Power From Your Rooftop

Solar Electric Basics

Investing in a solar photovoltaic (PV) solar system is a substantial capital investment to your home or business and requires an in depth analysis of product suppliers and installers before one commits.  

At this stage in South Africa’s renewable energy journey, various factors are at play, which does not make the decision any easier. One of these factors is the fact that each municipality handles the connection of these systems to the grid, differently. Yet, as the price of electricity continues to increase more municipalities are entertaining the idea of connecting solar PV systems to their grid. 

The words net-metering and feed-in-tariff are commonly used in conjunction with PV systems but consideration of your municipal office is required. 

Analysis of the payback is also needed, taking into account net metering (if available) where surplus power is fed back onto the grid, and tax credit and energy subsidies or incentives (if available). Another common misperception is what your solar PV system can do and this depends on what type of system you are investigating.

Consider these alternatives, a solar PV system with: 

  1. No batteries, grid connected system
  2. Some batteries, grid connected system
  3. Only batteries, no grid connection

System 1 is used to supplement your energy usage. In the event of a blackout or power outage, your solar system is by international standard requirements forced to shut down. Therefore, even if the outage occurs in the middle of the day during full sunlight hours- no power will be produced. If net-metering is allowed, this type of system provides a one for one credit on your monthly electricity statement. 

System 2 is commonly referred to as a hybrid system and with the correct installation will act a UPS (uninterrupted power supply) in the event of a power outage. The PV system will charge up the batteries first and the excess production will supplement your household/ business energy needs. 

System 3 is useful for areas where no grid exists. The energy produced will charge up the batteries which should allow for 3 days’ worth of energy needs and these batteries will feed the power requirements of the property. 

It is however even more important to note that as you add batteries, you add cost and therefore the systems are ranked from the least expensive to the most expensive. 

A minimum of 3 quotes should be obtained before a decision is made and the brand and reputation of the product should be considered. As with any and all products, there are some that are better than others and then there is the best. There are a number of good quality PV panels to choose from however Tier 1 panel producers are preferred by any of the large scale projects due to their warranty provisions and company stability prospects.    

With the price of PV panels having fallen considerably over the last few years, the economic viability is progressively better however do not forget to factor in the current Rand strength or weakness into your assumptions. 

PV is a major investment and all steps towards being as energy efficient as possible should be taken before you investigate installing a solar PV system. 

Recommendation from existing users is a good place to start and as for the type and size of system, consumers should carefully compare price quotes, warranties given, installation track record and keep a complete file of all documentation.