most domestic electric vehicle chargers are adept at taking power from the grid and delivering it to your car, but what if the vehicle could also keep the lights on automatically during blackouts and offset electricity costs by returning power to its source during periods in high demand?
A growing number of companies, including automakers GM and Ford, are touting the benefits of two-way charging to consumers. But research suggests the advantages go beyond the individual EV owner.
For example, a 2018 Environmental Research Letters document from Lawrence Berkeley National Laboratory said that in California, which has the largest deployment of electric vehicles in the US, “substantial, multi-billion dollar capital investments can be avoided if EVs are used instead of stationary storage.”
Vehicle-to-network (V2G) and vehicle-to-home (V2H) charging – also called two-way charging – have long been the stuff of demo programs. Only recently has technology emerged as a possible useful add-on to the more than 80% to 85% of EV charging that takes place at home.
And with a stream of EVs hitting the market, the race to introduce two-way charging is heating up.
Enter the aftermarket
At least two aftermarket vendors say they will have two-way home products on the US market soon, one later this year and the other in 2023.
But as some automakers are developing proprietary two-way charging systems, the question is whether the vendor’s solutions will be able to connect to them — at least initially. It’s not a certainty at this point, but it looks like automakers want that to happen, and compatibility discussions are ongoing.
Shawn McLaughlin, CEO of Colorado-based Emporia Energy, said in an interview that it will have a 240-volt two-way home charger for sale in the US, priced below $1,500, in the second half of 2023.
Emporia is working with BREK Electronics, a pioneer in the development of silicon carbide (SiC) transistors, in the inverter for its two-way charger. The company currently sells a $399 48-amp home charger and smart home power management system, among other products.
McLaughlin said acquiring certification from the global leader in electrical safety UL is the biggest hurdle to bringing the product to market. As offered, it will integrate with the power management system for features like charging paused when the air conditioner is turned on.
“We’re super excited,” McLaughlin said. “It’s still early days, but this is a natural evolution of technology – it’s mostly been pilot programs. Most major car manufacturers have announced that they will support two-way charging of electric vehicles in some form or fashion, including Volkswagen, Ford, Chevrolet, Kia and Rivian. It’s evolving as we speak, and the key will be how each manufacturer supports it.”
He said Tesla has been “silent” about V2H and V2G, but he projects the technology will eventually be integrated into the company’s charging.
McLaughlin said Emporia is building its two-way technology around the ISO 15118-20 communication protocol, which “is under final review.” A website calendar shows it in the approval phase. McLaughlin said its charger will be able to receive and return 240 volts back home with 11.5 kilowatts of power.
Wallbox North America, an arm of a Dutch company, said its upcoming Quasar 2 two-way charger will be “fully compatible with electric vehicles sold in North America”. The company said the Quasar 2 will automatically take over in a power outage and power a home for more than three days. Wallbox recently launched its $699 240 volt 48 amp Pulsar Plus charger (capable of responding to Alexa and Google Home voice commands) in the US market.
Just look at the number of products on the market to see that the two-way charging industry is in its early stages.
Wallbox sold the $3,600 Quasar 1 in Europe, but spokeswoman Elyce Behrsin declined to provide an actual sales figure.
She said the Quasar 1 is compatible with CHAdeMO two-way-enabled vehicles, including the Nissan Leaf and ENV-200, the Mitsubishi Outlander plug-in hybrid and the Kia Soul. She said the 11.5-kilowatt Quasar 2, which will use the dominant Combined Charging System (CCS) protocol, will be on the US market “during the fourth quarter of this year.”
The list of EVs on the US market is long and growing and Wallbox said it will be ready to sync with them.
“We are working with North American dealerships, automakers and other partners to test and validate Quasar and our two-way charging technology to ensure compatibility with regional electric standards and with makes and models of electric vehicles sold in North America.” , said the company. “In fact, part of the future success of Quasar and bidirectional charging depends on more EVs being bidirectional capable.”
Other companies are working on bi-directional charging of electric vehicles, including Rectifier Technologies, Delta and Nuuve.
Jeff Wandell, Nissan Motor Corporation’s Electric Vehicle Communications Manager, confirmed that the company is working with aftermarket suppliers.
“Right now, there is no commercially certified Nissan product available on the market,” he said. “However, there are companies that are in the process of developing and certifying their equipment – such as Wallbox – and hope to be on the market soon. We are actively working with several of these companies to take this technology forward and make it available to Leaf owners.”
Chris Martin, a spokesman for Honda US, said the company has no US news to share about two-way charging, but it is being explored for the future.
There are developments in Europe, mainly with automakers.
Honda said in January that it is partnering with the V2X Suisse consortium on a plan that will place 50 Honda electric vehicles and Switzerland’s Mobility car-sharing fleet in 40 locations. Equipped with Honda Power Manager units, the cars “will provide V2G energy recovery capability for Mobility, in various urban and suburban locations across Switzerland”. Honda e cars will be able to supply 20 kilowatts of power back to the grid when connected to the two-way station.
Late last year, Volkswagen called two-way charging “an innovative technology” that will be on every ID. models with 77 kilowatt-hour batteries in the future. The company said its plan includes special DC BiDi wallboxes and that over-the-air upgrades can be used to adapt the system to vehicles already delivered.
And, according to a Rivian spokesperson, “All R1T and R1S vehicles have Vehicle-to-Vehicle (V2V) and Vehicle-to-Home (V2H) capabilities. While two-way charging capabilities exist on Rivian vehicles, regulatory and other regional variables are a significant factor for potential future V2G applications.”
Other automakers are working on proprietary charging systems, though they may not be plug-and-play.
Electric vehicle startup maker Lucid said in 2020 that it was working with a charging company called QMerit for two-way V2G capability in the air. And Ford will offer what it calls Intelligent Backup Power on the upcoming F-150 Lightning electric truck. Ford will also partner with Sunrun, a leading provider of photovoltaics, in using energy storage and solar energy to power homes. 80 amp Ford Charge Station Pro will be required.
“For Lightning, it won’t work with a regular Tier II charger,” said Sam Abuelsamid, principal e-mobility analyst at Guidehouse Insights in Detroit. “It only produces backup power through the DC pins. It’s specifically designed to work with a smart inverter system that includes a transfer switch to cut power from the grid and take it from the truck when the power goes out, so the power doesn’t come back to the grid. SunRun is currently the only company offering a compatible kit to enable this.”
Two-way charging challenges
Marc Tarpenning, co-founder of Tesla with Martin Eberhard, emphasizes that powering a home from a car requires critical safety protocols – it’s not a simple matter.
Without protections, “the voltage you put in your house flows to the power pole on your street and, for a moment, lights up the high-voltage wires to 12,000 volts,” he said. “If a lineman were working these wires, like during a power outage, you would kill them pretty much instantly.” He added that “the house must fully disconnect from the grid before any power is applied internally. So your EV can certainly power your home, but power companies take their generator setups very seriously, making sure they have proper isolation ‘transfer’ switches. ”
Another challenge, according to Tarpenning, involves the smart inverter system referenced by Abuelsamid. “The inverter in your car will have to be able to handle the ‘inrush’ when you start a house,” Tarpenning said. “For a moment, the house will draw a huge amount of current as everything comes to life. This is not an issue if the inverter is designed to handle it, but this will be a design change for most EV inverters.”
Abuelsamid said AC electricity can be taken from the Lightning via the on-board ProPower system with the optional 9.6 kilowatt output, “but I’m pretty sure that won’t work with the Quasar.” Hyundai models, limited to 1.9 kilowatts via an adapter that plugs into the J1772 connector, “may be able to run the Quasar with a proper software update,” he said. “I haven’t seen any details yet on how Lucid is implementing its bidirectional capability.”
Ryan O’Gorman, Ford’s chief energy services strategist, said in an email: “At this time, the F-150 Lightning is not compatible with other options. From what we understand, ISO 15118-20 has not yet been released. And as with the ISO and SAE charging standards on the market today, when this 15118-20 standard is released – including bi-directional power transfer – manufacturers (such as Ford) that have implemented accepted standards in the past can be expected to support these standards. futures. So for now, the Ford Charge Station Pro would need to be installed with the Home Integration System which is available for purchase at Sunrun in 2022.”
Abuelsamid’s colleague Scott Shepard, Principal Energy Research Analyst at Guidehouse, said Lucid’s two-way system is AC-based, with Lucid also providing the AC two-way charging unit. He added that the Wallbox “has supported at least one V2G test in Europe – Powerloop in the UK operated by Octopus Energy”. That trial, supported by National Grid, involves more than 130 families in Britain.