Frequently Asked Questions – Colek Oil and Gas Sercices Ltd

FREQUENTLY ASKED QUESTION

Does solar work during load shedding?

As long as it is light, solar modules will be producing power. However, there is a misconception that a solar PV system will prevent load shedding – it’s actually a bit more complicated than this.

Firstly, there are different types of solar PV systems: grid-tied, off-grid (microgrids), and islandable on-grid microgrids. In South Africa, grid-tied solar PV systems are most commonly used, as these are the most affordable and have the best business case.

Unfortunately, grid-tied solar PV systems will generally be programmed to switch off during load shedding. Why is this? It comes down to international safety standards. Solar modules generate DC electricity, but this needs to be converted into AC to be used in buildings. As such, solar inverters are used to convert the electricity.

During a grid outage (such as Eskom’s load shedding), the solar inverters are designed to switch off. This serves as protection for grid personnel that might be working on transmission lines during outages. If buildings continue to generate power during a grid outage and potentially export power to the national grid, it could be fatal for maintenance personnel who are unaware that there is live electricity in the lines when the grid is off.

As such, grid-tied inverters cannot operate in off-grid conditions. However, it is possible to form one’s own “on-grid” microgrid, that essentially fools the inverters into thinking that they are grid-tied, but keeping them off-grid to maintain safety. This requires the use of a generator or battery and specialised control equipment.

How does solar power work?

Solar photovoltaic (PV) panels contain a semiconductor material (typically silicon-based) which converts sunlight into direct-current (DC) electricity. An on-site inverter converts the DC power to AC power, which can then be connected to a building’s power supply or directly to the electricity grid.

What makes RyanWrights Solar different to the other solar companies out there?

At RyanWrights Solar, we believe that future relies on affordable, clean and accessible energy. Our highly-skilled team is committed to working for the greater good and we take pride in facilitating Africa’s prosperity through our clean and reliable energy systems. RyanWrights Solar is able to handle projects of any size over 100 kW from feasibility, to design, through to procurement and construction. With over 12.5 MW of solar installed over the last four years and ISO 9001: 2015 quality assurance, we are able to provide a wealth of knowledge and experience to our clients.

Does solar make sense for my building?

Perform a spot check to determine if your roof if free of shaded by trees, mountains or other buildings? Is your roof is flat or mainly sloped in a northerly direction and has an uninterrupted northern exposure? If you have answered ‘yes’ to these questions your home, office or building may be ideal for solar PV.

What factors influence the economics of a solar system?

This is determined by a number of factors, including geographic location, specific energy consumption tariff, slope and shading of roof structure or piece of ground where solar panels will be mounted.

Can solar and batteries help us to bring down our peak demand, even if our peak is early mornings?

Peak demand is a significant contributor to your electricity bill and if you are mostly a daytime energy user, then your demand is likely to happen during the day. During sunny months, the chances are good that with the implementation of solar PV, your peak load will be reduced significantly, because the injection of solar PV coincides with the peak use in the building during the day. A battery solution, which stores energy during non-peak times and discharges during peak usage hours, can further supplement this and increase demand savings, particularly with a demand peak in early morning or evening.

What happens if my business shuts down after hours, but the solar system is still generating energy?

This depends on which grid your building or facility is connected to. Municipalities such as the City of Cape Town offer a reverse feed tariff, meaning that you can sell excess energy back to the grid and recoup costs. However, not all municipalities offer this facility. Ryan Wrights Solar designs systems to maximise self-consumption and minimise reverse feed, because generally the feed-in tariff is lower than what you would pay for energy.