Franklin Home Power Solution
In recent years, the concept of using electric vehicles (EVs) as a power source for homes, known as Vehicle-to-Home (V2H), has gained significant traction. This innovative approach allows homeowners to leverage the energy stored in their EV batteries to power household appliances during peak demand times or outages, offering a flexible energy management solution. However, while V2H presents certain advantages, many experts advocate for the use of dedicated energy storage systems (ESS) for home energy management.
This article provides a side-by-side comparison of standalone V2H setups and integrated ESS, highlighting their key differences. It also explores the benefits of combining EV power with an ESS, positioning it as the most efficient, flexible, and reliable solution for homeowners.
Battery Differences Between V2H and Home Energy Storage Systems
When comparing V2H setups and dedicated ESS, we need to understand the distinct battery characteristics of each system. These differences have a significant impact on system performance, safety, and sustainability for home energy management.
Energy Density and Chemistry
EV Batteries (V2H): Electric vehicles prioritize high energy density to maximize driving range. This is typically achieved using Nickel Manganese Cobalt (NMC) lithium-ion batteries, which offer a higher energy-to-weight ratio. However, NMC batteries are more prone to thermal runaway, posing safety concerns.
ESS Batteries: Home energy storage systems often use Lithium Iron Phosphate (LFP) batteries. While LFP batteries have a lower energy density compared to NMC, they are known for their thermal and chemical stability, elevating safety and longevity. This makes them well-suited for stationary applications where space and weight are less critical.
Cycle Life and Longevity
EV Batteries: Designed for transportation, EV batteries typically endure around 3,000 charge cycles, translating to approximately 6-10 years of use. This lifespan aligns with automotive expectations but may not withstand the frequent and rigorous daily cycling demands of home energy management. This means using standalone V2H as daily home energy management solution, such as for addressing time-of-use (TOU) tariff to reduce energy costs, can compromise your EV battery’s longevity.
ESS Batteries: In contrast, ESS batteries are engineered for longevity, often supporting over 6,000 cycles. Some advanced battery solutions, such as FranklinWH aPower 2, can provide more than 10,000 cycles over a lifespan. This durability can handle continuous charge and discharge cycles without significant battery wear or degradation, ensuring a reliable energy supply for residential use over extended periods.
Charging and Discharge Rates
EV Batteries: EV batteries are engineered for rapid energy output to facilitate quick acceleration and support fast charging capabilities. However, frequent exposure to high charging rates can lead to increased thermal activity and accelerate battery degradation, potentially reducing lifespan by up to 10% over 300 cycles.
ESS Batteries: Home energy storage batteries are optimized for steady energy release and typically undergo gradual charging processes, taking 1-2 hours to fully charge the battery. This controlled approach minimizes stress on the battery, promoting longevity and consistent performance, which is ideal for managing household energy needs.
VH2 vs. Dedicated ESS: Comparison of System Versatility
As homeowners look for ways to reduce electricity costs and improve energy resiliency, V2H setups and dedicated home energy storage systems are two potential solutions. While V2H can serve as a temporary backup power source, it lacks the versatility needed for efficient, long-term home energy management and efficiency optimization. In contrast, a dedicated home energy storage system is a purpose-built hybrid energy solution, capable of coordinating multiple power sources and home loads to maximize energy efficiency and reliability.
How V2H Works & Its Limitations
A V2H system allows an electric vehicle (EV) to supply power to a home, but it operates primarily as a single power source during outages. The key components of a standalone V2H system include:
- Bidirectional Charger: Enables energy flow between the EV and the home.
- Mechanical Transfer Switch: Isolates the home from the grid to prevent power backfeed from the EV battery to the grid and then switches to EV power once the EV is connected and set to supply power to the home during an outage.
- Basic Energy Management System (EMS): Controls energy transfer but lacks advanced energy optimization capabilities.
While V2H can serve as a temporary backup power source, it has significant defects for daily home energy management.
Limited Role as a Backup Power Source
- V2H is designed primarily for emergency power during outages rather than continuous energy optimization.
- Since it relies solely on the EV battery, power availability depends on whether the car is at home and fully charged.
Not Designed for Frequent Charge-Discharge Cycles
- Frequent charging and discharging in a V2H setup accelerates EV battery degradation, shortening its lifespan, reducing driving range, compromising its primary purpose as a transportation tool, and eventually leading to an expensive EV battery replacement.
- EV manufacturers do not tend to warranty their batteries for intensive home energy use.
Lack of Intelligent Energy Control
Standalone V2H operates as a single energy source without the ability of intelligent energy control. This means it cannot manage home power and loads efficiently, making it unsuitable for advanced energy saving strategies such as TOU control, load shedding and shifting.
How an ESS Provides Intelligence and Flexibility
A dedicated home energy management and storage system, such as the FranklinWH System, is a hybrid energy solution, built as an energy ecosystem that integrates multiple power sources and intelligently manages power output and input between power sources and home loads. Unlike V2H, a dedicated home energy storage system is designed for long-term, sustainable use in home energy applications.
A dedicated home energy storage system is highly versatile in home energy management and optimization.
Hybrid Energy Integration
- A home energy management and storage system can seamlessly coordinate solar, grid, battery storage, and generator power, optimizing home energy use.
- It ensures uninterrupted power supply when an unexpected outage occurs.
Optimized Charge-Discharge Cycles
- ESS batteries (typically LFP) are built for high-cycle life, handling daily deep discharge without significant degradation.
- Most ESS batteries are rated for 6,000–10,000 cycles, while EV batteries typically last 1,500–3,000 cycles.
Advanced Home Energy Management
- A home energy management and storage system can intelligently manage home power sources and loads, ensuring efficient power distribution based on individual demand and available energy.
- Features such as TOU optimization, load shifting, peak shaving, and participation in energy trading programs help homeowners reduce electricity costs and earn extra credits. With long lifespan and minimal battery degradation, homeowners can enjoy long-term savings and true energy freedom by leveraging these advantages of a home energy management and storage system.
Maximize Home Energy Management Flexibility: Integrate EV Power into Home Energy Storage System
While the debate between V2H and dedicated ESS often presents them as opposing solutions, they do not have to be mutually exclusive. Instead, integrating EV power into a dedicated home energy storage system can provide greater flexibility, enhanced resiliency, and smarter energy management—without compromising EV battery health.
The Role of V2H in a Hybrid Energy Solution: An Example of FranklinWH System
Using an EV battery as the primary source of home energy can lead to accelerated battery degradation. A more effective approach is to use Vehicle-to-Load (V2L) or V2H as a complementary power source to a dedicated home energy management and storage system rather than replacing it. Taking the FranklinWH System as an example, by integrating EV power into the system, homeowners can:
- Prioritize FranklinWH System for daily energy needs, reducing reliance on external power sources.
- Allow the EV battery to serve as a last-resort power source, only being used in critical situations when solar and grid are unavailable, and battery is completely drained.
- Protect EV battery lifespan by minimizing unnecessary frequent and deep cycling while still having it available for critical use, maximizing energy freedom while avoiding the pitfalls of excessive EV battery usage.
Conclusion
For homeowners, the optimal approach is not to choose between V2H and dedicated ESS, but rather to integrate EV power into a dedicated home energy management and storage system. This hybrid solution enhances energy flexibility, protects EV battery lifespan by reducing unnecessary deep cycling, and maximizes energy independence by utilizing multiple power sources efficiently.
