When electric vehicles operate in conjunction with stationary energy storage, the way homes and the power grid use energy is completely rewritten. Through V2H (Vehicle to Home) and V2G (Vehicle to Grid) technologies, electric vehicles are not only means of transportation, but also dispatchable mobile energy storage units. They can achieve peak shaving and valley filling by discharging during peak hours and charging during off-peak hours, thereby reducing electricity costs and improving grid resilience, thus opening a new paradigm of integrated energy for “vehicle-home-grid”.
How V2G/V2H technologies can reshape the energy consumption logic of homes and the power grid
With the continuous increase in the penetration rate of new energy sources, the core challenge facing the power grid has shifted from “whether there is electricity” to “when and how electricity is used.” Peak shaving and valley filling have become key means to improve the efficiency of energy systems, and the combination of electric vehicles (EVs) and stationary battery storage is emerging as the most promising new solution.
What is Peak Shaving? Why are Electric Vehicles "Natural Energy Storage Entities"?
Peak Shaving & Valley Filling
This refers to reducing grid load during peak electricity demand periods and increasing electricity consumption or energy storage during off-peak periods, thereby smoothing the load curve and reducing system costs.
Electric vehicles are essentially large-capacity batteries:
Mainstream EV battery capacity: 60–100 kWh, far exceeding that of ordinary household energy storage (5–15 kWh), and possessing inherent “distributed” attributes.
When an EV is connected to a bidirectional charging and discharging system, it is no longer an “electricity terminal” but a dispatchable energy asset.
V2H: A Peak-Shaving Tool for Vehicle-to-Home Service
V2H (Vehicle to Home)
On the household side, the core value of V2H is reflected in three aspects:
1. Household Peak Shaving: During evening peak hours (e.g., 6:00 PM–10:00 PM), EVs discharge into the household, covering air conditioners, water heaters, and kitchen loads, reducing reliance on high-priced electricity from the grid.
2. Coordination with Stationary Energy Storage: Stationary energy storage provides high-frequency, low-power regulation, while EV batteries offer low-frequency, high-capacity support. All systems are centrally managed by a Home Energy Management System (HEMS).
3. Enhanced Energy Resilience: Serves as a backup power source during power outages, acting as a “super-large UPS.” In markets with significant peak-valley electricity pricing (such as Australia and Europe), V2H directly translates into electricity cost savings and increased self-consumption rates.
V2G: System-Level Value from Home to Grid
V2G (Vehicle to Grid)
If V2H is the “home perspective,” then V2G is the “grid perspective.”
1. Grid-level Peak Shaving: A large number of EVs feed energy back into the grid during peak hours, reducing the start-up of gas turbine peak-shaving units and lowering the system’s marginal price.
2. Ancillary Services Market
EVs can participate in: Frequency Regulation, Voltage Support, and Spinning Reserve.
Through aggregators, dispersed EVs are integrated into virtual power plants (VPPs) to obtain continuous revenue.
3. New Asset Revenue Model
Electric vehicles → “Revenue-generating energy assets”
Users not only save on electricity bills, but can also sell electricity and services.
Electric vehicles vs. stationary energy storage: not replacement, but synergy
|
Dimensions |
Electric Vehicles (EVs) |
Stationary Energy Storage (ESS) |
|
Capacity |
Large (60–100 kWh) |
Small to Medium (5–20 kWh) |
|
Availability |
Mobility-Related |
7×24 Available |
|
Response Speed |
Medium |
Fast |
|
Key Values |
Large-scale Peak Shaving, V2G |
High-Frequency Regulation, Home Stability |
|
Optimal Mode |
In Collaboration with Energy Storage |
In Collaboration with EVs |
The optimal solution for the future is not “EVs or energy storage”, but rather “EVs + energy storage + HEMS + electricity pricing mechanism”.
Key prerequisites for technology and implementation
To truly unlock the value of peak shaving, four conditions must be met:
1. Bidirectional Charger
Supports V2H/V2G
Typically a DC bidirectional charger
2. Standards & Protocols
ISO 15118
OCPP (Open Charge Point Protocol)
3. Intelligent Energy Management System (HEMS/EMS)
Dynamic Tariff
Load forecasting and strategy optimization
4. Policy and Market Mechanisms
Peak-valley pricing
Ancillary service market access
User revenue sharing mechanism
The essence of peak shaving is making energy "smarter."
The synergy between electric vehicles and stationary energy storage is pushing energy systems from “passive power supply” to “active dispatch.”
V2H (Vehicle-to-House) makes homes more economical and safer; V2G (Vehicle-to-Grid) makes the power grid more stable and less carbon-intensive. In the future, the real value will not lie in a single battery, but in the intelligent energy system that integrates vehicles, homes, and the grid.