Advocates for renewable energy say a new coal deal may be necessary but should be the last of its kind.  

The big four power companies are investing in a strategic energy reserve which will add 600-thousand tonnes of coal to current stocks.  

Rewiring Aotearoa Chief Executive Mike Casey says this will be needed because we haven't reduced our reliance on fossil fuels.  

He told Ryan Bridge we need to accelerate the move towards sources like solar and geothermal.  

Casey says all renewable options should be on the table and there should be a focus on keeping power bills low.  

LISTEN ABOVE