Published on January 31st, 2012 | by Nicholas Brown7
New Type of Inverter Could Drive Down the Cost of Solar Power
ArrayPower says that it has invented a “sequenced inverter” design that could cut the cost of solar power by 10%.
For those that don’t know what an inverter is, don’t worry, it is easy to understand and I will explain it: a typical inverter for a solar-powered home converts the DC (direct current) power that solar panels generate into 120- and 240-volt AC (alternating current) power, the same as what your power outlet provides. Small solar setups often generate DC at 12 volts, and that 12 volts of DC power is converted into 120 volts of AC power, which is suitable for most household appliances, portable devices chargers, etc.
The new inverter setup mentioned above involves equipping each solar panel with a small inverter, instead of connecting all solar panels to one large inverter.
At a cost of one dollar per watt (of electricity generation capacity), commercial-scale solar panel purchases are less than one-third of the cost of the total cost of commercial solar power setups (including installation), which is $3.50 per watt, on average.
Typical solar setups suffer from lower efficiency because of the way the panels are connected, which is in series. A series connection means that electricity flows from one panel, through the other, and then the next, until it reaches the end of the circuit. When one panel is shaded, the power output of the rest of the panels is reduced because the electrical resistance of the shaded panel restricts the flow of electric current to the rest of the panels.
Each of the distributed inverters invented by ArrayPower attach to the back of each panel. They use rectifiers and transistors to boost the solar panels’ DC voltage from 60 volts to the 208 volts used on the grid. An inductor then briefly stores the current, allowing the device to emit discrete pulses of alternating current. The pulses are combined with those from a minimum of three other panels to provide three-phase AC current that is suitable for the electricity grid.
ArrayPower is a relatively young company that is headquartered in Sunnyvale, California.