16 “On the one hand, I think EVs are always going to be more expensive than combustion cars of a similar size. That’s almost guaranteed by function of putting a large battery pack into a car, but smartphones cost far more than house phones, and everyone still owns one, because they enable you to do much more than you could do before,” he notes. “Imagine if EVs could be engineered with capabilities not only for driving but as a huge home energy storage system. They could soon form an integral part of how homeowners track and optimise their day-to-day energy usage. “In the UK, for instance, we already have our e:PROGRESS solution – a time-of-use tariff to help customers recharge their EVs specifically when electricity is cheap. If the EV is then leveraged to charge devices all over their homes, you’ve made the EV a part of their life, 24 hours a day, just like their smartphone,” Fischer adds. Such a concept could be extended to create ‘energy communities’ in the future, and Fischer gives the example of a homeowner with a PV roof. If such an individual is not at home to charge their own EV, and the PV roof stands to generate an electricity surplus that might otherwise go to waste, they could leverage a blockchain solution to engage in energy trading with their neighbour – essentially selling electricity to their neighbour’s EV in a P2P charging arrangement. Charging forwards With the creation of such communities in mind, V2G and bidirectional charging take up much of Honda’s European research within its focus on energy management and intelligent charging. This began in earnest in 2016, when Fischer and his team started installing a fast-charging system at their facility, using the Honda R&D Europe base as a testbed for how the energy flows from EV charger to building could be optimised. These included installing 750 kW (peak) of rooftop solar cells, some Honda-designed bidirectional chargers, and a plethora of voltage and current sensors throughout the building to closely study energy flows. The bidirectional charger is referred to in-house as Honda R&D’s ‘Power Manager’, and is a 10 kW DC system, developed based on ISO 15118-20 (the standard for EV-to-EVSE comms, although it had not been officially published at that time). “We developed our charging manager – a hardware and software solution hidden behind the metre system – which controls the rates at which EVs charge, based on forecasts of weather and electricity consumption, as well as real-time measurements of energy flows across our facility. Key factors in its intelligence are parameters entered into the chargers by its users, including our own researchers, such as their target time for when they will leave, and how much SoC [state of charge] they want to have by that time,” Fischer says. “The charging manager computer optimises all the EVs’ chargings, such that everyone gets their desired SoC on time, and prioritises the rooftop PV cells over the grid as the preferred energy source, while also minimising peak load in the system. Widespread deployments of such smart charging infrastructure will be critical in the future; national grids cannot presently withstand every road user charging an EV at once.” Most work on developing the charging manager was software-related, falling into two categories: one was writing the algorithms necessary for intelligent control of charging loads and power draws; the other was optimising the communications links throughout the facility, between chargers, vehicles and other devices. “The problem with ISO 15118-20 and other charging comms standards today is that their interpretation is often left up to individual engineers. Hence, industry often holds ‘plugfests’, which are great opportunities for charger manufacturers and automotive engineers to test and improve their systems’ interoperability, and to improve how standards are written to better guide network and comms engineers towards a clearly defined way of writing charging comms,” Fischer notes. Through this EV charging system, Honda R&D Europe has qualified with its Honda e-fleet and bi-directional chargers to operate the frequency control reserve, a rapid and automatic In conversation | Michael Fischer March/April 2024 | E-Mobility Engineering Through technology such as bidirectional charging, V2G and blockchain, future EVs (such as Honda’s new e/NY1) could enable smart home energy allocation or P2P energy trading
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