Keep the lights on if you want to stay, Malcolm Turnbull

As the white paper says: "The policy of encouraging investment in renewable energy through the renewable energy target in a period of weak demand has contributed to Australia's excess generation capacity."

The white paper estimates that new generation capacity is not needed before 2023. But to build new coal-fired power stations, which the system needs, takes some years.

In other words, new entrants need some certainty now. The consequence of the RET is that the risk of building new power stations is too high, the returns too tenuous: the higher the proportion of renewables, the more precarious the life of coal-fired power, the less likely new investment.

Labor's 50 per cent renewable target may as well be 100 per cent because the damage is just as great. The system cannot operate without coal-powered base load. Australia begins to look like South Australia.

There are issues around the standard of emissions required of new power stations and carbon capture and storage technologies, and this is where Turnbull has to step in and create certainty.

Current policies are deterring investment in more efficient and lower emissions plants. Once the old plants are retired or electricity demand increases sufficiently, Australia will need investment in coal-fired power.

Keep the lights on, Malcolm: voters will reward you.