Drennen’s Model Accessible to Public – Hobart and William Smith Colleges \
The HWS Update

Drennen’s Model Accessible to Public

Thomas Drennen, associate professor of economics, chair of environmental studies and senior economist at Sandia National Laboratories, recently released for public access an educational computer model that illustrates the tradeoffs associated with various alternatives to gasoline.  The Alternative Liquid Fuels Simulation Model (AltSim) is available from the Web site of the National Energy Technology Laboratories (NETL).

Created with funding through Sandia Labs and NETL, the AltSim Model, Version 2.0 is a high-level dynamic simulation program, free for downloading, that calculates and compares the production and end use costs, greenhouse gas emissions, and energy balances of several alternative liquid transportation fuels.  These fuels include: corn ethanol, cellulosic ethanol from various feedstocks (switchgrass, corn stover, forest residue, and farmed trees), biodiesel, and diesels derived from natural gas, coal, and coal with biomass.

This semester, Drennen and Ryan Williams ’07, the main programmer on the AltSim project, have been busy promoting and demonstrating the model.  In addition to presentations at both Sandia and NETL, Drennen has demoed the model to the Senate Energy and Natural Resources staff.  Last month, he presented AltSim in a talk, titled “The Economics of Biofuels,” to a large audience at the Simon Graduate School of Business at the University of Rochester.

“The goal is to educate policy makers and other interested stakeholders about the tradeoffs associated with each alternative,” Drennen says.  “I’m really excited that this technology is available in the public realm.”

Allowing the user to compare and contrast alternatives to petroleum-based fuels using a consistent and transparent methodology, Drennen says that the AltSim is great for answering questions such as:

* Under what conditions can ethanol from corn compete economically with gasoline and how sensitive are the results to the price of corn?

* How do lifecycle greenhouse gas emissions from fuels derived from coal or corn or other biomass compare to gasoline and diesel?

* How would a CO2 tax affect the relative economics?

Users can change key economic and financial assumptions and yield different values of each energy source, depending on overnight construction costs, O&M, feedstock costs, taxes, depreciation, debt/equity ratios, financing costs, economic life of project and construction time.

“The cool thing is that anyone can download it and play around with it,” Drennen says.

In April, as part of Earth Week, Drennen will present the AltSim at the Tufts Energy Conference.