It’s cheaper than diesel, but compressed natural gas may still not be cheap enough to get Lawrence officials to switch their transit fleet to the fuel source.

Commissioners at their Tuesday evening meeting will receive a new staff report that recommends against the city making a switch from diesel to CNG. Some city commissioners are begrudgingly accepting the recommendation, for now.

“I still think CNG is going to happen,” City Commissioner Bob Schumm said. “But the pieces of the puzzle aren’t in place to have it happen right now.”

The biggest missing piece is a specialized, quick-fill CNG fueling station that transit officials are now estimating will cost $2 million to build. In addition to the costs, finding a location for the fueling center is a stumbling block.

Transit officials said they would prefer to have the station built at the existing maintenance facility it operates with Kansas University. The facility, in the Santa Fe Industrial Park in northern Lawrence, wouldn’t be convenient for city trash trucks and public works vehicles to use. Schumm said finding a location that could efficiently serve a variety of city vehicles would be important.

Even if a fueling station would cost $2 million to build, Schumm said the city should still keep exploring the idea. Transit officials estimated that compressed natural gas prices are about 40 percent cheaper than diesel prices.

A memo from transit administrator Bob Nugent estimated that the city would recoup its upfront investment in CNG equipment in nine to 10 years. Then the question becomes whether CNG prices will continue to remain lower than diesel prices for the long term.

Schumm said he thinks the large new supplies of natural gas being found in the U.S. suggests CNG will be cheaper than diesel in the long run.

“But there are other intangibles that go beyond price,” Schumm said. “One is that I think it will produce cleaner air, and the other is that it is basically a domestic product at this point.”

Commissioners at their Tuesday evening meeting will be asked to approve a contract to purchases two, 30-foot diesel-powered buses for $350,000 each and one 30-foot diesel-electric hybrid bus for $575,000. Transit officials have sought to buy the buses for several months, but the contracts were put on hold while the CNG issues were explored.

The new report raises questions about the city’s strategy of purchasing hybrid buses. Nugent’s analysis estimates that hybrid buses get about 35 percent better fuel mileage than standard diesel buses, but that savings isn’t enough to cover the hybrids’ higher purchase price.

Commissioners will meet at 6:35 p.m. on Tuesday at City Hall.