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How Electric Vehicles Stabilize the Power Grid

Electric vehicles (EVs) will be the key component that fills transportation needs in a world with climate change. Not only will EVs reduce greenhouse gas emissions, but they will also play a vital role in supporting the next generation electric energy grid.

When the grid experiences deviations from its standard frequency of 60 Hertz, EV batteries will come to the rescue. By implementing smart, bidirectional EV chargers, especially in residential areas, EV chargers will support the grid by discharging EV batteries when frequency dips and recharging EV batteries when frequency rises.

Let’s take a closer look at how bidirectional EV charging can stabilize the grid. We’ll also explore some challenges and benefits of EV grid support.

Standard Frequency, Overfrequency, Underfrequency

In North America, electric utilities provide energy with voltage waveforms that cycle 60 times each second, referred to in the industry as 60 Hertz. The ideal operating frequency for the grid is 60 Hertz. When frequency is above or below 60 Hertz, the grid could face serious operating issues. Electric utilities must constantly balance the energy equation with energy production and energy consumption.

Occasionally, the amount of energy produced by all energy generating facilities, including traditional power plants, wind farms, solar farms, and rooftop solar panels, exceeds the amount of energy that consumers demand. When this happens, electric utilities struggle to prevent frequency from rising above 60 Hertz. Presently, when the energy equation is off balance due to overproduction of energy, also known as an overfrequency event, some energy production facilities are shut down.

At other times, the amount of energy that consumers demand approaches or exceeds the amount of energy produced by all energy generating facilities. When this is the case, electric utilities balance the energy equation by initiating rolling blackouts to prevent underfrequency events. Most residential customers see rolling blackouts as an inconvenience, especially when power is restored in 15 to 20 minutes. However, for commercial and industrial customers, rolling blackouts are a risk that results in lost productivity and lost revenue.

Electric Vehicles to the Rescue

Electric vehicles are a key solution to keeping the energy equation balanced. New EV chargers should be designed to be bidirectional, capable of transferring energy from the grid to EV batteries and returning stored energy to the grid. This would assist the grid during both overfrequency and underfrequency events. When parked in residential areas, EVs should be connected to smart, bidirectional chargers that are always in standby mode, ready to actuate at any time depending on grid frequency.

If frequency rises, bidirectional EV chargers would begin charging EV batteries automatically. When 100,000 EV chargers within a 100 mile radius begin drawing energy simultaneously, overfrequency conditions will be contained.

If frequency drops below 59.95 Hertz, bidirectional EV chargers would return energy stored in EV batteries to the grid. When 100,000 EV chargers within a 100 mile radius begin returning energy, the underfrequency conditions will be contained.

Electric Utilities Worry EV Grid Support Will Reduce Profits

With the traditional model of energy production and transmission, there is little incentive to use EV chargers as part of the energy balance equation. This is because traditionally, electric utilities constructed energy production facilities in remote locations to transfer energy to areas with a high concentration of consumers. After constructing a new facility, utilities would apply for a rate increase to earn a profit for the facility they built.

This model of energy production and transmission was introduced more than 100 years ago, and is no longer useful. The traditional model must be updated to aid in the clean energy transition, not only because EVs present opportunities to change the system, but also because renewable energy production can occur anywhere on the system, not just at a remote energy production facility.

Standby Energy from EVs Cuts Utilities’ Costs

Although bidirectional EV chargers reduce the need for investment in more energy production infrastructure, which could potentially reduce utilities’ income, they also present an opportunity for significant cost savings. Using EV batteries as standby energy sources will reduce electric utilities’ expenses on maintaining standby energy sources. When an energy shortfall occurs, EVs can supply extra power to the grid at significantly reduced costs for utilities.

The PJM Interconnection, for example, spends millions of dollars each year on spinning reserve, energy production facilities that are ready to produce energy at a moment’s notice when consumer demand exceeds energy supply. Using EV batteries as standby energy sources eliminates this expense, as traditional standby energy sources would be replaced with standby EV chargers.

When this cost savings is compared to potentially reduced income, utilities will find that the lost income is less than the money saved.

Update Models to Better Understand EV Grid Support

Another challenge is that electric utilities have outdated models that predict the response of their facilities to changes in consumer load and energy production. Models must be updated to include bidirectional EV chargers, distributed renewable energy sources, and more. Once models are updated, electric utilities will have a better understanding of exactly how their system will respond to overfrequency and underfrequency events.

Incentivize EV Grid Support for Consumer Participation

For EV owners, incentives could include no-cost energy during overfrequency events, when EV batteries begin charging because excess energy is available. During underfrequency events, when EV batteries discharge to support grid frequency, EV owners would receive a small rebate on their monthly energy bill.

Or better yet, EV owners with bidirectional chargers that are designed to activate during a frequency excursion could be entered into a monthly lottery with the potential of winning a $1,000 cash prize. The number of prizes will be a function of cost savings. When the monthly cost savings are one million dollars, 1,000 cash prizes can be awarded – whether or not a frequency excursion occurred. With 100,000 enrolled EV owners, the odds of winning are 1 in 100 each month or 1 in 10 each year.

Implement Bidirectional EV Charging Today

The technology to develop smart, bidirectional EV chargers already exists, and is in use in some areas of the world, such as in Utrecht, Netherlands. The key to implementing a bidirectional EV charging system across the US is buy-in from both electric utilities and EV owners. The bidirectional EV charging system can benefit both stakeholders, with the right incentives.

EV battery grid support is a vital step to creating a next generation electric energy system that is ready for a future with climate change. Prescient is excited to help electric utilities prepare for expanded EV charging in their service areas. Contact us to schedule a consultation today.


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