Predictability problem with wind and solar

REGARDING the letter from Jenny Brown (TB August 8), the only reason wind power has surpassed hydro in Australia is because we have not built any hydro power stations in recent times.

Wind and solar are called Variable Renewable Energy for a reason.

They possess a very poor capacity factor, that is, their ability to produce their rated power when required.

They produce power when the sun is shining or the wind is blowing at the correct speed. Solar produces its potential output for 28 per cent of the time and wind for 34 per cent of the time.

The times that they do produce power is not predictable. The rest of the time there must be a back-up power generation system.

The figures you quote for renewable energy are a furphy based on the maximum manufacturers stated output of the generators when the wind is blowing or the sun shining.

You cannot guarantee that they will produce that power output 24 hours a day, seven days a week, 365 days a year or even that they will produce any power at all during peak demand times.

If you truly wanted sustainable renewable energy for North Queensland and stopped toeing the party line, you would be calling for the raising of the Burdekin Dam to its full potential and the completion of the Tully Millstream hydro scheme.

Both of these projects could provide over 1000 mega watts of reliable pumped hydro power.

In Greens terms you could then build 2000 megawatts of wind farms and have the fast acting hydro generators to come on line to make up the shortfall when the wind is not blowing.