Johannesburg, 11 Nov 2020
The pressure on South Africa’s power grid and the resultant load-shedding, escalating electricity tariffs and lockdown, are a triple threat to business continuity. While we can’t do much about lockdown, we can ensure an alternative source of energy that will enable businesses to be productive and avoid unnecessary downtime. Residential complexes are also exploring this option to reduce the impact of power outages on residents and their security.
Rudi Fourie, Executive for Fibre and Facilities Management at Sizwe Africa IT Group, says: “What keeps people from implementing alternative energy is primarily a lack of funding and concerns that it’s prohibitively expensive to implement. Most businesses and complexes just don’t have an immense portion of spare capex to invest currently. Particularly when it comes to solar energy.”
However, solar energy has many benefits: it’s cleaner than the alternatives; can be tailor-made to the business or residence; and is scalable, so can grow with future requirements.
Yolande Engelbrecht, Account Manager for Alternative Energy at Sizwe Africa IT Group, makes the case for solar energy: “It’s a sustainable and environmentally-friendly solution that can be designed to fit almost any application.”
Engelbrecht explains that while the majority of people may believe that it is the heat of the sun on the solar panels that generates the power, it is actually the UV rays that generate the power, which is why on cold, sunny days the system still works well.
Types of solar
There are three basic types of solar implementations, according to Engelbrecht.
“First and foremost there is the grid-tied system, which is simple and cost-effective. This involves solar panels installed with an inverter that converts the DC energy produced by the solar panels into AC power. The system is also tied to the grid, which means that when the solar is not producing enough energy, power is drawn from the grid to supplement it. This is a pure cost-saving system as it brings down the client’s usage of utility power.”
The return on investment for this type of solution is in the region of five years, after which the power being generated is free and the client’s utility bill is lower in terms of electricity. “This works well in cases when the majority of power is being used during the day. Important to note is that in a grid-tied scenario, when the power fails from the utility’s side, the solar switches off as a safety precaution.”
The second option is a hybrid solution, where batteries and/or a generator are added. These provide power to the premises in the event of a power failure by the utility. The hybrid inverter allows the solar to produce energy even though there is no utility power, unlike a grid-tied system. This allows the solar to supplement the load placed on the batteries and/or generator. It also brings down the generator’s fuel costs. The batteries can also be used to power the premises (through the hybrid inverter) at night, for instance, when the solar is not producing power, reducing the use of utility power. A hybrid solution can also be set to only provide backup power or to operate up to a certain threshold, if there is utility power, to ensure that in the event of a power failure, there is still battery capacity to power essential loads.
Finally, there’s the so-called ‘island’ system, which is the premium of the three varieties owing to the fact that there’s no utility power available in this scenario. An island inverter is required with sufficient batteries to ensure the facility is never without power. As with the hybrid system, a generator can be integrated as an extra measure to ensure the facility is never without power. Batteries contribute to an increase in cost in both hybrid and island systems; the more batteries required, the higher the cost of the system.
Engelbrecht says: “In order for a client to determine what system is best suited for their needs, they need to think of what they want to achieve. If the goal is purely to cut costs on the utility bill, they would opt for a grid-tied system. If the user needs backup of essential loads in their premises, a hybrid system would be best suited. If there is no access to utility power, then an island system is the way to go.”
Addressing the costs
The good news is that the cost of solar system components such as the solar panel itself has reduced over the past couple of years, therefore making it more affordable and shortening the ROI period. A typical solar installation comprises of solar panels, grid-tied inverters, cables and mounting structures. However, this varies according to the type of installation. For example, a hybrid system requires solar panels, hybrid inverters, batteries, cables and mounting structure, while a generator can also be added. Island systems require the same components as a hybrid system, the inverter will just be an island inverter in this case. The number and/or size of the batteries will be bigger in an island system scenario than a hybrid system to ensure the premises always has power.
Engelbrecht outlines another concern around the deployment of solar panels, which is theft. “To defend against this, the panels are usually installed on the roof of the premises or on a car park structure, which is not easily accessible. Additional security measures that can be taken include installing security cameras. It’s also advisable to insure solar installations against theft.”
There are five important things to consider when planning your alternative energy project:
- Determine the baseline load, which is your average power use for a day. Eliminate inefficient lighting and appliances - for example, replace inefficient lights with LED lights.
- Think about what you want to achieve realistically and choose or even design a system based on that.
- Evaluate available products specifically in terms of inverters and batteries. Not all of them can achieve the same results, hence the price difference between them.
- Solar is modular, which means you can add on to the system by, for instance, installing batteries in a second phase. It is important to remember that in order to do this the correct inverters need to be specified in order to avoid unnecessary additional costs down the line.
- Accessing finance for this type of project can be a challenge, so discuss this upfront with the service provider and establish how they can assist with this.
Fourie conclude:, “Although it sounds simple, deploying solar energy requires more than just installing solar panels on a roof and an inverter. Each solution is different and each environment in terms of installation is different and needs to be designed according to the client’s needs and physical location of the system.”
Share