The connection, to District Energy St. Paul’s downtown loop, which heats 80 percent of St. Paul city buildings, will hopefully became a solar focal point, attracting the attention of other cities and towns across America to help solar energy reach grid parity, when it becomes as cheap and abundant as coal-fired energy.
Funded by $1 million from the U.S. Department of Energy (DOE), the 1-megawatt installation is comprised of 144 commercial-grade solar collectors that cover an area equivalent to about 1.25 acres.
These collectors look like the type of solar panels that generate electricity but instead contain an antifreeze-type solution which will provide hot water for RiverCentre’s restrooms and kitchens, and heat for the 162,000-square-foot convention center during Minnesota’s notoriously cold winter days.
The size of the system precludes it being used on all but the largest buildings, but when used it can not only provide clean, renewable hot water and heat for indoor spaces, but flow over into established systems like that built by District Energy in 1983 to respond to the energy crisis of the mid- to late-1970s. Any leftover energy will flow into District Energy’s hot-water-heating loop.
The solar thermal system is sized to provide up to five percent of the district’s hot water needs in the summer, or one percent of yearly demand, and will offset enough natural-gas heating to prevent 484 metric tons of carbon dioxide a year, which is equivalent to 12,403 trees planted and nurtured for a decade.
It’s also a nice money-saver. According to RiverCentre spokeswoman Kathy O’Connor, the center spent $385,000 last year to heat its water and building space. Even one percent of that is some pretty hefty pocket change.
Photo Credit: mtellin via Flickr CC