The below screenshot of IESO data for the past several days clearly demonstrates why Ontario needs the reliability of natural gas to fill in for when the sun’s not shining and/or the wind’s not blowing. At the bottom left of the screenshot the “Generation by Fuel Type – Hourly” highlights Ontario’s baseload capacity which is principally nuclear and hydro in the orange and blue colours. Most hydro is classified as baseload but part of it is considered as “variable” generation so is able to ramp up or down as needed when grid demand rises or falls. Nevertheless daily demand frequently is well above what those two sources are able to provide so natural gas plants need to be at the ready when those renewable energy sources are in the doldrums.
The foregoing is demonstrated by the large and small hourly generation from the green (industrial wind turbines or IWT) and yellow (solar) portions of the chart which at times generate as much as hydro and at other times very little! Simply looking at the daily peak demand hours it is readily apparent from the visual observation of the chart that wind and solar often are missing. Natural gas generation (dark blue) and its rammable ability are required to fill in the gaps as is obvious once again from just a quick glance.
Just looking at one days IESO data contained in the above chart clearly shows why we cannot live without natural gas plants and their ability to step up when needed. Looking at February 24th at peak hour 19 (hour ending at 7 PM) natural gas generated 4,907 MWh, hydro 6,088 MWh but solar was absent and those IWT only generated 715 MWh versus their peak generation of 2,516 MWh for the day at 3 AM when peak demand was at its low point for the full 24 hours.
The above is a clear demonstration of the unreliable nature of IWT and why natural gas generation is needed unless the objective is to create blackouts!