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Transcript

When Your Car Park Becomes an Electrical Load · NOXTalks

• 0:07
  SPEAKER_00: Welcome to Knox Talks, the AI-generated podcast exploring the groundbreaking ways technology shapes our built environment.
• 0:14
  SPEAKER_00: Today we're diving into something that's quietly reshaping the electrical picture of a building.
• 0:19
  SPEAKER_00: Your parking garage, or more precisely, the EV chargers that keep showing up in it.
• 0:25
  SPEAKER_00: Here's the thing.
• 0:26
  SPEAKER_00: For most buildings, that electrical service was sized years ago, long before anyone pictured a row of chargers pulling serious power off the main switchboard.
• 0:35
  SPEAKER_00: So charging tends to get bolted on after the fact, living in its own software world, walled off from the building automation system.
• 0:44
  SPEAKER_00: The United States Department of Energy frames managed EV charging as balancing the vehicle's energy needs against the building and the grid, and it names avoiding demand charges and firm power ceilings as design goals.
• 0:57
  SPEAKER_00: So, this isn't just an amenity, it's a load to be managed.
• 1:02
  SPEAKER_00: Why does it slip under the radar then?
• 1:04
  SPEAKER_00: Well, EV charging usually gets sold as a sustainability win or a nice tenant perk.
• 1:10
  SPEAKER_00: But underneath it's also an electrical capacity question, a real load management challenge that touches the BMS, the mechanical systems, even fire protection.
• 1:20
  SPEAKER_00: And that part, it rarely makes the brochure, does it?
• 1:23
  SPEAKER_00: Let's start with the money.
• 1:25
  SPEAKER_00: For high power installs, demand charges can run into the thousands of dollars a month.
• 1:30
  SPEAKER_00: And here's what people miss: a demand charge isn't a penalty, and it isn't billed on your total energy use.
• 1:37
  SPEAKER_00: It's a capacity charge tied to your highest demand interval, often the highest 15-minute average across the billing period.
• 1:45
  SPEAKER_00: The Smart Electric Power Alliance gives a clean example.
• 1:49
  SPEAKER_00: A 350 kilowatt peak at$20 per kilowatt, tax on roughly$7,000 in one month, a bank of chargers all ramping up together?
• 1:59
  SPEAKER_00: That's exactly the peak that gets expensive.
• 2:02
  SPEAKER_00: Good news though, there's a smarter way to run this.
• 2:05
  SPEAKER_00: It's called dynamic load management, often handled by an automatic load management system, ALMS for short.
• 2:13
  SPEAKER_00: Instead of every charger pulling full power the instant a car plugs in, the system shares available capacity across sessions, so total demand stays inside the site's limits.
• 2:24
  SPEAKER_00: Cars charge a touch slower when the building's busy, faster when things quiet down.
• 2:29
  SPEAKER_00: EV Connect describes it just that way and points to avoided service upgrades and lower overload risk as the headline benefits.
• 2:37
  SPEAKER_00: The codes are catching up too.
• 2:39
  SPEAKER_00: California's 2025 Cal Green provisions recognize these load management systems as a way to reduce the EV charging a building must install.
• 2:49
  SPEAKER_00: Though, worth noting, some provisions still set a minimum simultaneous capacity per connected charger.
• 2:56
  SPEAKER_00: That's per the Cal Green Energy Services summary.
• 2:59
  SPEAKER_00: It's a California rule, not a New Zealand or Australian standard, but it signals where things head.
• 3:05
  SPEAKER_00: For any of this to work, the load manager has to actually see the building's demand in real time.
• 3:10
  SPEAKER_00: So make sure it's got a reliable demand signal, whether that's from current transformers, CTs, on the main incomer, a main meter, or a properly integrated energy meter.
• 3:22
  SPEAKER_00: Now a nuance on charger software, because this one bites people later.
• 3:26
  SPEAKER_00: A lot of chargers talk through an open protocol called OCPP.
• 3:30
  SPEAKER_00: But here's the catch.
• 3:31
  SPEAKER_00: The Open Charge Alliance describes OCPP as the protocol between charging stations and charging management systems.
• 3:39
  SPEAKER_00: It's not automatically a BMS interface, so it cuts vendor lock-in, yes, but you still have to specify the BMS or EMS export separately.
• 3:49
  SPEAKER_00: API, BACNET, Modbus, MQTT, whatever the site needs.
• 3:55
  SPEAKER_00: Otherwise, that charging load just stays a blind spot.
• 3:58
  SPEAKER_00: And then there's the wrinkle almost nobody raises.
• 4:02
  SPEAKER_00: Ventilation and fire.
• 4:04
  SPEAKER_00: Enclosed car park ventilation was traditionally built around carbon monoxide from engine exhaust.
• 4:09
  SPEAKER_00: CO monitoring, mechanical ventilation, that whole world.
• 4:13
  SPEAKER_00: EV fires are still relatively uncommon.
• 4:17
  SPEAKER_00: But in an enclosed garage, the consequence profile is just different.
• 4:21
  SPEAKER_00: Thermal runaway can release hydrogen fluoride and other toxic vapors, and there's reignition risk, charger shutdown, smoke control, and access to think about.
• 4:31
  SPEAKER_00: Belsham Fire in New Zealand frames it as low likelihood, high consequence.
• 4:36
  SPEAKER_00: And Fire and Rescue New South Wales lists detection, automatic shutdown, emergency ventilation, sprinklers, and access to plan for.
• 4:45
  SPEAKER_00: The takeaway?
• 4:47
  SPEAKER_00: Loop in your mechanical and fire protection people before the install, not after.
• 4:52
  SPEAKER_00: So pulling it together.
• 4:53
  SPEAKER_00: Three things to carry out of this.
• 4:56
  SPEAKER_00: First, give your load manager a real-time demand signal, often via CTS on the main incomer.
• 5:02
  SPEAKER_00: Second, specify the BMS or EMS export separately because OCPP won't hand it to you on its own.
• 5:11
  SPEAKER_00: And third, bring the mechanical and fireside in early because an enclosed garage changes the fire picture.
• 5:18
  SPEAKER_00: Treat charging as a managed building load, not a bolt-on amenity, and it stops being the thing that might trip your building and becomes just one more system you actually control.
• 5:33
  SPEAKER_01: Futuristic flights flow.
• 5:41
  SPEAKER_01: Innovations of the shells of life.