Use of solar telecom power heats up in Africa
By Bob Hurley, regional director of MEA, Eltek
Africa has an abundance of sunshine. What it does not have is an abundance of electricity. This is especially the case in sub-Saharan Africa, where there are vast stretches of remote, sparsely populated terrain.
Solar technology is just beginnning to play a role in bringing power to the continent – not only for grid-based energy to power homes and businesses, but also as primary or back-up power for mobile telecom basestations.
The mobile telecoms market in Africa has been growing substantially, and analysts have assessed its 2013 value at approximately $75 billion. Although smartphone adoption has been more rapid in specific sub-Saharan urban regions such as Ghana, Kenya, Nigeria, and South Africa, mobile network operators (MNOs) throughout Africa have begun to build more basestations and upgrade their network infrastructures by implementing 3G and 4G LTE services.
However, the lack of a reliable electric grid in remote areas has meant that instability in telecom services and pollution from non-green energy sources has been the norm. Many remote basestations are powered by diesel generators that run 24/7. Maintenance, onsite inspections and re-fueling, as well as theft of the diesel, can represent difficult, time consuming and costly issues.
One integral aspect of an alternative energy powered basestation is the DC power system, which can manage various energy sources, including diesel, mains, battery and/or solar. Most sites use two or three power sources, so the system must be able to switch between these inputs intelligently. This enables delivery of an optimal mix of energy sources, in order to balance uptime with lower cost and more environmentally friendly energy use.
In a typical African hybrid-power site, solar provides the bulk of the energy, with batteries providing the rest of the power. A diesel gen-set is used to charge the batteries. Without solar, a remote basestation would be powered by a gen-set, which would provide the bulk of the power with batteries used for back-up only. The addition of solar for telecom services can cut the run time of diesel generators to as little as 6 hours per day, running at 70%, of load (vs. 20% of load for non-solar sites) which not only decreases diesel consumption (and costs) but reduces maintenance visit frequency as well.
In a solar/diesel hybrid site, it is essential that the DC power system intelligence give priority to the solar power source, in order to achieve top efficiency levels. Specialized intelligence, such as the ability to run the generator in cyclic mode, can reduce diesel usage by 70%-75%.
Reduced site maintenance for the gen-set and batteries is another benefit of controller technology in a DC power system. The controller provides remote monitoring and system analysis, which extends battery life and reduces downtime. It can also dramatically decrease the number of routine maintenance visits required – saving thousands of dollars for each site visit eliminated.
Most controllers offer system configuration, alarms and set-up features. But advanced systems add battery charge control capabilities that can actively manage battery functionality and health. With the addition of high-tech sensors, the system becomes even more dynamic and can analyze and respond to environmental events, such as outside temperature fluctuations, to further reduce operating expenses.
Implementation of hybrid energy systems that leverage solar power to power telecom base stations can increase initial CAPEX. However, sites running on hybrid solar/diesel power offer the significant opportunity for mobile network operators to reduce OPEX – often times within several years of purchasing the new equipment. Given that the useful life of a DC power system can be 5-10 years, the total cost of operating a hybrid system can be very beneficial to a carrier – and to the customers it serves.
Bob Hurley is regional director of MEA Eltek. He has also authored a whitepaper titled How to Reduce the Total Cost of Ownership of 4G/LTE on the use of solar power in mobile networks. He can be reached at [email protected].