http://www.caiso.com/Pages/TodaysOutlook.aspx#SupplyandDeman...
It's even better for places where renewable generation is more weighted toward wind than solar, like Texas, because wind output tends to peak while people are sleeping and demand is otherwise low:
http://www.ercot.com/content/cdr/html/CURRENT_DAYCOP_HSL.htm...
jasonmaydie showed that even if a problem is solved it can still be a "problem"
http://www.caiso.com/Pages/TodaysOutlook.aspx#SupplyandDeman...
Although demand at 7:00 AM is 5 gigawatts above the 4:00 AM nadir, it's still 15 gigawatts below the 5:00 PM peak. Since electrical generating and distribution systems are sized to handle those early-evening peaks, shifting charging some hours away from the traditional peaks (either direction, later or earlier) should allow vehicles to recharge daily without increasing daily peak demand.
What about places that aren't California? Even places that have more seasonal electricity demand in the winter than in the summer, like the UK, see their daily peaks in the early evening. Peak demand hours are more about human behavior than geography. People come home after work, cook dinner, turn on lights, do chores... Traditional peak demand hours coincide with this burst of domestic activity. Scheduling charging away from the traditional peak electricity times makes more efficient use of existing infrastructure and allows peak distribution/generation capacity upgrades to be delayed and minimized even with rising adoption of home-charged EVs.
With smart metering, EVs can also feed energy back to the grid during transient demand peaks. Users won't notice if 5% of their battery is ringfenced for grid storage, but it'll provide a vast proportion of the storage capacity we need to manage an all-renewable grid.
Between the rebalancing of peak and off-peak demand and the potential to use EVs for grid storage, the widespread adoption of EVs is likely to be of net benefit to the electricity grid.
This got me thinking, what does the power draw look like?
A Model S has two battery options
- 60kWh / 335km @ 5.85km/kWh - 85kWh / 426km @ 5.01km/kWh
So a battery will need to recharge 1kWh for each 5km traveled. The typical US commuter travels 48km per day. 50km per day / 5km/kWh is 10kWh per day of required draw.
Say 10 hours of charging per day smooths this out to an additional draw of 1kW per driver (a big assumption).
With 100M additional electric cars (there are only 165M daily commuters) in the US, the additional draw on the power grid would require 1,000GW of additional capacity.
That's a 25% increase over 2016 power generation. Compared to the 1999-2016 growth rate of 9.5%, it is significant, but seems manageable. Especially considering it'll take 10+ years for electric cars to be widely used by a significant fraction of the US workforce.
10kWh × 165M on the night grid, that's big impact.
I went and got the miles travelled per year and the total nr of vehicles, you are not far off. although we are forgetting that most traffic is during weekdays, and the size of the cars varies (and with it the usage) For convenience I don't do anything with the size of the cars.
"According to the Bureau of Transportation Statistics for 2012, there were 254,639,386 registered vehicles. Of these, 183,171,882 were classified as "Light duty vehicle, short wheel base", while another 50,588,676 were listed as "Light duty vehicle, long wheel base". Another 8,190,286 were classified as vehicles with two axles and six or more tires and 2,469,094 were classified as "Truck, combination". There were 8,454,939 motorcycles also listed along with 764,509 buses." https://en.wikipedia.org/wiki/Passenger_vehicles_in_the_Unit...
250m vehicles in us, if 150m of those are electrical at some point, and the number of miles driven total might be 3.5T miles by then (3.5×0.6=2.1T) 2.1/150m/313×1.6 (6 days of driving a week, and miles to km) comes to 71 km per day, which is 14 kWh (6/7 days) of required draw. I think it is manageable like you said, considering that it will take a while.
> an additional draw of 1kW per driver
> 100M additional electric cars ... 1,000GW
Looks like you're off by an order of magnitude; that should be:
1kw (continuous) * 100M drivers = 100GW (continuous)
for the typical commuting patterns. That's a lot of power of course, I agree it would increase cumulative consumer demand for electricity by about 25%.
But the key is that this is nearly perfectly dispatchable demand. It won't cause anything like the same disruption to the grid as non-dispatchable, or even weakly dispatchable demand like air conditioning (which can flex how much is consumed briefly, but will annoy users if it varies across too long a time span).
This is key, plus I think we're overstating how fast this will happen.
In 2016 we're still at sub 1% of all new car sales being electric, at 0.9%. i.e. for every 100 cars we're adding to our roads, not even one full electric car is added. Not to mention about half of the electric cars are hybrids.
Average age of cars is about 12 years. So if the 1:99 ratio is overturned say in a decade to favour electric cars (which seems ambitious itself[0]), it'll take at least another decade to phase out existing cars and see the fleet get replaced by new, mostly electric.
So 10+ I think is conservative, it's probably 20+.
Another thing to mention is that we can generate a lot more electricity with our existing capacity than we do. Why don't we? Because at night the demand simply isn't there. But with a software-based transport & fueling system that EV offer, a lot of this extra demand can be shifted during times of low-demand, without needing to install extra capacity, but rather just not taking as much capacity offline nightly.
Finally, I cautiously expect a shift away from personal transport and public transport, but towards semi-public/personal. i.e., I'd be quite feasible if you could hail a self-driving pod in 20 years, get in, have your destination set via whatever has replaced our smartphone (e.g. software assistent), and get out, paying automatically, a la uber today. The pod drives according to your personal wishes, but it's part of a shared public transport system. I expect this to make driving safer and more fuel efficient in driving behaviour, more efficient in terms of capacity (no more 4-seater cars full of 1 person, no more driving around with vacation-level storage that's mostly empty on 9/10 trips), more efficient in terms of size (lighter vehicles, less crumple zone required). This shift too may significantly increase the km per kwh spent in the next few decades.
[0] As for whether electric becoming the majority of car sales within 10 or 20 years is feasible... a little context: it must be noted that the US sold 96k electric vehicles in 2013. In 2016 it's 157k. Growth rates are a little under 18% yoy. If you'd grow at 32% a year, which is twice the annual growth rate compared to the past few years, you'd sell 2.5 million electric vehicles in 2026, annually. But the US sells more than 17 million non-electrics annually today, so you're still not making a huge dent. That's a shitty calculation of course, but it's some context. Typical forecasts predict something like 30% of new car sales to be electric in 2030. Again, that's new sales. About 8% of cars are retired each year, if you replace them by 30% electric cars, it takes about a decade after 2030 to even get to 30% of the actual car fleet to be electric.
So all in all, I don't really think the grid is the biggest challenge here, although there are obviously very large investments to be made.
Obviously the total consumption will increase dramatically. If this shift takes place the society-wide energy mix will include a lot less petrol/gasoline/diesel and lot more electricity.
Hopefully the prices of solar & wind will continue to fall and the shift in this mix will be massively to the advantage of the environment - and to the quality of life in our cities.
I hope it holds a great shift towards decentralization of energy production. Not complete decentralization, but a blend of massive power plants like today, and lots and lots of homes with solar panels on roof tops and the like.
I also hope fusion research is accelerated. Fusion in the sky, plus fusion down on Earth, that would cover a lot of bases. Portable fusion reactors would also truly open up the solar system - ride the fusion torch to your destination, power your habitat with fusion reactors.
An always-connected EV fleet can dispatch charging from a central load-leveling server, passing a percentage of the utility revenue along to incentivize the EV owner. Such a car would always Do The Right Thing(TM) with respect to TOU/tiered metering, real-time (or forecast) renewable generation, local distribution grid loading, and the availability of any extra baseload generation at night.
Personally I would want the option to always immediately charge the car to X miles of range (to drive to the local hospital), and to always charge to Y miles by Z:00 every day (for commuting). Subject to those constraints, the service provider is free to shift around the charging schedule to suit conditions on the local electric grid. The more leeway the service provider has to shift charging around, the more the EV owner earns.
Obviously Tesla is pursuing this, but I hope they have competition.
Good idea, but the infrastructure would have to be tied to the building, not to the companies operating in it. A lot of companies change offices all the time, and then there are all those small companies that can't afford to build this sort of thing.
So it would have to be part of regular infrastructure just like running water or comm/data lines.
Can you supply some supporting documentation for this? All the studies I've seen have shown that the charge cycle is very flat, can be centrally demand controlled, and essentially "fills in" the night-time slump that saps much of the generating profit from major types (e.g., thermal) of generator plants.
The massive array of car batteries becomes an absolutely wonderful source of both positive and negative demand response. Currently, almost no one insists on driving around with a 100% full fuel tank. Those with electric cars commonly keep them around 80%. And daily usage of the battery is nearly always far less than 50%. And a decent sized EV battery is 1-2 days of household electricity usage.
If a significant chunk (20%-30%?) of our electrical demand is for battery-powered transport, we've solved a huge problem that comes with high wind and solar penetrance on the grid, without having stationary batteries. As car batteries age and have reduced capacity, they will potentially have a second life as stationary storage, where power density doesn't matter as much.
This means, that if we are able to install chargers at a percentage of workplaces, that car batteries will be able massively smooth out not only the daily duck curve of demand, but also deal with fluctuations where some days have more production and others less.
This will still put the baseline of the grid higher, just averages it out possibly taking more when its a good time. I think batteries should be hosted/hooked up by the power company, so they can attach them to a power management system. (I think that already exists)
I left out the "where will we get all this power" part, because that is already discussed a lot. I just wonder if the power grid will be able to handle this immense increase in usage, even if spread out. You still need to transport it.
edit: I think the powering down of offices and business makes enough room for the evening to use more.
The UK government recently performed an industry consultation on this subject and has released a plan to:
* remove barriers to smart technologies (such as storage and demand-side response)
* enable smart homes and businesses
* improve access to energy markets for new technologies and business models
https://www.gov.uk/government/publications/upgrading-our-ene...