Mark A. White

Environmental Life Cycle Comparison of Algae to Other Bioenergy Feedstocks

Algae are an attractive source of biomass energy since they do not compete with food crops and have higher energy yields per area than terrestrial crops. In spite of these advantages, algae cultivation has not yet been compared with conventional crops from a life cycle perspective. In this work, the impacts associated with algae production were determined using a stochastic life cycle model and compared with switchgrass, canola, and corn farming. The results indicate that these conventional crops have lower environmental impacts than algae in energy use, greenhouse gas emissions, and water regardless of cultivation location. Only in total land use and eutrophication potential do algae perform favorably. The large environmental footprint of algae cultivation is driven predominantly by upstream impacts, such as the demand for CO(2) and fertilizer. To reduce these impacts, flue gas and, to a greater extent, wastewater could be used to offset most of the environmental burdens associated with algae. To demonstrate the benefits of algae production coupled with wastewater treatment, the model was expanded to include three different municipal wastewater effluents as sources of nitrogen and phosphorus. Each provided a significant reduction in the burdens of algae cultivation, and the use of source-separated urine was found to make algae more environmentally beneficial than the terrestrial crops.

Comparison of algae cultivation methods for bioenergy production using a combined life cycle assessment and life cycle costing approach.

Algae are an attractive energy source, but important questions still exist about the sustainability of this technology on a large scale. Two particularly important questions concern the method of cultivation and the type of algae to be used. This present study combines elements of life cycle analysis (LCA) and life cycle costing (LCC) to evaluate open pond (OP) systems and horizontal tubular photobioreactors (PBRs) for the cultivation of freshwater (FW) or brackish-to-saline water (BSW) algae. Based on the LCA, OPs have lower energy consumption and greenhouse gas emissions than PBRs; e.g., 32% less energy use for construction and operation. According to the LCC, all four systems are currently financially unattractive investments, though OPs are less so than PBRs. BSW species deliver better energy and GHG performance and higher profitability than FW species in both OPs and PBRs. Sensitivity analyses suggest that improvements in critical cultivation parameters (e.g., CO(2) utilization efficiency or algae lipid content), conversion parameters (e.g., anaerobic digestion efficiency), and market factors (e.g., costs of CO(2) and electricity, or sale prices for algae biodiesel) could alter these results.

ENVIRONMENTAL FINANCE: VALUE AND RISK IN AN AGE OF ECOLOGY

Environmental issues are restructuring markets and redirecting capital flows throughout the world. An outline is provided of concerns facing the development of an environmentally responsible or ‘environmental finance’ perspective. It reviews the major ways in which organizations are responding to environmental threats and opportunities in the three major branches of finance — corporate finance, investments and financial institutions — highlighting in particular novel programs and initiatives. In the past, financial concerns have exacerbated the degradation of the natural environment; in the future, they probably hold the key to their preservation.

Will algae produce the green? Using published life cycle assessments as a starting point for economic evaluation of future algae-to-energy systems

Life cycle assessment (LCA) has become an important tool for evaluating the environmental sustainability of proposed algae-to-energy systems. The rapidly evolving body of literature on this topic demonstrates several important lessons, which can be leveraged to evaluate the likely economic sustainability of future algae-derived energy sources. A review of previously published algae LCAs is presented alongside preliminary economic information for three different kinds of algae cultivation systems (open ponds, photobioreactors and algal turf scrubbers), to demonstrate the relevance of algae LCA lessons learned and also contextualize the discussion of LCA-based life cycle costing (LCC) as it pertains to algae. Particularly important LCC themes arising from examination of current algae LCAs include: the critical role of co-products, the need for enhanced uncertainty characterization and the possible benefits of a meta-analysis approach to standardizing LCA and LCC evaluation of algae-to-energy systems.

Economic evaluation of algae biodiesel based on meta-analyses

ABSTRACT The objective of this study is to elucidate the economic viability of algae-to-energy systems at a large scale, by developing a meta-analysis of five previously published economic evaluations of systems producing algae biodiesel. Data from original studies were harmonised into a standardised framework using financial and technical assumptions. Results suggest that the selling price of algae biodiesel under the base case would be

Lessons from Germany: The ‘ecobalance’ as a tool for pollution prevention

5.00–10.31/gal, higher than the selected benchmarks:

A Cost-Benefit Model for Evaluating Remediation Alternatives at Superfund Sites Incorporating the Value of Ecosystem Services

3.77/gal for petroleum diesel, and

Environmental Impacts of Algae-Derived Biodiesel and Bioelectricity for Transportation

4.21/gal for commercial biodiesel (B100) from conventional vegetable oil or animal fat. However, the projected selling price of algal biodiesel (

Sustainability: I know it when I see it

2.76–4.92/gal), following anticipated improvements, would be competitive. A scenario-based sensitivity analysis reveals that the price of algae biodiesel is most sensitive to algae biomass productivity, algae oil content, and algae cultivation cost. This indicates that the improvements in the yield, quality, and cost of algae feedstock could be the key factors to make algae-derived biodiesel economically viable.

Environmental and economic assessment of integrated systems for dairy manure treatment coupled with algae bioenergy production

(1996). Lessons from Germany: The ‘ecobalance’ as a tool for pollution prevention. Social and Environmental Accountability Journal: Vol. 16, No. 1, pp. 3-6.