Folks in North America have woken up to the fact that gung-ho enthusiasm for converting the petroleum economy to ethanol has serious environmental and resource implications. We’ve been hearing for a while about the rising cost of food caused by switching to growing biomass crops. Here’s the latest bad news: water.
In Minnesota, one of the few states that require reporting of water use, a 2005 state study found that ethanol plants used an average of 4.5 gallons of water to produce 1 gallon of ethanol.
A proposed $165m ethanol plant in south-west Missouri will draw 1.3 million gallons of water from local aquifers every day. It will also generate 400,000 gallons of contaminated water per day — water that would be sprayed on land around the plant by irrigation equipment and then seep back into the ground.
A 100 million gallon-per-year ethanol plant is just one of many that have been proposed in the past few months across Illinois, which already has seven operating plants and is the nation’s No. 2 ethanol producer after Iowa. High oil prices and support from Washington have inspired such interest in ethanol that the Illinois Corn Growers Association now says at least 30 plants are in various stages of planning across the state. This proposed plant alone is estimated to require 300 million gallons per year, leading to pressure on aquifers and lowered well levels.
And don’t forget that even the most efficient methods of ethanol production yield only 1.3 units of energy for each unit of energy put into the system to make it. Read the figures carefully, as some companies conveniently forget to factor in the energy used by farmers in growing the raw materials.
Can someone remind me why this seemed such a good idea?