By Doug Peeples, Smart Cities Council

When the concept of vehicle-to-grid technology was first proposed in 1997, and for years afterward, the idea of using electric vehicles as storage batteries to help balance electric grids was seen by at least some as unrealistic, far-fetched.

But it seems the landscape has changed. Enel and its equally forward-thinking partners recently completed a V2G commercialization project in Denmark.

Denmark electric utility Frederiksberg Forsyning now has bragging rights for having what is said to be the world's first completely commercial V2G hub. It's the result of a collaboration between car maker Nissan, V2G services provider Nuvve and Enel, a Council Associate Partner. Launched in August, the system provides grid operator Energinet.dk with a new way to help balance its electric grid network.

"Only a few years ago, the idea of commercializing V2G would have seemed unrealistic," said Ernesto Ciorra, head of Innovation and Sustainability for Enel. "Now we have a fully functioning hub of EVs delivering balancing services to the Danish grid. With V2G we can enhance grid stability, further enabling the integration of renewables into the generation mix, which is the core of Enel's overall energy strategy. V2G is one of the sustainable innovation areas that is taking us towards a low carbon society for the benefit of present and future generations."

Frederiksberg Forsyning, the partnership's first customer, is integrating and hosting 10 V2G units at its Copenhagen headquarters and has bought 10 Nissan all-electric eNV200 vans to add to the company fleet. When not being used, the vans are plugged into V2G units and are either charging their batteries or discharging them to the electric grid on demand.

Essentially, the vans are mobile storage batteries for the electric grid. The 10 units provide a total of about 100 kW of power. A well-designed EV can provide about 10 kW of electricity, about the same as the average power demand of 10 homes.

Nuvve's platform controls power flow to and from the cars, and that dual power flow is made possible by Enel's V2G chargers connected to the Nissan vehicles. In the future, Energinet wants to adapt its grid network to better integrate EVs and use V2G on a broader scale.

And partners Enel, Nissan and Nuvve are confident enough in their system that they plan to roll out numerous V2G projects using both commercial and standard vehicles in Denmark and additional countries in the near future. The companies involved in the initial installation expect to publish their findings on the project later in the year.

Doug Peeples is a staff writer for the Smart Cities Council, which helps cities use technology to become more livable, workable and sustainable. The Council is awarding Readiness Challenge Grants to five U.S. cities to help them use technology to become more innovative, inclusive and investment-ready. Learn how to apply.