Reducing energy demand in the transportation sector is one of the most difficult challenges we face to meet our CO2emission reduction targets. Due to the sector’s dependence on fossil fuel energy sources and the monumental negative consequences for climate change, air pollution and other social impacts, countless researchers, policymakers and other stakeholders view a widespread transition to electric mobility as both feasible and socially desirable.

How do we go about making it happen? As researchers working on low carbon mobility we need to start looking beyond technical challenges and look at the role of consumer acceptance and driver behavior, as well as the role for policy coordination, to move forward. My colleagues and I have been looking at research on vehicle-to-grid (V2G) and vehicle-grid-integration (VGI) and found that the focus has been too narrow so far. To help make the transition to electric mobility happen, we need to understand the benefits of the technology and propose areas where research should expand.

How does V2G work?

V2G and VGI refers to efforts to link the electric power system and the transportation system in ways that can improve the sustainability and security of both. As our figure below illustrates, a V2G configuration means that personal automobiles have the opportunity to become not only vehicles, but mobile, self-contained resources that can manage power flow and displace the need for electric utility infrastructure. They could even begin to sell services back to the grid and/or store large amounts of energy from renewable and distributed sources of supply such as wind and solar.

Visual depiction of a Vehicle-to-Grid (V2G) or Vehicle-Grid-Integration (VGI) network         Source: Willett Kempton

What are the benefits of V2G integration?

A transition to V2G could enable vehicles to simultaneously improve the efficiency (and profitability) of electricity grids, reduce greenhouse gas emissions from transport, accommodate low-carbon sources of energy, and reap cost savings for vehicle owners, drivers, and other users.

The four main benefits of V2G integration are:

• Turning unused equipment into useful services to the grid

A typical vehicle is on the road only 4–5% of the day, so 95% of the time, personal vehicles sit unused in parking lots or garages, typically near a building with electrical power.[1]

• Using underutilised utility resources

Many utility resources go underused, which is an implication of the requirement that electricity generation and transmission capacity must be sufficient to meet the highest expected demand for power at any time. One study estimates that as of 2007, 84% of all light duty vehicles, if they were suddenly converted into plug-in electric vehicles (PEVs) in the United States, could be supported by the existing electric infrastructure if they drew power from the grid at off-peak times[2].

• Financial and economic benefits

Automobiles in a VGI configuration could provide additional revenue to owners that wish to sell power or grid services back to electric utilities.  Some studies suggest that some types of vehicle fleets could earn even more revenue than passenger vehicles, especially fleets with predictable driving patterns.[3]

• Reduced air pollution and climate change, and increased integration and penetration of renewable sources of energy.

PNNL projected that pollution from total volatile organic compounds and carbon monoxide emissions would decrease by 93% and 98%, respectively, under a scenario of VGI penetration and total NO_x emissions would also be reduced by 31%. [4]  A VGI system can further accrue environmental benefits by providing storage support for intermittent renewable-energy generators.[5]

The unexplored questions

The vast majority of studies looking at VGI simply assume that consumers will go along and behave as the system tells them to. We need to better understand people, what cars they want to buy, and what it would take for them to be comfortable in letting someone else control the charging of their electric vehicle.

Furthermore, we need to understand how the societal benefits of the technology are distributed, especially among vulnerable groups. A transition to low carbon mobility needs to be just and equitable too.

V2G clearly has the potential to provide a wide variety of benefits to society.  However, research needs to broaden its focus and consider the following aspects:

• Environmental performance of V2G in particular, rather than electric vehicles more generally;
• Financing and business models, especially for new actors such as aggregators who may sit between vehicle owners and electric utilities;
• User behavior, especially differing classes of those who may want to adopt electric vehicles and offer V2G services, and those who may not;
• Natural resource use, including rare earth minerals and toxics needed for batteries and lifecycle components;
• Visions and narratives, in particular cycles of hype and disappointment;
• Social justice concerns, notably those cutting across vulnerable groups;
• Gender norms and practices; and
• Urban resilience in the face of intensifying climate change and consequent natural disasters.

Although the optimal mix is hard to discern, the share of V2G and VGI studies that focus on technical matters and rely on technical methods seems too large and imbalanced—as demonstrated by the many socially relevant research questions that remain unexplored.

Ultimately, these gaps in research need to be addressed to achieve the societal transition V2G advocates hope for.

This post was originally published on the INNOPATHS blog.

Further reading:

This blog is based on two studies – “The Future Promise of Vehicle-to-Grid (V2G) Integration: A Sociotechnical Review and Research Agenda” and “The neglected social dimensions to a vehicle-to-grid (V2G) transition: A critical and systematic review”—are available in the October Volume of Annual Review of Environment and Resources and Environmental Research Letters.

Read more about CIED’s research on urban transport and smart freight mobility.

Citations:

Sovacool, BK, L Noel, J Axsen, and W Kempton. “The neglected social dimensions to a vehicle-to-grid (V2G) transition: A critical and systematic review,” Environmental Research Letters 13(1) (January, 2018), 013001, pp. 1-18.

Sovacool, BK, J Axsen, and W Kempton. “The Future Promise of Vehicle-to-Grid (V2G) Integration: A Sociotechnical Review and Research Agenda,” Annual Review of Environment and Resources 42 (October, 2017), pp. 377-406.

References:

[1] G. Pasaoglu et al., Travel patterns and the potential use of electric cars – Results from a direct survey in six European countries, Technological Forecasting & Social Change Volume 87, September 2014, Pages 51–59

[2] Michael K. Hidrue, George R. Parsons, Is there a near-term market for vehicle-to-grid electric vehicles?, Applied Energy 151 (2015) 67–76

[3] Michael K. Hidrue, George R. Parsons, Is there a near-term market for vehicle-to-grid electric vehicles?, Applied Energy 151 (2015) 67–76

[4] Kintner-Meyer, Michael, Kevin Schneider, and Robert Pratt. 2007. “Impacts Assessment of Plug-In Hybrid Vehicles on Electric Utilities and Regional U.S. Power Grids Part 1: Technical Analysis,” Pacific Northwest National Laboratory Report, available at http://www.pnl.gov/energy/eed/etd/pdfs/phev_feasibility_analysis_combined.pdf.

[5] Okan Arslan, Oya Ekin Karasan, Cost and emission impacts of virtual power plant formation in plug-in hybrid electric vehicle penetrated networks, Energy 60 (2013) 116-124