SO2 Purchases

The Clean Air Act Amendments of 1990 made it possible for 1-ton sulfur dioxide permits to be bought and sold by coal burning utilities. This program is part of the EPA’s Acid Rain Program and is an example of a market-based allowance trading system for air pollution control. An interesting aspect of this program is that any entity (individual, corporation or municipality) may buy a permit to emit sulfur dioxide. 1-ton permits are typically sold in large blocks, but once a year the Chicago Board of Trade hosts an auction at which permits can be traded in single units.

For the past five years, Bates Environmental Economics students have researched, bid on, and successfully purchased SO2 permits. All of these permits have been retired.

Year Permits Purchased Purchase Price
2001 1 $173.57
2002 1 $160.50
2003 1 $171.80
2004 9* $260.00
2005 1 $690.00

* Class received a $1,200 challenge grant from Community Organization for Renewable Energy. The class raised a $1,400 match in 3 days! We were thus able to bid on 9 permits and retired 9 tons of sulfur dioxide. This is the equivalent of the amount of SO2 that would be emitted if you were to leave 3,600 100 watt light bulbs burning for one year straight!!

Auction Details:

Press Releases and Articles:

Lynne Lewis featured in Wired Magazine

Grant Enables Bates College Students to Retire Pollution Permits Worth Nine Tons of Acid-Rain Agent

For Students: