Solar energy for Hyundai and Jeep

Charging in the garage

Roman Rubanovich, NENCOM

Increasingly, owners of home solar power plants are thinking about buying an electric vehicle (EV), in order to use excess solar energy more efficiently. They want to receive free and clean «fuel» in their garage instead of buying the constantly increasing in price gasoline, gas or diesel.

It may not always be possible to completely phase out internal combustion engines in 2022. The energy density in the batteries of most electric vehicles is not yet sufficient for long-distance travel. But for the city or short countryside trips, electric cars are already ideal. Especially for those drivers who have their own house.

Charging from a household grid, even at a daily rate, is much cheaper than combustible fuel per kilometer of travel. At night it is even cheaper, but free charging from the sun is beyond competition. This is exactly the conclusion our client from Sofia came to, for whom we built a power plant last year.

The photovoltaic (PV) system turned out to be quite powerful, more than 40 kWp (kilowatt-peak), which periodically leads to overproduction. Excess energy can either be sold to the grid (which is not always profitable and requires time for complex bureaucratic procedures), or use it somehow. Of course, it is not at all obligatory to use the excess energy, this is not dangerous for a PV system: if the power plant is set to prohibit the supply of energy to the electrical grid, it will automatically adjust the power so as not to produce more than is currently required at the site. Nevertheless, the owners of such systems prefer to find a use for excess energy, at the end of the day — it is free.

The most obvious way — is to add an energy storage system (ESS) to the solar power plant. On a sunny day, when the power plant produces more energy than is consumed in the household, the excess will be used to charge the batteries, and after sunset it will be possible to continue using the solar energy accumulated in the batteries. Even more profitable is to add a big water heater (300-500 liters for a family of 3-4 people) and use it as a heat accumulator. But what to do if the batteries are already charged, the water in the water heater is hot, yet the PV system can still produce more energy than is currently required? A good solution is to charge an electric car.

Since the solar power plant in this house was based on components from the Netherlands manufacturer Victron Energy, we installed a charging station of this brand in the garage. The Victron EV station can operate as a standalone device, but its full potential is revealed when it is part of the Victron Energy ecosystem. In this case, full control over the station is possible through the VRM Portal (Victron portal for monitoring, control and settings), as well as the option to use adaptive mode, in which only excess solar energy is used to charge the electric vehicle.

Victron Energy ecosystem

Hyundai IONIQ 5

To get around the city, our client chose the Hyundai IONIQ 5 in version Long Range. This all-wheel drive electric vehicle is equipped with two motors: 155 kW on the rear axle and 70 kW on the front one.The total power of the two engines is 225 kW (306 horsepower), torque — 605 N·m, acceleration from zero to 100 km/h — 5.2 s.

Charging Hyundai IONIQ 5 from the sun

Typically, in electric vehicles are used 400-volt or 800-volt architectures (system voltage level). Higher battery voltage reduces the current at the same charging or discharging power, which in turn allows for smaller cable cross-sections and lower vehicle weight. The Hyundai IONIQ 5 uses an 800-volt architecture, and the power source for its engines is a lithium-polyme (LiPo) battery with rated voltage of 653 V and available capacity of 70 kW·h. The battery consists of 360 cells grouped into 30 modules (in the newer version two more modules were added):

Battery device of Hyundai IONIQ 5, © BaStro

When using fast direct current (DC) charging stations, IONIQ 5 can accept power over 200 kW at the initial stage of charging.

DC charging power graph of Hyundai IONIQ 5, according to Fastned

When charging from a household alternating current (AC) grid, the charger built into the electric vehicle is used, which converts alternating current into direct current necessary to charge the battery. Typically, built-in chargers can work with 1-phase and 3-phase grids, accepting an input current of up to 32 amperes. However, some of them work with only one phase and/or have an input current limitation of less than 32 amperes.

LEDs to the right of the connector indicate battery charge level

The Victron Energy charging station can operate in 1-phase and 3-phase grids, delivering current up to 32 amperes per phase. The built into Hyundai IONIQ 5 charging device has a limit of 16 amperes per phase when charging from a 3-phase grid (11 kW) and 32 amperes when charging from a 1-phase grid (7.36 kW):

AC charging power of Hyundai IONIQ 5, according to EV Database

In our case, the grid is 3-phase, so we can supply up to 11 kW to the built-in electric vehicle charger, spending about 7.5 hours to fully charge. Taking into account losses during energy conversion and the operation of some systems in IONIQ 5 during charging, about 10.3 kW of electric power goes directly to the battery:

IONIQ 5 display while charging

LED ring on the charging station shows charge status

The Victron Energy EV station is equipped with a touch display. The photo below captures the moment when the charging station is operating in manual mode with a current limit of 15 A. Total consumption in the house is 12.7 kW (green rectangle), from which about 9.5 kW goes to charging the electric car. The solar modules produce 16.9 kW (two yellow rectangles), from which 4.2 kW charge the household energy storage system (charged to 45%). The consumption from the grid is 0.2 kW (red rectangle):

Much more detailed information can be obtained using a smartphone or computer through the free VRM Portal. Let’s look at the graphs of three system parameters during partly cloudy weather on May 5, 2023:

Power of the PV system

We see that at 12:36 the solar power plant was producing approximately 31.8 kW of power, of which about 15.4 kW went to the storage system, and for charging the electric car — about 9 kW. The resting 7.4 kW is the current household consumption.

Charge/discharge power of the ESS system

Two minutes later, the sun disappeared behind a cloud and the PV system generation decreased to 10-12 kW, but the electric car continued to charge at 9 kW, since the charging station operated in manual mode with a fixed charging current. The PV power deficit during this period was compensated by the home energy storage system.

EV charging station power

When charging with a fixed power, solar energy is used as a priority, and when it is in short supply, a home energy storage system or grid joins the charging process, depending on the settings. This ensures the specified charging speed regardless of weather conditions or the operation of other energy consumers.

In adaptive mode, only excess solar energy is used to charge the electric vehicle. For example, if the sun hides behind the clouds or the water heater turns on, the charging station may temporarily stop charging or reduce its power, and if conditions are favorable, continue charging again at full power.

Jeep Wrangler Sahara

In addition to Hyundai IONIQ 5 our client bought a plug-in hybrid (PHEV) Jeep Wrangler 4xe in the version Sahara, to be used for both short trips and long journeys.

Charging Jeep Wrangler 4xe from the sun

The car is equipped with a 2.0-liter turbocharged gasoline engine, and an electric motor is installed inside the 8-speed gearbox. The total power of the two engines is 280 kW (380 horsepower), torque — 637 N·m, acceleration from zero to 100 km/h — 6.4 s.

The lithium nickel manganese cobalt oxide (Li-NMC) battery with a capacity of 17.3 kW·h with 400-volt architecture, consists of 96 Samsung SDI cells and is located under the rear seat of the vehicle in a waterproof housing. All the off-road capabilities of the classic Jeep Wrangler are fully retained, while at the same time, torque at low speeds has been increased, allowing for smoother overcoming obstacles. In all-electric mode, this hybrid can travel about 30 kilometers.

PHEV system Wrangler 4xe, © Jeep

Under the hood of the Wrangler 4xe there is another small electric motor-generator connected to the gasoline engine by a belt drive. This motor serves both for smooth operation of the «start-stop» system, and for charging a high-voltage battery in a situation where the gasoline engine is running while the vehicle is stationary. The main electric motor built into the gearbox can only charge the battery when coasting or braking (recuperation).

The Wrangler’s built-in charger can only operate with one phase, accepting up to 32 amperes at the input. Thus, the maximum charging power is approximately 7.3 kW, and it will take about 2.5 hours to fully charge the battery.

The Victron station allows you to charge electric vehicles according to a given schedule, and also has many other settings. Our company is the official representative of Victron Energy in Bulgaria. We use charging stations in our projects, sell them wholesale and retail, and train installers and dealers.

Documentation

In this folder we have placed technical documentation for the Victron Energy charging station:

Victron Documentation