Sending these funds as equity rather than debt would reduce the risk for poorer nations, tying foreign investors to renewable-energy projects over the long term, finance officials say. But that means more risk for institutional investors, an unwelcome prospect for them. Big money managers such as BlackRock worry about sudden policy changes in a developing nation that could wipe out their investment. Legal systems lack the independence to stand up to a government that might seek to expropriate a project.