In the Details

Here’s an article from MIT’s Technology Review filling in some of the gaps in analyzing the President’s proposals on fueling our cars with ethanol produced from crop waste and energy crops. The upshot is that we need to be alert to overly optimistic assumptions and possibly conflicting goals. The strategy is fine, but the details matter.

Last week I suggested that measures to reduce greenhouse gas emissions would automatically move us in the direction of greater energy independence. However, as this article points out, the converse isn’t necessarily true. As our largest domestic energy resource, coal has an important role to play in both areas, but employing it in ways that will make it nearly impossible to capture and sequester its greenhouse gas emissions in the future--as a source of small-scale process heat in renewable energy plants, for example-- could exact an unnecessarily high environmental price for reduced reliance on imported oil.

Cellulosic ethanol has truly exciting potential. Unlike some of the other future energy pathways we’re pursuing, it is a new net source of primary energy, something we will need badly in the years ahead. Despite this, we need to pay careful attention to the associated issues of land management and the environmental impact of fertilizer and other inputs, before pronouncing this the solution to our energy needs. There’s a long history of creating new problems in the process of solving the old ones, and we need to learn from that experience.