The CNMV market regulator approved Ecoener's plans to sell between 38.5% and 43.5% of its share capital in a range of 5.90 euros to 7.25 euros per share to fund the expansion of wind farms, solar parks and hydroelectric plants.
Scheduled for April 30, the listing would generate gross proceeds of 181.8 million euros, rising to around 200 million euros if an over-allotment option is fully exercised, the company said in its prospectus.
That would give Ecoener company a market capitalisation of between 418 million and 472 million euros.
Founded in 1988 and with a combined installed capacity of 141 megawatts, Ecoener is the latest in a wave of Spanish energy firms to announce plans to go public and capitalise on booming demand for green assets.
It has a further 142 MW under construction and 1.5 GW in planned future developments across 11 countries.
Acciona, a much larger conglomerate, has hired banks to list its renewable unit in a deal expected to value the business at 8 billion euros.
($1 = 0.8351 euros)
(Reporting by Nathan Allen, editing by Andrei Khalip)