1: OPTIMISE sizes of your electrical and mechanical equipment
First and foremost, this has a direct impact on line charges. It is also of utmost importance that all electrical and mechanical machinery, as well as fans, need to be accurately specified. I often walk into a factory where they are using a 1.1kW fan where they might only need a 0.37kW, because most fans run 24/7 you’ll be tripling the operation electrical cost. Remove these fans immediately size the fans correctly and change them out. The recovery of the cost to pay for this fan change would be within one season.
2: AUTOMATE the electrical control for the plant
Control your energy by switching circuits on or off smartly with a PLC. What is key here is SMART PREFERENTIAL SWITCHING (SPS), this allows you to prioritise, share or isolate critical | non-critical functions choose exactly what turns on or off during load shedding. When dehusking one can automatically monitor and control supply for the drying units to either be switched off or down to (limp mode) low power consumption mode, IE it keeps one heat pump going with a recirculation fan, until dehusking is finished.
3: INVERTER TYPE TECHNOLOGY
Using inverters type heat pumps and electrical appliances saves up to 30%, they also regulate startup spikes due to their capacitive and variable frequency control. Using VFD (variable frequency drives) or VSD’s on electrical motors can also save power and limit power spikes.
4: HEAT PUMPS
Converting drying system from boilers to heat pump / dehumidifying technology can reduce energy usage by 30%, and converting drying system from elements to heat pump / dehumidifying technology can save the heating energy up to seven times more efficiently (700%!)
5: POWER FACTOR CORRECTION
Power Factor Correction (PFC) can provide several benefits for your electrical system, such as lowering electricity bills by reducing apparent power and demand charges, increasing available capacity and reducing overload risk of equipment, improving voltage stability and quality, it will also reduce demand in some instances with up to 40%! (Typically 5-10%)
6: SOLAR POWER
Of course this discussion would not be complete without talking about solar. Clients are often dissuaded from a Solar option when they see the massive amount of capex required to run their entire plant. However, systems should be sized to run what is required rather than be sized for everything running simultaneously. From our experience, we’ve established that a 3-phase 15kw system is adequate to run and manage a 400t-600t plant using a 30KVA lithium battery backup (provided you have spec’d and sized your plant correctly). The cost of a 15kva 3-phase system is R300/R400k as opposed to a 100kva 3phase system which would cost you in the region of R3/5 million. Also bear in mind that it is scalable, so you can always start off with a smaller system and increase this when budget and demand is required”.
