Home Solar Systems
Grid tie Solar systems
A grid-tie system is a special type of circuit where a grid tie inverter converts direct current(DC) electricity from your home solar panels and converts it into alternating current(AC) electricity and feeds it directly into an existing electrical grid. Grid-tie system are often used to convert direct current produced by many renewable energy sources, such as solar panels or small wind turbines, into the alternating current used to power homes and businesses. You can also sell the excess electricity produced back to your electricity supplier. The technical name for a grid-tie inverter is “grid-interactive inverter”. They may also be called synchronous inverters. Grid-interactive inverters typically cannot be used in standalone applications where utility power is not available.
Stand Alone Systems
A standalone system do not connect to the electricity “mains” (aka “grid”). If the load is to be supplied independently of solar insolation, the generated power is stored and buffered with a battery. In non-portable applications where weight is not an issue, such as in buildings, lead acid batteries are most commonly used for their low cost. A charge controller may be incorporated in the system to:
a) avoid battery damage by excessive charging or discharging and,
b) optimizing the production of the cells or modules by maximum power point tracking. However, in simple PV systems where the PV module voltage is matched to the battery voltage, the use of MPPT electronics is generally considered unnecessary, since the battery voltage is stable enough to provide near-maximum power collection from the PV module. In small devices (e.g. calculators, parking meters) only direct current (DC) is consumed. In larger systems (e.g. buildings, remote water pumps) AC is usually required. To convert the DC from the modules or batteries into AC, an inverter is used.
If you live in a residential area then its best to go for a Grid Tie System. Invest in as much Wattage as your budget can accommodate because you can sell the excess electricity. But if you live in the middle of nowhere far away from civilization then you have no choice but to go for a stand alone system.
