Solving a Heat Load Hardship

At best, the road to finding an efficient and economic means of heating the Plumas County Health and Human Services Center has been rocky. In 2006, the facility was rebuilt to consolidate and centralize operations, and with the new design, the existing heating solution was replaced with a ground-source geothermal system. Though appealing in theory, the system—undersized and unable to keep up with the buildings’ heat load—has been very expensive to operate. A decade later, it’s close to failing, and the building’s heating and cooling costs are significant. That will soon be changing, however, as a new solution will be in place by spring—a biomass-fueled, combined-heat-and-power system, a project that has been in the making for the past couple of years.

Camille Swezy, biomass program lead at the Sierra Institute for Community and Environment in Taylorsville, California, has been working on the concept since day one. Back when the current heating system was being constructed, in a bid to even out cost overruns, fewer geothermal wells were drilled than what were initially planned, resulting in those heat pumps being overworked, and thus drawing from increasingly cold water. Swezy explains that glycol is added to keep it in liquid form, and that since the system has been incredibly inefficient, the county purchased an electric boiler to actually heat the water up before it goes into that geothermal system. “It still hasn’t been enough,” she says. “The employees use a lot of space heaters in the winter, and it’s just been a huge issue for the county.”

At $8,000 to $12,000 per pump, the cost of expanding the geothermal system would have been more expensive than replacing it with other heating options, and, with the help of the Sierra Institute, it was eventually determined that biomass heat was an ideal solution.

Moving Forward
The Sierra Institute, a research-based nonprofit working to bridge the gap between community and forest health, developed its biomass program in response to widespread recognition that there is a need to create outlets and markets for low-value wood in the region, Swezy says. That, coupled with the fact that Plumas County’s Indian Valley is socio-economically depressed. “It lacks significant industry and large employers,” she says. “Historically, it was home to a dozen mills or so, but they all closed in the ‘90s. The community is in need of a wood products revitalization to create jobs and spur some economic development in our community, so we thought we should identify some strategies to move that low-value biomass material out of the woods—it’s just going to sit there, and the forests won’t get treated if there is no outlet for it. We have air quality issues from pile burns, and unhealthy forests resulting in catastrophic wildfires—a number of them in the past 10 years.”

First, modeling its strategy after what was done years prior in Montana, the institute assessed heat demands of various large, public buildings throughout the region, including hospitals, schools and county buildings. That initiative was funded by a California Energy Commission grant, and working in partnership with Wisewood Energy, the institute developed a vision that included replacing the buildings’ current fuel systems with biomass. “We saw an opportunity with the CEC again, for an implementation grant, and we recognized that it would be a good fit for the Plumas County Health and Human Services Center,” Swezy says. “They’re spending thousands on electric costs to heat that building, and they’re in desperate need of a fix. The CEC grant ($2.6 million) was the perfect opportunity.”

Wisewood Energy, lead contractor on the project, is armed with plenty of experience in working on similar installations, including a biomass district heating system in Burns, Oregon.  “We’ve done a number of commercial and institutional thermal project—providing heat through the form of either steam or hot water, by pellets or wood chips,” says Andrew Haden, founder of Wisewood. “We’ve also done design work for projects in other states including Alaska and Idaho—we work throughout the West.”

Though the scope of Wisewood Energy’s work has historically been thermal projects, he says momentum around power projects is growing, and the project in Plumas County will actually be the company’s first small-scale electric project. The system will be equipped with an Organic Rankine Cycle turbine that will generate enough energy to offset what is needed to run the boiler—supplied by Wisewood subsidiary KW Energy—and heating system. Haden points out that though there is increased interest in using the abundant hazardous forest material for energy projects, policy aspects are complicated. “It’s not a straightforward market like other places,” he says. “It has its own opportunities, but also its constraints.”

Construction began on the Plumas County project in August, and as of late October, the concrete slabs have been poured, according to Haden. “The building will go up in the next month and a half or so, and then we’ll come in with the equipment by the end of the year,” he says. “We should be commissioning into the beginning of next year.”

Fuel for the plant will consist of low-value biomass material, mostly the byproduct of forest restoration/thinning activities, and come from a variety of land managers and agencies, according to Swezy. “Everybody around here is anxious to get rid of their material,” she says, highlighting the fairly unique nature of the chip storage system Wisewood will deploy. “It’s a concept that is used in Austria and communities in Europe that have biomass heat, and [Wisewood] installed this kind of system up in Burns.”

Haden explains that because the system will use wood chips, which are bulky and can potentially bring dust and particles into the infeed system, a mobile, containerized system is ideal. “These sort of dropbox containers have an active floor in them, and they’re filled offsite, and then brought onsite to be unloaded into the fuel system as needed, sort of like two independent, interchangeable fuel cartridges,” he says.   

In winter months, each will need refilling about once a week, Haden says.

Challenges Overcome, Ahead
Wisewood will assist the Sierra Institute in operating the system for a year after the system comes online, before it is turned over to the county. Haden says that though it’s a complex question to answer since the entire heating system is being replaced, in simple terms, the county will save about $30,000 annually with the new system, and payback is expected in about 13 years, about halfway through the expected lifespan of the system.

On other unique components of the project, Swezy says the biomass system will be housed in a cross-laminated timber building, a late design change that she says has complicated the project, but made it even more innovative. “We kind of created another hurdle for ourselves opting to do that, but it will be the first boiler building in California made out of the material, which is advertised to be a cost-effective alternative to concrete and steel.”

As with most projects of this nature, there have been hurdles that have resulted in some delays, one of which was going over budget, according to Swezy. “We have had to put a lot of money into engineering, and as a small nonprofit that doesn’t normally take on this sort of work, it was a lot for us to handle,” she says. “I think we may have involved too many players to help make the project happen, and so there were some inefficiencies involving so many engineers from different companies.”

Another unforeseen challenge, the most significant in terms of time and cost, involved preparing the system’s site. “We chose to build this facility next to the county building, but we actually explored a variety of areas nearby for this facility, settling on the current building site because there would be less issues in terms of having to remove existing infrastructure, or old trees, and it was away from the steam area,” Swezy says. “It turns out, we hit a bunch of water during excavating, so money had to go into putting more raw material down to stabilize the ground.”

 Additional delays were caused by a slow grant reimbursement process, which negatively affected cash flow. But hurdles now behind them, the project is moving along smoothly, Swezy says. “We’re really pushing hard to get some heat flowing this winter.”

At the same time, the Sierra Institute is working on another biomass project at Crescent Mills that involves redeveloping an old mill site into a wood products campus that will process low-value biomass into value-added products, such as wood chips that could fuel the boilers at the Plumas County facility. Swezy said her organization is actively looking for a heat user, such as a greenhouse that could be colocated with the campus, as part of the project would involve a small-scale bioenergy plant that the institute hopes to bring onboard to the state’s BioMAT program. “If someone wanted to set up their own operations, then we could provide them with some lower-cost heat,” she says.

Beyond the Plumas County and Crescent Mills projects, the Sierra Institute continues to work with other entities around the county to steer them in the direction of biomass heat, Swezy says. “We have paid for a number of feasibility studies to be done for these entities to see if biomass heat would be a good fit for them and what the cost might be, like the nearby high school in Quincy—they are actually following the study we developed, and applied for a Forest Service Wood Innovations Grant to fund engineering of a biomass heating system.

The biggest challenge in getting more entities to adopt to biomass heat is that while they recognize they need a more affordable, sustainable heating system, the unknown is a deterrent. “People around here are pretty risk averse,” she adds. “Money is always an issue, so it really comes down to helping them find capital, identify ways that the work can be funded, and help them feel more comfortable about it by reducing some of the risks. After this project, we hope it will be a model for other entities around the county to see that it is working out, so they’ll continue converting to biomass heat.”


Author: Anna Simet
Managing Editor, Biomass Magazine
701-738-4961
[email protected]