Grid connected systems
A solar energy system for generating electricity and deliver the produced electricity direct to the grid. At the moment following systems are common in RSA:
1. Net Metering - You connect a PV installation without Batteries to the grid and sell the produced Energy to ESKOM or the City. Only for Domestic users, no limitation on size
2. Bi-Directional - These systems are grid connected and can deliver electricity to grid, but they work also in case of power failures throughtout the installed batteries.
3. REBID - Tender Process for systems larger 1MW. You sell the produced power back for a fixed price over a fixed period of time
There is a new system in discussion from DoE for systems from 1MW to 5MW.Stand-alone systems
These systems are not grid connected. They are most common at the moment on farms, for pumping water, telecommunication towers etc. The systems can be specially configured according to the customers' energy requirements. The number of photovoltaic modules depends on how long they last and how much electricity the consumer requires.
The direct current generated by the photovoltaic modules can be consumed directly or stored in rechargeable batteries for later use. Storing electricity also means that there is a basic supply for lighting or to keep the fridge running during the night or during bad weather.
The photovoltaic systems allow solar power to be used for various AC and DC electrical devices as well as generator-supported hybrid systems and backup systems for emergency power supply.