Background
In November 2017, Agulhas Utilities Corporation was commissioned by the owners/shareholders of the Kanonkop SuperSpar in Middelburg, Mpumalanga, to design a PV Solar Energy System for the Shopping Centre. Because of the “urgency”, Agulhas Utilities Corporation issued a Request for Proposals (RFP) in February 2018. After scrutinising and evaluating of the four submissions, one company was selected as the one closely matching the criteria which I set for this project. However, the structural designs submitted by this company became a major issue and the owner of Kanonkop SuperSpar instructed me to redesign the entire system including the structural layout. The owner then decided to delay the project to investigate making changes to the building.
After scrutinising and evaluating of the three submissions, Blue Storm Trading CC was selected for the electrical work and Schletter South Africa was selected to supply and erect the structures on which the PV panels were to be mounted. Without our prior knowledge, Schletter appointed a subcontractor to do the erection of the structures. This subcontractor brought about several delays and frustrations which I had to manage on the behalf of the client – owner of Kanonkop SuperSpar since the contracts for the electrical and structural work was between Kanonkop SuperSpar and the contractors.
In late March 2019, the structural material was delivered, and the erecting thereof began. Not to inconvenience the shoppers, a fair amount of work on the carport-type structure took place after hours. Working at night-time does not always go without problems and many a time, mistakes only became noticeable during the daytime. This meant a fair amount of rework and often with certain lasting consequences.
Finally, during the second week of June 2019, the electrical contractor – Blue Storm Trading – came on site and began the horizontal drilling for the sleeves. Due to a lack of proper drawings of the services that were laid on the site, before it was bought over by Kanonkop SuperSpar, the company who was subcontracted to do the horizontal drilling struck a sewer pipe which caused delays and extra work for the electrical contractor. Soon after the cable sleeves were installed, Blue Storm Trading began laying the cables, fitting the distribution boards and mounting the inverters. This had to be done in record time since the switch-on was scheduled for end of June 2019.
One very important point is that we – the owner of Kanonkop SuperSpar and I – decided not to compromise on quality and therefore selected the KACO Inverters – now owned by Siemens. These inverters were supplied by MicroCare, the local agent for the KACO Inverters.
At the end of June 2019, I issued a Certificate to the owner of Kanonkop SuperSpar stating that the PV Solar Energy System – Embedded Generation – is generating power, this is after checking that everything is working as it should.
A few weeks before the final switch-on, I installed a Power Quality Monitor to record, amongst others, the power consumption of the entire building. I also recorded the power generation from the PV Solar System.
The graph below depicts a twenty-four-hour period of the three readings: total consumption for the entire shop (blue), the PV Solar Energy (orange) and the energy from the municipality (grey) for June/July. Due to the inclination of the sun in the winter period, the power generation is not the same as summertime. Therefore, this graph is specific to a single snapshot in time and does not mean that it would be the same for any other day.
In October 2018, the new building plans reached the final stages of approval by the owner. Those preliminary plans were given to me whereupon I started looking at a totally new design for the PV Solar Energy System. I ran several studies to look at different options to find the optimal layout. However, this was somehow restricted due to the design limitations of the structural design on which the PV panels would have to be mounted. In addition, the various components of the entire system had to be looked at making sure that substandard components are not being used. On completion, in January 2019, Agulhas Utilities Corporation issued a detailed tender document which was sent to several preselected companies.
One of the primary criteria was to ensure that the system never exceed the total consumption for the entire Shopping Centre. For this to happen, a load limiter system was installed. In November 2019, it limited the output of the inverters to prevent any back-feed into the grid.
This PV Solar Energy System is a great success judging by the savings it generates. The client – owner of Kanonkop SuperSpar has at several occasions told me that he does not want to tell me how much he is saving since he said that I do not believe him. It is exceeding my original calculations by far.