply of biomass from commercial 

thinnings. Increases in the price per ton for bioenergy fuel 

will greatly influence how South Carolina’s poletimber 

resource is utilized. The effect of price on the utilization of 

poletimber was considered outside the scope of this study.

Overstocked Stands: Potential Biomass From 

Precommercial Thinnings

There are almost 425,900 acres of natural sapling-seedling 

stands with no evidence of cutting in South Carolina 

that offer a potential source for biomass (table 3). These 

overstocked timberland acres support nearly 7.2 million 

green tons of biomass in small-diameter trees (1.0–4.9 inches 

d.b.h.). Just over 4.7 million tons would come from thinning 

acres of hardwood forest types. Assuming markets are 

available, a precommercial thinning on 10 percent of the total 

acres annually, removing 75 percent of the biomass in small 

trees, could provide about 540,000 tons annually to supply 

South Carolina’s bioenergy industry.

Mill Residue: Nearly All is Utilized for Other 

Products

Estimates from the 2007 forest industry survey (Johnson 

and Adams 2009) indicate that nearly 6.2 million tons 

of wood and bark residue were generated from primary 

0

20

40

60

80

100

120

140

160

180

1981 1984 1987 1990 1993 1996 1999 2002 2005 2008

Year

Seedlings planted (millions)

Cost share

Noncost share

Figure 2—Number of seedlings planted in South Carolina, 1981 to 2008.
10

0.0

0.2

0.4

0.6

0.8

1.0

1.2

Age class (years)

Acres (millions)

0 to 5

11 to 1521 to 25

31 to 35

81 to 8591 to 95

100+

41 to 4551 to 5561 to 6571 to 75

Figure 3—Distribution of southern yellow pine forest land by age class, South Carolina, 2007.

Topping pine trees on a pine logging operation in upstate South Carolina. (photo by Nathan Smith)
11

Table 4—Primary mill residue by roundwood type, species group, and residue 

type, South Carolina, 2007

Roundwood type 

and species group 

All

types

Residue type

Bark Coarse Sawdust Shavings

green tons

Saw logs

Softwood 3,580,514 553,019 1,554,385 920,326 552,784

Hardwood 279,525 55,731 120,306 102,351 1,137

Total 3,860,039 608,750 1,674,691 1,022,677 553,921

Veneer logs

Softwood 589,248 95,815 232,300 261,133 0

Hardwood 117,846 19,143 49,233 49,470 0

Total 707,094 114,958 281,533 310,603 0

Pulpwood

Softwood 697,655 697,655 0 0 0

Hardwood 313,961 313,961 0 0 0

Total 1,011,616 1,011,616 0 0 0

Other industriala

Softwood 585,382 475,523 107,304 2,555 0

Hardwood 0 0 0 0 0

Total 585,382 475,523 107,304 2,555 0

Total

Softwood 5,452,799 1,822,012 1,893,989 1,184,014 552,784

Hardwood 711,332 388,835 169,539 151,821 1,137

Total 6,164,131 2,210,847 2,063,528 1,335,835 553,921

a Includes poles, pilings, posts, and all other industrial products.

processors in South Carolina (table 4). The bulk of this 

residue, 5.5 million tons, comes from processing softwoods. 

Sawmills and veneer mills combined generated 4.6 million 

tons. Bark (2.2 million tons) and coarse residues (2.1 million 

tons) together comprised 69 percent of the mill residue 

produced. The State’s primary processing mills generate a 

substantial amount of residue, but virtually all of this material is currently used to manufacture primary and secondary 

products, or used as energy sources to fire boilers and kilns.

Table 5 shows the disposal and use of South Carolina’s 

mill residue for 2007. More than 3.3 million tons were used 

for industrial fuel either at pulpmills for boiler fuel or at 

sawmills for dry kiln operations. Bark and sawdust, at 1.9 

and 1.2 million tons, respectively, accounted for 95 percent 

of mill residue utilized for fuel. Nearly 88 percent of bark 

residue produced was utilized for fuel, with the remainder 

going for mulch or miscellaneous products. The bulk of 

coarse residue produced, 1.8 million tons, was utilized for 

pulp or fiber products.

Table 3—Biomass in trees < 5.0 inches diameter at breast height 

(d.b.h.) in overstocked natural sapling-seedling timberland 

stands with no tree harvest activity, South Carolina, 2006

Forest-type group

Overstocked natural

sapling-seedling

timberland acres, 

no cutting

Biomass in 

trees <5.0 

inches d.b.h.

thousand acres green tons

Natural longleaf-slash 11.0 46,241

Natural loblolly-shortleaf 106.1 2,435,985

Natural oak-pine 73.2 700,693

Oak-hickory 183.0 2,651,072

Oak-gum-cypress 45.6 1,043,029

Elm-ash-cottonwood 6.9 316,995

Total 425.9 7,194,014
12

Reallocation of Mill Residues by Price Points

Mill residues are currently 98 percent utilized, but their 

disposal and utilization could change as bioenergy markets 

develop. With increasing demand and rising fuel prices, 

biomass already being used for fuel could be reallocated 

to new markets in closer proximity to the producing mill. 

Increased prices would also make bioenergy markets more 

competitive for the biomass that currently goes to mulch 

and fiber products. Additional research on the sales price 

of biomass to existing markets is needed to better assess 

potential reallocation of mill residues.

Results from the mill survey provided the price point at 

which mill residue could potentially be used as feedstock for 

biofuels. Nineteen mill surveys were returned and ranged 

from 1 to 10 mills reporting for each of the mill residue 

types. The price and hauling distances are shown in table 6.

Table 5—Disposal of residue at primary wood-using plants by product, 

species group, and type of residue, South Carolina, 2007

Product and

species group

All

types

Residue type

Bark Coarse Sawdust Shavings 

green tons

Fiber products 

Softwood 1,641,314 0 1,641,314 0 0

Hardwood 147,753 0 147,753 0 0

Total 1,789,067 0 1,789,067 0 0

Particleboard

Softwood 389,573 0 45,835 14,862 328,876

Hardwood 0 0 0 0 0

Total 389,573 0 45,835 14,862 328,876

Sawn products

Softwood 58,910 0 58,910 0 0

Hardwood 0 0 0 0 0

Total 58,910 0 58,910 0 0

Industrial fuel

Softwood 2,856,535 1,591,300 74,031 1,101,587 89,617

Hardwood 481,384 346,952 15,592 117,713 1,127

Total 3,337,919 1,938,252 89,623 1,219,300 90,744

Miscellaneous

Softwood 505,360 230,523 73,324 67,222 134,291

Hardwood 73,270 41,424 6,159 25,677 10

Total 578,630 271,947 79,483 92,899 134,301

Not used

Softwood 1,107 189 575 343 0

Hardwood 8,925 459 35 8,431 0

Total 10,032 648 610 8,774 0

All products

Softwood 5,452,799 1,822,012 1,893,989 1,184,014 552,784

Hardwood 711,332 388,835 169,539 151,821 1,137

Total 6,164,131 2,210,847 2,063,528 1,335,835 553,921
13

Table 6—Annual production of biomass, delivered price per 

green ton, and average distance hauled for existing biomass 

producers, South Carolina, 2008

Species group and 

residue type

Mills 

reporting

Average 

pricea

Average 

distance 

hauled

Price point 

to include 

biomass

number dollars 

per ton

miles dollars

Softwood

Sawdust 6 23.75 27 20 to 28b

Shavings 9 49.85 35 NA

Bark 10 14.30 24 20 

Chips 7 27.00 30 28 

Other coarse residues 1 18.00 30 20 

Hardwood

Sawdust 2 12.92 26 20 

Shavings NA NA NA 20 

Bark 2 10.66 20 20 

Chips 2 20.07 57 20 

Other coarse residues 2 13.49 45 20 

NA = not available.

a Average price is price per ton delivered to producing mill.

b Apportion 20 percent of the biomass in sawdust per $2 price increase.

Table 7—Annual production of urban wood waste in 

South Carolina, fiscal year 2007a

Biomass source Facilities Biomass Utilized

number tonsb percent

Recycled wood and paper NA 994,028 100

Wood grinding/

composting operations 93 579,985 90

Construction/

demolition landfills 150 351,195 0

Land clearing debris landfills 40 133,461 0

Incinerators 7 21,997 0

Total 2,080,666 73

NA = not available.

a Department of Health and Environmental Control (2008).

b

 Includes both green and dry tons.

Based on the results of the survey, most types of mill 

residue could become available at a delivered price of $20 

per ton. The exceptions include softwood shavings which 

generally are utilized for higher-valued animal bedding, 

softwood chips which would become available at $28 to as 

much as $30 per ton, and softwood sawdust which would 

become available over a price range of $20 to $28 per ton. 

Urban Wood Waste: A Potential Primary 

Contributor to Bioenergy

Urban wood waste is a diverse category of biomass that 

likely will be a primary contributor to the expansion of 

biomass energy facilities in South Carolina. It is perhaps 

the most readily available source of biomass. The average 

landfill tipping fee is $42 per ton, so the avoidance of land 

filling costs makes urban wood waste a low-cost option 

for bioenergy projects. How to best collect and utilize 

this material, however, is an issue that could benefit from 

additional research. Therefore, our estimates of available 

biomass from urban wood waste are conservative.

From July 2006 to June 2007 (FY07), 17.2 million tons of 

total solid waste (TSW) were generated by South Carolina’s 

population of 4.3 million people (Department of Health and 

Environmental Control 2008). This estimate includes both 

green and dry tons. The South Carolina Solid Waste Policy 

and Management Act of 1991 and its amendment in 2000 

regulate the management of solid waste and set recycling 

goals that have increased the availability of urban wood for 

bioenergy projects. Currently, just over 50 percent of TSW 

is recycled and kept out of landfills.

In FY07, just over 994,000 tons of wood and paper—the 

largest source of urban biomass—were recycled (table 7). 

This category includes 726,876 tons of paper, along with 

241,679 tons of yard trimmings, and 25,473 tons of wood 

packaging materials. The bulk of this material has low 

moisture content and therefore a higher Btu value than some 

other sources of biomass. Demand for this material varies 

with overall economic conditions. 

In South Carolina, there are 93 fixed-site wood grinding/

composting operations. These facilities are sometimes 

colocated with C&D landfills, but can be stand-alone 

facilities. In FY07, nearly 580,000 tons of biomass were 

processed primarily for boiler fuel, mulch and compost. 

Ninety percent of this material was utilized with the 

remainder going to landfills. 

A total of 3.6 million tons of C&D debris was generated in 

FY07. The 150 C&D landfills are broadly classified into 

four categories based on the material they receive. The 

40 LCD landfills are the only landfills used solely for the 

disposal of trees, stumps, wood chips, and yard trash. In 

FY07, the LCD landfills received 133,461 tons of woody 
14

biomass. In 1998, Wiltsee (1998) reported that 18–20 

percent of all C&D debris was wood. With South Carolina’s 

success in recycling previously landfilled materials, it is 

judged that 10 percent of the C&D debris is useable (not 

treated or painted) woody material that could be utilized for 

bioenergy. This amounts to 351,195 tons of woody biomass 

going into C&D landfills, in addition to the 133,461 tons 

going into LCD landfills.

Seven incinerating facilities are located in South Carolina 

that process 21,997 tons of LCD. This volume could be a 

potential source for bioenergy production.

In FY07, a total of 2.1 million tons of urban wood waste 

was generated in South Carolina. This material ranges 

in moisture content from kiln-dried lumber to green land 

clearing debris. Seventy-three percent of the urban wood 

is currently being utilized for boiler fuel, mulch, compost, 

or recycled paper content. Increased competition for urban 

wood could result in reallocation of the material currently 

utilized. A reduction in the urban biomass going to existing 

industry operators would necessitate substitution from other 

sources. 

Estimating Recoverable Logging Residue: Timber 

Producer Survey Results

Twenty-five of the 148 timber producers in South Carolina 

responded to the survey. Six producers indicated that they 

were currently producing biomass from logging residues 

while 19 producers responded that they would invest in the 

equipment necessary to harvest the material. There was no 

appreciable difference in responses by region.

The six producers already recovering biomass from 

logging operations estimated their annual production 

level, the average delivered price per ton, and the average 

hauling distance within their region of operation. Biomass 

production for the six current producers totaled 225,500 

tons, ranging from 10,000 to 100,000 tons per year, and 

averaged 37,583 tons per year (table 8). Given 2008 market 

conditions, delivered price ranged from $19 to $22 per ton, 

with an average of $20.82 per ton. Haul distance ranged 

from 20 to 55 miles, averaging 44 miles. 

Table 8—Annual production, average delivered price per green ton, and 

average haul distance for existing biomass producersa

, South Carolina, 2008

Region

Annual 

production

Average 

delivered 

price

Average 

haul 

distance Value 

tons per 

year

dollars per 

ton

miles tons per year

x price per ton

Southern Coastal Plain 32,500 19.00 40 $ 617,500

Southern Coastal Plain 100,000 22.00 50 $2,200,000

Piedmont 15,000 20.00 35 $ 300,000

Northern Coastal Plain 50,000 20.00 45 $1,000,000

Southern Coastal Plain 10,000 20.00 55 $ 200,000

Southern Coastal Plain 18,000 21.00 20 $ 378,000

All 225,500 $4,695,500

a Average production was 37,583 green tons per year, average delivered price was $20.82 per 

green ton, and average haul distance was 44 miles.
15

The 19 timber producers not currently recovering biomass 

were asked to determine what their price per ton might be to 

recover the cost of investing in the equipment necessary to 

harvest logging residues, assuming a 30-mile haul distance. 

They were also asked to estimate the weekly production of 

biomass material they could potentially recover. Their estimates reflect their operating costs and production capacity 

as of 2008. 

The estimated annual production capacity of biomass for 

the 19 potential biomass producers totaled 652,426 tons 

(table 9), or an estimated average production of 34,338 tons 

of biomass per year. Their estimated delivered price for a 

30-mile haul averaged $27.50 per ton. When weighted by 

production level, their estimated delivered price declined 

slightly to $26.29 per ton.

We assumed that the 25 existing and potential biomass 

producers who responded to the survey represented all 

timber producers in the State. Responses were combined 

to determine total potential biomass production (877,926 

tons) and to establish a range of delivered price points per 

ton of biomass, based on 2008 conditions. As the price per 

ton increased, we assumed that more of South Carolina’s 

loggers statewide would begin harvesting an increasing 

percentage of biomass in logging residue. The price points 

ranged from $20 to $30 per ton:

Table 9—Estimated annual production and target delivered 

price per green ton for potential biomass producersa

, South 

Carolina, 2008

Region

Estimated 

annual 

production 

Target 

delivered 

price Value

tons per 

year

dollars 

per ton

tons per year

x price per ton

Piedmont 52,000 26.00 $ 1,352,000

Piedmont 45,500 28.00 $ 1,274,000

Piedmont 6,500 30.00 $ 195,000

Piedmont 52,000 25.00 $ 1,300,000

Southern Coastal Plain 26,000 26.00 $ 676,000

Southern Coastal Plain 78,000 24.00 $ 1,872,000

Piedmont 7,800 28.00 $ 218,400

Piedmont 32,894 28.00 $ 921,032

Piedmont 18,200 26.00 $ 473,200

Southern Coastal Plain 78,000 28.00 $ 2,184,000

Southern Coastal Plain 15,600 22.50 $ 351,000

Piedmont 26,000 25.00 $ 650,000

Southern Coastal Plain 26,000 22.00 $ 572,000

Piedmont 6,500 50.00 $ 325,000

Piedmont 18,200 30.00 $ 546,000

Piedmont 32,894 27.00 $ 888,138

Piedmont 26,000 26.00 $ 676,000

Southern Coastal Plain 34,338 25.00 $ 858,450

Southern Coastal Plain 70,000 26.00 $ 1,820,000

Total 652,426 $17,152,220

a Average estimated production of biomass was 34,338 green tons per year 

and average delivered price for a 30-mile haul was $27.50 per green ton.

Delivered price point 

(dollars per ton for 

30-mile haul distance) $20 $22 $24 $26 $28 $30 

Cumulative percent 

of logging residues 

recovered 12% 30% 39% 74% 96% 100%

At $20 per ton, South Carolina’s existing biomass producers could recover a combined 125,500 tons of the available 

biomass in logging residue (table 8). This equates to 12 

percent of the total available, which we assumed would represent the percentage collected if all 148 timber producers in 

the State harvested logging residue. The price for biomass 

would have to rise to $22 per ton before a potential producer 

could afford to harvest the material (table 9). At that price 

per ton, existing and potential producers combined could 

harvest a cumulative 30 percent of the biomass in unutilized 

logging residue. Nearly three-fourths would be recovered at 

$26 per ton. At $30 per ton, it is assumed that all biomass 

producers in the State would be involved, resulting in a 

100-percent recovery of available biomass.

Obviously, a 100-percent recovery rate is unlikely, if 

not impossible. Other studies suggest that a 60-percent 

recovery rate is plausible (Perlack and others 2005). Using 

60 percent as the maximum rate of recovery, we applied 

the price points and cumulative percentages recovered to 

the estimates of logging residue from tree cutting activity 

(shown in table 2) to estimate the proportion potentially 

recoverable. 
16

Table 10 shows the distribution of recoverable logging 

residue by price point at the State level for softwood and 

hardwood biomass combined. The estimates in table 10 

do not include stump volume that, for this study, was considered unrecoverable. Based on expert opinion, we also 

adjusted the logging residue from nonmerchantable trees 

(<5.0 inches d.b.h.) killed during the logging to include only 

20 percent as recoverable biomass (Lupold 2008).

With those adjustments, we estimate that, at $20 per 

ton, South Carolina’s loggers could recover just over 

Table 10—Biomass of recoverable logging residue by potential price per green ton, recovery 

rate, and green tons per acre, South Carolina, 2001 to 2005

Potential

price per tona

Size class of

 harvested 

trees

Recoverable logging residue in harvested treesb

Merchantablec

Nonmerchantabled Total

Tons 

per acre

inches green tons

$20 >5 208,533 321,594 530,127 1.3

<5 0 74,014 74,014 0.2

All trees 208,533 395,608 604,141 1.5

$22 >5 469,201 723,587 1,192,788 2.9

<5 0 166,531 166,531 0.4

All trees 469,201 890,118 1,359,319 3.3

$24 >5 625,601 964,783 1,590,384 3.9

<5 0 222,042 222,042 0.5

All trees 625,601 1,186,825 1,812,426 4.4

$26 >5 1,173,003 1,808,969 2,981,972 7.2

<5 0 416,327 416,327 1.0

All trees 1,173,003 2,225,296 3,398,299 8.2

$28 >5 1,642,310 2,201,121 3,843,431 9.3

<5 0 536,599 536,599 1.3

All trees 1,642,310 2,737,720 4,380,030 10.7

$30 >5 1,564,010 2,411,952 3,975,962 9.6

(60% recovery rate) <5 0 555,105 555,105 1.3

All trees 1,564,010 2,967,057 4,531,067 11.0

a Potential price per green ton determined from statewide logger survey.

b Distribution of logging residue by potential price per green ton assumes a maximum of 60 percent of total 

residue produced is recoverable.

c For harvested trees ≥5.0 inches diameter at breast height (d.b.h.), the volume in the bole from a 1-foot stump 

to a 4-inch top.

d For harvested trees ≥5.0 inches d.b.h., it is the volume in the portion of the tree above a 4-inch top, and 

the volume in limbs to a 1-inch end diameter. Also includes total volume (from 1-foot stump to 1-inch top 

diameter) of trees <5.0 inches d.b.h.

604,000 tons of biomass per year, including >74,000 tons in 

the small-diameter trees. At each $2-increment in the price 

per ton established by the timber producer survey, more 

biomass would become available to supply a bioenergy 

industry. At $30 per ton, the proposed 60-percent maximum 

recovery rate would be reached and > 4.5 million tons of 

biomass would potentially be recovered from the 412,400 

acres of timberland with tree harvest activity. At that price 

per ton, all potential biomass producers in the State would 

be able to invest in the needed equipment to harvest the 

previously unutilized logging residue.
17

Summary: Total Biomass Potential at Price Points

Table 11 summarizes the total biomass potential from all 

sources identified in this study. The price points and cumulative percent recovery rates established by the logger survey 

were again used to apportion the total potential biomass by 

increasing price per ton. Individual estimated values have 

been rounded to the nearest thousand tons. Table colors 

identify whether the biomass is currently utilized (black), 

partially utilized (light gray), or unutilized (medium gray).

At $20 per ton, biomass from all sources could provide 

> 4.8 million tons to supply a biofuels industry in South 

Carolina. Increasing the price per ton to the $30 maximum 

could result in a total of 16.5 million tons of biomass each 

year, assuming all of the biomass would be available for 

bioenergy production. As of 2008, just over 8.8 million tons 

were unutilized, including 540,000 tons from precommercial 

thinning. However, the technology and experience needed 

to efficiently and economically harvest this small-diameter 

(precommercial) material and logging residue currently are 

lacking. 

Results from the mill survey established that virtually all 

mill residue currently produced is utilized for other purposes. However, assuming competition for this material 

would arise from the development of a bioenergy industry, 

mill residue alone would supply the most biomass across the 

range of prices. At $20 per ton, nearly 2.6 million tons of 

mill residue could be diverted to use as biofuel. That rises to 

>5.6 million tons at $28 per ton. 

Table 11—Potential biomass in South Carolina, by source and cost

Source

Cost per ton (dollars)

20 22 24 26 28 30

tons

Unutilized

Logging residuea 600,000 1,360,000 1,800,000 3,400,000 4,380,000 4,530,000

Standing residuals 448,000 1,121,000 1,457,000 2,765,000 3,587,000 3,736,000

Precommercial thinning 0 0 0 0 0 540,000

Total 1,048,000 2,481,000 3,257,000 6,165,000 7,967,000 8,806,000

Utilized

Mill residue 2,571,000 2,931,000 3,291,000 3,651,000 5,610,000 5,610,000

Urban wooda 1,252,000 1,418,000 1,584,000 1,749,000 1,915,000 2,081,000

Total 3,823,000 4,349,000 4,875,000 5,400,000 7,525,000 7,691,000

Total 4,871,000 6,830,000 8,132,000 11,565,000 15,492,000 16,497,000

Numbers in shaded areas: black = currently utilized; light gray = partially utilized; and medium gray = not utilized.

a

 Includes both green and dry tons.

At $26 per ton, volume from logging residue and standing residuals combined (< 6.2 million tons) would surpass 

mill residue (> 3.6 million tons) as potential feedstock for 

biofuel. At this price and higher, the two sources together 

account for more than one-half of the potential biomass 

produced in the State. Biomass from urban wood waste 

could add almost 2.1 million tons at the $30 price per ton.

Discussion

Interest in woody biomass for energy production rises and 

falls with the changes in fossil fuel costs. Energy costs 

are once more on the rise creating an environment where 

investing in biomass for energy feedstock is again a financially viable alternative. The biofuels producers are vital 

to expanding the bioenergy industry in South Carolina. 

Industry expansion may hinge on efforts by the Federal government and private industry to encourage capacity building.

Successful development depends on many factors, not the 

least of which is an available and sustainable supply of raw 

material. Results from this study indicate that a substantial 

amount of wood fiber in South Carolina, primarily in the 

form of logging residue and standing residuals, is currently 

underutilized. This untapped volume of biomass could 

support development of a biofuels industry without an 

increase in harvesting. 
18

Logging residue is not utilized for a variety of reasons but 

for the most part it is simply material that has not “paid its 

way” out of the woods. Markets for unused logging residue 

and for harvesting small-diameter trees (<5.0 inches d.b.h.) 

from plantation thinnings, for example, largely have been 

lacking (Straka and others 2004). Growing interest in biofuels, including biomass gasification to ethanol, may create 

needed markets (Scott and Tiarks 2008, Straka and others 

2004). New markets and improved technology would make 

recovering small-diameter logging residue and harvesting 

standing residuals financially viable for loggers. This, in 

turn, could create an additional source of income for forest 

landowners, and would reduce their site preparation costs. 

Millions of dollars are being invested for research and 

development to produce energy from these sources more 

efficiently. Biomass can be chipped and burned for fuel, or 

processed into other biofuels products. Wood pellet manufacturing is somewhat new to the South, but it is a $250 

million industry nationwide. A few Southern States are now 

producing pellets, or have announced plans to build wood 

pellet plants (Timber Mart-South 2007). As of 2007, there 

were 24 pellet fuel manufacturers in the South, including 5 

in Arkansas, 4 in Georgia, 3 in Kentucky, and 3 in Virginia 

(Southern Bioenergy Roadmap 2009). 

There are several ways to gauge the impact that biomass 

can have on electrical production. In terms of total retail 

sales, renewable biomass has the potential to supply 12–14 

percent (depending on assumptions) of the electricity sold to 

all users in South Carolina. The top five electricity producers in South Carolina produce 64.0 million megawatt hours 

of electricity annually (Energy Information Administration 

2009). Renewable biomass could account for 18 percent of 

their current production.

A very important measure of capacity to the electric utility 

industry is the generating capacity for the hottest day of the 

summer when electricity demands are highest. Renewable 

biomass could increase the peak summer generation 

capacity by 6.2 percent and help prevent brownouts.

Unutilized hardwood logging residue. (photo by Tony Johnson)
19

Conclusions

The objectives of this study were to provide estimates of 

unutilized biomass and determine the price per ton needed 

by South Carolina’s timber producers to make collection 

of the material financially viable. These critical pieces of 

information provide the basis for assessing the potential 

for developing a biofuels industry in the State. Our results 

show that, over the estimated range of price per ton, the 

estimates of biomass produced from all sources considered 

in this study would support and sustain a biofuels industry 

of increasing scale in South Carolina. Considering only the 

8.8 million annual tons of biomass currently unutilized, new 

facilities that use wood to produce energy could operate in 

the State without overly impacting existing forest industries 

or increasing harvest levels above current rates. 

Obviously, the situation is dynamic, and there are other 

factors outside the scope of this study that should be considered. For example, draft legislation under consideration 

by Congress would establish a Renewable Energy Standard 

requiring that a percentage of the electricity generated in 

the U.S. to come from renewable fuels, including biomass 

(Wilent 2009). Proposed definitions of what qualifies as 

renewable sources could restrict the availability of logging 

residue as feedstock for bioenergy production. The full 

extent of the impacts from the proposed legislation is as yet 

unknown. However, we believe that the biomass sources 

considered in this study should readily qualify as renewable.

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energy and conventional wood products. Southern Journal of Applied 

Forestry. 32(1): 33-37.

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Energy Resources Alliance. Research Triangle Park, NC. 127 p.

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problem or opportunity? Carolina Forestry Journal. July: 4-5.

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expanding in the South. Market News Quarterly, 1st Quarter 2007: 22-25.

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Conner, Roger C.; Adams, Tim O.; Johnson, Tony G. 2009. Assessing the potential for 

biomass energy development in South Carolina. Res. Pap. SRS–46. Asheville, NC: U.S. 

Department of Agriculture Forest Service, Southern Research Station. 19 p.

An assessment of the potential for developing a sustainable biomass energy industry in South 

Carolina was conducted. Biomass as defined by Forest Inventory and Analysis is the aboveground 

dry weight of wood in the bole and limbs of live trees ≥1-inch diameter at breast height, and 

excludes tree foliage, seedlings, and understory vegetation. Several possible sources of biomass 

were analyzed: unutilized logging residue and standing residual inventory trees on acres with 

tree harvesting; commercial thinning; precommercial thinning on overstocked natural saplingseedling stands; mill residue; and urban wood waste. A range of prices from $20 to $30 per ton 

was established by surveys sent to South Carolina’s timber producers. Prices reflect 2008 market 

conditions. The estimates of potential biomass distributed across these price points rose from 4.8 

million tons to a total of 16.5 million tons annually. Nearly 7.7 million tons are currently being 

utilized. New facilities that use wood to produce energy could capitalize on the 8.8 million annual 

tons of unutilized biomass and operate without overly impacting existing forest industries or 

increasing harvest levels above 2006 estimates. 

Keywords: Biofuel, biomass markets, FIA, forest landowner, green tons, hardwood poletimber, 

haul distance, softwood poletimber, timberland.
The Forest Service, U.S. Department of Agriculture (USDA), 

is dedicated to the principle of multiple use management of the 

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to provide increasingly greater service to a growing Nation.

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