Biomass Feasibility Project Final Report - Xcel Energy

District Energy’s intervention reveals its concern about the sufficiency of available feedstocks in
the Twin Cities Metropolitan Area. A recent study for the Rock Tenn plant supports the notion
that the woody biomass growing in the Twin Cities Metro Area is almost fully utilized (Nelson,
2007). This reminds us that biomass fuels sometimes are in limited supply. Potential consumers of
those fuels conduct due diligence to confirm that sufficient fuels are available, and that
competition for them is unlikely to develop.
St. Paul District Energy
In 1997 District Energy and Trigen-Cinergy proposed to NSP a wood fired CHP plant to satisfy part
of the Biomass Mandate. At that time, wood waste from the Twin Cities was landfilled or burned
in open fires. But the Biomass Mandate and new regulations banning open burning were
suggesting that the time had come to use urban wood waste as fuel. The wood-burning plant
would adjoin District Energy’s existing coal fired boilers that provided much of downtown St.
Paul’s heat. The new boilers would supplant up to 80% of the coal used to fuel the district
heating system and consume up to 280,000 tons of chipped urban wood waste per year.
In early 1999 NSP submitted a PPA for PUC approval. In March of that year the Department of
Public Service proposed substantial modifications to the PPA, and recommended approval of
the PPA if those modifications were accepted. The PUC in August of 1999 deferred
consideration of the PPA and encouraged District Energy to improve upon its proposed terms
(PUC, 1999a). In early October NSP submitted updated terms of the PPA and in January of 2000
the PUC approved the PPA (PUC, 2000b). The plant planned to begin operation in 2001 ("Trigen-
Cinergy", 1999); but regulatory delays delayed start-up until May of 2003 ("Cinergy Business",
2003).
Two episodes in the project’s history illustrate (1) the need for biomass plants to prove they are
good neighbors and (2) the challenges biomass consumers face in securing their fuel supplies.
The plant is located in downtown St. Paul, clearly visible from the river. As the start of
construction approached, people involved in redeveloping St. Paul’s downtown began to
express concerns about how well an industrial facility would fit in. The utility explained that they
were designing the plant to blend in with its surroundings. They also sought suggestions from
their neighbors and other downtown groups (Karlson, 2001). District Energy appeared to
successfully allay the concerns of the downtown communities.
Another neighborhood incident concerned the location of a fuel processing facility near a
residential area. The boiler plant opened several months later than planned. Meanwhile, one of
its wood suppliers had gathered and chipped several months worth of wood fuel on a lot near
some houses. Exposed too long to the elements, the chip piles began to smolder and emit
odors, leading to fire department calls and neighborhood opposition to a conditional use permit
for the processing facility (Monsour, 2003).
The other lesson that St. Paul District Energy teaches is that obtaining a consistent, high-quality
fuel supply can be difficult. District Energy initially relied upon independent contractors to
deliver wood to their processing yard, but its inconsistent quality became a problem. So the
utility created a for-profit subsidiary to manage its fuel supply. Environmental Wood Processing
instituted several improvements. They still accept fuel deliveries from independent parties, but
they reprocess those to meet plant specifications (Deering, 2006). They also manage the St. Paul
transfer station and seek fuels at other municipal transfer stations and compost sites either by
signing on as facility managers or by simply offering to chip materials at municipal sites and
remove them free of charge (City of St. Louis Park, 2007; City of Albertville, 2007).
Identifying Effective Biomass Strategies: Page 93
Quantifying Minnesota’s Resources and Evaluating Future Opportunities