The goal of the pilot is to provide PG&E with up to 100 kW of capacity at any given time, regardless of how many BMW electric vehicles are charging, as part of a voluntary load-reduction program known as “Demand Response.”

The benefit to PG&E of more efficient use of existing power grid resources through EV charging management is passed on in the form of monetary incentives to program participants. Improved grid utilization, resulting from EV charging management combined with a solar-powered “second life” battery system, is expected to reduce stresses on the grid and reduce the need for additional peaker plants, thus reducing consumer costs while supporting the integration of renewable energy.

Managed charge. In the managed charge pilot program, BMW i3 owners will allow BMW to delay the charging of their vehicles by up to an hour, based on requests received from PG&E when grid loads are at their peak. Throughout the 18-month pilot, BMW will manage the charging of participating BMW i3 vehicles, while prioritizing the e-mobility needs of participants based on timing by which vehicles should be fully charged, as communicated through a smartphone app.

For each program “event”—when PG&E experiences peak load conditions—participants whose vehicles are selected for delayed charging will receive a text message notifying them that their vehicle charging will be halted for up to one hour, thereby temporarily reducing the load on the power grid.

Using the BMW i ChargeForward smartphone app, participants can choose to opt out of any request based on their driving needs, however, and their vehicle charging will continue uninterrupted—for example, if they need to depart for a trip during peak load times and need a full charge sooner.

As an incentive for participating, selected drivers will receive $1,000 initially, and an additional reward of up to $540 at the conclusion of the program, based on their level of participation in charging Demand Response “events,” as well as participation in occasional BMW or PG&E sponsored surveys or questionnaires.

One thing that we’ll be investigating with this pilot is understanding how people charge, how flexible they are with respect to when they charge, and how best to design future products in way that benefits both customers and utilities.

—Julia Sohnen, Advanced Technology Engineer - Sustainable Mobility at the BMW Group Technology Office USA

Second-life. The program also includes a “second life” for used MINI E batteries, repurposing these batteries into a stationary solar-powered electric storage system located at the BMW Technology Office in Mountain View, California.

The battery second life portion of the project involves a full-scale stationary energy system built from eight used MINI E batteries to store energy and return it to the power grid. This 240 kWh system, located at the BMW Technology Office in Mountain View, California, is currently one of the largest second life systems in the world.

At the end of a vehicle’s life, these batteries still have at least 70% of their original storage capacity available, making them suitable for re-use. By removing them from the vehicle and installing them in a stationary storage system with integrated solar power generation, new renewable capacity can be added to the grid.

This additional power will supplement the energy load reduction by intelligent management of BMW i3 charging, to ensure PG&E grid needs are met, based on signals sent to BMW by PG&E as part of Demand Response.