St. Paul RiverCentre's new $2 million solar-energy installation unveiled

A five-year payback period sounds relatively short, and rather attractive, yet still isn't fast enough for many building owners reluctant to make the upfront outlay.  That's why publicly financed projects and public-private partnerships may be what's necessary to generate widespread acceptance of renewable energy. 


Earlier this week I told how solar hot water heaters have the fastest payback of new solar energy projects (compared to photovoltaic, or PV).  This large scale solar hot water installation in St. Paul should inspire many building owners to consider the same thing on their large roofs.

From The Pioneer Press:

St. Paul's new $2 million solar energy installation on the roof of the St. Paul RiverCentre not only is the largest solar thermal project in the Upper Midwest, it also will serve as a model for other cities to follow, federal energy official Vipin Gupta said at its unveiling Friday.
The U.S. Department of Energy contributed $1 million in federal stimulus money two years ago to build the 1-megawatt project, which will heat water for the city-owned convention center's restrooms and kitchens as well as warm the 162,000-square-foot building's indoor air.
Any leftover energy will flow into a hot-water-heating loop built by District Energy St. Paul, the utility that heats 80 percent of downtown buildings.
The rooftop project could supply up to 5 percent of the district's needs for heating water in the summer and 1 percent of total demand year-round, District Energy CEO Ken Smith said.
"This has long been on our to-do list," Smith told a crowd of well-wishers that included St. Paul Mayor Chris Coleman and U.S. Rep. Betty McCollum, D-St. Paul. District Energy's long-term goal is using only renewable energy sources for all its needs, he said.
The solar heat will offset the need for conventional natural gas heating, said Gupta, of Sandia National Laboratories, who is an ambassador of sorts for solar energy.
Officials estimate the project can produce enough clean energy to offset 900,000 pounds of carbon dioxide emissions a year, the equivalent of taking 90 cars off the road. The project's 144 commercial-grade solar collectors — which look like solar electric panels but contain an anti-freeze-like glycol to capture heat — cover an area of roughly half a football field, so it's not suitable for every building, Gupta acknowledged.
But the Department of Energy hopes more buildings large and small will begin sprouting solar panels in the coming decades and have their energy tied back into a grid, Gupta said.
That's the attraction of the RiverCentre project. It is the first solar thermal project to connect into a city network of hot-water heating pipes in North America, and officials at the utility and federal government hope it will spark interest from other cities and then take solar energy mainstream.
Solar energy still is more expensive than conventional energy from coal and natural gas, but Energy Secretary Stephen Chu recently launched an initiative to bring the cost down on par with fossil fuels.
The price of natural gas is low for now, but it has a history of volatility, and solar energy promises long-term price stability — essentially free sunshine — once the equipment is installed, Gupta said.
Borrowing a phrase from hockey great Wayne Gretzky, Gupta said, "We want to go where the puck is going to be, not where the puck is now."
RiverCentre spent $385,000 last year to heat its water and building space, said Kathy O'Connor, the facility's spokeswoman. It will take a while to quantify how much it can save with the new solar heating, she said.