MARQUETTE - Every half-block of households receiving electrical power in the city of Marquette requires a transformer. These ubiquitous boxes, which transform high voltage into usable voltage, have become more environmentally friendly. David Lynch, superintendent of distribution for the Marquette Board of Light and Power, said the BLP's transformers used to require a petroleum-based coolant. But within the last few years, the BLP has been exchanging the old petroleum-based transformers for "greener" ones that use a soy-based fluid. "In regular transformers, the cooling liquid, which is oil, was a petroleum-based product," Lynch said, adding that the petroleum is highly flammable and dirty. Therefore, if the petroleum spilled, it would be difficult to clean up. The natural seed-based oils, however, have a much lower flammability. "And if there is a spill, there is a 99 percent biodegradability after 21 days," Lynch said. The new and "greener" fluid is made out of highly refined soybean oil. It is called Envirotemp FR3 and has received an environmental certification from the U.S. Environmental Protection Agency. These green transformers last longer, too. "It extends the life of the transformer by 25 percent," Lynch said. The old transformers lasted about 30 years; the new ones are good for 40 years, he said. This change in transformer fluid is crucial because it affects the BLP's large inventory, according to Lynch. Currently, 4,700 transformers are installed in the BLP's service area - which includes about 15,000 customers in the city of Marquette and nine townships in Marquette County - with another 100 transformers stored as backups. Each uses from 15 to 300 gallons of fluid. Transformer size depends on the size of the business or household that requires the electricity. The BLP started replacing old and installing new transformers with the soy-based fluid in 2006. "We expect to be totally green in our transformers in 10 to 15 years," Lynch said. Although the green transformers are a bit more expensive than the old ones, Lynch said it's worth it. A transformer can cost anywhere from $800 to $45,000. "We may pay a little more upfront, but in the end we see a 25 percent life cycle cost extension," he said. "By saving money in the long run, we can keep our rates down." In addition, Lynch said the BLP is doing its part to preserve the environment. "We look at our environmental stewardship very seriously," he said. Soy-based fuel is a renewable resource. By not importing petroleum from other countries the BLP is supporting the nation's economy. "The farmers in America are growing this for us," he said. The BLP has other green projects under way. Lynch said he's working to provide customers with devices that would let them know in dollars and cents how much electricity they are using. He said there are a lot of "phantom power" loads in a household -devices that suck electricity from the grid even when they're not in use. Televisions, VCRs, answering machines and computers are examples of appliances that draw current when plugged in but turned off. Devices that measure electricity usage can help customers control these drains. "You can adjust your usage pattern to keep everyone's cost down," Lynch said. Also, the BLP has been working on using biodiesel, or B-20 fuel, instead of petroleum in all of its work trucks, he said.