Introduction:  

EV charging is the talking point of the moment in the automotive industry lately, whereas sustainability is the buzzword in the energy industry. Bidirectional charging lies at the convergence of both these, bringing tremendous possibilities to tap the value from both these emerging technologies.  

The bi-directional electric vehicle charger market was valued at USD 1.4 billion in 2023 and is estimated to register a CAGR of over 22.8% between 2024 and 2032. You can read more about it here. 

If one is looking to develop solutions around bidirectional charging, it is important to understand and assess its advantages and disadvantages to make informed decisions. This blog addresses key terminologies, pros & cons, and examples of implementation of this technology.   

The sustainability / Greentech market is set to grow from to $105.26 Billion by 2032 from current size of $17.21 billion. 

Sustainability is the need of the hour for multiple reasons: 

• Lower energy cost 

• Positive environmental impact 

• Waste reduction 

• Optimum use of resources 

• Climate change mitigation 

Electric vehicles (EVs) are a revolutionary step towards sustainability. The EV market is set go from $500.48 billion to $1,891.08 billion in the next 9 years and will be the largest contributor to the adoption of sustainable technology  

EVs neither use fossil fuels nor emit CO2, thus helping conservation of natural resources and reducing environmental pollution. This helps sustainability both at the source and by-product levels. Most importantly, by leveraging bidirectional charging, sustainability and cost savings are further enhanced.  

Definition & terminology: What is bidirectional charging?  

Bidirectional charging enables energy to flow in both directions between an electric vehicle (EV) and the other energy sources during charging (EVSE to EV) and discharging (EV to Load) cycles. such as:  

• Grid or microgrid (V2G): Enables electric vehicles (EVs) to send energy to a power grid by acting as mobile batteries, storing energy, and supplying power to the grid as needed. This helps reduce the load on transformers, grid balancing and help the driver earn some money. A good example is partially powering a facility through an on-campus microgrid run by EV cars or providing an hour of battery to the facility even in case of a blackout due to storm etc. 

• Homes (V2H): Stored energy in parked vehicle batteries is supplied to households. This can serve as back-up power without having to invest in a home battery.  Some examples are running refrigerator, hot plate, domestic tools power by EV supplied power. 

 Benefits of Bidirectional charging:  

1. Grid Support: The battery of an EV can send power back to grid to support peak loads. A vehicle to grid supply is based on the demand response and can be used to handle peak loads and cost reduction by sending energy back to grid. This can prevent grid disruptions. E.g.: One study in England found that an electric car owner who connected their car to the grid at least 75% of the time could earn around DKK 3000-4000 per year.  
2. Mobile source: An electric vehicle can generate and supply energy to devices such as washers or juicers through an adapter.  
3. Power backup: In case of a power outage, a bidirectional charging-enabled EV can work as an inverter. Although, its effectiveness in supporting more loads for longer durations depends on capacity of battery and level of charge, it is still a viable option.  e.g.: For backups, Nissan’s blue switch program – Nissan leafs were brought to an area recently hit by a natural disaster to connect to homes, buildings, or specific loads 
4. Cost optimization: Charging during non-peak times and powering homes with an EV in peak hours can help save users significant amounts of money.   

However, though it is an ideal solution for multiple problems, this technology is not yet mature and is not easy to implement due to following reasons:   

1. Infrastructure availability: Current electrical systems require significant improvements for effective usage as bidirectional charging stations.  
2. It is a developing technology, and industry standardization is missing in terms of regulations and protocols for provider-agnostic solutions.    
3. Grid management: Bidirectional charging poses challenges of maintaining grid reliability and stability.  
4. The life of the battery degrades because of frequent cycles of discharging and charging.   
5. Individual users need EV compatible vehicles, adapters, and private space to install the system. The initial cost of setup can be prohibitive.  
6. Loss of energy during bidirectional energy transfer is significant and can outweigh the cost benefits.  
7. Increased need for foolproof cybersecurity because of highly connected system.   

 Standards and compliances angle: 

This is still an evolving technology and is hence guided by many standards that the system needs to comply with. These include: 

• National electric vehicle infrastructure (NEVI) – department of transportation needs to submit a deployment plan of EV infra annually. 

• RPS – Renewable Portfolio Standards – This is a California-specific standard that requires a specific percentage of electricity to be from renewables.  

These standards go hand in hand and hence, bidirectional charging is something that helps industry comply with both the above. 

Other development standards and compliances include: 

• Safety standards:  

• • SAE J1766: To ensure enough barrier between EV battery and occupants  

• • ISO 17409: Safety mandates for connecting external electric loads to the EVs  

• • IEC 61140: safeguarding from electric shock 

• Performance standards: ISO 12405, ISO 18243, and ISO 15118 

• Charging infrastructure standards:  

• • ANSI EVSP – light-duty, on-road plug-in EVs and the corresponding EV charging infra  

• • 23 CFR Part 680: Mandate for 4 network connected ports at the minimum. 

Bidirectional charging – at the intersection of sustainability and the EV revolution:  

Sustainability focusses on minimizing the negative impact of technological advances on the environment. Some key levers are the sourcing of materials and energy, implementation process, and bi-product disposal. EV technology passes with excellence in all these aspects due to lower emissions, dependance on renewable energy, long life of batteries and recyclability.    

Bidirectional charging takes it up a notch on a few aspects by:  

• Harnessing solar energy to power vehicle batteries.   

• Reducing costs and using renewable energy with lower emissions and longer battery life.  

• Lowering the emissions causing less pollution  

• Increasing cost efficiency: Storing excess energy and supplying back to grid / home to reduce cost, wastage, and blackouts.  

• Improving air quality: Lower emissions vis-a-vis diesel generators or traditional power back-ups.  

Harnessing these technologies in the most optimistic manner, with the expertise and experience across charging system design, battery management solutions and home energy management, eInfochips is poised to bring you, our best automotive offerings and building automation solutions.