Enecsys is looking to raise up to $20 million in an initial public offering on London's Alternative Investment Market, according to U.K. business website City A.M.

Mike Fister, CEO of Enecsys, targets going public on the AIM next month, according to reports.

The AIM doesn't have the same heft as an IPO on the Nasdaq -- but going public on that exchange is one more way of raising capital in a difficult time for cleantech venture funding. Since 2009, Enecsys has been able to raise more than $55 million in venture funding from investors including Wellington Partners, NES Partners, Good Energies and Climate Change Capital Private Equity.

City A.M. reports, "During its financial year ending 31 March 2013, Enecsys’ revenue soared 66 percent to $11.5 million, adding, "For 2014, Enecsys recorded a loss of $18.2 million." as well as a $40 million loss in 2012.

Earlier this year, Enecsys VP Kevin Bushby told GTM that Enecsys has shipped 160,000 microinverters worldwide through distributors and in cooperation with module makers.

Microinverter market leader Enphase Energy had record Q2 revenue of $82 million, having shipped 132 megawatts (or 598,000 microinverters), up 54 percent year-over-year. 

There is a long list of microinverter market entrants -- and most of them will have to contend with Enphase as the 800-pound gorilla in the channel to the U.S. residential customer. These firms will have to differentiate their product or their channel in order to succeed. The list includes: SMA, SolarBridge, ReneSola, Power-One, APS, Chilicon Power, SPARQ Systems, CyboEnergy, iEnergy, Involar, LeadSolar and Samil Power.

Solar optimizer firm SolarEdge is also threatening an IPO.

Source: The Microinverter and DC Optimizer Landscape, 2014