‘Solar-powered EV charging reduces carbon footprint, enables true green mobility’ – EQ Mag Pro
Pilot project on the Bescom corporate office premises reveals that SRTPV systems offer a number of advantages in EV charging.
With the transport sector widely acknowledged as a significant contributor to air pollution in cities, electric vehicles (EVs) are being deemed as a key player in helping decarbonise the sector. But what powers EVs is a question that is haunting the sector, preventing it from being termed truly green.
The Centre for Study of Science, Technology and Policy (CSTEP), recently conducted a pilot project on the Bangalore Electricity Supply Company (Bescom) corporate office premises to demonstrate the use of clean energy to power EVs. The report, Solar Energy–Based EV Charging: A Pilot and Techno-Economic Study, indicates that solar rooftop photovoltaic (SRTPV) energy could be an economically viable option for EV charging in addition to being a green source of energy.
“SRTPV systems offer a number of advantages in EV charging. They are easy to install because of their modular design, they are a cost-effective alternative to charging from the grid, and they could help reduce the detrimental effects of a surge in EV charging demand on the grid,” the centre said. The mismatch between solar energy generation and consumption could be solved by deploying net metering at charging stations, it suggests.
The study examined the commercial aspects of using grid-connected SRTPV with and without a battery energy storage system (BESS) to power an electric vehicle charging station (EVCS). A parameter used in the study to estimate the economic benefits of using solar energy and BESS for EV charging was the levelised cost of charging (LCOC) – which considers all the costs incurred over the lifetime of assets.
CSTEP’s analysis included the effect of charger utilisation, initial subsidies, and the contribution of grid electricity on the LCOC. “The levelised cost of energy generated by the solar plus storage power plant is strongly influenced by the utilisation of the battery storage. Higher utilisation of battery storage increased the cost of energy from the power plant,” CSTEP explained.
The levelised cost of EV charging service from an EVCS was evaluated and compared with three cases: a baseline case where the EVCS is solely reliant on grid electricity and two other cases where it is connected to RTPV and RTPV plus energy storage systems.
“The EVCS connected to the RTPV (without battery) under the net-metering policy served as the best-case scenario with the lowest LCOC. This is predominantly because the cost of energy from SRTPV is becoming increasingly competitive (in certain cases cheaper) with grid electricity. A battery storage capacity equal to 40 kWh was considered for the analysis, which stored approximately 16% of the total daily solar energy (on average) generated.
From the analysis for these system specifications, the costs of upstream electricity for the cases of the grid only, PV only, and PV plus BESS were calculated to be ₹5 (within Bescom limits), ₹4.6, and ₹8.9 per unit, respectively. The net-metering policy plays an important role in lowering costs, which otherwise would increase owing to the mismatch between energy generation and consumption,” the centre said.
Key authors of the study, Vinay S. Kandagal and Milind Ravindranath, told The Hindu that the study was borne out of the idea of systematically assessing the benefits of using solar energy and stationary battery energy storage for EV charging, with the cost of SRTPV energy increasingly competing with rates of grid electricity, and battery costs reducing. BESCOM was also especially interested in the role of battery storage in smoothening out demand peaks due to EV charging, they said.
But with solar rooftop scheme and EVs yet to become popular, how will the scenario improve? “EVs are picking up at a fast pace, especially two-wheelers. Adoption of EVs in the light and heavy commercial vehicle segment and personal car segment might take a little longer. Wider deployment of charging infrastructure, especially fast-charging and ultra-fast-charging points, can really unlock the value of EVs and accelerate adoption,” they said.
But they acknowledged that both these technologies have upfront cost barriers that hinder their adoption. “However, certain schemes can help to distribute the associated ownership, and hence, the investments, of the technologies and effectively pair them to achieve the desired goal. Virtual metering, group net metering, peer-to-peer energy trading, and open access procurement of renewable energy are few examples of such mechanisms that can effectively link the two technologies across the electrical grid,” they explained.
With concerns also being raised about how green the technology really is in terms of solar farms as well as EVs, the authors said many of these challenges are being addressed at the research, technology, and policy levels – and product innovation is constantly tackling these issues. “Solar-powered EV charging reduces its carbon footprint and enables true green mobility. It can also help reduce the detrimental effect of EV charging demand spike on the grid. This can in turn help defer the costs associated with upgrading the existing electrical infrastructure,” they concluded.
Source: thehindu
