country FOCUS p l a n t s h a v e t h e a d v a n t a g e t h a t construction time is extremely short . Solar energy can be very cost efficient in Zambia . �e bid tariffs for two 50 MWp PV plants start at US ¢ 6.02 / kWh16 and are thus well below the power costs that the Zambian government had for emergency measures and below the new energy tariff for mines of 10.35US ¢/ kWh17 that is expected to constantly increase over the coming years . �e solar power plants could be either built centralized and provide power through the grid or decentralized , i . e . in proximity of a mine with a direct power line to the mine . In the second case , the solar power plant would be part of a microgrid . Back-up diesel gensets or stationary energy storage such as batteries could also be a part of the microgrid which is also called solar-diesel hybrid power plant . In recent years , the technical feasibility of electricity generation for mines through solar powered microgrids has been proven as well in large scale applications . 18 Connecting the mining microgrid to the national power grid might be advisable as diesel genset usage can be reduced considerably . In the microgrid , diesel gensets are very likely to be the generator with the highest direct costs and with the biggest environmental impact . In the gridconnect microgrid scenario diesel generators provide only missing gap between the solar output and the load from the mine which is not available from the grid . �is might be the case during loadshedding . �e objective of the microgrid is to provide robust and stable power to the mine . Energy storage solutions , e . g . in the form of batteries , can further stabilizes the microgrid by shaving peak loads and providing peakpower . Critical processes are o�en secured with UPS-system already today . Some manufacturers aim using the UPS storage system for the microgrid . �e combination of microgrid and national power grid might also have additional advantages in the future . If the solar power plant generates more electricity than the mine consumers , the energy might be fed back into the grid . �e decentralized microgrid solution ensures that the grid is utilized less by the mine . �e current power crisis in Zambia presents a chance for solar energy . Many mining companies see the risk that arises from power outages and load shedding in form of higher energy costs or production losses . Electricity costs are expected to further raise in Zambia . A�er a long period of inexpensive energy from abundant hydro power the paradigms have changed in Zambia . Solar power can be installed extremely quickly and can contributed to save costs in comparison to power from expensive back-up diesel gens ets immediately . Energy costs advantages can be an important differentiator in the very competitive copper market which be characterized by supply surplus due to falling copper demand from China . More and more mining companies have a strategic look at energy .
FMDZ | Jan - Feb 2017 | Page15