Agriculturally related industries are major energy consumers with large quantities of digestible waste, and many have direct associations with waste producers, which are also large energy consumers. These small and medium enterprises (SME) could very easily, and at low cost, become self-sustainable, off-the-grid solutions with biogas digestion systems.
Food waste has vastly more methane potential than other waste. About 9.3 million tons of food waste is dumped every year, while the food producers continue to use fossil fuels for cooking, heating and electricity. Depending on the waste substrate, it can have as much as 30 times more energy potential than other wastes.
The real problem is that food and agricultural producers only look at renewable energy projects as “income generating” projects, but should instead view them as a way to reduce or even eliminate energy expenses.
The South African parastatal utility Eskom, and the only licensed buyer and distributor of energy, must purchase at least 1 MW of capacity from any Independent Power Producer (IPP). This mandate has crushed any interest to produce energy below 1 MW of capacity. For example, a farm with 7,000 pigs downgraded their biogas installation from 260 kW to a mere 40 kW because there was no reason to run the bigger system — its surplus methane is simply flared.
In an attempt to attract the <1-MW SMEs, the State offered a rebate system for renewable energy projects, but then put the incentive on hold in 2013 citing financial constraints.
These uncertain rebate offers and unstable utility finances do not spur renewable energy solutions.
Consequently, biogas potential is not generating interest. There is only a handful of agriculturally orientated operations that have more than 1 MW of capacity potential at any one site, such as cattle feedlots and few large dairies, but since most could never reach 1 MW of capacity, they do not produce anything at all.
This table shows the awarded Renewable Energy Independent Power Producers Procurement Program (REIPPPP) from 2011 to 2014. Note that zero biogas projects were approved. Clearly it seems as though biogas is not welcome.