Krishna P. Paudel, Huizhen Niu, Chandra Theegala, Quizhou Ma, Doleswar Bhandari and Naveen Adusumilli

Poultry production, which is the largest animal industry in Louisiana, generated approximately $1.8 billion combined in farm revenue ($904.9 million) and value-added activities ($882.3 million) and employed 4,361 individuals in 2017. The poultry industry in Louisiana has had steady growth since 1990. Economic opportunities created by the poultry industry also translate into large amounts of poultry litter as a byproduct. Disposal of this valuable resource and unavoidable byproduct in an environmentally safe manner is one of the priorities of poultry farmers. Consisting of all 13 essential plant macro and micro nutrients (nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, manganese, copper, zinc, chlorine, boron, iron and molybdenum) and valued three-times as cost-effective as a commercial fertilizer, the litter is an economic replacement of fertilizer input in crop production. However, over the years, a quest for answers for proper management of litter has been an agenda item for several parishes. This is mostly due to relatively decreased demand from crop producers, citing both concerns over phosphorus management in fields treated with litter over a number of years as well as supply issues.

LSU AgCenter researchers have conducted a study evaluating an alternative economic opportunity for poultry farmers, and that is electricity generation using poultry litter. Several states dealing with poultry litter as a byproduct have evaluated such alternatives to enable discussions on creating sustained economic opportunities as well as environmentally safe solutions. The broiler industry contributes most to the Louisiana economy among poultry production but also is responsible for the lion’s share of litter production. Broiler birds are produced in 11 central and northern parishes of Louisiana. In the past, land applications of broiler litter as a plant nutrient source had been the norm. To some extent, this has been a successful way to reduce the pressure to dispose of a large volume of litter. While correctly applying litter on land has been shown to reduce the rates of erosion and nutrient runoff over time by strengthening the soil, overapplication can lead to phosphorus buildup in soil and potential leaching and runoff of nutrients to nearby waterbodies. These latter concerns have necessitated looking for alternative ways to dispose of manure safely and economically. Several alternatives, including composting and use in animal feed, are being used. However, none of these disposal methods can alleviate the problem completely.

Recently, there has been increased interest in producing electricity as a means of providing alternative ways to dispose of poultry litter. Fibrowatt, a company located in the United Kingdom, has been converting poultry litter to electricity since the 1990s. In the U.S., a similar operation, Fibrominn, is in existence in Minnesota, and other states are actively pursuing the construction of such a plant to address litter disposal issues. Poultry litter can be used as an energy source using a thermochemical process (anaerobic digestion) and combustion process (pyrolysis, gasification and cogeneration).

LSU AgCenter researchers identified the location of all commercial broiler houses in 11 central and northern parishes using Google Earth and verified the number of broiler birds using data from the 2017 LSU AgCenter Louisiana Summary of Agriculture and Natural Resources. The challenge is to find an optimal location to build an electric plant to use broiler litter at the minimum cost. The optimal location of electricity plants depends on the spatial distribution of broiler houses, volume of litter produced in each broiler production facility, location of the urban area, location of water bodies or other environmentally sensitive areas, and the road, rail and electricity network. Several methods can be formulated to optimally locate electricity plants and allocate broiler litter to those plants. In this study, researchers use the second order conic programming for location identification and linear programming approach for allocation amount. The optimized model maximizes the profit from allocating litter to electricity plants as well as minimizes total pollution related to transporting litter from a broiler house to a proposed electric plant. To identify the road network from each broiler house to power plant locations, researchers use an actual road network, road slope and speed limits on the roadways.

It is possible to build one or more power plants to use all the broiler litter produced in the state. If only one power plant is built, the transportation costs from a broiler production facility to an electric plant could be prohibitively high. If many power plants are built, it may not be profitable given the high variable and fixed costs of building and operating an electricity plant.

When only one electricity plant is built to use all broiler litter produced in the 11-parish area, results from the optimization model indicate that the plant should be built in Lincoln Parish. This parish is one of the major broiler-producing parishes and is close to other major broiler-producing parishes such as Union and Jackson. However, this may be too restrictive for the large number of broiler production facilities in Sabine, Natchitoches and Vernon parishes. An alternative is to build three electricity plants — one each in Union, Lincoln and Vernon parishes. The total volume of manure transported from broiler production to electricity plant is 170,412 metric tons, and the total cost to transport litter to these plants is $5.3 million. Assuming all litter produced is used for electricity, this amount of litter can generate 18 MW of electricity with a direct electricity value of $10.5 million per year. The ash value left after electricity production equals $443,071. Therefore, the direct value of electricity production from broiler litter in the study area is approximately $11 million.

If the cost of poultry litter were to be only $2 per ton, which is much lower than the prevailing rate, and all of it was used for electricity production, then the rate of return per year from an electricity plant would be 26.6 percent. The low purchase price for poultry litter may be acceptable to producers because it would provide a steady stream of revenue and an alternative and an economically desirable solution to disposal of poultry litter. This payment amount per ton of litter is also consistent with what Fibrominn pays to poultry producers in Minnesota. The total economic impact to Louisiana from building electric plants would be approximately 48 jobs created, resulting in $2.6 million in labor income, $7 million in total value added, and $14.5 million in industry output.

It is time for poultry-dominant parishes and industry to consider alternatives to address national concerns regarding the role of poultry litter in water pollution using voluntary methods that prevent enforcement of restrictive regulations. Litter to electricity provides that alternative. Some other states, including North Carolina and Minnesota, have used cogeneration plants (combining poultry litter with wood chips), which may be a possibility for Louisiana, considering that forestry is the state’s No. 1 agriculture industry and that there are wood chip pellet plants built recently by Drax Biomass in Morehouse and LaSalle parishes. As per the Clean Air Act of 1963 and its subsequent amendments, a poultry litter-based electricity generation plant needs to follow all regulations related to the emission of air pollutants.

Krishna P. Paudel is the Gilbert Durbin Endowed Professor, and Huizhen Niu is an instructor, both in the Department of Agricultural Economics. Chandra Theegala is a professor in the Department of Biological and Agricultural Engineering, and Naveen Adusumilli is an assistant professor in the Department of Agricultural Economics. Quizhou Ma is with Guangdong University of Foreign Studies, and Doleswar Bhandari is with New Mexico State University.

(This article appears in the winter 2019 issue of Louisiana Agriculture.)

Inside one of two broiler houses used for demonstration and research at the LSU AgCenter Hill Farm Research Station in Homer, Louisiana. Photo by Olivia McClure

The first flock of chickens were placed in the two demonstration poultry houses at the LSU AgCenter Hill Farm Research Station in 2010. The state-of-the-art houses are 42 feet by 500 feet. Photo by Olivia McClure