Managing PEV Loads

Moderator: Russ Harrison

Speaker 1: Saifur Rahman, Professor at Virginia Tech.

Saifur's talk was entitles "Managing Electric Vehicles in the Electric Power Distribution Network". His talk covered three main topics:

- Where and when will EV be charged?
- Impact of distribution network.
- Is there a way to manage household loads?

He explained that a typical battery charger is DC and the EV charging stations are AC and he compared the different type of charging stations that are available for a few EV models.

He follow with details of a simulation performed on feeder in Blacksburg, Virginia where a case study 100 vehicles that was randomly charged at night resulted in minimal impact on the typical load profile. This simulation also studied the effects of a controlled 240v household devices based on priorities to see impact to load profile.These devices included: A/C, Water Heating, Clothes Dryer and EV. The resulting load profiles showed that load control reduced the peaks during times where there would be an addition of EV loads. The conclusions from this study were:

- Uncontrolled charging will increase peak demand in distribution network.
- Demand response can be used to mitigate the impact
- Must consider customer comfort level.

Saifur has spoken with charging station manufacturers and was told these stations can sense other utilities and therefore delay charging if there are other priorities.

It was great to hear about what a alternatives utility can have other than upgrading infrastructure.

Speaker 2: Mark Kapner, Senior Strategy Planner at Austin Energy.

Mark's talk was entitled "A look to the future: electric vehicles as an energy storage device for ancillary services."

Austin Energy started the Plug-in Partners in 2006 which includes the following projects:

- PHEV school bus
- PHEV trouble truck
- Airport electrification project (ground vehicles)
- Pecan Street Project

Another aspect of of the project looked into the use of wind energy. The wind energy production profile is the opposite shape of the load profile so it would work well with the PEV charging time of day. This extra energy production for EVs can replace carbon output generation that would have been used and reduce NOx emissions by 95% and CO2 by 54%.

The question that we they are trying to answer is: Can PEV batteries be used for ancillary services? The following options are available ancillary services that Mark discussed:

V2G (Vehicle to Grid)
LaaR (Load acting as a Resource)
EILS (Emergency Interruption of Load Services)

He concluded the grid infrastructure has issues that keep this from happening in the near future.

It was nice to hear about what Austin Energy is doing for EV and pioneer charging infrastructure.

Speaker 3: Paul Wattles, Supervisor of Demand Response at Electric Reliability Council of Texas (ERCOT)

Paul's talk was entitled "PEV Impacts to the Bulk Electric Grid". He work for ERCOT who is an Independent System Operator (ISO) of 75% land and 85% load of Texas.

He discussed a ISO-RTO Council study of PEV impacts on bulk power grids. This study projected a penetration rate of about 43k EVs by 2020 for ERCOT and a 237MW demand if all cars were charging at the same time. This study recommends 'smart charging' and V2G was out of scope and therefore not studied.

Based on data, ERCOT has plenty of capacity for EV loading.

Paul concluded that PEVs are often cited as candidates to provide wholesale ancillary services to the ISOs but there are lots of hurdles.

It good to see what alternative uses PEVs can be in the long run.

Overall, this session provided a lot of insight into how to manage PEV loads and what is and is not possible.