With global electric vehicle (EV) sales projected to grow by 29% in 2023, reaching 13.7 million units and a penetration rate of 17.1%, EVs are increasingly becoming a popular choice worldwide, according to a Canalys research report. China leads this rapidly expanding market with 7.6 million units, holding a 55.5% market share. Europe and North America are expected to reach sales of 3.2 million and 1.8 million units, respectively. By 2024, the global EV market is poised for further growth, with sales anticipated to hit 17.5 million units.

Direct Current Charging: A More Efficient Charging Method

Despite this surge, consumer concerns over EV range persist, posing a significant barrier to technology adoption. One key strategy to address this issue is enhancing charging efficiency. Increasing the number of public fast-charging stations can offer quicker energy replenishment, though many countries currently face a shortage. Moreover, home charging stations' rapid charging capabilities are increasingly crucial, making direct current (DC) charging posts a vital product.

DC charging posts can directly charge an EV's battery without any power conversion module, thus avoiding additional power loss. In contrast, traditional alternating current (AC) charging posts require the vehicle's onboard charging circuit (OBC) to convert AC to DC, leading to inevitable system loss. Therefore, DC charging posts are more efficient.

DC Coupling Systems: The New Trend in Energy Storage Products

As photovoltaic systems shift towards energy storage, compensating for the intermittent nature of solar power, energy storage has emerged as a pivotal industry trend. DC coupling systems offer significant advantages for energy storage—the solar-generated DC can be directly stored in batteries without needing to convert from DC to AC and back. Only when supplying power to loads is a DC to AC conversion necessary. In contrast, AC coupling systems undergo a more complex conversion process, resulting in efficiency losses.

Sigenergy believes that with the global pursuit of carbon neutrality and the rapid growth of energy storage systems, DC coupled energy storage systems are expected to become the industry trend, gradually replacing AC coupled systems.

SigenStor: Energy Storage System with DC Charging Module

In response to the emerging demand for rapid EV charging, Sigenergy has pioneered the integration of an EVDC fast charging module into its 5-in-1 energy storage system, SigenStor, marking the advent of a new, fast, and eco-friendly charging solution. SigenStor offers two charging power specifications: 12.5 kW and 25 kW, with the 25 kW charger capable of replenishing 130 kilometers of range in just one hour—significantly more efficient than the roughly 40 kilometers provided by slow-charging facilities (7 kW) in the same amount of time.

SigenStor draws from three different energy sources to ensure full-power rapid charging. If grid power is insufficient, it can utilize energy storage batteries and PV for power compensation, achieving 25 kW rapid charging.

Beyond faster charging speeds, the EVDC charging module also supports V2X functionality, allowing energy storage batteries and EV batteries to serve as a backup power source for homes during emergencies. With EV battery capacities generally ranging between 55 to over 100 kWh, plus energy storage batteries, a household can have at least 60 to over 100 kWh of backup power. Assuming a daily household electricity demand of 10 kWh, the system can support approximately a week's worth of electricity, effectively addressing sudden power outages.

Turning ESS into a Bridge Between EVs and Electrical Devices

Furthermore, V2X technology opens up more economic possibilities. Charging EVs with solar power or drawing electricity from the grid during low-price periods (V2G); during peak times, the electricity from EV batteries can support household use, significantly saving on energy costs. Users need not worry about battery wear from this slow discharge process, which has minimal impact on battery life. Combined with Virtual Power Plants (VPPs) for the rational distribution of nearby electricity, it can also aid grid stability and renewable energy integration. In the Netherlands and Denmark, smart charging networks utilize EV batteries as dynamic energy storage units through V2G technology. Some Dutch projects allow EVs to charge during low-price nighttime periods and sell electricity back to the grid during daytime peak prices, reducing grid pressure and creating economic benefits for car owners.

In European countries, including Germany, EVDC charging products are being widely promoted. In September 2023, the German KfW bank specifically mentioned the "Solar Power for Electric Cars" funding project 442 in its list of subsidized charging station projects, offering up to €10,200 in subsidies for products equipped with EVDC charging modules.

It's foreseeable that more countries will begin to adopt this new technology, not only for its convenience in charging but also for its contribution to reducing carbon emissions, aiming for zero-emission EV usage.