The mining industry has long relied on conventional fossil-fuel based sources to address its energy requirements. However, increasing carbon emissions, fuel prices and unstable supply are prompting mining organisations to re-examine their strategies and consider tapping into renewable energies, including off-grid mining locations.
A recent study conducted by the Carbon War Room found that off-grid mining sites can greatly reduce energy costs by deploying solar hybrid systems*, particularly in areas where there is a lack of stable energy supply. The traditional approach of installing power cables can be costly. Installing generators that operate 24 x 7 can have operational challenges, including maintenance, supply availability and fuel delivery costs. For example, diesel delivery can be hampered by poor weather conditions and often require specialised delivery vehicles such as 4 wheel drive tankers. Additionally, unscheduled breakdowns and maintenance schedules can be costly as generator contractors have extended travelling time to get to these difficult sites.
Mining companies need a reliable and cost-effective solution that provides off grid continuous power, while reducing fossil fuel consumption and providing lower maintenance costs and enhancing reliability.
The solution is a rugged IP55 outdoor enclosure from Emerson Network Power, designed to withstand even the harshest environments.
This outdoor enclosure solution houses Zinc Bromide Module (ZBM) 10kWhr batteries next generation rectifier and solar/ wind converter
– as well as associated electrical protection devices.
The system is designed so that wind, solar and batteries are the primary energy sources with the generator as the top up and back up source. This solution has replaced the standard 24 x 7 generator operation with four interconnected energy sources that significantly reduces a 24 x 7 generator reliance. All four (solar, wind, battery & generator) of these energy sources are interconnected and remotely monitored and controlled using Emerson Network Power’s SiteWeb solution, which provides a real-time reporting dashboard for the amount of energy harvested and stored.
*Sunshine for Mines, Carbon War Room, 2014

ƒ ZBM Batteries - Zinc bromide module (ZBM) batteries has intelligent battery management, remote monitoring and re-charge capabilities. High temperature rating and low environmental emissions make this an attractive alternative to its VRLA (valve-regulated lead-acid battery), competitors.
Zinc bromide electrolyte is a water-based, natural fire retardant that can tolerate high-operating temperatures of up to 50 degrees Celsius without any active cooling. With a depth of discharge of 100 percent, this is ideally suited for unstable grids and renewable energy sources. Unlike traditional battery technologies, inherent 100 percent depth-of-discharge characteristics prevent battery damage caused by prolonged outages.
ƒ Solar & Wind - Using natural energy sources such as wind and solar means mining operations can leverage multiple energy sources to top up the batteries and to power the load without any reliance on the grid. The energy production for the typical site is very good with at least 4 kWh/ m2/day solar radiation and 6m/s wind speeds, this makes a good ROI using 6-12kWatts of solar and
1-4kWatts of wind.
ƒ Generator – The generator still plays a critical role; however less reliance translates immediately into at least 50 percent saving on CAPEX and OPEX when compared with the traditional standalone generator solution. Savings on maintenance costs, fuel transport and storage are also achieved due to a reduced load on the generator and less running hours.
Significant fuel savings cannot be ignored. Take for instance if you spend $70,000pa on a standalone diesel generator running 24 x 7 and you reduce the genset run time by 60 percent. This equates to considerable annualised savings. Carlos Ordonez, Product Manager, Energy Systems from Emerson
Network Power says “It’s not so much the cost of the fuel; it’s the cost to transport the fuel to site. For instance some locations require four return trips for a tanker to refuel the generator.”
ƒ Monitoring - What makes this solution unique is the smart monitoring and control. All four energy sources are interconnected and monitored via the IoT using Emerson Network Power’s SiteWeb monitoring system. The hybrid system has its own IP address, where live data is transmitted from the site to the customer’s operational hub. This smart technology provides a real-time reporting dashboard recording every component of the solution, including genset run times, actual fuel levels, oil pressure, solar power, solar voltages, wind power and wind voltages. Load values are then automatically translated to give the users predictability to how the system is running for servicing and fuel needs.
ƒ Service - Emerson Network Power’s service team is able to seamlessly integrate this into their existing kit bag. All Emerson Network
Power service technicians are trained to maintain the monitoring equipment. Having the ability to check fuel levels and service schedules means that fuel deliveries and maintenance servicing can be executed in just one visit, saving time and cost.
ƒ the costs - TCO becomes a very simple calculation as this system is easily replicated with predictable, installation commissioning and service maintenance costs. This enables customers to calculate CAPEX/OPEX vis-a-vis payback period when compared with stand alone generator supply or a full pole to pole power connection to the site.
While every precaution has been taken to ensure accuracy and completeness herein, Emerson Network Power assumes no responsibility, and disclaims all liability, for damages resulting from use of this information or for any errors or omissions. Specifications are subject to change without notice.
Emerson Network Power is a trademark of Emerson Electric Co. or one of its affiliated companies. All other names and logos referred to are trade names, trademarks, or registered trademarks of their respec tive owners. ©2015 Emerson Electric Co. API5ENT-Application Paper OGHPS V1-CS