At Likusasa we understand the complexities and difficulties faced by operators and are focussed on providing power systems that address the needs of specific situations. Our philosophy is to supply systems and solutions that are geared around the reduction of operational costs, within
the budgetary and situational constraints imposed. The most basic system is the stand-alone Reduced Opex Power System (ROPS)
What is ROPS?
The Reduced Opex Power System (ROPS) is a power system that is designed to reduce the costs of running offgrid power systems. This is typically achieved by alternately running a site on generator and battery power. Smart control of a generator can even achieve this with existing DC power systems or the installation of tailor made systems. Generally, the savings can be up to 50% of the cost of running the generator 24 hours a day. Power generation efficiency is
increased from about 15% to the order of 35%.
The Likusasa eROPS
Enhanced Reduced Opex Power Systems focus on the total cost of ownership (TCO) of power systems, and seek to provide customised solutions that optimise savings over the lifetime of the system. These systems are generally more capital intensive than the ROPS, but are more efficient and have a reduced TCO. Power generation efficiency can be increased to the order of 60%. The eROPS is characterised by the integration of an intelligent management system that
not only controls various power consumers on the site, but also manages the energy storage system. The eROPS system is therefore very flexible and can be easily upgraded
to include other sources of energy such as wind and solar power.
Alternate energy generation sources
eROPS solutions are easily integrated with different energy generation systems. These can be renewable sources such as wind and solar energy, or can be active systems using fuel cells. Renewable energy systems are more difficult to work with and are very much dependent on local conditions. They are also an intermittent source of power, which is why energy storage systems are essential to their success. Careful and in-depth planning of these systems is key to
being able to provide cost effective solutions, as they are capital intensive. However, they are extremely effective in areas where servicing and refuelling diesel generators is very difficult or costly. Other benefits include extending the life of cycling batteries and reducing generator runtimes. The geographic impact on renewable energy resources is illustrated in the NASA metrology maps below. New and innovative fuel cells are also entering the market and these
are also prime candidates for inclusion in the Likusasa stable.
Smart power utilisation
Likusasa is also able to assist operators in reducing the power consumption of off-grid sites. When running sites off generators 24/7, optimisation of auxiliary power consumption
is unnecessary since generated power is either consumed by these loads, or it is burnt off in the generator dummy load. In order to preserve the generator motors, it is essential for
the generator to be run under a minimum load of 60% to 70% of rated output, so that dummy
loads are used to maintain the load. Once you start operating the site off battery power, every watt starts to count!
Some ways of reducing power consumption are:
• Converting power hungry equipment to low powered alternatives.
(Equipment vendors are addressing this aspect)
• Eliminating as many power conversion stages as possible, i.e. run DC loads directly off the
batteries;
• Making use of separate batteries and electronic equipment. Electronic equipment can operate at much higher ambient temperatures and therefore require less cooling
• Replacing AC powered equipment with low powered DC alternatives e.g. lights, aircraft warning lights and fans
• Implementing more efficient cooling systems e.g. DC air conditioners, heat exchangers, inverter air conditioners and passive cooling systems.
Alternate energy storage systems
Likusasa is convinced that energy storage is the key to all of the African power systems, and we have researched and explored this environment very extensively. Likusasa has also become a member of the Energy Storage Association which has brought us closer to many of the major players in this market. Because of our independence and flexibility, Likusasa is not constrained to the use of specific technologies or equipment from specific sources, and therefore we are
actively pursuing the implementation and integration of different energy storage technologies. New technologies range from flow battery systems to flywheel energy storage
systems.
New or existing sites?
Equipping of new sites and retrofitting of existing sites are both cost effective, and therefore possible solutions.
• New systems, if planned correctly, can be very cost effective and easily upgradeable. The provision of an eROPS capable energy storage system, the erection of a wind turbine ready (or capable) tower and the layout of the site with future solar power possibilities in mid can all
be achieved with only marginal expenses.
• Retrofits are more difficult because you are faced with an existing infrastructure which you have to plan and work around.
However, the benefits of the conversion are clearly visible as soon as one year after installation.
Typically, the basic ROPS solution can pay for itself within the first year of operation. eROPS solutions can deliver a positive return within a period of 3 to 5 years depending on
the design parameters and requirements of the site. Likusasa is able to assist clients in identifying suitable sites for conversion and provides full turnkey project roll-outs,
managing the project from conception to commissioning and handover.