Vermont’s capital city has a brand-new biomass plant burning wood chips and providing steam heat to the state capitol and other government and private buildings throughout its downtown.

The push to modernize the old plant was part of an initiative called Net Zero Montpelier.

District heating systems were once commonplace in U.S. cities, but were replaced as power utilities expanded and brought in lines to provide buildings with individual furnaces and boilers.

But district heating still exists and thrives in certain downtowns, said Leonard Phillips, director of business development for the International District Energy Association, based in Massachusetts.

St. Paul, Minn., for example, heats about 85 percent of its downtown corridor – some 30 million square feet of building space – through hot water, mostly by burning wood chips, waste wood and other biomass.

Co-generation is another component that Phillips believes is an increasing important advantage of district heating systems. Co-generation, involves burning fuel to create electricity and using the waste heat from the generator to create stem or hot water for district heating, rather than burning the fuel to create the heat directly.

There are technical advantages to this system, but even more financial advantages, since electricity sales provide income even when heating isn’t needed, said Phillips.

Although the Montpelier system was not built with co-generation, there is room in the plans for it.

Another technology that promises potential for promoting biomass district heating is gasification, according to Phillips. This system turns woods chips into a synthetic gas and then creates heat by burning this gas – and moving gas from point to point is much easier than moving woodchips.

More details here.

Source: Concord Monitor