AC solar panels are increasingly capturing attention – so what are they, how do they work and what are their reported advantages?
“Traditional” solar panels output Direct Current (DC). DC electricity cannot be used directly by common household appliances; so it first needs to be converted to Alternating Current (AC). The conversion is performed by a solar inverter – a separate component located some distance from the array. A number of solar panels may be routed through a single inverter.
AC solar panels still output DC, however on the back of the panel is a micro-inverter converting the DC to AC. The reported benefits include simpler and safer installation, improved electricity harvest and the elimination or reduction of other componentry.
In a standard solar array scenario where multiple panels are connected to a single inverter, one shaded panel can impact on the overall performance of that array – the microinverter arrangement addresses this issue.
Among the companies to recently announce a rollout of AC Solar Panels is AU Optronics (AUO). AUO are currently showcasing their AC Unison solar panel at Solar Power International 2011. AUO’s offering is understood to incorporate a SolarBridge microinverter. AUO says the AC Unison increases system performance by up to 25% through reducing the overall impacts of system shading, soiling and degradation losses.
Hanwha SolarOne says its first AC Module (ACM) combines high performance SolarOne solar modules with third generation microinverter technology from Enphase Energy; a company widely considered as the leader in the field of microinverter development. In January, Enphase announced it had shipped 500,000 microinverter units and expected to triple its output this year in order to meet demand.
SunPower Corporation also recently announced their SunPower E18 & E19 AC Solar Panel series, utilising SolarBridge Pantheon micro inverter technology.
While AC solar panels aren’t widely available in Australia as yet, national solar power solutions provider Energy Matters says it will commence testing of AC modules to determine if they are suitable for Australia’s often very hot conditions.