Africa needs $93 bln/yr for infrastructure -report

* Simple efficiency gains could narrow funding gap

* Electricity supply is most pressing infrastructure problem

* Power, water, phone costs high by global standards

By Ed Cropley

JOHANNESBURG, Nov 11 (Reuters) - Sub-Saharan Africa needs to double its infrastructure spending to $93 billion a year, 15 percent of regional output, to drag its road, water and power networks into the 21st century, a report said on Thursday.

The research compiled by the Infrastructure Consortium for Africa (ICA) identified the continent's woeful electricity grids as its most pressing challenge, with 30 countries facing regular blackouts and high premiums for emergency power.

Despite the gulf between its target figure and the $45 billion spent now, the report said governments could narrow the funding gap to $31 billion by making $17 billion in relatively simple efficiency gains, such as making more electricity users pay their bills.

The report said that infrastructure improvements to date, mainly in telecoms, had accounted for more than half of the pacy growth rates of recent years on the poorest continent. Analysts and policymakers have tended to regard high commodity prices, debt relief and improved governance as drivers of the 5 percent average annual growth experienced from 2003 to 2008.