What is Solar Power?
Solar Power is the Photovoltaic (PV) process where solar radiation is converted to direct current (DC power) and with a grid or island inverter the DC power is converted to alternating current (AC power).
AC power is the most common form of electrical energy in the today's applications.
A grid-tie system is a system where the solar power that is generated during the day, gets used by the applications on the same grid connection point. When the solar power isn't enough the grid can supplement the extra power that is needed.
The drawback of a grid-tie system is that in the event of a grid failure it will stop to produce power. It can be linked to a generator setup but the necessary safety control mechanisms needs to also be install to properly regulate the feedback power onto the generator system.
An island system is a system where the PV modules charge a battery bank via a charge controller (in some insanses the regulator is built into the inverter itself). The island inverter uses the battery bank and convert it into AC power to supply power to the applications it is connected to. The system is primerally designed to to be an off-grid system, however you can connect a grid or generator to the system to supply power if the system runs out of capasity due to the following reasons:
- To recharge the battery bank when there are a prolonged cloudy conditions and the battery bank is depleted
- The load is to large for the inverter system. It will then pass the grid straight through to the loads
A hybrid system is the combination of both a grid-tie and an island system. It combines the benefit of a grid system but also the battery back-up all rolled up in on system.
The real benefit is that the island system can keep the grid-tie system active even when there is a power failure (the system needs to be properly sized and designed). The battery power is then only used to supplement the loads during day time when the load is bigger than what the PV modules can produce when the sun is shining.