With more residents turning to solar power due to loadshedding and the prospect of the power supply situation worsening, it seems rooftop PV (photovoltaic) systems have been deemed the ideal household solution.
Also read: Loadshedding: Here are your options
The City of Cape Town says it is often approached for guidance as to how to choose the right system and installer.
While the City does not vet installers in the private sector, it has developed a checklist to assist residents who are exploring this option. Customers are encouraged to weigh up the information they have, ask questions and ensure they choose a legitimate installer.
The three types of systems
1. Grid-tied solar PV system:
This system is connected in parallel to the electricity grid either directly or through the household’s internal wiring. It includes grid-tied with an export of excess electricity or with no export.
2. Grid-tied hybrid solar PV system:
These grid-tied systems are able to disconnect the incoming electricity supply and connect the essential load to the PV system or stored energy in batteries.
3. Standby solar PV system (interconnected with electric installation)
Electrical loads (homes) are supplied by either the PV system or the grid but never both at the same time. The system includes the use of passive standby UPS as an alternative supply and for hybrid, small-scale embedded generation.
According to the City, this system is often incorrectly configured and poses risks to household and grid safety. It also slows down the authorisation process, thus the City discourages customers from this alternative.
Checklist for safe and legal rooftop PV installations
- Ask if the solar PV service provider has substantial prior experience in solar PV installations, with references.
- Establish whether the solar PV service provider designed, supplied and installed the systems or only carried out one or two of these steps.
- It is recommended that the PV service provider is an accredited service provider under a third party quality assurance programme such as: PV Green Card (a South African Photovoltaic Industry Association (SAPVIA) endorsed programme; or P4 Platform quality assurance programme.
- Request proof of electrical Certificates of Compliance (CoCs) and/or professional engineer sign-offs on previous installations.
- Ask for proof of previous installations that have been City-authorised.
- Find out if the solar PV service provider employs or subcontracts qualified staff to design and install systems. Ask for proof of up-to-date registration (a wireman’s licence and DoLE registration).
- Ensure that the inverter proposed is on the City’s approved inverter list.
- Grid-tied systems must be signed off by an Engineering Council of South Africa (ECSA) registered professional. Check that the solar PV service provider has such a professional available.
- Find out if the installer is registered with SAPVIA and the Electrical Contractors Board (ECB) – it’s not compulsory but shows commitment to industry best practice.
Be energy-wise to reduce system costs:
- Before installing a solar PV system, become more electricity-efficient to reduce the size and thus cost of the system required
Systems must be safe and legal:
- Installers must apply to the City to authorise the system for grid connection to ensure the safety of the electrical network, your home and all who work on the electrical grids.
- If City staff and contractors do not know about systems connected to the grid, they run the risk of electrocution.
- Regardless of the type of solar PV system being installed, authorisation must be obtained in writing from the City prior to installation.
No City-charged authorisation fee:
- An installer may charge a fee for the professional services rendered to perform the authorisation on the customer’s behalf.
Get a structural engineering assessment:
- Make sure roofs can withstand the weight and wind load of solar PV panels where necessary.
Building plans not required for PV systems:
- Unless the panels protrude more than 600 millimetres above the highest point of the roof;
- or they are raised more than 1.5 metres above any point on the roof;
- or if ground-mounted, the panels in their installed position project more than 2.1 metres above the natural/finished ground level.
Buy the correct inverter:
- You can find the list of approved inverters here.
Check solar PV panel standards:
- At the very least, get a Certificate of Compliance with the SANS/IEC standards:
- SANS/IEC 61215: 2015 – Crystalline silicon terrestrial PV modules.
- SANS/IEC 61646: 2016 – Thin film terrestrial PV modules
Store batteries safely:
- In a properly racked, dry, well-ventilated room.
Ensure specialised circuit breakers are used:
- The DC current from the PV panels requires specialised circuit breakers.
Get all available warranties and manuals:
- For the installation as a whole and for its components (solar modules, inverters, structural system).
Recourse for poor work:
- An independent inspection of the installation may be requested.
- In Cape Town, an organisation that carries out this work is the Electrical Approved Inspection Authority of Southern Africa (EAIASA).
- Before it can carry out an inspection, it must be provided with the Certificate of Compliance and the customer will need to pay an inspection fee.
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