Duck
Curves & Coming Waves
Electric charging industry veteran Clay Collier spoke in a panel at VERGE 2019 about electric vehicles and connecting them to the grid. Afterwards, I caught him for some insights on what’s going on and where we’re headed.
Collier, after picking up a BA in physics from U.C. Berkeley, co-founded Akuacom. As CEO he worked with the Lawrence Berkeley National Laboratory and electrical utilities to connect cars to buildings and the grid using Automated Demand Response (ADR).
He sold that company and started Kisensum, a company that developed a suite of software for bidirectional V2G (vehicle-to-grid) applications. Again working with Lawrence Berkeley Lab and also the Department of Defense and California Energy Commission, Kisensum found a way to use “load shaping” to optimize vehicle charging assignments and also to limit and equalize the vehicles’ state of charge.
Kisensum participated in the four-second utility market. To meet
the market requirements a resource must adjust the amount of energy
supplementing the grid on a four-second basis, up and down, based on a signal
from the utility.
“That just doesn’t pencil out,” Collier found. The costs of the
vehicles, equipment, schedule coordination, and the rest make it too expensive.
“Someday, with scale, it may become profitable,” he said.
For a project at the Alameda County Parking Facility, Kisensum enabled vehicle smart charging using an optimizer engine to flatten out power peaks, which achieves demand charge savings on the utility bill. They monitored the cycle changes and moderated the level–-what’s known as “smart charging.”
When ChargePoint bought Kisensum, Collier became their VP of Energy Solutions.
Expanding Smart Charging
Smart charging uses sophisticated software to coordinate charging. It works especially well with fleets of buses and trucks.
“It turns out that 80 percent of delivery truck routes are less
than 100 miles—perfect for electrification,” said Collier.
Yard trucks that never leave the site are even easier, since they can be charged while the other trucks are out working.
Smart charging provides two main benefits to balance loads on the electrical grid—adding capacity and grid balancing.
- Capacity–-The goal is to get as much power on the grid as possible at the times it’s needed most
- Grid Balancing–-Software monitors the grid to charge vehicles during lower usage periods and stop charging during peak usage periods.
Microgrids have an application for smart charging, too. For example, in a vehicle charging system you can balance the grid load by using battery power during peak usage periods, such as 6-9 p.m., and allow charging directly from the grid when electricity is abundant.
Flattening the Duck Curve
In utility-scale electricity
generation, the peaks and valleys of electricity usage are commonly depicted on
the Duck Curve.
The Duck Curve is a graph of power production over the course of a day that shows the timing imbalance between peak demand and renewable energy production. The belly of the duck is over-generation and the neck is the peak load. The term was coined in 2012 by the California Independent System Operator (Wikipedia).
The problem is that there is a mismatch as the highest demand
for electricity is in the early evening, but solar generation is highest in the
afternoon. Electricity storage is one solution to that discrepancy, and a major
goal of setting up a two-way EV-to-grid connection is to use electricity stored
in EV batteries to help “flatten the curve” as needed.
What’s Coming
Collier sees mass electrification coming in two waves. The first is in commercial fleets. Electrification of fleets can save a lot on operation expenses. This will be especially relevant as cities start charging fees similar to existing “congestion charges” specifically to internal combustion engine vehicles (potentially $50/day). Regulations are driving this change, and with charges like this, EVs become cheaper to operate than ICE vehicles.
The next electrification wave will be when passenger EVs take
off. This will happen as people understand that with larger batteries and a
built-out charging infrastructure, range anxiety isn’t really an issue.
Autonomous fleets will help move people away from individual vehicles, too. The
more these vehicles can be linked to the grid, the more they’ll help to balance
electrical generation and flatten the Duck Curve.
Source: Electric, Hybrid, Clean Diesel & High-MPG Vehicles
