Solving Electric-Vehicle Popularity Problems with Smart EV Charging

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Smart EV Charging Products Help Avoid Transformer Overload

California residents have purchased about 142,000 of the approximate 339,5oo plug-in vehicles sold nationally since 2011,  according to the Plug-In Electric Vehicle Collaborative.

While that’s good news for California’s environment, it’s not always good news for utilities that must cope with high peak loads in plug-in popular neighborhoods. However, it’s creating a market for companies like eMotorWerks, which helps manage high loads from electric-vehicle charging.

About 10 percent of cars sold in the San Jose area are now plug-ins, says Valery Miftakhov, CEO of eMotorWerks.

“That creates a problem,” he says. “In a lot of neighborhoods, with the time-of-use rates, which incentive people to start charging cars at certain times, you have local load spikes that create difficult situations at the local grid level,” he says. “Transformers are getting overloaded.”

The Silicon Valley is especially vulnerable to transformer failures due to EVs, he says. “The utilities are interested in solutions that would allow them to modulate the load so it doesn’t exceed a certain amount.”

The California Public Utilities Commission now allows utilities to invest in EV charging infrastructure, and Pacific Gas & Electric has asked for PUC approval to partner with the private sector and build more than 25,000 charging stations.

To help utilities solve the charging overload problem, EMotorWerks ensures that an EV load doesn’t exceed a certain amount.

“We can say to a utility, ‘for this particular node, the EV charging load cannot exceed say 15 MW,'” says Miftakhov. The company is now talking to California utilities about its smart charging products, which improve grid stability.

The company’s JuiceBox product, sold to car owners, is a Level 2 EV charging station that includes energy metering, WiFI, and smart phone control options. “Our system takes into account driver preferences about when they need their car. They use a smart phone app and say, ‘I need to be charged by 7 am.’ We move the load around so there’s no peak.”

To date, the company has sold about 5,000 units, 50 percent of which are in California.

Another hotspot is Colorado. The number of EVs in Denver has jumped 150 percent since 2011, which makes it one of the top ten cities for EVs in the country, according to a press release from NRG Energy.

NRG is working to make EVs even more popular. One of the biggest barriers to EV purchases, the company says, is “range anxiety,” meaning worries that owners won’t be able to recharge on the road. To address this challenge, NRG has created the largest EV charging network in the country, called EVgo.

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“With hundreds of electric vehicle (EV) charging stations across America, EVgo is the largest provider of public ‘Fast Charging’ locations.  EVgo fast-charging Freedom Stations can be used by any EV and can deliver 40 miles of range in as little as 15 minutes, allowing drivers to quickly charge their vehicles,” said an NRG press release. The company recently launched its first public DC fast charging network in Denver.

Fast charging means big draws on the utility. Will Denver be the next center of transformer failures due to EV charging?

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  1. Telematics in the cars do all of this! My car controls all of this. There is a whole other world outside of the Bay Area. Peak demand is becoming less of an issue with solar and lower amperage charging, like at workplaces during the day time. The need for a networked charger isn’t necessary most of the time. We need to be careful not to over complicate EV Adoption because of one EV community.

    • Grant Kluzak says:

      Car based telematics only go so far. Yes, they allow you to tell your car when to connect to the grid and start charging, or when you need to ready to depart. But, they don’t allow the utility to adjust that charging demand even more. What the Juicebox offers is the ability to have the Utility company have a bit of say of when or how many Amps your car can draw, thus allowing them to finely control the load. Say you need 4 hours to charge your car tonight, you plug it in around 8pm, and tell it you need it ready to depart at 7am. Depending on they car you have, it may start charging right away at a lower level, or wait until 3am and give you a full power charge right up until 7am. Works great for you, but here in California where we have large neighborhoods with Solar and EVs, the supply and demands come in very large spikes, on a neighborhood level. So we wind up putting loots of excess power onto the grid from 8am-3pm and draw lots overnight when we charge our EVs. Add in the EV Time of Use incentives the Utilities are offering, and we now have all of the EVs wanting to charge between midnight and 6am, in most markets. That could be a very high demand in some neighborhoods. I happen to have two EVs in the garage, so I could draw 80 Amps for just the two EVs during that time, plus my normal loads. The Juicebox still allows me to be ready to go at 7am, but the Utility have the ability to adjust my charge rate between midnight and 7am so that we don’t overload the neighborhood transformer. Emotorwerks even offers a Green Juicebox that would allow me to only charge when clean energy is provided to the grid, and my car could still be ready when I need it in the morning.
      Onboard telematics are great for the single car owner, but a smart grid connected Level 2 EVSE makes a whole lot of sense if they can prevent brown-outs or the need to bring older dirty power plants online to meet shifting electrical demands that our aging electrical distribution grid was not designed or optimized for.