Las Reglas de Origen de las Mercancías Un contexto general

National. Since the publication of the 2005 BTS, there

has been a proliferation of biomass assessments at various spatial scales, from the state-level to the global level. For example, a Forest Service website lists 30 states with some type of woody biomass assessment and three major regional studies (U.S. Forest Service, 2011b). Many states also have an agricultural biomass resource assessment and some include forest resources. Some assessments go into great detail. As an example, in a study completed for the State of Washington by Oneil and Lippke (2009), field surveys of forest residues on federal, state, and private lands were conducted to develop a model for logging residues as a function of harvest volume.

A recent economic biomass assessment estimates that about 700–1000 million dry tons of agricultural biomass will be available in 2030 at a price up to

availability estimates are similar to the BTS update;

however, at higher prices and a different mixture of feedstocks. The timeline is 2007–2030 for this report whereas the update timeline is 2012–2030. At a comparable $60 per dry ton with the transport costs removed, the report estimates range from about 450 to 780 million dry tons. The study does not include wood, nor does it include any currently used biomass. This will compare to about 250–1300 million dry tons in the update at $60 per dry ton over the range of scenarios and up to 2030.

Parker et al. (2011) use a spatially specific supply model to assess the potential for large-scale biofuels production in the United States. The report includes the same feedstocks as in the update, except it includes more than just wood from MSW and has less optimistic energy crop assumptions. The analysis

baseline assessment data for 2022. For the developed assessment, a low-, baseline-, and high-yield scenario result in about 317, 533, and 797 million dry tons, respectively, at a maximum roadside cost of $200 per dry ton. However, for the baseline scenario, a majority of the MSW and agricultural and forestry residues become available at less than $70 per dry ton, and energy crops are available at costs between $80 and $120 per dry ton. The model is then used to determine the amount of biofuels volumes available using the

BTS update data, where the biorefineries would be

distributed to meet the RFS.

An analysis of the biomass demand for meeting both a theoretical 25% RFS and a 25% RES (renewable electricity standard) by 2025 estimates a need for 1,302 million green tons from agricultural and forestry residues, urban wood wastes, and energy crops (EIA, 2007a). Sample et al. (2010) compare the estimated demand to a Department of Energy supply estimate of 491 million dry tons (approximately 715 million green tons). The available supply is based on several assumptions, including a high energy cost of $5 per million Btu. The limited amount of available biomass is projected to result in a significant shortfall that will be made up from using roundwood (i.e., wood from the bole of trees rather than limbs, tops, and other wastes). The updated BTS estimates approximately 980–1440

total dry tons available in 2025 at a price of $60 per dry ton, which may not result in such a large shortfall if the market supports that price. However, these estimates

include “currently used” biomass and no differentiation as to what biomass is available to meet a specific target or use.

The National Academy of Sciences (NAS, 2009) completed an assessment of biomass for energy and reports that approximately 550 million dry tons per year of cellulosic biomass can be produced by 2020 without any major impact on food production or the environment (see Table 6.3). The estimate does not include corn for ethanol and oil crops for biodiesel. The Academy estimates compare very well to the updated

BTS for the baseline when the currently used biomass

is removed.

International. The Biomass Energy Europe organization invests considerable efforts in standardizing biomass assessments (Rettenmaier, 2010). A comparison of over 150 studies in the European Union concludes that nearly all of the assessments are technical and economic potential studies as compared to the theoretically maximum. The studies are resource based and include land- use competition for biomass with other uses. The deviations in estimated total potentials among these studies are substantial, with differences up to five fold. The authors attribute the large deviations to varying methods, data, and assumptions with the latter being the most significant source of differences, especially the assumptions regarding land availability for energy crops. The updated BTS uses the POLYSYS model

to handle this specific issue, but as explained below, assumptions are very important. Scenarios are used to better present and compare underlying assumptions in the update.

Bauen et al. (2009) estimate that biomass can theoretically provide between one-quarter and one- third of the global primary energy supply by 2030 (see Table 6.4), even when factoring in land use and raw material competition. The current estimate is that biomass supplies about 50 exajoules of primary energy (heating value) (calculated67 _{to be about 3.2 billion} dry tons). This is mostly conventional biomass that is used for heating and cooking in developing countries. An optimistic estimate of the technical potential of sustainable biomass by 2050 is between 200 and 500 exajoules per year (roughly 12–31 billion dry tons).

Feedstock Millions of dry tons

Corn stover 112

Wheat and grass straw 18

Hay 18

Dedicated energy crops 164

Woody 124

Animal manure 12

MSW 100

Total 548

Estimate of U.S. Cellulosic

Biomass by 2020 (NAS, 2009)

Table 6.3

Region Energy crops (M acres) Dry tons (Billion) Europe 62-222 0.4-1.5 USA 2005 BTS 74 1.1 USA 2011BTS 63 1.4 Latin America 299 1.5 China & India 212 1.7

Australia - <4M

Estimate of Global Biomass Potential

by 2030 (Bauen et al., 2009)

Table 6.4

spatial and technical levels. The updated BTS

provides a national-to-county-level economic biomass availability analysis for all agricultural and forest lands. The results from the update roughly align with other assessments, but the underlying assumptions vary and must be addressed in any comparison.

Notes: Timeframes are 2017–2030. 2011 BTS added at $60/

ton for 2030 with 2% scenario. Conversion to dry tons based on 63 million tons per exajoule.

6.3.2 Significance of Underlying