I think you're confusing general power usage peak with residential usage peak. Or maybe you're talking about what you've learned 20 years ago (or Australia industry is 20 years late).
As AC use increased, industry switched from oil to electricity, coal to electric arc, and as power grid stabilized, peak usage shifted a lot in the last ~20 years. That's why summer/winter time do not make sense anymore and a lot of European countries are talking about not switching anymore.
As AC use increased, industry switched from oil to electricity, coal to electric arc, and as power grid stabilized, peak usage shifted a lot in the last ~20 years. That's why summer/winter time do not make sense anymore and a lot of European countries are talking about not switching anymore.