As the name suggests, the system is solely reliant on its own solar modules and does not generate power from other sources such as wind or diesel generators. In addition, it does not connect to any electricity grid. This gives the system the advantage of being located in remote areas where it is impossible to supply electricity due to many factors.
The system has three main components and a sub-component. The main components are the solar modules or panels, battery and inverter. The solar modules generate electricity in the form of direct current (DC) which is then stored in the battery. When power is needed in the household or building, DC from the battery is converted into alternate current (AC) by the inverter before being put to use.
The sub-component of the system is the charge controller. This is connected to the battery in a way which supports it, given the circumstances of a prolonged period of overcast conditions or when high power loads are needed at a certain time. Furthermore, it safeguards the battery, increasing its operational life. All these in turn contribute to another advantage - availability of electricity even during nighttime and in case of dark weather.
However, because of the requirement for a sizeable battery capacity and solar generation capacity, the cost of the system increases. Plus, the solar modules need to be positioned so that it is pointed directly towards the sun to generate more power.Scope of Service
The set-up of a Solar Stand-Alone system or any renewable energy systems will require system specifications to be determined:
Solar modules mounted on roof
Batteries, charge controller and inverter in secured cabinets
With its improved reliability, energy services, operational life and energy efficiency, the hybrid system has brought forth the highest form of perfection in electricity generation. This system combines two energy sources: the sun and a diesel generator (genset), where the genset supplies excess load and recharges the battery during overcast conditions.
The hybrid system provides backup power in case of a power shortage, say during the peak demand period. It also reduces downtime during maintenance or repairs since the system, on its own, ensures that all the components are used efficiently at an optimum rate. For example, during the day, the solar modules will generate energy in the form of Direct Current (DC) which is stored in the battery or is straight away put to use by converting DC into AC through the inverter. During night time,, when the solar modules do not generate energy, the DC stored in the battery is put into use.
However, the DC stored in the battery may not be enough to support the energy demand throughout the night especially, when during day time, rain or overcast skies have reduced the energy production. This situation will maximise the discharge level of the battery, decreasing its operational life or, in other words, exhausting the battery. This is where the genset comes in. The genset produces AC that can be used immediately, and at the same time the AC current is rectified to produce DC to recharge the battery. The mechanism can also kick in during peak loads or when a prolonged period of overcast occurs.
Due to this alternate operation, the life of the overall system is prolonged as the discharge level of the battery is kept at optimum. The hybrid system adopts an environment-friendly technology whereby the diesel generator is used discontinuously and the whole operation itself is much quieter. All this is governed by a microprocessor-based controller unit.
The first installation may come at a higher cost, but the subsequent maintenance cost is very low due to the system’s self preservation mechanism. In addition, we can save fuel consumption of the genset because the solar photovoltaic (PV) modules support the base electricity load while the genset provides additional energy should there be a sudden peak in the energy demand.Solar Hybrid Concept