MINING POWER
Extractive power
Power solutions are becoming ever more
innovative with hybrid solutions and mine-wide
contracts now on the able, reports Paul Moore
lot of the power provision that has to be
made for mines beyond grid connection
relates to bridging power, that is
providing enough power as a mine ramps up to
a full grid connection or to a more permanent
solution; and where the grid connection is in
place but for various reasons cannot be relied
upon for 100% of the mines’ power needs all of
the time. Mines are often at the very end of a
grid network therefore susceptible to power
fluctuations. Certain countries and regions
where mines are located are also more at risk of
power outage due to weather or natural
disasters such as earthquakes, where again
mines look to have a back-up solution.
Matthew Fredericks, Aggreko’s Head of
Mining in South Africa told IM: “New
innovations in on-site power generation can
reduce a mine’s reliance on the grid, allowing for
improved reliability and scalability of power as
well as more cost effective operations. Mines
are energy intensive operations, so access to
energy and rising costs can have huge
implications on a minesite’s ability to not only
grow, but survive. Increasing pressures on the
grid, particularly in developing regions or rural
areas, reduces the reliability of electricity and
inhibits day to day operations, let alone
expansion. Access to sustainable sources of
electricity is mission critical to a minesite and
without it poses significant risk to investment
opportunities and the overall economic health of
the sector.”
Another issue with power provision to mines
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22 International Mining | SEPTEMBER 2015
in challenging regions is that is has often been
somewhat incoherent due to different power
needs across the operation but also due to
different decision makers whether it be an
EPCM, mine manager, head office energy
executive, country manager etc.
A mine may start out with some diesel
generators then add to these with heavy fuel oil
then gas generators as power needs increase,
particularly if there are issues with grid
reliability. Mines also tend to cover a large area
(with electric machines running off cables
connected to numerous transformers); there are
often many large contractors involved; and so
operations can end up with a diverse but not
necessarily very organised power network, with
some generation equipment owned and some
leased.
Increasingly mines are looking for a more
consolidated and coherent solution to bridging
power needs, as well as one that incorporates
some element of alternative to 100% diesel,
such as combining diesel gensets with some
solar or wind power. As with other aspects of
service provision, mines want to be left to the
business of mining, leaving complex power
needs up to an expert power company or
provider that can be paid an overall cost per
kWhr and make key decisions on generation
equipment needs based on demand level and
available fuels etc. These power specialists are
better able to make decisions on how best to
boost power supply in certain situations; such
as where a mine decides to do more upgrading
Aggreko worked with Sibanye Gold to develop
innovative generation technology at the Beatrix
mine
of ore onsite meaning a boost is needed in
power supply to the processing plant. An
extreme example of this might be where an iron
ore mine opts to build a pelletising plant.
Not only helping mines with power solutions,
temporary and bridging power providers are
now stepping in to provide whole utility
companies with power solutions to supplement
their national grids where they are having
difficulty meeting demand – these so-called
short-term distributed generation solutions are
becoming more common and important. A good
example is where there are severe droughts in
countries (and the mines within them) that rely
heavily on hydroelectric power plants. Countries
with the potential for natural disasters or that
could be severely impacted by droughts can be
identified, but it is impossible to predict exactly
when and where disasters will occur.
Mark Manint, Rental Power Manager at
Caterpillar Inc talked about this utility back up
demand to IM: “A short-term distributed
generation project fills an immediate need for a
utility company or larger scale utility consumer.
In the majority of cases, the distributed
generation plant will be interconnected to the
utility grid at voltages ranging from 14 to 225 kV.
There are situations where the plant would
operate as its own utility grid, such as in a
remote region, a remote mine site or a large
construction site. The contract period for these