PROMIT MUKHERJEE SOUTH Africa, where daily blackouts are a fact of life, knows better than most that it cannot rely on coal power. But just when its plans to shift to renewable energy to help drive Africa's most industrialised economy were gaining momentum, rising costs linked to the pandemic and the war in Ukraine threaten further delay. After a six-year hiatus, the country in 2021 held a bidding round for companies to operate wind and solar projects, attracting aggressive offers from more than 100 renewables companies, eager to make up for the shortfalls of state power generator Eskom. The winners…