- Solar panels on the roof
- A charge controller to regulate the flow of energy from the solar panels to the battery bank
- A battery bank where the solar electric energy is stored
- An inverter to change the battery energy into normal household power.
The daily electrical energy requirement of the property will determine the required number of solar panels and other system components. The amount of reserve energy required for periods of little or no sun and the climatology of the specific location will also play a role when we design such a system. A wind turbine could even be added as an additional source of energy (with the provision that it is feasible) and a generator could be employed as a final back-up source of power.
Main benefits of standalone off grid solar systems:
- Dependable and reliable.
- Complete Energy Security.
- Cost of energy yield fixed for at least 25 years.
- Expandable and modular – can be enlarged at any time.
- Renewable resource with minimal impact on the environment.
- No more costly line availability fee (if you had Eskom before).
- Total independence – all electricity provided by sunlight.
- No grid power required, avoiding expensive infrastructure.
Main disadvantages of standalone off grid solar systems:
- Higher initial cost due to larger battery banks.
- Understanding and management of the system and energy usage is required.
- Energy usage limited to what the designed system can yield on a daily basis (could be supplemented by a generator).
- Battery banks need replacement eventually. Depending on design and type of batteries used, a lifespan of anything from 2 – 15 years is possible
An off-grid solar system is not connected to the electricity grid and requires battery storage. Off-grid solar systems must be designed correctly in order to generate enough power throughout the year and have the necessary battery capacity to meet the installed locations electrical energy requirements or demand.
In Africa, we are very fortunate with abundant sunshine. A backup generator or alternative back up power source may be necessary to supplement your electrical demand and recharge the batteries during times when the batteries are inadequately charged due to very bad weather patches or other unforeseen circumstances. We recommend that the size of the backup power source should be adequate to supply energy to your house and charge your batteries at the same time.
Generally, off-grid solar system sizing or specifications are based on your daily wattage usage and peak Wh requirement. Daily watt-hour usage can normally be calculated from your utility bill over a time-period but may require more accurate usage pattern monitoring with energy metering data loggers.
