Koda Energy is an innovative combined heat and power plant which burns agricultural byproducts, virgin wood waste, and urban tree trimmings to create energy in the form of electricity and heat. The project gets its name from the word “Koda”, which means “friend” in the Dakota language.Koda Energy is the only combined heat and power facility in the United States which burns exclusively natural, non-manmade materials in suspension.
Koda is a joint partnership of the Shakopee Mdewakanton Sioux Community ( SMSC ) and Rahr Malting Company ( Rahr ).
The burning of byproducts from malting and food processing along with raw materials like wood chips, grain dust, chaff, and other plant seed material is used to generate electricity and thermal energy at Koda Energy.
Electrical power generation averages 19.7 megawatt hours, with a net electrical output of approximately 16.7 megawatt hours on average. This relies on the production of 220,000 lb/hr of high pressure steam produced at 900 degrees F. Electricity generation fluctuates, based on the needs of thermal energy by Rahr, which is cyclical in nature.
Rahr Malting Company and the Shakopee Mdewakanton Sioux Community Partnership
- Rahr Malting is the world’s largest single-site producer of malted barley, used in the brewing process. The Rahr family has been producing malt in the United States since 1847.
- The facility is located on the Rahr campus on Highway 101, approximately seven miles from the SMSC.
- The SMSC and Rahr formed Koda, a limited liability company, in 2006 to build and operate the facility.
- The SMSC is the majority partner.
- The Koda Energy Board of Directors consists of two members from Rahr, and two members from the SMSC.
Benefits of Koda Energy
- By-products from malting, food processing, and tree trimming are used to generate heat and electricity.
- The plant burns considerably cleaner that a coal plant, and is considered CO2 neutral.
- Rahr uses heat from the generation of electricity in their malting process to displace the use of ~80 million cubic feet of natural gas each month.
- Biomass fuels are one of the largest sources of renewable energy.
- The products burned at Koda Energy do not deter land from use for row crops.
- There is very little remaining solid waste. What does remain is used for soil amendment purposes, returning these minerals for use by new plant growth.
- Renewable or green energy meets the goals set by the State of Minnesota.
- Koda Energy’s location is in a high demand area for energy usage.
- The $60+ million project has created 23 full time good paying jobs in direct employment. And many positions in entities providing other services for the facility.
- Each year $6 – $10 million is spent into the local area for biomass fuel purchases.
- Biomass fuel
- Product delivered to the facility must meet certain specifications for size and moisture content, and contain no foreign materials or hazardous wastes.
- All fuel arrives at the facility in self-unloading walking floor trailers.
- Koda samples all fuel deliveries to insure quality and compliance.
- The majority of Koda Energy’s fuel comes from facilities and processes within 75 miles of Shakopee, MN.
- Incoming fuel must be no larger than 1 inch in two dimensions, ¼ inch thick, and must be less than 14% moisture content. Decomposed materials are not accepted.
- Koda uses four hammer mills to pulverize 21 tons/ hour into a biomass flour prior to combusting in the boiler.
- It requires ~175,000 tons of biomass fuel, or between 8,000 and 9,000 semi-trailers full of biomass material, to power Koda for one year.
- Koda combusts many different types of biomass fuels like, malt dust and sprouts, barley dust and chaff, sawdust, oat hulls, wheat hulls, rice hulls, wood shavings, ground pallets, sunflower hulls, pea screenings, corn screenings, and many other dry agricultural waste by-products.
- The boiler is suspended from the ceiling structure in the facility, and expands downward as it heats up.
- The boiler has six wall fired burners, each capable of 62 million btu output. These burners feed a self-sustaining fireball that is ~ 20ft x 25ft x 87ft tall, the heat source inside the boiler used for steam generation.
- The temperature inside the fireball is between 3,000 and 3,500 degrees F, and provides enough energy for the boiler to produce > 220,000 lb/hr of high pressure steam flow at 900 degrees F.
- The steam is used to drive a Siemens steam turbine generator at 6,834 revolutions/min. with a rated capacity of 23.4 megawatt hours of electricity production.
- A variable amount of steam flow is extracted from the turbine generator and used in a heating application. This steam heats a food grade glycol loop, that is used to transfer the heat energy into the Rahr malting facility to heat the industrial kilns.
- 12 megawatt hours of electricity is sold into the local power grid, approximately 3 megawatt hours are used by Koda, and the remainder is sold to Rahr to power their facility.
- All of the thermal energy produced, is sold to Rahr to displace natural gas usage. ~ 2500 million btu/day on average.
- Koda Energy operates at full output approximately 50 weeks each year, with maintenance and repair outages necessary for one week in the Spring and one week in the Fall.
- The entire facility was constructed on a 3 ½ acre site.
- Between 40 and 50 tons of biomass ash are produced each day, the ash is spread on farm fields as a soil amendment.
- Over half of every btu of energy content found in the biomass fuel is sold as either heat or electricity, a very efficient conversion rate.
- Natural gas is used as a warm up and supplemental fuel, utilized as less than 10% of total fuel.
- Koda employs many baghouses and other pollution controls in the process, and has very low particulate matter emissions.
- Koda Energy is staffed 24 hours/day 7 days/week, with at least three operators on shift at any given time.
- Control room operators have a 1st class “A” State of Minnesota Engineers license at a minimum, at least one is on duty 24/7.
- 2006 – SMSC and RMCO formed a partnership
- 2006 – 2007 – Project design
- March of 2006 – MISO interconnection submission
- May of 2007 – MISO interconnect approval
- September of 2007 – MPCA permit approval
- September of 2007 – Construction began
- January of 2009 – Steam blows complete
- January of 2009 – Purchase power agreement
- May of 2009 – began commercial operation
- October of 2010 – attained the ability to provide 100% thermal load to RMCO
- February of 2013 – completed a facility to process urban tree trimmings as a fuel source, in cooperation with SMSC
- February of 2014 – completed a re-design and rebuild of the fuel receiving system at the Koda plant to enhance safety and capability