by year-end. They shipped their 500,000th inverter in early 2011, and their 1,000,000th in September of the same year. In early 2011, they announced that re-branded versions of the new design will be sold by Siemens directly to electrical contractors for widespread distribution. Enphase has subscribed an agreement with EnergyAustralia, to market its micro-inverter technology. Major players Enphase's success did not go unnoticed, and since 2010 a host of competitors came and largely left the space. Many of the products were identical to the M190 in specs, and even in the casing and mounting details. Some differentiate by competing head-to-head with Enphase in terms of price or performance, while others are attacking niche markets. Larger firms also stepped into the field: SMA, Enecsys and iEnergy. OKE-Services updated OK4-All product was bought by SMA in 2009 and released as the SunnyBoy 240 after an extended gestation period, while Power-One has introduced the AURORA 250 and 300. Other major players around 2010 included Enecsys and SolarBridge Technologies, especially outside the North American market. In 2021, the only microinverter made in the USA is from Chilicon Power. Since 2009, several companies from Europe to China, including major central inverter manufacturers, have launched microinverters—validating the microinverter as an established technology and one of the biggest technology shifts in the PV industry in recent years. APsystems is marketing inverters for up to four solar modules a microinverters, including the three-phase YC1000 with an AC output of up to 1130 Watt. The number of manufacturers has dwindled over the years, both by attrition and consolidation. In 2019, the few remaining include Enphase which purchased SolarBridge in 2021, Omnik Solar and Chilicon Power (acquired by Generac in July 2021). In July 2021 the list of big name PV companies who have partnered with microinverter companies to produce and sell AC solar panels include Siemens, Trina Solar, BenQ, LG, Canadian Solar, Suntech, SunPower, NESL, Hanwha SolarOne, Sharp. Market As of 2019, conversion efficiency for state-of-the-art solar converters reached more than 98 percent. While string inverters are used in residential to medium-sized commercial PV systems, central inverters cover the large commercial and utility-scale market. Market-share for central and string inverters are about 36 percent and 61 percent, respectively, leaving less than 2 percent to micro-inverters. Price declines The period between 2009 and 2012 included unprecedented downward price movement in the PV market. At the beginning of this period, wholesale