Reviewer Comments - EERE

2011 Algae Platform Review – Reviewer Comments
Reviewer Comments are direct transcripts of commentary and material provided by the Platform’s
Review Panel. They have not been edited or altered by the Biomass Program.
presentation, and that from INL (Newby). It seems to duplicate that work, and its difficult to see the
interconnection.
That said, its an important resource model and these efforts are important. However, a much more defined
relationship to the other PNNL model would be recommended.
Reviewer: 7 Criteria Score: 7
The project management plan would benefit from some in-progress validation process, perhaps including
virtual and real visits to sites deemed suitable for alagla biofuel production.
Definition of goals for model accuracies might have value.
Presenter Response
1.1 N/C 1.2 The canonical Redfield ratio is a valuable starting point for incorporating nutrient use into our
general model. As with any model, keeping the underlying assumptions in mind is necessary for
interpreting the model. It will be beneficial to ensure the model is built with flexibility in regarding later
adjustments in the C:N:P ratio. After completing the general model, adjusting the C:N:P ratio to reflect, in
turn, a diatom and a green alga may be good next steps. The caveat to these iterations of the model would
be that different strains are likely to be employed in different climates and latitudes, so we will utilize
different strain-specific ratios as appropriate and as data become available. Furtrher, future algal
biological and cultivation research may provide data and understanding leading to a more mechanistic,
improved approach to modeling nutrient use. We are collaborating with the NAABB Algal biology and
Algal Cultivation Teams as they generate new information on algal productivity as a function of nutrient
sources and use and climatic conditions. 1.3 N/C; 1.4 N/C; 1.5 N/C; 1.6 Related projects are WBS
.9.6.1.2, “Microalgae Analysis,” and WBS 9.1.3.1, “Algae-Based Biofuels Integrated Assessment
Framework: Development, Evaluation, and Demonstration,”. WBS 9.6.1.2 is responsible for much of the
original Biomass Assessment Tool (BAT) development, as well as ongoing selected enhancements
including analysis of freshwater availability, saline water sources, web-based interface development and
linkage to the KDF. WBS 9.1.3.1 is, by design, a collaborative project with WBS 9.6.1.6 such that the
BAT’s GIS-based, high-resolution resource assessment capabilities are coupled with INL’s Algae
Logistics Module (ALM) to create the Integrated Assessment Framework (IAF). In short, INL’s efforts
are focused on development and delivery of the ALM, including providing pioneer supply system design
for feedstock logistics encompassing algal harvesting, storage and transport, and cost and engineering
performance assessment. The IAF will provide a resource assessment capability that addresses the
complete feedstock supply chain. The 3 tasks within WBS 9.6.1.6 are distinct in scope from the 2 projects
above. Task 1, being executed by PNNL building on the existing BAT, is focused on addition of critical
data base and analytical elements to the BAT. Task 2, being executed jointly with INL, is to develop the
IAF, coupling the high spatial and temporal modeling capabilities of BAT with ALM. The result will be
an analysis framework encompassing the complete microalgae feedstock supply chain. Task 3, working
with INL, is using the IAF to conduct selected national, regional, and site-specific analyses of microalgae
production potential and tradeoffs. 1.7 Validation is an important issue for resource use and algal biofuel
production assessments. For this project and the overall BAT development, we have approached this at
several levels: 1) Early on we worked with J. Benemann and D. Anderson to create the conceptual design,
data requirements, and underlying assumptions for the algal growth model 2) Based on limited published
values and anecdotal information provided by J. Benemann, we have benchmarked our analytical results.
For example, our results indicate an average conversion efficiency of total solar energy to organic mass of
approximately 1%. This is consistent with the published value of 1%-3% for observed yields from
Williams and Laurens (2010). 3) During 2011 the team will visit research sites where algal growth
experiments are underway: a) PNNL lab experiments representing different U.S. regional climates for
fresh and saline water strains; b) U. of Arizona focused on design and operation of raceway's in arid
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