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So far as charging electric vehicles and off-peak loads are concerned the big issue there is that with so much solar PV being installed (mostly on house roofs but also businesses and large scale solar power stations) things are changing.
In SA already the true off-peak period on a mild day occurs around lunch time not in the middle of the night. That's already a problem in some areas with SA Power Networks (the electricity distributor in SA) changing the off-peak hot water timers (which in SA are simply a timer at the switchboard, no remote control as in NSW and Qld) to turn on in the middle of the day. A "solar sponge" they call it.
Reason they're doing that is that without that additional load there are quite a lot of areas in SA which have now exceeded what the network can cope with so far as distributed solar generation is concerned. Nobody knows for sure how much potential household solar production is being lost due to over voltage issues in the grid but it's not zero, is increasing on an annualised basis literally every working day when more systems are installed, and would be even higher without that water heating load being turned on during the day.
Also there's a problem with wind farms being constrained in output in SA because there's nowhere for the power to go. Thermal generation (in practice gas) could be off loaded even further but only at the expense of system stability so that's not a good solution. The big battery will help a bit but it's nowhere near big enough to do the lot.
So running a conventional off-peak water heater is zero emissions on a mild sunny day or any day that is windy and not seriously hot. That's a very significant % of all days in SA.
Vic is the next state in line for that problem and is fast heading the same way. Not there yet but they're on the way certainly. In due course WA and NSW will get there too.
No problems of that nature are expected in the medium term in Qld or NT but it could happen someday.
Unlikely Tas will ever get to that point for a few reasons. Climate is one but the bigger factor is that we've got a pretty high capacity distribution network compared to other places and that's a consequence of the relative lack of gas usage combined with higher need for heating. Two thirds of all homes electrically heated, 90% with electric cooktops, virtually 100% with electric ovens and about 94% with either electric, heat pump or solar + electric hot water. Highest level of household consumption in the country and close to double that of states like Vic where gas is common. So the network will also cope with far higher levels of household solar than it will in places like Vic.
Back to electric vehicles and all this is a bit of a problem. Ideally we need to be charging them 10am - 3pm on typical days and doing so in residential areas not the city CBD. That's not going to work unless we radically change society to the point that "9 to 5" is considered shift work and most people work nights. Not likely to happen anytime soon.
Electric vehicle charging can be done certainly but I'm not convinced it's going to work as a means of leveling out demand in a serious way. To some extent yes but there are limitations.
Midday charging could be done by putting the infrastructure in place and that's not ridiculously expensive. That doesn't get that solar power out of the suburbs however.
Price is one thing that could modify consumer behaviour and both Tas and the NT are already onto that one. Appropriate times will vary between regions due to other influences on the grid but using the Tas example:
10am - 4pm and 9pm - 7am = go for it.
4pm - 9pm and 7am - 10am = hand over your wallet.....
Some other states also have various schemes like that but in general they're not designed taking EV's and solar into account and are best fitted to the world as it existed 10+ years ago where all supply was from centralised generation.
In SA already the true off-peak period on a mild day occurs around lunch time not in the middle of the night. That's already a problem in some areas with SA Power Networks (the electricity distributor in SA) changing the off-peak hot water timers (which in SA are simply a timer at the switchboard, no remote control as in NSW and Qld) to turn on in the middle of the day. A "solar sponge" they call it.
Reason they're doing that is that without that additional load there are quite a lot of areas in SA which have now exceeded what the network can cope with so far as distributed solar generation is concerned. Nobody knows for sure how much potential household solar production is being lost due to over voltage issues in the grid but it's not zero, is increasing on an annualised basis literally every working day when more systems are installed, and would be even higher without that water heating load being turned on during the day.
Also there's a problem with wind farms being constrained in output in SA because there's nowhere for the power to go. Thermal generation (in practice gas) could be off loaded even further but only at the expense of system stability so that's not a good solution. The big battery will help a bit but it's nowhere near big enough to do the lot.
So running a conventional off-peak water heater is zero emissions on a mild sunny day or any day that is windy and not seriously hot. That's a very significant % of all days in SA.
Vic is the next state in line for that problem and is fast heading the same way. Not there yet but they're on the way certainly. In due course WA and NSW will get there too.
No problems of that nature are expected in the medium term in Qld or NT but it could happen someday.
Unlikely Tas will ever get to that point for a few reasons. Climate is one but the bigger factor is that we've got a pretty high capacity distribution network compared to other places and that's a consequence of the relative lack of gas usage combined with higher need for heating. Two thirds of all homes electrically heated, 90% with electric cooktops, virtually 100% with electric ovens and about 94% with either electric, heat pump or solar + electric hot water. Highest level of household consumption in the country and close to double that of states like Vic where gas is common. So the network will also cope with far higher levels of household solar than it will in places like Vic.
Back to electric vehicles and all this is a bit of a problem. Ideally we need to be charging them 10am - 3pm on typical days and doing so in residential areas not the city CBD. That's not going to work unless we radically change society to the point that "9 to 5" is considered shift work and most people work nights. Not likely to happen anytime soon.
Electric vehicle charging can be done certainly but I'm not convinced it's going to work as a means of leveling out demand in a serious way. To some extent yes but there are limitations.
Midday charging could be done by putting the infrastructure in place and that's not ridiculously expensive. That doesn't get that solar power out of the suburbs however.
Price is one thing that could modify consumer behaviour and both Tas and the NT are already onto that one. Appropriate times will vary between regions due to other influences on the grid but using the Tas example:
10am - 4pm and 9pm - 7am = go for it.
4pm - 9pm and 7am - 10am = hand over your wallet.....
Some other states also have various schemes like that but in general they're not designed taking EV's and solar into account and are best fitted to the world as it existed 10+ years ago where all supply was from centralised generation.
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