Falling oil prices could have a negative impact on global efforts to develop renewable energy sources, experts warned Saturday at a conference in Abu Dhabi.

Oil prices have fallen by almost 60 percent since June, crashing on worries over global oversupply and weak demand in a faltering world economy.

Participants at the International Renewable Energy Agency (IRENA) conference that opened Saturday in the United Arab Emirates said the trend could spell doom for plans to shift to clean energy.

The fall in oil prices could be a "game changer", Italy's Deputy Minister for Economic Development Claudio Vincenti told the meeting that concludes on Sunday.

In the past a rise in oil prices had encouraged clean energy investments, said Vincenti, adding that a longterm fall in prices could shift the balance among various energy sources. He did not elaborate.

Salem al-Hajraf, who represented the oil-rich emirate of Kuwait at the conference, agreed saying falling oil prices are posing a "major challenge" this year as was the case two decades ago.

"The fall of oil prices in the 80s was a main reason behind the collapse of many renewable energy projects," he told participants.

Renewable energy, which relies on solar, wind and other sources, is essential for meeting global CO2 emission targets.

Delegates from more than 150 countries attended the opening session of the IRENA conference, including Israel with has no diplomatic relations with the UAE .

Representatives from more than 110 international organisations are also taking part in the meeting.

"The story of renewables is rapidly evolving and as the importance of renewable energy grows, so does the relevance of the agency's work," IRENA director general Adnan Amin told the conference.

He said that total world investments in renewable energies have reached $264 billion in 2014, $50 billion more than the previous year.

During the meeting, the Abu Dhabi Fund for Development, in partnership with IRENA, will announce a series of loans for five renewable energy projects in developing countries, organisers said.

Abu Dhabi-based IRENA, with 137 member-states and the European Union, aims to promote the sustainable use of all forms of renewable energy.

The conference coincides with a series of events organised under the banner of Abu Dhabi Sustainability Week, including Future Energy Summit on Sunday and International Water Summit on Monday.

Egyptian President Abdel Fattah al-Sisi is expected to attend Future Energy Summit while French Energy and Environment Minister Segolene Royal will take part in International Water Summit.