If it is a low-wind evening and prices on the grid are higher than normal what fraction of people are going leave their electric cars with depleted batteries instead of charging them? Say a charge takes say 8 hours, there isn't a lot of room overnight to shift the load around. How many people will refrain from charging because it is going to cost you $50 instead of $10? I think the answer to that can be seen from how much people refrain from driving when fuel costs go up. Given that traffic never gets better I would say none!
1) electricity is cheap. it will have to get a lot more expensive for anyone to care enough to change the way they are using it 2) a lot of the demand is inflexible, regardless of price. lights are going to be on, dinner is going to be made when kids are hungry, car is going to be charged overnight because must go to work tomorrow.
there is going to come a point where all wind and solar must have a certain amount of firm capacity - say it has to be able to deliver 50% of nameplate rating for 5 days straight - and this is going to significantly add to the $/MWH cost of renewables. Then after 5 cloudy days in a row (unthinkable!) the output of the solar farm is 10% of nameplate until it is sunny again.
People who have those tariffs do tend to alter behaviour to suit them - it mainly makes sense for homes with electric space and water heating, where it's more "set and forget" (and people also do change behaviour by eg putting washing machines or tumble dryers on late at night when the cheaper tariffs apply too).
Over time I imagine we might see more dynamic algorithms in use to pick and choose times when electricity is used together with more dynamic per-unit pricing.
These measures in the U.K. were put in place to shift demand due to constraints in total system capacity - total generation, total transmission, total distribution capacity. Eg a substation transformer couldn’t handle normal daily loads plus heating, so heating load is shifted to night.
What happens when power at night becomes more expensive due to increases demand such as car charging or low supply such as high renewable penetration and no wind?
It’s all about having the firm capacity to deliver power for hours on end. So the $/mwh of wind or solar power has to go up because grids are going to say you can only have more if you can supply firm capacity. This is already happening in Hawaii.
I implemented hot water tank load switching through smart meters on at a town with its own power plant of only 850 kw so they wouldn’t run out of power at dinner time when the river was low (and we didn’t have to fire up the diesel either)
One way this could work is that you have eg a smart heating thermostat which plans which hours of the day/night to turn heating on and then buys power to cover that in a day-ahead market, with the aim of minimising cost on that basis.
Wind and solar power are relatively preditable a day out so you wouldn't be paying too much to power traders for providing day-ahead liquidity vs on-demand pricing.
Likewise, EVs all end up parked somewhere during the day - the challenge is ensuring that as many of those places as possible (car parks, workplaces, etc) have charging points too; you could do something very similar there with an algorithm deciding whether to charge based on a spot price and how much is in the battery (say, owner programs car to top up to 65% and then only continue charging if power is cheap).
The beauty of this type of approach is that it can be done by incrementally building on things which already exist.
There's already an electricity market, including day-ahead pricing in most pools. Professional power traders already trade these markets. Smart meters already exist and are capable of dealing with pool prices not just flat rates. Smart thermostats already exist. EVs already have the capability to stop/start charging based on more than just whether they're plugged in or not. Even better, most of these already have standardised APIs.
What's missing is the software stack which ties all of these together - and that can be done incrementally, device by device (on the load side).
Are you honestly trying to argue it doesn't have any effect? "What day of the week is best to fill your tank" is like an age-old question. Obviously within reason. Not if your tank is empty and you have to be somewhere. Less so for people who think this to be beneath them. And probably also less so in places with cheap fuel (US i hear?). But it certainly changes behavior and is a good & easy first step.
I live near Vancouver which features the most expensive gas in North America, and decent public transportation, and I believe traffic is the only thing that keeps people from driving more, not cost. So demand seems inflexible over the long term, and with electric cars I think you have even less flexibility to choose your time and place to charge, unless charging becomes ubiquitously available.
I think the more realistic scenario is that people charge less if the power is expensive, to full otherwise. Managed by a programmed policy.
Also, commute length will start trending down as we leave the cheap-gas phase of history behind - EVs are also too CO2 intensive to sustain the car based lifestyle.
I think your examples are actually all flexible use cases. Car can be charged any time, if price is unpredictable you won't leave your battery empty on a work night. But also you don't necessarily need a car. Lighting is a silly example because it consumes negligible energy, but if you look at history it's actually very flexible. Dinner also takes negligible energy but it's also very flexible (see how people cook in places without cheap eletricity - biofuels).
As heavy industry has declined in the West though, we have less of that than we used to.
This was the idea of "smart grids", which we seem to hear rather less about than a few years ago now.
Without some form of storage, peaking power plants are required to support wind and solar, and these are typically gas-fired.