Berlin had previously estimated that it would collect around €400 million, Juergen Hacker, head of the German emission trading association BVEK told the Handelsblatt newspaper.
As part of the European Union's emissions trading scheme, nearly 12,000 utilities and energy-intensive plants across the continent can buy or sell emissions credits.
At the start of the second national allocation period from 2008 through 2010, around 10 percent of emission allowances were auctioned off instead of being distributed for free.
While the government had expected each certificate to sell for €10, prices reached €24.25 in April Handelsblatt reported. Germany was nonetheless one of the countries that expressed opposition to the change, saying it would place domestic industries at a competitive disadvantage.