Microgrids are not necessarily restricted to a single household. A small neighborhood could have one. Probably not much bigger than that.
Well, California (PG&E with approval of the California utility commission) recently decided to replace three gas-peaker plants with large battery units. cite I guess they’re just asking for brownouts.
Of course customers aren’t personally going to manage their electrical usage by price. What I’m envisioning is a smart charger, which has data in it on the typical distribution of prices. The user would only need to tell the charger “I want my car fully charged by 6 AM every weekday, and by 9 AM on Saturdays and Sundays”, or whatever, and the charger would look at its data and the current price to decide how best to do that.
You could also implement smart metering for things like air conditioners. There, the user would tell the device an acceptable range of temperatures, and it would use that and the prices to decide when to turn on. While the price is low, the AC keeps temperatures near the floor of the acceptable range, and then lets it drift upwards to the upper limit while the price is high.
No, these smart devices mostly haven’t hit the market yet. But there’s nothing inherently impossible about them, and in fact they could be engineered fairly easily. The biggest thing holding them back is a chicken-and-egg problem: The devices are useless if the utility company isn’t doing dynamic pricing, and dynamic utility pricing doesn’t work unless a significant fraction of the customer base is using smart-metered devices.
The battery backup in Australia was in the news a while ago - Tesla installed a giant battery to kick in to provide extra capacity when other plants went offline or demand increased. One problem - it was so efficient it kicked in in less than a second, and so covered interruptions so short that it was not online long enough to create a billing interval. However, it has apparently greatly reduced peak costs and hence overall costs of electricity in that state.
My problem is that I drive in slow stop-and-go traffic on my commute, so I see consumption in really really cold weather in the 400wh/km or higher averaging 20mph or worse overall.
The trouble with open market and demand pricing is that there is a perverse incentive - the cost of jumping in is too high. So the incentive is to reduce generation and let prices go through the roof (think Enron, deliberately taking plants off line). Plus, witout guaranteed prices, nobody will be incentivized to build expensive power plants.
Power utility already controls my AC. That’s for a flat discount, but it doesn’t have to be.
You didn’t misinterpret what you saw. IC cars use mechanical power take-off (via serpentine belts) for many things, including A/C compressors. It would be silly to add conversion steps you don’t need unless there was some compelling benefit. I guess some cars could use electrically-driven A/C compressors; if anyone can cite specific examples, I’d be curious about that.
That said, hobbyists and some mainstream manufacturers are using electrically-driven superchargers (rather than the traditional mechanically-driven ones for two reasons: they can operate independently of engine speed (unlike superchargers) and load (unlike turbochargers); also, they are fully disengaged at cruising speeds, incurring no parasitic drag.
All those EVs out there, with their big batteries standing idle while parked represent a large distributed power source that could supply a building or a small localised grid. Maybe even the main grid?
Here is a little talk about an E2B (Electric Vehicle to Building) installation, apparently the first in Europe.
There is still a long way to go before you can hook up your EV to your home with solar, wind and grid connection. It is all too new, too big and too expensive at the moment. But the race is on.Smart Metering is also at an early stage, there are some huge rollouts happening in many countries. But again, it will be a while before we have smart appliances integrated such that power suppliers can attenuate demand to even out the peaks and troughs on a grid scale. That has to be integrated with the smart contracts for electricity supply down to consumer level. Such things have been around a long time for small numbers of large scale industrial power users. That has to be cascaded down to households. Domestic appliances are all pretty dumb as far as power consumption is concerned.
There seems to be everything to play for in this market, a good time to be an electrical engineer. These gaps in the technology need to be filled but there is a lot of momentum. EVs may get the glamour, but they are just part of a very big change in how we generate and consume energy.
Even if a car did convert mechanical energy to electrical and back to mechanical to run the AC, yes, there’s some inefficiency there, but it’s not very much. Electric motors and generators both routinely have efficiencies in the high 90s.
I would argue that the purpose of dynamic pricing is not to change people’s habits, but to provide an incentive for investing in technologies that reduce peak energy usage. Off-peak water heating, ice storage air conditioning, rooftop solar panels, etc. Or even storage batteries like the Tesla Powerwall. Dynamic pricing means these devices will pay for themselves.
There’s even a pilot program somewhere(California?) trying that out. But it’s been pointed out there’s a downside to using car batteries that way: it’ll shorten the life of the car battery. Exactly how much is impossible to say in advance. Depends on how many additional charge-discharge cycles it adds to the battery.
Apparently there is a big difference between the charge/discharge cycle while driving and a cycle managed by a grid charger. The latter can be contrived to put far less stress on the battery.
Soon enough, there will be a huge number of EVs, all with large batteries sitting around in car parks doing very little. That is quite substantial resource to be tapped if the charging questions can be addressed.
However, I suspect that it will company owned fleets that upgrade vehicles every couple of years where this will find application first. They will be rather less worried about battery life than a private owner. The market for fleet vehicles is huge, especially in countries like the UK where a company car is a common company benefit for management grade employees.
An electric car goes about 2-3 miles per kwh. The average person drives maybe 30 miles a day, so thats about 10kwh of energy needed per day.
Even if you have 100 million cars, that is about 1Twh of energy needed per night to refuel the cars. I think the US produces something like 4000 Twh of electricity per year, and as others have said nighttime demand is lower so we probably wouldn’t need to add capacity, just turn on some capacity that normally shuts off at night.
Electric grids are designed to handle electricity demand at peak hours. That is roughly during midday during summer when everyone is at work and AC is on everywhere (both at work and at home). Nighttime demand is much lower, so we just turn on the plants we normally shut off at night.
4000/365=10.989 - call it 11 TWh per day. So the grid needs to supply about 9% more not trivial but not a showstopper - most likely just making better use of existing capacity. But as mentioned, fleet use will also be a decisive factor. You will know the future has arrived when taxi stands have fast chargers - a taxi cannot accept an hour downtime twice a day or so, but being able to incrementally top up at any opportunity will keep then running all day.
The problem with automobiles is that they are sitting around away from home connections during the day when their connectivity is most needed. I assume some giant parking lot would accept cars for free parking if it could plug them in and use a fraction of their battery power instead of a parking fee…We charge 1KWh for each hour parked here…
The more likely scenario is the home with a Tesla Powerwall that charges all day and drains as needed using the grid as a supplement and also the local battery as a peak modulator. A clever grid system would exploit this to supply the homes without battery capacity.
(At the peak of the California electrical crisis, someone mentioned a smelter in Washington or Oregon that found it was cheaper to shut down and pay employees to stay home so the plant could sell their guaranteed quota of cheap power to California rather than make metal. An analysis of the Enron debacle said that the market was structured in California to deliberately discourage longer term, more stable contracts; allegedly t was to encourage a competitive market, but instead it had the opposite effect. For half a decade while the possibility was seriously debated and implemented, the major utilities did not invest in expansion, assuming a plethora of opportunist operators would jump in to make up any capacity shortfall; while investors stayed away specifically because the instability meant no guaranteed price or return. )
I see the bolded becoming a major concern, with Musk refusing to convert the Supercharger Network to accomodate, say, Ford, or Volkswahen EVs.
Great posts, Stranger.
In fact, Tesla has said they will allow other cars to charge - but the adapter and other details are up to the other manufacturers. I have seen photos claiming some other vehicles can use Tesla superchargers, but not aware of the details. The main point would be, your Tesla charges based on an account you have with Tesla, credit card on file, so presumably anyone else would need to sign up. The car would need to have the software to detect and the protocol to communicate with Tesla chargers as well as CCS. Plus a plug adapter.
It’s coming.
Meanwhile, Teslas built in the last year or so have CCS support also (mine from late 2018 says “not installed”, I presume it would be a hardware board replacement). Following on the requirement in Korea that CCS is standard, and that only Japan seems to standardize on ChaDEMO, the CCS standard seems to be the de facto for North America. (Europe mandates the same CCS communication protocol with a different plug arrangement, and Teslas have been delivered there with that socket for a few years). Tesla has announced the CCS adapter available in Korea (to plug CCS into the tesla socket) will be available “soon” in North America. (that’s “soon” in Elon Standard Time - EST - so YMMV).
As the infrastructure bill rolls out CCS chargers across North America, it makes sense for Tesla to add CCS charging capabilities. Meanwhile, if the CCS network(s) will soon match the Tesla network, it would not be a priority for other car makers to add Tesla Supercharger capability.