STORY: Here are five business stories making headlines in sub-Saharan Africa this week.

U.S. Treasury Secretary Janet Yellen starts a three-country trip to Africa on Friday (January 20).

After decades in which China has dominated investment on the continent, the U.S. is pitching itself as a more sustainable alternative.

Yellen's visit takes in Senegal, Zambia and South Africa.

Democratic Republic of Congo expects to reach an agreement on overhauling $6bn of an infrastructure-for-minerals deal with Chinese investors this year, its finance minister has said.

President Felix Tshisekedi's government has been revisiting a 2007 deal struck under his predecessor Joseph Kabila.

South Africa is developing new legislation to speed up energy projects, a presentation by the country's energy crisis committee has showed.

Amid some of the country's worst-ever power cuts, the committee said emergency legislation could add capacity more quickly.

Several other African countries will also be adding more capacity - via United Arab Emirates renewables company Masdar.

On Friday it said it had agreed generation projects with a capacity of up to 3 gigawatts in Angola and Uganda.

Earlier in the week 2 gigawatts of projects were announced in Zambia and a 500 megawatt solar plant in Ethiopia.

And finally, Zambia received a "debt for nature swap" proposal from the WWF as a parts of its $13bn restructuring discussions, the government confirmed on Wednesday (January 18).

In its simplest form, that means replacing expensive bonds or loans with cheaper financing in exchange for protecting fragile ecosystems.

The approach helped both Belize and Seychelles secure writedowns that put tens of millions of dollars into ocean protection.

Conservationists see Zambia, with its vast national parks, as an obvious candidate.