PV Drive

E-mobility opportunities for solar

The world is rapidly moving towards electric-powered, shared and connected vehicles. With low emissions, greater efficiency and reduced technological costs, electric vehicles (EVs) are increasingly becoming popular among consumers. If businesses and fleet operators use renewable energy to power vehicles, emission reduction will be even more effective, making EVs cleaner and greener. Thus, to ensure clean mobility, the incremental power demand associated with EVs should be met by renewable energy.

India is a very unique market in terms of vehicle composition, kilometres travelled and land availability. Although lessons can be learnt from EV adoption in other countries, the issues and challenges as well as the opportunities will be very specific to India. Owing to the high cost and infrastructure requirements, the bulk uptake of EVs is expected to be in big cities.

 Impact on the renewables sector

If the growing EV segment were to be powered by renewable energy, this would impact the power sector to some extent. The power demand from EVs, particularly during peak hours, will put a load on the local grid. A key consideration while meeting this demand is the location of demand generation and whether the transmission and distribution (T&D) systems are ready to handle this load.

In a business-as-usual scenario, the total power demand in India from EVs is expected to reach 45 GWh by 2030. In an advanced scenario, where 30 per cent of all vehicles sold in India are EVs, the total power demand could reach 69 GWh by 2030, accounting for 2.3-3 per cent of the total power demand in the country. Thus, this demand is not expected to change the power sector dynamics on a pan-India level.

In terms of daily demand patterns, the charging demand is expected to rise in the evening or late night hours. Further, most of this demand is expected to come from private charging points. Slow charging vehicles will continue to dominate, requiring more time in a day for charging. Owing to these factors, night-time and daytime loads will vary. During the night, there may be a power demand gap between the load and the renewable energy output. The gap is expected to increase with greater EV adoption. Therefore, the consumption profile of EVs is not compatible with the renewable power output profile. To integrate EVs with PV, proper monitoring and control of charging infrastructure is required as any unplanned increase in EV penetration can lead to spikes in peak load, burdening the already stressed distribution network.

Case for solar in EVs

With the government targeting over 100 GW of solar power capacity by 2022, EVs can improve the reliability and utilisation of renewables by acting as a storage system, while generating distributed and reliable demand. The EV charging equipment can also feed the grid at peak timines if price incentives like dynamic tariffs are provided as part of smart grid implementation (vehicle to grid).

EVs are connected directly to the grid. This leads to high demand charges caused by spikes in power usage, creating a barrier in the development of EV charging stations. Solar-powered EV charging stations can reduce the power demand during peak times although they are vulnerable to weather changes. Battery-integrated EVs can significantly smooth out the charging spikes by transitioning from on-peak time charging to off-peak time charging. Combining the EV charging equipment with an energy storage system and solar PV will eliminate the high demand charges, and maximise the use of renewables locally.

A study conducted by the National Renewable Energy Laboratory drew some conclusions about the use of solar power in EV charging. As per the study, daytime charging leads to more petroleum displacement, reduced range anxiety for drivers and increased adoption. Further, the use of controlled charging to synchronise the time of EV charging with that of solar generation increases the benefits for both technologies. While uncontrolled EV charging presents a threat to the grid, controlled charging can help EV users plan their charging and ensure grid optimisation.

Issues and challenges

A host of technical, policy and market initiatives will be needed to improve grid flexibility. These are required to match the power demand with the renewable power supply. Another issue is that commercial tariffs are still applicable, even in the states where EV tariffs have been proposed, while some states have fixed demand charges for EV tariffs. Thus, the EV tariff structure should be reviewed in order to ensure commercial viability. Further, thermal power plants need to become more flexible, which will require further investments.

There is a need to focus on grid ancillary services. There are many services that power generators and other ancillary service providers can give to the grid. Ancillary services keep the grid stable by providing ramping-up and ramping down services, reserve services and frequency reserves. A series of regulatory reforms is required to ensure the effective implementation of ancillary services to meet system fluctuations throughout the day without destabilising the grid. There is also a need to curb uncontrolled charging, which puts pressure on the grid. Instead, a smart charging system should be established. In order to deliver power effectively, a demand-response mechanism should be put in place for signalling to consumers. This can be achieved through time-of-day tariffs. Besides, there is a need for upgrades in the T&D systems and significant grid-scale storage deployments to accommodate the shifting power demand and renewable power output throughout the day.

The way forward

There is a strong case for the use of renewable energy, especially solar, to meet the growing power demand from EVs. That said, there are still many challenges that need to be addressed. The issue of intermittency associated with solar can be addressed with storage integration. However, this will be viable only if battery prices reduce significantly.

The demand for power required for charging EVs is projected to increase. Controlled charging with solar is one of the solutions that can help in meeting the power demand for EV charging. Renewable power generation supported by ancillary services can be used to meet this demand. Integrating charging infrastructure with the power grid can surely fast-track the transition to clean mobility. n

Based on presentations by Vinay Rustagi, Managing Director, Bridge to India; and Ankit Maheshwari, Chief Manager, Business Development, Fortum India


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