Scientists from Kyung Hee University (South Korea) and National Institute of Technology in Nopal (Senegal) evaluated the level of preparedness of global electricity grids to the massive switch to e-vehicles. They developed an integrated model based on the S-curve of new technology implementation and analyzed the data from 20 countries having the biggest e-vehicles fleets.
Today, the electricity-driven transport already is displacing about 1.5 mln bbl of oil per day. This is an important step towards reducing the emissions, but simultaneously it is a serious challenge for electricity grids. By 2030, the number of e-vehicles in the world will grow up to 300 mln, and their simultaneous charging, especially in the evening hours, when the electricity consumption reaches its peak, is a risk of extra duty for power transformers, of voltage loss and local outages. The main problem here is not simply the amount of electricity, but peak capacity required for simultaneous charging of the growing number of e-vehicles.
To solve this problem the researchers propose not only to boost the generation, but to correctly manage the demand. In the process of simulation they demonstrated that up-grading the grids should be accompanied by implementing smart systems for managing the charging process. The key instrument is application of dynamic tariffs providing incentives for charging during the low load hours, using day-time charging while at work when there is redundant solar energy, and Vehicle-to-Grid (V2G) technology allowing for e-vehicles to return part of the energy back to the grid. All this will turn the e-vehicles from potential stability threat to the resource for balancing the grids.
The results of country-based analysis demonstrated that only Norway, Iceland and Sweden have sufficient capacities today to simultaneously charge all their car fleets as if they consisted of only e-vehicles. Other countries including the USA and China will face a serious capacity shortage, given similar inputs. In the USA, for example, under 100% electrification of vehicles the need may reach 6 TW, while as the current installed capacity makes only about 1.2 TW and may double only by 2050.
For heavily populated cities, where the majority of citizens do not have the possibility to charge their e-vehicles at home, the researchers propose the development of public charging stations as one of the solutions. It is easier to integrate them into the load control systems. Another high-potential vector is the development of autonomous stations driven by solar energy, but for them to soundly replace the traditional gasoline filling stations, the breakthrough in battery technology is required: their power density should be at least twice as big as that of the current lithium-ion batteries.
