Currently utilities buy power during peak times from other utilities, or fire up expensive peaker generators to manage the load.
A network of charging cars could be managed as another resource with a price attached to it that may be cheaper than the alternatives. I like the concept of varying the price of the charge based on your participation in the network.
At least in Florida, USA, most residential electric meters are flat-rate (same price per KWh, no matter what time of day you are using). A good portion of commercial meters have a peak and off-peak rate, as well as a single line item charge, based on peak demand, that is often 30-40% of the entire bill. The off-peak rate is often 50% or more cheaper than the peak rate.
Since most people would charge at night, it would probably make sense to have these residential services switched to a demand and time-of-day based meter, which would further reduce the cost of electricity. If someone spends a significant time at home, the charging car could buffer peak loads during the day to offset the additional draw of the nighttime charging.
Also think about when peak demand happens -- late afternoon on hot summer days. Right at the time when people are getting home, with their EVs discharged (or at least, not at full capacity) after a day's use.
The grid is already perfectly capable of consumer feed-in, hence the huge deployment of photovoltaic solar systems. The metering is not particularly difficult. There is an emerging standard for smart grid communications (LTE on the 450MHz band) that is already in widespread use across the EU.
Completing this transition won't be cheap, but there are no significant roadblocks. We know what needs to be done and we have the technology to do it.
https://www.drive-electric.co.uk/driveelectric-launches-vehi...
http://www.energynetworks.org/assets/files/electricity/futur...
http://450alliance.org/wp-content/uploads/2014/05/WhitePaper...
Not completely discharged - the little available per car will add up to a lot when there are a lot of EVs. The EV owners who decide to sell to the grid at peak hours (at higher prices) might make a profit doing so.
Long story short: NRG wanted to build a natural gas peaker plant, California Energy Commission said "can you do this cost-effectively with storage?", NRG said no, then people realized the "no" was based on 4-year-old battery figures. With updated figures (storage follows a manufacturing curve where the more we build the cheaper it becomes, so prices are dropping every year just as they've done with solar), turns out that yes, storage is a potentially cost-competitive alternative to nat gas peakers.
The application to build the plant is on hold to let the battery folks submit a few bids, I believe, but the econmic trends are clear: you can do peaker plants with storage now (or at least very soon).
It's just a matter of safety margins and probability. Traditional powerplants break too, and with enough cars the probability that enough of them wouldn't be available at once is smaller than the probability that enough powerplants break at once.
https://energy.gov/oe/services/technology-development/transm...
We will see far more volatile supply, because of the less reliable output of renewable sources. Supply and demand need to be perfectly balanced at all times to prevent brownouts or outages. Balancing supply and demand will become more challenging as we start to take fossil fuel generators offline. This is where smart grid management becomes vital.
EVs could adjust their charging rate in real-time, drawing maximum current when prices are low and discharging at a high rate when prices spike. Smart air conditioning units and refrigerators could respond to pricing on a minute-by-minute basis, running their compressors when electricity is a fraction of a cent cheaper and allowing the temperature to drift upwards by a fraction of a degree when prices are slightly higher. Industrial consumers could pause energy-intensive processes when prices are high and store power locally in battery, pumped water or thermal storage when prices are low.
A slightly extreme example from the UK is the notorious TV pickup. We drink lots of tea and use 3kW electric kettles to make it. During the commercial break in popular TV programmes, there's a surge in demand that often reaches hundreds of megawatts as millions of people simultaneously switch their kettles on. The national grid employ a dedicated team to manage these rapid demand spikes. They study the TV schedules and continuously monitor the grid frequency, turning on extra generation capacity and drawing from pumped-water storage to balance the extra demand. With smart grid technology, the TV pickup could be automatically managed through a real-time market.
Edit: lol, I get downvoted for relaying what a professor of EE told me. Stay classy HN.
TOU (Time of Use) rates are becoming more and more common.
In 2019, TOU rates will be the default rate structure for new accounts in California. Many more states are following suite.
Even if they're not the default, tons of places have opt-in TOU structures. EV owners and home storage owners use this a lot.
Some states have even already adopted complicated shit only seen in C&I customers: demand charges. Basically, a portion of your bill will be dependent on your peak demand during a period (ie peak kW, not total kWh).
I think this is the way things are moving in other jurisdictiins as well. In case of Germany and France one of the reasons why the systems have mot been upgraded lies in the privacy rules for the power consumption data according to one smart meter manufacturer.
Not just that, in addition the smart meters cost a bunch of money to install... people don't like paying anything very much.
Norway is going all-in on smart meters, installation has been rolled out this year to ~80% of the country, due to reach 100% next year. The total installation cost is estimated at around 2.5 billion USD for around 2.2 mill. houses, i.e $1000 per house. Which of course we as consumers will be paying for through higher electricity prices.
This is still the case, see: http://www.nyseg.com/YourHome/pricingandrates/daynighrate.ht...
Perhaps you misinterpreted the scope of applicability of what the professor said.
I have a plan which charges significantly less during off peak hours.
Something as modern as time-variable tariffs... not gonna happen soon here.
The vast majority of people will usually charge overnight and don't need to regularly charge at peak times. Through intelligent charger management, you can distribute the load of charging across the entire off-peak period. The UX for this can be fairly straightforward - by default you charge at the cheapest rate, or you can press a button to get the quickest possible charge.
The real dividend comes from bidirectional charging, using the collective resources of plugged-in cars as a load balancing reservoir. In exchange for a discount on your electricity, the grid can take a small percentage of your EV's battery capacity when needed. A typical mid-range electric car has a 40kWh battery, which represents about four days of electricity consumption for a typical European household.
Nissan and the British utility regulator ran a two-year trial to examine the long-term impact of EVs on local grid infrastructure. The trial used intelligently-managed unidirectional charging. They concluded that about 32% of local electricity circuits will need to be upgraded by the time that EVs represent a majority of vehicles on the road. This figure could potentially be lowered further by bidirectional charging technology.
http://myelectricavenue.info/
America still has huge potential for efficiency savings, because of the immensely high average household electricity consumption. The average American household uses nearly three times as much electricity as the average European household. Air conditioning is only a small part of this disparity, representing about 18% of the electricity consumption of American households according to the Energy Information Administration.