"Between Earthquakes, Hurricanes and Grid Failures, Solar can Save You Money Everyday and Protect Your Home from Power Outages"
Between Earthquakes, Hurricanes and Grid Failures, Solar can Save You Money Everyday and Protect Your Home from Power Outages
The vast majority of all solar electric systems are called grid tied systems. That means that the solar array feeds electricity through an inverter, changing the Direct Current (DC) the solar panels create into Alternating Current (AC) the grid uses. This AC current is fed into the grid through a Net Meter that turns backward when the system is creating more power than the home is using and turns forward when the home uses more power than the array is creating.
In this way the grid tied system uses the grid as a giant battery that actually can store electricity from the summer for use in the winter when the days are shorter and the system produces far less electricity. This is cost effective for the owner of the solar system and is also good for the grid, because solar homes product the greatest amount of electricity in the middle of the day in the summer when air conditioning and manufacturing demand on the grid is the greatest and uses current from the grid at night when demand is the smallest.
There are many more advantages to a Grid Tied Solar System including unlimited storage, no need to buy batteries and substantial economic benefits, but there is one disadvantage of a Grid Tied System compared to an Independent Battery Storage system. A Grid Tied System goes down when the grid goes down, and an independent system is unaffected by the failure of the grid. This seems to be happening more and more like the 4,000,000 homes that are without power after Hurricane Irene. The Natural Homes Team of Keller Williams Realty has been building homes that have a net annual energy cost of around zero and now offer battery backup systems.
Positive Energy (www.positiveenergysolar.com) has hybrid systems available that are grid tied with battery backup. There is very little loss of efficiency and backup batteries have a much longer life than batteries used to store electricity in the daytime and discharge the electricity for nighttime use. A grid tied system with battery backup is a good choice if you have equipment that is damaged by power loss, because a solar system like this can keep equipment operating for an extended period of time without the need for a generator.