It’s Time to live unbound

Do-it-your-way!

California Leads the Nation
In 2006, California made a major long-term commitment to solar power by passing the California Solar Initiative, a ten-year incentive program with the goal of installing 3,000 megawatts of solar panels on the equivalent of one million rooftops. California leads the nation in solar panel installations, as it currently has more photovoltaic systems installed than any other state. This incredible boom has taken place mostly due to California’s Renewable Portfolio Standard, which requires that 20 percent of the state’s electricity come from renewable resources by 2010. In 2008 the state decided that it was not moving fast enough in meeting these goals and enacted a feed-in tariff, requiring utility companies to buy back excess power produced by homeowner’s and private photovoltaic installations. In the same year, the state also raised the Renewable Portfolio Standard to 33 percent by 2020, greatly helping spur growth in the renewable energy industry.

Solar Panel Components
Photovoltaic solar panels are the main building block in a solar power system. Since each solar module produces a limited amount of power, installations usually consist of multiple panels, called an array. The array produces DC (direct current), which can be stored in batteries or instantly converted into AC (alternating current) required by conventional appliances.

Equipment that converts the power from DC to AC is known as a solar inverter, and they come in a few varieties, modified sine wave or pure sine wave. They are further classified based on which type of system it is to be used in, whether it is off-grid or grid interconnected. Recently the innovation of micro inverters has greatly simplified installations, and makes it easy to add on panels to an installation. Each solar module is paired with its own micro inverter, which then converts the power directly at the panel. For off grid installations the use of a charge controller is necessary to properly manage the power harvest, charge the batteries, and prevent overcharging.

The greatest innovation in charge controllers would have to be the relatively new feature called maximum power point tracking (MPPT). This innovative method of charging batteries constantly monitors peak power voltage from the array and input voltage on the batteries adjusting amperage to compensate for the fluctuations. This provides the most efficient means to manage the power harvest. The function of MPPT charge controllers is analogous to the transmission of a car, keeping your charging system in the “right gear”. Other components of the solar system would include the wiring and mounting hardware, while some installations use a tracker that changes its tilt angle and direction throughout the day.

Off Grid versus Grid tied
Solar panels are used extensively in rural areas, where access to the grid is non-existent or inaccessible. These installations are called off grid (or independent, stand-alone) solar power systems, and require the use of batteries to store the energy for use at night or on long stretches of overcast weather. The energy stored in the batteries leaves the batteries as DC electricity which can power DC appliances (as in RV’s) or be converted to alternating current (AC) for use with conventional appliances. Much like running your own mini utility company, this method gives you full independence from the national grid.

You can eliminate the cost of batteries by going with a system that connects right into your home’s main junction box and use the grid as your power source at night or on long stretches of inclement weather. These installations are known as grid-tied or grid-interconnected systems. This version of solar system enables you to sell any excess power you produce back to the utility companies who have chosen to support “net metering”. Once you are signed up on a net metering program, your utility company will have a smart meter installed known as a Time of Use Meter, which will actually run backwards when you are producing excess power. It is wise to keep in mind that Grid tied systems without a battery backup, are only functional when the grid is operational. Due to anti-islanding features on grid tied inverters, which protect utility workers from working on a live line, grid-tied systems without a battery back up will not continue to produce power during a power outage regardless of whether you have sunshine or not.

Since solar panels produce DC, or direct current, they must be coupled with a solar inverter to convert the energy from DC to AC, or alternating current. In a grid tied system this can be done by a large central inverter, or each solar panel can be outfitted with its own micro inverter. Once the power is converted to alternating current and its phase is synchronized with that of the grid, it is then tied in to your main junction box, which is ultimately interconnected to the national grid.