Vehicle-to-grid (V-2-G) technology faces a struggle for commercialisation in the short-to-medium term, as the industry is swamped by a lack of standardisation and difficult product testing environments, according a new white paper from automotive technology research firm Keysight.
V-2-G technology allows energy stored in an EV's battery to be returned to the grid to be redistributed at higher demand times, or else power homes and businesses off an EV's charge. It is seen as an important technological step in addressing potential grid strain resulting from higher EV numbers, as well as a key facilitator for integrating additional intermittent renewable energy generation.
There are three primary forms of V-2-G architecture, which differ based on where the inverter and control unit, or SMCU, are located. Direct current V-2-G involves both the SMCU and inverter being placed in the charging device, while alternating current V-2-G involves both being placed in the EV. Split AC-DC V-2-G architecture involves the converter being located in the EV and the SMCU in the charging device.
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As a result, concerns about standardisation and compatibility are abundant, with the situation complicated even further by competing standardisation and certification bodies and procedures.
"The direct current V-2-G architecture has multiple certification paths, but not many OEMs are undergoing certification because there is a harmonisation issue between the standards bodies. It can still be done today, but having a single standard would improve the situation," says Matthew Borst, automotive and energy solutions lead at Keysight .
"Alternating current V-2-G, meanwhile, is like the Wild West. There is not a way to be certified today," he adds.
And this places extra importance on laboratory-based testing of V-2-G systems by both OEMs and Evse manufacturers. But the varying electrical architecture of built-in grid infrastructure makes it difficult to emulate real-world environments for compatibility testing.
“Many experts see V-2-G technology as the next frontier for EVs, but transforming battery packs into energy sources for the grid requires extensive conformance testing of interconnection, communication and power flow,” notes Jessy Cavazos, Keysight's automotive and energy solutions manager.
Keysight and news agency Reuters recently polled V-2-G industry figures, finding that the primary use case envisioned for V-2-G is fleet operators. Fleet operators often use slow overnight charging, but still have large depots which risk placing heavy strain on local substations and grid infrastructure. V-2-G at fleet depots would offer a potential solution to managing that demand more efficiently.
"At present 40pc of respondents see V-2-G being developed as a commercial feature rather than for personal benefit (27pc), although 39pc believe it could apply in both contexts," the survey finds.
The poll finds that the benefits of V-2-G technology will mostly be for utilities, with 41pc of the survey's sample citing the integration of renewables as the main advantage, with a further 34pc highlighting grid stabilisation.
"Due to its importance to grid operators, 41pc of respondents believe governments and local authorities will be the most important stakeholders in advancing the implementation and adoption of V-2-G," the Keysight whitepaper says, although it also concedes that respondents believe that co-operation between stakeholders, such as OEMs and utilities, is the biggest barrier facing the adoption of V-2-G.
Ciaran has written about finance, politics and culture. He is passionate about e-mobility and what it means for our way of life.
Ciaran has a Masters in Ancient Philosophy from Oxford University.
