An academic predicts problems ahead for New Zealand's renewable energy strategy

Latest figures show we burned twice the amount of coal for electricity production in the three months to the end of March, compared to a year earlier.

The reason given is because of a lack of wind, rain and natural gas.

Victoria University climate change expert Adrian Macey says 100 percent renewable energy will need some work.

He says we should aim for the goal, but we need to look at technology and how the market is organised.