In the push to reduce CO2 emissions in the United States, consumers are purchasing electric vehicles (EVs) at an unprecedented rate, with the newest data showing that 2014 U.S. sales of 100 percent electric cars were up 58 percent. While this is good news for the EV industry, increased EV ownership presents challenges to utility providers since the typical EV driver recharges during the evening at peak demand. Growing along with this dramatic paradigm shift in transportation are concerns about the impact to our nations aging power grid.
With EV home charging stations generally drawing an electricity load of 6.6kW (240V at 30 amps) approximately the same load of an entire house at 7kW a single EV can double a homes peak load. In fact, even low levels of EV adoption in a particular neighborhood could strain existing power infrastructure at times of peak demand.
This is not a power generation issue, but rather one of power delivery. Approximately 160 million vehicles in the U.S. more than half the cars and light trucks on the road today could be powered solely from existing off-peak generating capacity. This means that many utilities could initially support EV charging by simply managing existing generation. Smart grid technology in electricity distribution and load management makes this possible, while significantly reducing generation and network investment needs. Smart grid technology provides a two-way flow of information, connecting customers and utilities with real-time data, and enabling EV owners to automatically recharge their batteries in the most efficient way possible.
Smart grid charging extends the existing distribution network and ensures capacity. When an EV driver plugs into the charger, the smart system automatically calculates the amount of electricity required to top-off the EV batteries, and adjusts charging activities to begin later when demand for electricity is low.
Reliance on smart technology allows utilities to proactively transform a potentially overburdened grid into one that can handle the load:
Manage when and how EV charging occurs while adhering to customer preferences
Collect EV-specific meter data
Apply specific rates for EV charging
Engage consumers with information on EV charging
In the long run, smart grid technology will enable EVs which are typically parked 95 percent of the time to be used as distributed storage devices, feeding electricity back into homes when demand is high, and recharging when the grid congestion is low.
Solar energy will also play a role in easing grid congestion. A sun-powered filling station that recharges 20 cars per hour would require a 10 MW, 40-acre solar farm. This would work fine for suburban and rural locations, and combined with commercial-scale energy storage, solar-powered EV recharging stations could operate well into the evening hours.
Continued investment in research and development will improve the efficiency and lower the cost of various technologies, including those related to EV charging infrastructure. Fortunately, a large number of organizations, including utilities, car manufacturers, academic institutions, public research agencies and private research institutes are advancing smart grids.
There is some risk that power companies failing to keep pace with technological advances in transportation risk an over-loaded grid and the potential for reliability issues. By planning now, utilities will optimize their existing infrastructure, increase their revenue and improve customer satisfaction by enabling the rapidly growing EV market.
Source: Energy Efficiency Markets
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