Solar power systems have two basic architectures, the grid tied and standalone solar power applications. Residential grid tied solar systems consist of solar panels connected to a grid-tied inverter only. The grid-tied inverter imports and exports power from a utility connection to guarantee a consistent supply of electricity to the house.

 

In daylight when the sun is up the panels produce DC power which is inverted into AC power by the inverter. The inverter then supplies the power to the load (home appliances and other electrical equipment). The following reasons justify the need for synthesizing the solar power system with the grid:

 

• To ensure consistent power supply to the load

• To enable excess power to be exported to the grid

• To eliminate the need for a power storage facility

 

Grid tied systems do not require batteries and charge controllers as the power generated is conceptually stored in the grid. Power storage systems escalate the cost of a solar power system making grid-tied solar power significantly cheaper.

 

Standalone systems consist of a pack of batteries connected to the system to provide power after the sun sets. Batteries have a short lifespan that is largely determined by their charge cycles. Well maintained systems can last not more than 5 years and require constant attention. This effectively means the batteries will be replaced 5 times during the lifespan of the panels. Standalone systems therefore cost more from the first day of installation and throughout the lifetime of the system.

 

Grid tied systems do not have any power storage component eliminating 30% of the upfront costs. The system only consists of an array of panels and grid tied inverter as well as power protection equipment. During the day when there is sunshine the array will produce power that is used by the consumer. Excess power from the system is fed back into the power lines for consumption by neighboring power consumers. Switching between the grid and solar system in the morning and evening occurs seamlessly.

 

At night the customer imports power from the utility to supply appliances in the house for cooking and heating. The difference between the imports and exports determines the monthly electricity bill of the consumer. The export tariff is however higher than the import tariff resulting in a net negative bill. Grid tied systems can therefore go beyond saving the consumer money by earning power credits from the utility. The system also protects the customer from future energy tariff hikes

 

To get the highest return from the installation the customer can either install a net meter or earn credits (in Kwh) from the utility through feed-in tariffs. A net meter runs backwards when the array feeds power to the grid and forwards when the array fails to supply enough power to the load. Net meters can also be work with a pre-paid system. Feed in tariffs are currently not available in the country with regulations set to be passed before the end of 2013.

 

SolarSky installs grid tie limiter with its grid tied systems to ensure no power is exported to the grid. 

 

Switch to solar today and enjoy the benefits of reduced electricity bills and a contribution towards a cleaner environment.

 

SolarSky (Pvt) Ltd