Electric Vehicles: driving towards an efficient electricity grid.

Electric vehicles (EV’s) represent a paradigm shift in the transport and the power sector. As the number of EVs increases rapidly around the globe, it is expected that there will be 18.7 million EVs on US roads by 2030.[i] EV’s have a clear environmental advantage over traditional vehicles as they produce no tailpipe emissions and are two to three times more energy-efficient. According to the US Department of Energy, EV’s are capable of converting 60 percent of their spent energy to move the vehicle whereas internal-combustion engine vehicles convert only 20-30 percent.[ii] Experts worry that the rise in EV demand can negatively impact the electricity grid, beginning with a change in load curve due to increasing evening peak loads that would consequently lead to greater investment in gas-fired peaking capacity. Additionally, experts believe EV’s would create a strain on the existing aging infrastructure due to its high volatility and spiky load profiles, making the grid less reliable and stable.  However, beyond their environmental benefits, EV’s do present a genuine opportunity to enhance the same electricity grid that experts argue they will overwhelm. 

EVs can provide a multitude of benefits to the electricity grid if proper planning is undertaken in advance to utilize their potential. Innovations such as managed charging that utilizes vehicle-grid integration technology (V2G) can help EV’s behave like a distributed energy storage resource by providing them the opportunity to discharge power back to the grid through bidirectional flow; smart charging meaning adapting the charging cycle of EVs to both the conditions of the power system and the needs of vehicle users; smart meters, and improved batteries, will further play a critical role in facilitating a smoother transition. The benefits of integrating EVs on the electricity grid with the help of such innovations are discussed below.   

  1. Reduced need for new investments in grid infrastructure – All cars (including electric vehicles) are typically parked for about 95 percent of their lifetime.[iii] During these hours, EVs can be an appealing solution for the power system due to their battery storage capacity.[iv] They can store excess electricity produced when the demand is low and feed it back into the system during peak hours, helping level the load curve while also limiting the need for constructing new peak load generation capacity. Such capacity is usually underutilized for a longer period leading to higher costs for the price of electricity in order to keep them in operation. This may not only reduce costs but also help level the rising peaks and troughs that are visible in a load curve. Although estimating the rate of adoption in a given region presents challenges, planning for the addition of EVs in advance, and, incorporating innovations of managed charging and smart charging together, can help utilities support EV charging within the existing generation capabilities. Roughly 160 million vehicles in the United States can be powered solely from the existing off-peak generating capacity, according to the Pacific Northwest National Laboratory (PNNL). This statistic helps address a rising concern among experts regarding the possibility of electric vehicles overwhelming the system. Furthermore, EV batteries can be utilized for grid storage long after the EVs are retired. In Eleverlingsen, Germany, batteries from 2000 retired Mercedes Benz EVs were collected to create a stationary grid-sized battery that held almost 9 MW of energy.[v]
  • Integrating renewable energy and reducing curtailment – Several states in the US are aggressively pursuing the integration of renewable energy in their power system. With California taking the lead by requiring a 100 percent carbon-free generation of their retail sales by 2045 and states like New Mexico, Washington, and Maine following suit with similar targets, the electricity grids all across the US are getting greener by the day.[vi] However, integrating a variable and intermittent source of energy does pose challenges for maintaining the stability of the grid and can increase the reliance of natural gas peaker plants as often renewable energy is in abundance when demand is low, which leads to curtailment of excess electricity. For example, although California has made strides in incorporating renewable energy, according to the PV curtailment data obtained, about 432,000 MWh of solar PV was curtailed in 2018, a number representing approximately 1.5% of the potential PV output. In 2019, this number increased to about 3% of potential output or 922,000 MWh.[vii] Electric vehicles can be a superb solution for this state as storage can help overcome the temporal mismatch that is often associated with renewables.  According to a study conducted by Imperial College London in 2012, storage (including EVs) can more than halve the curtailment of renewable energy. Electric vehicles can store renewable energy during periods of excess capacity and low demand and convert it into a dispatchable source. For solar this would mean storing energy when the sun’s rays are the strongest (midday) and dispatching it in the evening during peak consumption hours, reducing the need of ramping up supply with peaker plants. In 2015, a study by Cambridge Econometrics cited the Imperial College London study and estimated that reduced curtailment alone could provide roughly twice the value in beneficial services to the grid that vehicle to grid (V2G) services would provide. A recent study published in the Energy Policy Journal analyzed how the widespread adoption of plug-in electric vehicles and renewable energy could together decarbonize the transportation and energy sectors. Focusing on California, the study found that with a 50% renewable energy grid and EV adoption scenarios between 0.95 to 5 million “smart” charging EVs helped the state avoid $120 to $690 million in California grid operating costs annually (up to 10% of total costs). Also, renewable energy curtailment was reduced up to 40 % relative to unmanaged EV, achieved by the amalgamation of residential smart charging and time-of-use tariffs with added daytime periods.[viii]
  • Ancillary services  Ancillary services aid in balancing the electricity grid as it facilitates the movement of electricity from generating sources to consumers and help maintain the stability and security of the grid. Balancing the grid has become an increasing priority with the increasing incorporation of renewables. Electric vehicles have the potential to provide a host of grid services that can aid in this green transition with the aid of managed charging and smart charging. First, EVs can provide regulation services, i.e., they can respond quickly to an instantaneous change in electricity demand. As the number of EVs on the road increase, so does their capacity to act as a mobile energy storage system that can discharge electricity to the grid when required or absorb the excess with the help of the vehicle to grid integration technology allowing the bidirectional flow of energy. Second, a rising number of EVs can act as a spinning reserve. A spinning reserve is a generation capacity that is online but unused and that can come online within a short timeframe to compensate for power shortage or frequency drops. As the quantity of EVs increase, they can work together to result in a. virtual power plant with a fast response and the ability to provide services for the needed period. Aggregator business models facilitate the use of EVs as a source of flexibility.  Lastly, EVs can also provide voltage regulation. Similar to frequency, if the electricity grid isn’t balanced, it can potentially cause voltage fluctuations. EVs can help balance the system when distributed power generators, such as photovoltaics increase significantly on the grid leading to a voltage rise due to the reverse flow of power to the distribution system. EVs in the same distribution system can absorb the electricity, thus the reverse flow can be minimized leading to stable voltage.[ix][x]

Thus, electric vehicles underpinned by numerous technological innovations, have the potential to be a boon for the current energy systems rather than a threat. They have the potential to transform the transportation sector, which is the largest emitter of greenhouse gases, into a carbon-neutral sector while also modernizing and transforming the electricity grid to integrate renewable energy and reduce its dependence on fossil fuels. As the world waits for a vaccine to end the pandemic, plans to utilize innovative technology like EVs, to address the global climate crisis can make the best of this lost time.  

[i] Edison Electric Institute. “EEI Celebrates 1 Million Electric Vehicles On U.S. Roads.” Edison Electric Institute, 30 Nov. 2018. Web. <https://www.eei.org/resourcesandmedia/newsroom/Pages/Press%20Releases/EEI%20Celebrates%201%20Million%20Electric%20Vehicles%20on%20U-S-%20Roads.aspx&gt;.

[ii] Boloor, Madhur, Patricia Valderrama, and Ada Statler. “Electric Vehicles 101.” The Natural Resources Defense Council. 31 July 2019. Web. <https://www.nrdc.org/experts/madhur-boloor/electric-vehicles-101&gt;.

[iii] Morris, David. “Today’s Cars Are Parked 95% of the Time.” Fortune, 14 Mar. 2014. Web. <https://fortune.com/2016/03/13/cars-parked-95-percent-of-time/&gt;.

[iv] Innovation Outlook: Smart Charging for Electric Vehicles. Rep. International Renewable Energy Agency, 2019. Web. <https://irena.org/-/media/Files/IRENA/Agency/Publication/2019/May/IRENA_Innovation_Outlook_EV_smart_charging_2019.pdf?la=en&hash=CC1035D2E5A36AE98BA860005233D3EF5A80E6E8&gt;.

[v] “Fact Sheet: Energy Storage (2019).” Environmental and Energy Study Institute, Feb. 2019. Web. <https://www.eesi.org/papers/view/energy-storage-2019&gt;.

[vi] S&P Global Market Intelligence. Rep. 2020. Web. <https://www.spglobal.com/marketintelligence/en/documents/111919_the-2020-us-renewable-energy-outlook_finalv4-revised.pdf&gt;.

[vii] “Managing Oversupply.” CAISO. California ISO, 2019. Web. <http://www.caiso.com/informed/Pages/ManagingOversupply.aspx&gt;.

[viii] Szinai, Julia K., Colin J.R .Sheppard, Nikit Abhyankar, and Anand R. Gopal. “Reduced Grid Operating Costs and Renewable Energy Curtailment with Electric Vehicle Charge Management.” Energy Policy 136 (2020). Sciencedirect. 2020. Web.

[ix] Aziz, Muhammad. “Electric Vehicle Utilization for Ancillary Grid Services.” AIP Conference Proceedings 1931 (2018). Web. <https://aip.scitation.org/doi/pdf/10.1063/1.5024128&gt;.

[x] Edison Electric Institute. “EEI CELEBRATES 1 MILLION ELECTRIC VEHICLES ON U.S. ROADS.” Edison Electric Institute, 30 Nov. 2018. Web. <https://www.eei.org/resourcesandmedia/newsroom/Pages/Press%20Releases/EEI%20Celebrates%201%20Million%20Electric%20Vehicles%20on%20U-S-%20Roads.aspx&gt;.

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