Editors Note, 2018-03
August 24, 2018

Executive Insights – Dr Chris Ettmayr

The Best Time for Solar?


So with the work that I do in the renewable energy sector I am often asked about costs associated with going green and then I get the challenge of practicing what I preach. So is my home green yet? No, but now that I have run this exercise below let’s see if the time is right for this move.


To start off with, your business or household should be as energy efficient as possible, otherwise you are installing solar panels to run inefficient products and this is simply a waste of money. I have a gas stove and a solar geyser but I could look at converting my pool pump into a more energy efficient pump or even a solar alternative. My lighting is a mix of some LED but mostly traditional incandescent bulbs and downlights. However, for the sake of this study let’s just assume I have tweaked all my appliances that consume energy and they are now as efficient as possible.


I contacted Sustainable Power Solutions (SPS) who ran a desktop study on my house. I provided a google image of the property and 12 months utility billing which the municipality can email through to you upon request. According to my household consumption SPS recommended a 6.6kWp system which is 20 solar panels taking up 40m2 of roof space. The system will be grid tied, therefore supplementing my household consumption with renewable energy and always using green energy before municipal supply. So no need for batteries!


The total cost of a system on my house? R122 100 (excl VAT). But before you say this is not feasible we need to compare to the overall project lifespan. The calculated Buffalo City 2018/19 energy charge is 178.52c/kWh (excl VAT). With an 8% per annum increase in tariff this project will breakeven in 6.8 years. So before tax that gives you an internal rate of return of 17.3%. Not bad for a small household project.


However, there may be some businesses wanting to run the same exercise. SPS have recently completed a second phase to the Lourensford Wine Farm. This is a 586kWp project which takes up about 4600m2 roof space. That is a total of 2780 solar panels in a project that will save 987 tons of CO2 emissions into the atmosphere in the first year alone. In more practical terms, this system could run 191 average households, operate 5600 fridges for 24 hours, run 1120 washing machine cycles, or allow you to travel 14000km in an electric vehicle.


So should I be practicing what I preach? Let me phone our tenant, ILB Helios (featured later in this publication) and try negotiate a good deal on their panels!