“it is vital that before we build more network, we use more network” – AER Chair, Clare Savage
Electrification and population growth will both drive significant increases in electricity demand over the coming decades. This study investigates how the effect of this growth on zone substations could be mitigated by scheduling water heating and electric vehicle charging to occur during solar hours and overnight.
Taking the ACT as a case study, we find that the complete electrification of water heating and private vehicles, together with population growth would drive a large increase in total demand. By 2045 – when the ACT Government plans to get off gas – the increase is on the order of 75% for high growth regions such as Gungahlin. 30% is due to population growth and 45% from vehicle electrification. The electrification of water heating is compensated for by the efficiency of heat pump hot water systems, which we assume make up 75% of heaters in 2045.
We find that the super simple approach of scheduling water heating and vehicle charging loads to occur at fixed hours each day throughout a year effectively avoids these appliances contributing to peak demand on zone substations. Modelled zone substation demand continues to peak on winter evenings due to other loads (significantly space heating in the cold Canberra climate), which we model to be inflexible.
It concludes that simple strategic policies that shift loads into low demand periods would enable significant growth in total demand to be accommodated within existing zone substation capacity limits. For example, in the suburb of Gungahlin, such measures could limit peak demand increases to just 25%, while all private vehicles and domestic hot water are electrified, and the population grows by 30%.
For the avoidance of doubt, the study does not purport to predict how demand growth and demand scheduling will develop, but to provide quantified, plausible scenarios of how they could develop to motivate and guide policy and public initiatives.
Noting that zone substations are only one link in the electricity grid, three goals stand out:
- Realising the tremendous opportunities to schedule/flex electrified demand, even with simple and suboptimal approaches.
- Reducing winter evening demand, such as through better housing insulation & efficiency.
- Building frameworks to develop and drive uptake of services that more dynamicly optimise the power consumption of appliances. These must foreground free, prior, and informed consent and could harness the literature on responsible innovation.
Full report below