The definition of the indicators would need to specify whether energy needed to prepare land and to transport resources to the site is included. Land indicators are highly dependent on where the land is, though all the indicators have at least some site specificity. DOE could help address these indicators through more detailed studies of the potential biofuel production capacities of specific technologies in various regions of the country.

4.3.5 Information and Data Gaps

Land-use availability databases, land-suitability databases, and geo-spatial resource maps compiled specifically for the purpose of assessing the potential for algal biofuel production are incomplete (Darzins et al., 2010). A number of relevant resource maps for the United States and the world can be found in Lundquist et al. (2010), who also present a detailed geographic information systems (GIS)-based analysis of algal biofuel production in California. Continued efforts to perform meta-analyses of existing LCAs are desirable to comprehensively assess the land requirements and the most likely site locations for future algal biofuel production.

4.3.6 Effects on Social Acceptability

Part of the appeal of algae production as a renewable fuel source is the potential small land area required to produce a given quantity of energy relative to terrestrial crops. However, commercial-scale algal biofuel facilities, especially those relying on open-pond cultivation systems, still will require thousands of hectares of land to achieve sufficient economies of scale. Despite the algal industry’s general focus on using marginal and degraded land for development of commercial-scale facilities, questions still may be raised as to the potential social and health-related risks of developing such large areas for the purpose of algae production.

Land in the desert Southwest is suitable for the scale-up of algae cultivation facilities because of favorable climatic conditions for algal growth. While much of the land in this region has been designated as marginal due to its inability to support food production, public support for large-scale land developments, even in the renewable-energy sector, is not guaranteed. The arid conditions and infertile soil in the desert Southwest support highly fragile ecosystems that take far longer to recover following major disturbances than ecosystems in wetter climates. These areas also contain a number of threatened or endangered species that are the focus of major conservation efforts and public awareness campaigns, such as the desert tortoise. Setbacks to the construction of commercial-scale photovoltaic facilities have resulted over concern for the vulnerability of these ecosystems, forcing solar developers to purchase additional land as conservation easements and to create wildlife rehabilitation and protection programs (BLM and DOE, 2010). The algal biofuel industry likely will face similar hurdles as it continues toward commercialization; actively engaging the public and conservation organizations during the site selection and permitting process could help overcome those barriers.

Even if algae developers have gained acceptance from the public, the definition of marginal or degraded land is fluid and depends on both the technology available for farming and the macroeconomic and geopolitical conditions at a given time. For example, land that is considered marginal and unsuitable for traditional freshwater farming today may be considered suitable in the future if a cultivar of a food crop is developed to tolerate dryer or less fertile soils. Pressure to use that land for food rather than energy production



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