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Backup Energy | Alternatives to Grid Power

Backup Energy and Grid Stability

Rolling blackouts (loadshedding) of between 6 and 12 hours a day cost the South African economy between R204 million and R899 million daily, as the South African Reserve Bank recently disclosed. This makes the provision of backup energy an economic imperative as opposed to a matter of choice. The announcement of a state of emergency by President Ramaphosa to help deal with the electricity crisis is a clear indication of the seriousness of the problem.

In conjunction with the rolling blackouts caused by loadshedding, there has been a significant increase in breakdowns and other technical faults. Large, utility-scale switchgear is designed for a set number of on and off cycles. In normal operation, they would last decades but quickly reach the end of life when switched on and off daily for scheduled loadshedding. In addition, lengthy technical outages are on the increase as the lack of maintenance, sabotage, the decline in the number of skilled technicians at Eskom, and corruption continue to cripple the utility.

From the point of view of declared policy, South Africa’s focus on promoting the adoption of the 4th Industrial Revolution is underpinned by the availability of stable electrical energy and is an absolute non-starter in the prevailing energy environment.

 

Generators for Backup Energy

Generators, and particularly diesel-powered units, are the backup energy sources of choice in the commercial and industrial space. These are a combination of a diesel engine and an alternator that converts the chemical energy stored in the diesel into rotating kinetic energy, which then produces electrical energy. The rotational energy turns an armature within a magnetic field created by a series of magnets to provide alternating current (AC) electrical output. While most large-capacity generators use diesel as the fuel source, petrol, natural gas, or even steam can be used to rotate the armature of the alternator.

Generators are extremely flexible sources of electrical backup energy. They can be configured to produce virtually any commonly encountered electrical power, whether Alternating current (AC) or Direct Current (DC), single or three phase. Multiple generators may be connected in parallel to provide increased capacity or redundancy. Where additional load is added, an additional generator can simply be deployed to cover the added requirement. Two or more gensets can be joined to combine the power output of each unit.

The downside of a diesel generator as a backup energy solution is the fact that it takes time for the engine to start and ramp up to full capacity. In many applications, this is not an issue but at sites with sensitive electronic or medical equipment, for instance, the gap between grid loss and production of power from the generator is unacceptably long. The running and maintenance costs of generators are high compared to some of the other possible solutions, and burning diesel is not environmentally friendly.

 

A UPS for Backup Energy

An Uninterruptible Power Supply (UPS) is another alternative backup energy solution available to commercial and industrial enterprises. A UPS uses an inverter to convert DC current stored in a battery into AC current for conventional AC loads. The more backup energy stored (the larger the UPS), relative to the load that needs to be carried, the longer electrical equipment is able to remain operational in the absence of the grid.

A UPS will use grid power, while it’s available, to charge the battery and energise the loads on its output. When the grid fails, stored battery energy is converted into AC to power the equipment connected to it. UPS-based backup energy systems allow equipment to continue with normal operation when grid power fails.

Most people will be familiar with the UPS that keeps their desktop computer running for a relatively short duration while they save their work and shut down their PCs. When the grid is present, the batteries are kept topped up and replenished after outages. A UPS for a commercial or industrial user can be orders of magnitude bigger than the one connected to your office PC, but the principle of operation will be very similar.

UPS systems are well-suited as backup power solutions for sensitive electronic equipment. Certain UPS designs provide continuous power with zero break in supply on grid failure.

The limitation of a UPS solution is that large batteries are required to provide enough storage for extended outages. Batteries are still relatively expensive, and at sites where large loads need to be carried for long durations, the cost quickly becomes a limiting factor.

 

What About Renewables?

Renewable backup energy systems are also available as alternatives to grid power. The most common renewable backup energy systems use solar panels or wind turbines to generate electrical power. Due to the fact that both these technologies suffer from intermittency (the sun goes down every evening, and the wind isn’t always blowing), to make these systems attractive, some form of battery or energy storage technology is required to store all or some of the power produced for later use. Chemical batteries are by far the most used storage solution, but many alternatives for storage exist. Backup energy can be stored in compressed air, pumped water, and hydrogen fuel cells, to name a few.

Conventional renewable energy systems, unlike industrial generators, cannot be deployed rapidly and are, by nature, not portable. Solar farms and wind turbines take time to construct and are not an “off the shelf” install. Even large industrial diesel generators are relatively easy to move and can be rapidly brought online. Size for size, the capital cost of a generator will also be substantially lower than a renewable energy solution of similar capacity.

 

Large-Scale Backup Energy Provision Requires Expert Knowledge

Industrial-scale backup power provision is a specialist field, and it is vital to choose the right partner, with the right track record, to provide you with the optimum backup energy solution. At PacB, we have a long history of providing service and technical excellence. We are a leader in the power-generation industry in Southern Africa. We provide leading engine brands and alternators for large-capacity industrial diesel generators. We also provide large-scale UPS solutions and renewable energy systems.

Let our experienced engineers and technicians design and implement a class-leading, fit-for-purpose power solution for your company and avoid the financial and operational risks of not getting it right the first time. Choose PacB for your backup energy system.

We have an unimpeachable reputation and are experts in creating integrated hybrid solutions using diesel generators, UPSs, and renewable energy sources. We can assist with UPS units from as small as 1 kVA through to and including 800 kVA units. Our competent technical team is always available for telephonic or on-site assistance to support our products. Explore our website today and engage with an industry leader.