Shannon Goulden, P.Eng | MEL Candidate | Dec 17, 2021.
Mentor: Barbar Moawad, AIM Solutions;
Abstract
This project highlights the implications of increased transportation electrification on the electricity infrastructure feeding Vancouver’s downtown core. The Federal and Provincial governments are putting pressure on car manufacturers to develop a larger selection of EV models for consumers. Longer range means larger batteries, which increases the need for more level 2 and 3 charging stations, which correlates to higher power demand. Access to at-home charging stations and adequate public charging infrastructure is required to support the transition to renewable transportation. BC Hydro has forecasted the rate of EV adoption for Metro Vancouver, so this report will focus specifically on a forecast for downtown Vancouver and project the future demand requirements for a system which is reaching capacity. This report will raise awareness of the fact that increased electrification will put stress on the already strained electric infrastructure feeding the downtown core. The substations are at capacity and BC Hydro is challenged with balancing the additional electricity demand imposed by EVs on the distribution system they draw electricity from. Building owners may need to upgrade their electrical capacity to meet the new bylaw requirements for level 2 charging stations. The findings of this report aims to estimate the peak load and annual energy consumption of EVs over the next 10 years. The capacity of the substations feeding the downtown core will be compared to the forecast and a timeline for electrical infrastructure upgrades will be developed to support the expansion of EVs in downtown Vancouver.
Introduction
The client, AIM Power Solutions, is focussed on understanding how increased electric vehicle (EV) charging will affect the existing electrical infrastructure in downtown Vancouver.
The scope of this project is to assess the implications of increased EV adoption on the electric infrastructure in existing buildings and the distribution system feeding electricity to the downtown core. The key stakeholders include the public at large, AIM Power Solutions, BC Hydro and provincial and federal government for policy requirements. To encourage purchases of low emission vehicles, the federal and provincial governments have offered rebate programs for plug-in hybrid and battery-electric vehicles. Additionally, British Columbia has a zero-emission vehicle mandate where all new light-duty car sales and leases must be 100% electric by 2035. With increased ownership of ZEVs, the electric infrastructure system will likely require upgrades to meet increased demand for electricity. Furthermore, building owners will need to upgrade their electric charging infrastructure to comply with the updated building by-laws to include more EV-ready parking stalls. The findings of this project should establish a timeline that key stakeholders can follow for future upgrades to the current downtown electric infrastructure and buildings’ electric charging stations by forecasting the energy consumption of additional electric vehicles.
Objectives
There are 2 main goals of this project:
- Forecast the peak load and annual energy consumption of electric vehicles on Vancouver’s downtown core
- Assess and identify reasonable upgrades to the infrastructure feeding electricity to the downtown core and estimate a timeline to complete the required improvements
Methodology
To forecast the additional electricity demand required to support increased EV adoption, both public and private EVSE were considered. To estimate the peak load required from private EVSE, the number of EV owners in downtown was estimated using population information from the Canadian Census data. The analysis showed that over a 5-year period there is a negative growth rate of Vancouver’s downtown population. Next, the 2020 Vancouver Panel Survey indicated 60% of downtown residents have access to a private vehicle. Assuming there is 1 car per household and on average 1.7 people per household, the downtown vehicle ownership rate was estimated to be 35%. Finally, ICBC data for the City of Vancouver identifies insured EVs as a % of total vehicles. Applying this ratio to the downtown core yields the number of downtown residents who own an EV. If each EV owner has a level 2 at-home charging station which uses 6kW, the total load from private EVSEs can be calculated.
To forecast the peak load required from public EVSE, the number of EV parking stalls, frequency of use, and SOC on arrival needed to be estimated. A breakdown of public EVSE by level and location was obtained from NRCan’s Alternative Fuels Station Locator. The total number of parking spaces was obtained from Vancouver’s open data portal. When performing the forecast, the ratio of the levels of charging stations remained constant. EV projections for downtown Vancouver were estimated using BC Hydro’s model for EV uptake in Metro Vancouver and scaled down for downtown. Finally, to estimate the time spent charging, a 2018 report surveyed EV charging stations and documented the frequency of arriving at each SOC.
Results and Discussion
The city has updated the building code to increase the minimum number of at-home charging stations. Section 10.2.3 of bylaw No. 10908 outlines the requirement for level 2 EV-ready stations in new construction dwellings. Single family homes must have 1 energized outlet capable of level 2 charging, multi-unit residential building 100% of residential parking stalls, commercial buildings 10% of parking stalls. To determine the number of EVSEs that can be installed, the building’s available electrical capacity needs to be calculated by performing a load assessment. Using the rated capacity of the transformer, the overall electricity capacity can be estimated. For many older buildings there is insufficient electrical capacity to support EV charging infrastructure. For a generic MURB in Vancouver, adding only 4 level 2 charging stations will overload a 250A circuit breaker and will cost $10,000-15,000 for electrical upgrades.
Downtown’s electricity infrastructure doesn’t behave like other areas because of the flux of vehicles that enter from outside the city. There are 3 substations currently distributing electricity to downtown Vancouver: Murrin, Dal Grauer, and Cathedral Square. The MUR substation has a maximum capacity of 200 MVA with the potential to upgrade to 400 MVA if 2 of the 3 transformers are replaced with larger ones. DGR substation is currently at its maximum capacity of 190 MVA but if the transmission line voltages were increased, there is the possibility to increase this to 400 MVA. However, to do this DGR would need to be shut down during the construction work and it’s not currently possible to transfer the load to another substation because of the overall lack of spare capacity downtown. Additionally, the cabling infrastructure is reaching the end of its useful life and will require serious upgrades to keep the two substations in operation. For this reason, a new substation in the West End is expected to be built by 2028 to replace DGR. The CSQ substation had a maximum capacity of 335 MVA but a third transformer was installed at this substation to increase capacity and reliability of the system. Using a 90% power factor, in total, MUR, DGR and CSQ currently supply the downtown load with a total capacity of 652 MW.
Conclusion
Existing substations are at capacity, and by 2022 infrastructure expansion is required to keep up with the projected rate of EV ownership. The installation of more EVSE’s will put stress on the already strained electric grid. Vancouver’s building electrical infrastructure and electric grids were not initially designed to support this kind of magnitude and acceleration of electrical load increases. Most existing buildings don’t have sufficient capacity to accommodate the load of uncontrolled EV charging without costly renovations. Temporary control strategies can be put in place to manage the loads, but long-term solutions involve upgrading the distribution and transmission lines.
References
2020 Vancouver Panel Survey
Electrifying Vehicles: Insights from the Canadian Plug-in Electric Vehicle Study
Electric Charging and Alternative Fueling Stations Locator
Fleet Carma Charge the North
Geotab Energy EV Driver Insights
City of Vancouver Open Data Portal
Appendix E: Metro Vancouver Strategic Supply Plan
Energy for Sustainability: Foundations for technology, planning and policy
Contact
shannon.k.g@hotmail.ca