Renewable energy made its biggest contribution in history to the NSW electricity mix last year, but the state barely reduced its dependency on coal and will have to make significant headway to meet the 2020 national target for renewables.

Critics warn that renewable sources of energy will have to be significantly boosted or households will face more blackouts and higher electricity prices, as early generation coal-fired electricity plants are gradually decommissioned.

Williamsdale solar farm in the ACT. Credit:Lannon Harley/ACT government

The Renewable Energy Action Plan annual report for 2016 shows that NSW drew 14 per cent of its energy from renewable sources, 7 per cent from gas and 79 per cent from coal in 2015.

This compared to 10.8 per cent of energy sourced from renewables and 82.3 per cent from coal in 2014, and 12.9 per cent from renewables and 79.5 per cent from coal in 2013.