Elgin Fruit Juice
By utilizing biogas as an alternative fuel solution, Elgin Bio-digestion will improve the year-round viability of the anaerobic digester at Elgin Fruit Juice. Biogas is used to replace coal as a fuel source within the EFJ’s steam boilers.
Challenge
Elgin Fruit Juice, a leading fruit processor in Grabouw, South Africa, installed an anaerobic digester to convert wet pomace (30t), waste fruit (7200t) and biomass from surrounding farms (600t) into methane rich biogas, and then into 527 kW electricity and 650 kW thermal energy in a combined heat and power (CHP) unit. This provides improvements in plant efficiency, 30-40% savings in operational energy costs and reduced demand on the service provider’s grid. However, during the off crop season (Jul-Dec) on-site demand for energy is very low which forces flaring of the gas in the absence of a utilisation intervention.
Solution
Initially, Elgin Fruit Juice pursued a generating license to feed the excess electricity produced back into the grid. The intention was to set up an annual power purchase agreement (PPA) with Eskom at the very attractive wholesale energy price (WEP). However, at the time of writing this case study (September 2020), this had not been granted – resulting in a significant opportunity cost. As a result, a new business, Elgin Bio-digestion, has been formed with the intention to acquire, operate and maintain the biogas plant. Elgin Bio-digestion has implemented a proactive use of the excess biogas as a coal fuel replacement by supplementing Elgin Fruit Juice’s coal based boilers with biogas boilers, which reduces the need for, and expense of coal and which reduces Elgin Fruit Juice’s carbon footprint.
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