Vietnam is battling electricity cuts caused by a heat wave that has exposed structural and bureaucratic problems limiting available power to half of installed capacity and crimping efforts to unlock $15.5 billion in global climate funding.

The manufacturing hub hosts large factories run by tech firms Samsung and Foxconn, among others, but has struggled to upgrade its grid, a key step to satisfy demand and lure companies diversifying from China and elsewhere.

"Many factories have had to suspend production due to severe power cuts, and the cuts are regular," said Hong Sun, chairman of the Korean Chamber of Commerce in Vietnam.