Conversion of Biomass to Renewable Energy at a Feedlot

Summary

​The red meat supply chain spends an estimated $1.3 billion per annum on fossil fuel energy, of which$512 million or 39% of all of the energy costs may be attributed to energy used at feedlots[1]. Whilst feedlot energy contributes only 26% of all energy usage from production through to retail ready products (i.e. excluding cold chain and transport post-processing plant), due to feedlots being in regional and remoter areas means that the available energy sources are more expensive compared to processing plants (i.e. high grid power costs per unit; higher boiler fuel costs per unit due tohaulage of fuel to site).

Due to rising fossil energy costs, falling capital costs for renewable technologies, support for renewable power and/or future potential greenhouse gas emissions costs, and the goal of the red meat industry being carbon neutral by 2030, it is recommended that the red meat industry rapidly transition to renewable energy.

This project assumed a 20,000 head of cattle feedlot with co-located steam flaking / grain milling operations. For this site LPG fuel for raising steam represented 74.8% of energy costs for the mill facility operations with the balance being grid power.

The key findings were that renewable energy solutions exist which can immediately save energy costs at feedlots without the need for any capital outlay. The table below summarizes the most competitive submissions received. The highly-innovative concentrated solar thermal/power proposal that was received is also presented here in the executive summary, to show the relative standing amongst less technically complex plant. Feedlots and the wide industry will benefit by seeing that the falling costs of renewable technologies coupled with innovative business models can immediately reduce energy costs with low operational risk and no capital outlay.

Not itemized separately in the table below, a biomass boiler can be procured to generate steam at around 24 barg with a minimal overall impact on the capital cost of the boiler (e.g. 5%). This higher pressure steam can be run through an expanding screw or backpressure turbine to create power. Thermodynamic modelling shows that the feedlot considered would be able to generate approximately 100 kW of power or around one third of its power requirements via abackpressure turbine. Taking capital costs for a backpressure turbine into account, an additional 9% fuel consumption due to raising the steam to 24 barg rather than 7 barg, and Renewable Energy Credits at $60/MWh, the LCoE over a 15 year period for a backpressure turbine was estimated at $0.12 / kWh.

[1]MLA project V.SCS.0003, 2017.