[Fuzzy_Logic]

Even if the expensive infrastructure was put in place to allow electric car batteries to be used as a peak load reservoir, utilities would still need to maintain traditional on demand resources, such as natural gas fired power plants. Using a large number of cars is not dependable, utilities need on demand dependability. What happens if during peak consumption in the evening winter months more people stay out late (such as on New Years Eve) and most people park in places where there's no way to plug in? This would only add to overall infrastructure costs, adding a huge bidirectional grid in addition to traditional power sources that must be maintained year round for on demand use.

[floatrock]

We've reached the point where utility-scale storage is a cost-effective alternative to natural gas peakers. The big story has been the California Puente peaker plant -- https://www.greentechmedia.com/articles/read/battery-storage...

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).

[ajuc]

> Using a large number of cars is not dependable

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.

[Fuzzy_Logic]

There is so much work and planning that goes on between the utilities and regulatory agencies to ensure we almost always have reliable electrical supply. Traditional plants have planned outages for regular maintenance, and they are constantly working to ensure there are enough backup systems and alternate routes to ensure there are not outages even during maintenance windows. The amount of cars and the amount of extra grid you would have to build to completely replace these traditional plants would be prohibitively expensive. It's not just a matter of plugging a few million cars into homes.

https://energy.gov/oe/services/technology-development/transm...