Ethiopia opens 300 MW dam, starts producing 80 MW

* Six hydropower projects being built

* Government says will spend $12 billion over 25 years

ADDIS ABABA, Nov 14 (Reuters) - Ethiopia opened a dam on Saturday that it says will produce 300 MW of hydropower as part of efforts to overcome chronic energy shortages and become one of Africa's only power exporters, state media said.

Power shortages are common in Africa and have hindered investment, even though the continent has abundant potential resources of solar, hydro, oil, gas, coal and geothermal power.

The Tekeze Dam has started producing 80 MW and that will rise to 300 MW, state-run Ethiopian Television said. It did not say when the dam would reach full capacity.

The dam is on the country's Tekeze river and its $356 million cost was financed by the China National Water Resources and Hydropower Engineering Corporation.

At 185 metres, it is the tallest hydroelectric dam on the world's poorest continent.

Outages have been common in Ethiopia for five years. The country rationed power for over five months this year with lights going off every second day, closing factories, hampering exports and fuelling a shortage of hard currency.