When emerald ash borers were found in St. Paul in 2009, experts warned an infestation could be afoot, and it would best be contained by the swift removal of infected trees. As the infestation accelerated, trees started coming down and the process continues 11 years later.
So what happens to all that wood? Well, a lot of it is used to keep downtown St. Paul buildings (including the State Capitol complex) cool in the summer and warm in winter.
The St. Paul District Energy plant burns urban tree waste and uses it to heat and cool 80% of the buildings in downtown St. Paul. In addition to the 65 megawatts of thermal energy the plant produces for downtown St. Paul, it also creates 25 megawatts of electricity for Xcel Energy. Those 25 megawatts are part of a biomass mandate from the state. And that’s where the Legislature comes in.
On Tuesday, the House Energy and Climate Finance and Policy Division had an informational hearing about an as-yet-unintroduced bill sponsored by Rep. Jean Wagenius (DFL-Mpls). It would lay out parameters for a new power purchase agreement between District Energy and Xcel Energy.
Under the agreement, waste wood would continue to be the primary fuel source for the electricity, and any wood that’s been quarantined by the Department of Agriculture to stop the spread of emerald ash borer infestation must pass department inspection before being called into energy-producing duty.
The bill would also require the cost of that electricity be comparable to what Xcel pays for refuse-derived fuel. And that a new agreement cannot be approved by the Public Utilities Commission unless it has also approved a proposal for electrification of the District Energy heating and cooling system from renewable energy sources, a project that must be completed by the end of 2027.