Source: MITRUBISHI
This article is extracted from the DNV report: Energy Transition Outlook 2022 and a relevant DNV paper.
In most power systems, electricity demand can change very quickly. To cope with these changes, the system needs to respond quickly and ensure that the amount of electricity produced matches the amount used. This means that the system needs to be monitored continuously in real-time to track things like voltage, frequency, and power flow. The system also needs to be able to adjust the amount of power being generated and how transformers are configured in real time to maintain stability. As more and more renewable energy sources like wind and solar are being used, there is an even greater need for power systems to be flexible and adaptable to balance supply with demand.
Historically, the source of variability in the electricity system has been changes in demand, as electricity consumption varies on a daily and monthly basis. In 2010, for example, this variability amounted to an average of 13%, or roughly 5.5 GW based on the annual average demand of 42 GW. To address this issue, the power system relied on the dispatchable generation technologies such as coal and gas-fired power plants, which could be easily adjusted to accommodate changes in demand.
According to projections, solar energy will account for 10% of the UK's electricity production by 2050, while onshore and offshore wind power will together provide two-thirds of the total output. However, the intermittent nature of these renewable sources will result in nearly twice the annual variability in residual demand (the difference between overall demand and the electricity supplied by wind and solar sources) compared with today.
Rising variability in electricity supply is poised to trigger fluctuations in wholesale prices, ranging from zero or even negative electricity prices during periods of ample solar and wind power, to hours of supply scarcity when costly gas generators dictate rates. This new reality, when paired with the declining cost of storage, presents an opening for energy storage to offer greater flexibility by way of ancillary services or price arbitrage. Yet, storage providers must brace for stiff competition from alternative solutions vying for a slice of the flexibility market.
Despite its diminishing share in overall annual electricity supply, dispatchable generation will remain an essential component for ensuring flexibility. In addition, interconnections with neighbouring nations will become increasingly critical. In the case of the UK this includes France, the Netherlands, Ireland, Norway, and potentially even with Morocco. The production of hydrogen using inexpensive electricity is another means of enhancing flexibility, with most of the hydrogen destined for the hard-to-electrify aspects of manufacturing or to be used as e-fuels in the aviation and maritime sectors. Owing to the energy losses associated with thermal power generation, only a minor proportion of this precious green hydrogen will be converted back to electricity.
An increasingly viable option for enhancing flexibility in the energy sector is leveraging the battery capacity of electric vehicles (EVs) as a means of storage. With the power grid transitioning from a conventional, unidirectional energy delivery model to a more decentralized one, where consumers actively contribute to the generation of electricity, the significance of flexible solutions at the consumer level, such as EV batteries, is critical. It provides grid-connected storage for overall flexibility and, as we detail below, potentially much more…
V2X technologies, including vehicle-to-grid (V2G), vehicle-to-home (V2H), and vehicle-to-building (V2B), have the potential to revolutionize the way we use and manage energy in transportation and buildings. V2G is a concept that enables EVs to not only draw power from the grid but also provide power back to the grid. Fundamentally, this process entails the utilization of parked and unutilized EVs as a source of power for the electricity grid during periods of high demand, while simultaneously returning that power back to the same EVs during times of low demand. This mechanism permits the grid to draw on EVs' stored energy to accommodate sudden surges in power requirements, such as when households collectively activate high-powered electrical appliances, like kettles, during half-time breaks in a football game. The EVs' battery power is replenished in the early hours of the morning when people are sleeping, and the electricity load is low.
V2H is a small-scale version of V2G. It allows homes to be supplied with power stored in the EV’s battery through the home power network, serving as a backup energy source. V2B follows a similar concept, and setups can vary between the connection to a single-family home or an apartment building. V2H and V2B do not directly affect the grid but contribute to a local balance by providing energy to power the building even during power outages.
V2X systems use a combination of hardware and software, including vehicle controllers, inverters, and communication protocols, to enable the bi-directional flow of power and data between EVs and external systems. These systems rely on standard communication protocols such as CHAdeMO, Combined Charging System (CCS), and Open Charge Point Protocol (OCPP) to ensure interoperability between different systems and technologies. The EV is equipped with a bi-directional charger (AC–DC and DC–DC) that can both charge the vehicle's battery and discharge energy back to the grid or home/building (Tan, 2019). Additionally, the charging infrastructure includes a smart charging station that communicates with the vehicle and the respective grid, monitoring the battery's state of charge and adjusting the charging rate to optimize the vehicle's charging and discharging behaviour. Most major OEMs committed to deliver V2X-compatible electric cars in this decade while charge point manufacturers have made a similar commitment.
One major benefit of V2X technology is its potential to stabilize the grid by providing additional flexibility and balancing services to better manage peak demand periods and reduce the need for costly and polluting peaker plants and thus allow for the integration of more renewable energy sources (Ravi and Aziz, 2022). For end users, V2G technology can provide an additional revenue stream. EV owners can sell the stored energy in their vehicle's battery back to the grid during peak demand periods, earning credits or cash payments. This can help offset the cost of owning an EV and make it more affordable for more people to adopt this clean energy technology.
One of the biggest barriers to wider V2X integration is the lack of interoperability and standardization between different systems and technologies. There are currently no universal standards for V2X communication protocols, making it difficult for different systems to communicate and exchange data. This can lead to compatibility issues and increased costs for implementation, as different systems may require different hardware and software.
Another barrier to V2X adoption is the limited availability of charging infrastructure and grid capacity. V2X technologies rely on a reliable and accessible charging network and sufficient grid capacity to manage the bi-directional flow of electricity.
Additionally, the cost of implementing V2X technologies can be a significant barrier. While V2X has the potential to provide benefits to both the grid and end users, the upfront costs of hardware and software installation, as well as ongoing maintenance and monitoring, can be prohibitively expensive for many.
Finally, the digital steering of the technical integration needs to be intuitive and accessible, for example the UX for older homeowners or late-night workers who might need a charged battery to commute to a shift.
Source: MITRUBISHI
本文摘自 DNV 报告：Energy Transition Outlook 2022 和一篇相关的 DNV 论文。
在大多数电力系统中，电力需求变化非常快。 为了应对这些变化，系统需要快速响应并确保产生的电量与使用量相匹配。 这意味着系统需要持续实时监控，以跟踪电压、频率和功率流等信息。 该系统还需要能够实时调整发电量以及变压器的配置方式以保持稳定性。 随着越来越多的可再生能源（如风能和太阳能）得到使用，电力系统需要更加的灵活且适应性强，以保障供需平衡。
从历史上看，电力系统的变化来源一直是需求的变化，因为电力消耗每天和每月都在变化。 例如，在 2010 年，这种可变性平均达到 13%，或者根据 42 吉瓦的年平均需求计算大约 5.5 吉瓦。 为了解决这个问题，电力系统依赖于可调度的发电技术，如燃煤和燃气发电厂，这些技术可以很容易地调整以适应需求的变化。
根据预测，到 2050 年，太阳能将占英国发电量的 10%，而陆上和海上风电将合计提供总发电量的三分之二。 然而，与现在相比，这些可再生能源的间歇性将导致剩余需求（总需求与风能和太阳能供电之间的差异）的年度变化几乎增加一倍。
电力供应的不断增加的可变性将引发批发价格的波动，从太阳能和风能充足时期的零电价甚至负电价，到昂贵的天然气发电机决定费率时的供应短缺时间。 这种新的现实，再加上存储成本的下降，为储能提供了一个机会，可以通过辅助服务或价格套利的方式提供更大的灵活性。 然而，存储供应商必须准备好迎接来自替代解决方案的激烈竞争，争夺灵活性市场的一部分。
尽管可调度发电在年度总电力供应中的份额正在下降，但仍将是确保灵活性的重要组成部分。 此外，与邻国的相互联系将变得越来越重要。 就英国而言，这包括法国、荷兰、爱尔兰、挪威，甚至可能还有摩洛哥。 使用廉价电力生产氢气是提高灵活性的另一种方式，大部分氢气用于难以电气化的部门，或用作航空和海事部门的电燃料。 由于与火力发电相关的能量损失，这种珍贵的绿色氢气中只有一小部分会被转化回电能。
提高能源部门灵活性的一个越来越可行的选择是利用电动汽车 (EV) 的电池容量作为存储手段。 随着电网从传统的单向能源输送模式转变为更加分散的模式，消费者积极参与发电，在消费者层面提供灵活的解决方案（例如 EV 电池）的重要性至关重要。 它提供并网存储以实现整体灵活性，正如我们在下面详述的那样，它可能还有更多……
V2X 技术，包括车辆到电网 (V2G)、车辆到家庭 (V2H) 和车辆到建筑物 (V2B)，有可能彻底改变我们在交通和建筑物中使用和管理能源的方式。 V2G 是一种概念，它使电动汽车不仅可以从电网获取电力，还可以将电力回馈给电网。 从根本上说，这个过程需要在高需求时期利用停放和未使用的电动汽车作为电网的电力来源，同时在低需求时期将电力返回给相同的电动汽车。 这种机制允许电网利用电动汽车储存的能量来满足电力需求的突然激增，例如当家庭在足球比赛的中场休息期间集体启动水壶等大功率电器时。 电动汽车的电池电量在人们睡觉的凌晨补充，电力负荷较低。
V2H 是 V2G 的小规模版本。 它允许通过家庭电网为家庭提供存储在 EV 电池中的电力，作为备用能源。 V2B 遵循类似的概念，连接到单户住宅或公寓楼的设置可能会有所不同。 V2H 和 V2B 不直接影响电网，但即使在停电期间也能通过为建筑物供电来促进局部平衡。
V2X 系统结合使用硬件和软件，包括车辆控制器、逆变器和通信协议，以实现电动汽车与外部系统之间的双向电力和数据流。 这些系统依靠 CHAdeMO、联合充电系统 (CCS) 和开放式充电点协议 (OCPP) 等标准通信协议来确保不同系统和技术之间的互操作性。 EV 配备双向充电器（AC-DC 和 DC-DC），既可以为车辆电池充电，也可以将能量放电回电网或家庭/建筑物（Tan，2019 年）。 此外，充电基础设施包括一个智能充电站，可与车辆和相应的电网通信，监控电池的充电状态并调整充电率以优化车辆的充电和放电行为。 大多数主要原始设备制造商都承诺在这十年内提供兼容 V2X 的电动汽车，而充电点制造商也做出了类似的承诺。
V2X 技术的一个主要好处是它有可能通过提供额外的灵活性和平衡服务来稳定电网，以更好地管理高峰需求期并减少对昂贵且污染严重的峰值发电厂的需求，从而允许整合更多的可再生能源（Ravi 和 阿齐兹，2022 年）。 对于最终用户，V2G 技术可以提供额外的收入来源。 电动车车主可以在用电高峰期将车辆电池中储存的能量卖回电网，赚取积分或支付现金。 这有助于抵消拥有电动汽车的成本，并使更多人能够更负担得起采用这种清洁能源技术。
更广泛的 V2X 集成的最大障碍之一是不同系统和技术之间缺乏互操作性和标准化。 V2X通信协议目前还没有统一的标准，导致不同系统之间难以通信和交换数据。 这可能会导致兼容性问题并增加实施成本，因为不同的系统可能需要不同的硬件和软件。
V2X 采用的另一个障碍是充电基础设施和电网容量的可用性有限。 V2X 技术依赖于可靠且易于访问的充电网络和足够的电网容量来管理双向电流。
此外，实施 V2X 技术的成本可能是一个重大障碍。 虽然 V2X 有可能为电网和最终用户带来好处，但硬件和软件安装以及持续维护和监控的前期成本对许多人来说可能过于昂贵。
最后，技术集成的数字化指导需要直观且易于访问，例如为年长的房主或深夜工作者提供的用户体验，他们可能需要充了足够电的电池才能上下班。
END
