Why behavioural load shifting needs to be a part of your EV charging load management strategy
July 31, 2019
July 31, 2019
The Demand Response landscape is changing, and although shedding or curtailing electricity for high consumption appliances has been well established, the need to manage residential load as well as the way load is managed has changed. While smart thermostats and other smart home devices have increased the energy efficiency of homes and demand programs alike, there is still one device that needs to be managed, Electric Vehicles.
Electric vehicles require more energy than an air conditioner or an electric water heater. A long-range BEV like the Tesla Model 3 can draw up to 11.5 kW, double the amount of power than a standard 1.5 ton AC unit, which is why utilities want direct load control (DLC) access to them. However, unlike residential appliances, owners of electric vehicles are less likely to give up control of their vehicle charging for Demand Response programs since there are more serious implications, being that they might not have enough of a charge to make it to their destination. Another issue is that these programs require the purchase and installation of a networked charging station (EVSE).
Some forward-thinking utility companies, such as Con Edison, have begun to use behavioural programs to shift EV charging load to avoid peak times. However there is still a need to address the immediate needs during a DR event. So if current EV-related DLC programs have a lower impact, and behavioural programs aren’t effective during a DR event what is the next best option? Utilities should combine both programs to create a more complete solution for managing EV load.
Demand Response programs for electric vehicles should be different than air conditioners
Given that EVs can consume up to 100 kWh to fully charge, it is logical that utilities want to use direct load control during a DR event, however there are large barriers that prohibit their effectiveness. The first problem is that the opportunity to control EV charging load is extremely limited. The best current option to directly control EV charging load is with networked Level 2 EVSE home charging stations, and currently these only account for approximately 11% of total charging. This percentage is even lower if a utility doesn’t have agreements with all competing network charging station providers. Even with multiple providers would leave upwards of 80% of all EV charging in-eligible for direct management.
Another issue is that utility companies are not able to see the vehicle’s state-of-charge through a networked EVSE. This means they can’t guarantee the vehicle will have enough charge for it’s next trip, which is the main reason why EV drivers are less likely to participate in DR events. They are relying on their vehicle to get them to get to their next destination and won’t want to risk not having enough of a charge.
Benefits of a behavioural load shifting program
Many utilities can try to mitigate the risk of peak load coinciding with EV charging load by preventatively shifting load with behavioural programs. The most common method is through a time-of-use rate structure that encourages customers to reduce consumption during specific periods. The issue with including EV charging load into a standard residential TOU program is it will create an unintentional coincident load. Drivers will typically start charging immediately after peak-pricing ends, which means it will align with other shifted load like laundry. In order to differentiate and manage this load separately utilities would need customers to install submeters, which are an undesirable added cost. A different, more effective approach to behavioural load shifting is by implementing an EV-specific time of use rate. An off-peak incentive could be created for EV owners to avoid coincident load from appliances and EV charging on local distribution grids.
SmartCharge Rewards is managed through vehicle-side data gathered from an OBD-II device, which means the program can include any EV make or model, and includes charging data from any location. This gamification-based program has high enrollment, as drivers are treated like a part of the solution instead of part of the problem, and they continue to participate thanks to ongoing points accrual, achievement levels and rewards. Drivers are able to share their recent achievements and EV charging status in the form of badges via social media sites, which encourages others to participate and increases the overall market share of drivers in the service territory. Another great benefit of programs like these is that it gives utilities a platform to engage with their customers in a positive and meaningful manner. Overall behavioural programs are a great way to reduce load during peak periods and an EV load management program provides utilities with additional value, such as preventing distribution infrastructure degradation.
Combining direct load control and behavioural load shifting in a single program
The best way for utilities to manage EV charging load is to align Demand Response and Demand Management efforts into a single solution. A behavioral load shifting program like SmartCharge Rewards has the ability to influence 90% of the EVs in a service territory and can shift a majority of the EV load. This not only reduces the overall impact of a DR event but can also promote more desirable charging behaviours which make the load more predictable. During a critical event a DLC program could be initiated and the combined results of both programs offer the most load reduction.
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