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Electric cars have the potential to be a key part of the solution to load management on a fully renewable grid. The vast majority of people will usually charge

Electric cars have the potential to be a key part of the solution to load management on a fully renewable grid. 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/ 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.

sathackr 9y ago
Great comment! 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.
- ams6110 9y ago
  This sounds great and sensible in a hand-wavy way, but getting the technology in place to effectively use plugged-in EVs for extra peak load capacity will take a long time. This sort of thing was never thought about in grid design engineering until very recently. 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.
  - sangnoir 9y ago
    > 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. 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.
  - jdietrich 9y ago
    Vehicle-to-grid technology is already being piloted in the UK and will be available to consumers in Q2/Q3 2018. There is an industry-wide roadmap for the development of local electricity markets with real-time pricing. Any customer can choose to have a smart meter installed free of charge; the goal is to have full deployment of smart metering by 2020. These meters use Zigbee to provide real-time consumption data to a wireless display unit. With future firmware upgrades, they will be capable of providing real-time pricing information to smart appliances. 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-vehicle-grid-charging-service-uk-homes-workplaces/ https://www.drive-electric.co.uk/driveelectric-launches-vehi... http://www.energynetworks.org/assets/files/electricity/futures/Open_Networks/14574_ENA_Open%20Networks%20Report_AW_v9_Web.pdf http://www.energynetworks.org/assets/files/electricity/futur... http://450alliance.org/wp-content/uploads/2014/05/WhitePaper_450MHz_SmartGrid_SmartMetering.pdf http://450alliance.org/wp-content/uploads/2014/05/WhitePaper...
Fuzzy_Logic 9y ago
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.
- ajuc 9y ago
  > 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 9y ago
    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/transmission-reliability https://energy.gov/oe/services/technology-development/transm...
- floatrock 9y ago
  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-is-threatening-natural-gas-peaker-plants#gs.xGWGgAA 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).
enraged_camel 9y ago
I was talking to a professor of electrical engineering who performs research on the electric grid. She said that while in theory it is possible to configure cars to charge themselves when electricity is cheapest, currently residential utility plans don’t adjust pricing based on time of day. Your electricity bill’s tiers are based on your total consumption. Edit: lol, I get downvoted for relaying what a professor of EE told me. Stay classy HN.
- neild 9y ago
  This is not true. (It is for some plans and some locations, but not all.) I have a plan which charges significantly less during off peak hours.
  - rangersanger 9y ago
    Interesting (and probably by design) I had to opt out of such a plan when I signed up for "100% renewable energy" with my plan.
- kurthr 9y ago
  Definitely not the case in California. Everyone is on a smartmeter now, and adding an electric car charger will both give you a $500 rebate and put you on variable pricing.
- deelowe 9y ago
  This professor has no idea what they're talking about. Every energy supplier I know of in my area offers an off peak discount specifically tailored to electric vehicles.
  - mschuster91 9y ago
    That depends on the country. In Germany the only discounts I know are for people using electric central heaters which heat up over night (Nachtspeicherofen). Something as modern as time-variable tariffs... not gonna happen soon here.
- 9y ago
rangersanger 9y ago
A potential issue I see with this is the fact that some people need to get to and from work during hours that would prohibit them from charging at off-peak hours. Night-shift jobs tend to be on the lower end of the pay scale (though there may be a bonus for taking that awful shift compared to their day-time peers.) So there is an opportunity for some regressiveness in this scheme.
- jdietrich 9y ago
  As we move towards renewable generation, the shape of the peak and off-peak periods will start to change. In the southern states, you might see very flat pricing, as higher consumption during the day is offset by higher generation from photovoltaic sources. 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. https://en.wikipedia.org/wiki/Demand_response https://en.wikipedia.org/wiki/Demand_response https://en.wikipedia.org/wiki/TV_pickup https://en.wikipedia.org/wiki/TV_pickup

sathackr 9y ago

Great comment! 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.

ams6110 9y ago
This sounds great and sensible in a hand-wavy way, but getting the technology in place to effectively use plugged-in EVs for extra peak load capacity will take a long time. This sort of thing was never thought about in grid design engineering until very recently. 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.
- sangnoir 9y ago
  > 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. 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.
- jdietrich 9y ago
  Vehicle-to-grid technology is already being piloted in the UK and will be available to consumers in Q2/Q3 2018. There is an industry-wide roadmap for the development of local electricity markets with real-time pricing. Any customer can choose to have a smart meter installed free of charge; the goal is to have full deployment of smart metering by 2020. These meters use Zigbee to provide real-time consumption data to a wireless display unit. With future firmware upgrades, they will be capable of providing real-time pricing information to smart appliances. 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-vehicle-grid-charging-service-uk-homes-workplaces/ https://www.drive-electric.co.uk/driveelectric-launches-vehi... http://www.energynetworks.org/assets/files/electricity/futures/Open_Networks/14574_ENA_Open%20Networks%20Report_AW_v9_Web.pdf http://www.energynetworks.org/assets/files/electricity/futur... http://450alliance.org/wp-content/uploads/2014/05/WhitePaper_450MHz_SmartGrid_SmartMetering.pdf http://450alliance.org/wp-content/uploads/2014/05/WhitePaper...

Fuzzy_Logic 9y ago

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.

ajuc 9y ago
> 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 9y ago
  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/transmission-reliability https://energy.gov/oe/services/technology-development/transm...
floatrock 9y ago
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-is-threatening-natural-gas-peaker-plants#gs.xGWGgAA 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).

enraged_camel 9y ago

I was talking to a professor of electrical engineering who performs research on the electric grid. She said that while in theory it is possible to configure cars to charge themselves when electricity is cheapest, currently residential utility plans don’t adjust pricing based on time of day. Your electricity bill’s tiers are based on your total consumption. Edit: lol, I get downvoted for relaying what a professor of EE told me. Stay classy HN.

neild 9y ago
This is not true. (It is for some plans and some locations, but not all.) I have a plan which charges significantly less during off peak hours.
- rangersanger 9y ago
  Interesting (and probably by design) I had to opt out of such a plan when I signed up for "100% renewable energy" with my plan.
kurthr 9y ago
Definitely not the case in California. Everyone is on a smartmeter now, and adding an electric car charger will both give you a $500 rebate and put you on variable pricing.
deelowe 9y ago
This professor has no idea what they're talking about. Every energy supplier I know of in my area offers an off peak discount specifically tailored to electric vehicles.
- mschuster91 9y ago
  That depends on the country. In Germany the only discounts I know are for people using electric central heaters which heat up over night (Nachtspeicherofen). Something as modern as time-variable tariffs... not gonna happen soon here.
9y ago

rangersanger 9y ago

A potential issue I see with this is the fact that some people need to get to and from work during hours that would prohibit them from charging at off-peak hours. Night-shift jobs tend to be on the lower end of the pay scale (though there may be a bonus for taking that awful shift compared to their day-time peers.) So there is an opportunity for some regressiveness in this scheme.

jdietrich 9y ago
As we move towards renewable generation, the shape of the peak and off-peak periods will start to change. In the southern states, you might see very flat pricing, as higher consumption during the day is offset by higher generation from photovoltaic sources. 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. https://en.wikipedia.org/wiki/Demand_response https://en.wikipedia.org/wiki/Demand_response https://en.wikipedia.org/wiki/TV_pickup https://en.wikipedia.org/wiki/TV_pickup