Farmers Review Africa Nov-Dec 2018 Farmers Review November-December 2018-6 | Page 17

can and does work. Unfortunately, there have been some well-publicised early failures in the South African space, primarily due to attempts to apply Euro-centric technology in the South African context, without an appreciation of local factors. Global Energy have adapted well- proven European technology and practices, to make them somewhat simpler and better-suited to the local environment, and in the process have developed true “home-grown” technology that has been demonstrated to be both reliable and cost-effective. Biogas is expensive Through a broad-minded approach, understanding of the process, simplification of management thereof, and a concerted effort to adapt and utilise local products and technology, Global Energy has managed to significantly reduce the cost of a fully-functioning, fully automated, safe and efficient biogas plant. The typical cost of a full turn-key project, including commissioning, is around R35 000 per installed kW(electrical). Further energy is available for heating purposes. Solar Energy is more cost- effective: While it is true that the quoted R/kWh of solar energy is somewhat lower than biogas, the effective power output of such an installation need to be clearly understood. Typically, for a 100kW solar installation the output of this system will be quoted as 100kW(peak). What this means is that clean panels, on a clear day, at noon, during mid- summer, will produce 100kW. However, what needs to be factored in is the fact that this solar installation will only start electricity production an hour-or-two after sunrise, and that is depending on panel orientation. It will also only generate at peak out-put for 3-4 hours around mid-day, and will stop generating completely an hour-or- two before sunset. At best, a 100kW solar electricity installation will produce an average of 450kWh per day. By comparison, a 100kW biogas plant could produce as much as 2 400kWh per day. The maths is not complicated. The cost of the energy from the biogas system is 3.6 times less expensive than from the solar system. Furthermore, the power output from the biogas system is continuous, it includes integrated storage so that when production exceeds consumption, it is automatically stored for later use. Up to twice the electrical power output is available for heating purposes, and there may be significant savings on organic waste disposal. The technology can be applied to any organic wastes, such as animal manure from feedlots and dairies, waste from food processing and packing factories and abattoir waste. The energy derived from the process is specific to the waste stream in question. The biogas plants are specifically designed for each waste producer’s site and is sized based on the waste stream quantities and energy consumption of the waste producer. The design ensures that the waste producer does not export electrical power and so eliminates the need for power purchase agreements with the utility. November - December 2018 | 15