Puerto Rico plunged into darkness last week after the second major hurricane in a month crippled its aging, debt-laden electric utility. The island is projected to be without power for six months or more, as people swelter and lifesaving medical equipment saps generators in what House Speaker Paul Ryan declared a humanitarian crisis on Tuesday.

But its not just old, storm-vulnerable transmission lines that need to be replaced.

Forty-seven percent of the power the troubled Puerto Rico Electric Power Authority generates is from burning oil one of the most polluting and least efficient sources of electricity. An additional 51 percent of Puerto Ricos energy blend comes from a mix of coal and natural gas. Just 2 percent was drawn from renewable sources last year.

The utilitys dependence on imported fossil fuels has devoured funding that could have been spent on upgrading the islands grid and building cleaner infrastructure, a sign of years of mismanagement and incompetence. But it also stems from a colonial history in which Puerto Ricos development was put in the hands of a few mainland corporate interests seeking tax breaks.

Now the debt-strangled island finds itself in the grip of Wall Street creditors who hold much of the $74 billion in municipal debt racked up over the past few decades. And under the Trump administration , which denies climate change is a concern and has dismissed the need for clean energy, Puerto Ricos hopes for a greener grid after power is restored seem dim.

PREPA declared bankruptcy in July, but its problems began years earlier. Puerto Rico suffers four to five times more blackouts than an average U.S. state, despite paying the countrys second-highest electricity rates after Hawaii, at nearly 20 cents per kilowatt hour. The utility operates in what Slate called a permanent state of triage.