Around half the countries represented are expected to sign a founding treaty for the agency, which aims to boost the use of renewable sources of energy around the globe.
German Environment Minister Sigmar Gabriel said the creation of the IRENA agency was "a huge step forward" for the renewable energy sector, which has "enormous potential" not only for climate protection but also for economic development.
"The potential for solar, wind, hydro and biomass energy is so big that we could supply energy to more than nine billion people on Earth," Gabriel said.
The founding members of IRENA will decide in June 2009 where the agency will be located. Germany is pushing for it to be based in Bonn – also the home of the secretariat of the UN Framework Convention on Climate Change (UNFCCC), the body tasked with crafting a new global climate deal in Copenhagen in December.
Representatives from the United States, China and Japan would attend the conference, but are not expected to sign the founding document immediately, Gabriel told reporters.
But he said Germany is looking to a breakthrough on climate protection after US President Barack Obama's pledge to "roll back the spectre of a warming planet" during his inauguration speech on Tuesday.
"The United States appears to have awoken from its Sleeping Beauty slumber when it comes to climate change with the new direction indicated yesterday by the White House," Gabriel said. "With the United States' ambitious objectives for reducing emissions, we should also reach an accord with major countries such as China, Mexico, Brazil and South Africa on an international pact on climate protection in 2009."
The EU is aiming for use renewable sources for 20 percent of its energy needs by 2020. In Germany, 15 percent of electricity consumption comes from renewable sources of energy and the government aims to double this by 2020.
Gabriel said that a quarter of a million jobs had already been created in Germany's renewable energy sector and Berlin also aims to double this by 2020.