Benton School District Heats with Locally-Grown Switchgrass

 

Lisa Z. Leighton

Central PA Correspondent

BENTON, Pa. — Benton School District, a district that is 30 percent agriculture, is putting the concept of supporting local farmers into action.

Business Manager Beverly Ribble explained, “We wanted to do something to add value to the community and to the farmers.”

The district is entering into its second year of heating their Elementary School, Middle/Senior High School, and maintenance buildings with switchgrass, the majority of which comes from seven local farmers in Columbia and Montour Counties in addition to donations of switchgrass from the school’s project partner, Ernst Conservation Seeds.

The district estimates that it will save more than 25,500 gallons of oil each year, reflecting a savings of nearly $60,000 a year — a huge impact for a district with an $11 million total budget.

Switchgrass, a tall, native, warm-season prairie grass can be grown easily in this part of the state with minimal fertilizer and water. Two local outreach coordinators for USDA’s Natural Resources Conservation Service (NRCS), Scott Singer and Ryan Koch, emphasize planning in the beginning stages, focusing on the details of seedling establishment so that invasive weeds don’t take over. The switchgrass is harvested using traditional agricultural equipment, and can yield 3-4 tons per acre. When densified into briquettes, it is four times as dense as ground switchgrass, allowing easier storage and transport.

While the district is still in an experimental phase, they estimate needing less than 200 acres of switchgrass per year to heat their schools for the entire winter. While they currently have half a dozen farmers that they purchase from, they would ideally buy the majority from farmers within 10 miles of the school.

Singer said, “We want local farmers to understand that there is a growing market in the local area for this native grass and we can help them get started with financial and technical assistance.”

NRCS has emphasized short term contracts of four to five years to local farmers, noting that incentives of up to $325 per acre are available in the first year to help with establishment costs, and up to $180 per acre for the management of the grass for the first two to three years while the grass is established.

Singer continued, “Our goal is not to have (the funding be) a long-term solution. We want this to be an economically feasible crop for the farmer. But our goal is to cut some of the risks at the beginning.”

In the winter of 2009, when the 7.5 million British thermal unit (MMBtu) per hour input boiler was used for the first time, they used 210 tons of switchgrass in briquette form. It is estimated that this year it will use closer to 265 tons, and an entire heating season will need about 550 tons.

The district estimates payback to be within 13 years for the $2.1 million project. $700,000 was funded by DEP (department of environmental protection) and PEDA (Pennsylvania Economic Development Association) grants, $1 million was borrowed by the district, and the remainder was incorporated into the district’s budget.

The boiler system is relatively simple thanks to computer technology that automates and monitors each step of the process — the briquettes move through a series of belts and augers from the holding pit up the fuel conveyor to the boiler, water is heated through combustion at approximately 1378 degrees F, and then transported to the 2,100 feet of underground pipes by hot water pumps that run to each building. Any left over ash is sent to the ash pit by three inside augers, and the ash is emptied every two to three days.

The more difficult component is turning round bales of locally-grown switchgrass into dense briquettes that produce optimal results — high BTUs with little ash, particulates, and clinkers. Presently, that is the responsibility of Vermont-based company Renewable Energy Resources.

The briquettes are made on site, using a mobile briquetting unit developed by the company. While they didn’t develop the first mobile unit, this is the first one to be used by this company in Central Pennsylvania. Adam Dantzscher and his business partner John Bootie are spending 60 days in Benton producing 300 tons of briquettes, enough to last the entire winter. On average, the district uses 3-3.5 tons of switchgrass per day.

While the district is still in an experimental phase, determining the ideal density for their briquettes, the amount needed to supply the entire winter, and the time of year to begin the mobile unit processing, they are pleased with the results so far, and have received positive reinforcement from the community and other school districts in the state considering the same technology.

An educational meeting will be held on Jan. 20 from 5:30-9 p.m. at the Benton High School, beginning in the cafeteria for dinner and then in the auditorium. The meeting is intended for any local farmers, entrepreneurs, or rural landowners that have an interest in becoming involved with any facet in the project from growing the crop, to processing the material, to replicating the project for other facilities.

The following topics will be discussed: opportunities with warm season grasses as biomass, grass densification and combustion, financial assistance opportunities, plus a question and answer session.