Hacker News new | ask | show | jobs
by oliwarner 460 days ago
Haven't they seen Die Hard 2?! /s

Grid power is hard. Even with local generation failovers for air and ground safety systems, Heathrow is massive and uses a lot of power (1-2MWh/day). It's hard to route around that sort of demand.

I don't disagree that this is something that shouldn't happen, but that's what we say for almost every preventable grid failure. I think this is a national inconvenience rather than a security issue though. There are short-term alternatives which will be used.
2 comments
speakeron 460 days ago
> Heathrow is massive and uses a lot of power (1-2MWh/day)

It's 3 orders of magnitude more: 1-2GWh/day.

https://www.heathrow.com/content/dam/heathrow/web/common/doc...

link
oliwarner 460 days ago
Yeah I munched the maths but yours is 10 years old!

The 2022 version of that sustainability report puts their annual bought in electricity at 272,610 MWh, 747 MWh per day.

My wonky maths aside, it's amazing how much energy they've saved. In your link, the switch to LEDs alone saw a 20% total power reduction. I'm sure I've seen electric vehicles there so I'm surprised this number is still apparently in freefall. Perhaps they're doing more local generation (eg) PV

link
Eavolution 460 days ago
While we're doing wacky units for energy instead of the joule, I'd personally prefer roughly 360 DeLorean's per day (assuming the 1.21 gigawatts are required for roughly 10 seconds)
link
LargoLasskhyfv 460 days ago
> Heathrow is massive and uses a lot of power (1-2MWh/day).

That number doesn't seem that high, compared to a single high-speed train running at about 300kph or above. Or lets say all of the London Tube/DLR.

Seems like nothing, actually.

link
oliwarner 460 days ago
Yup I think I missed a comma when originally reading the sustainability report. They buy-in an average of 747 MWh a day (2022).

The point I was stumbling to try and make was that Heathrow is dense. Just under a GWh a day delivered to a 1200ha site isn't going to get a natural diversity of supply, especially compared to a rail system does.

link
p1mrx 460 days ago
Yeah, that can't be right. You can tow a 100 kW generator (2.4 MWh/day) with a pickup truck.
link
zimpenfish 460 days ago
[0] suggests (without a useful link and my searching has not found one) that Heathrow is doing 460GWh annually. Presumably[1] that equates to 1.25GWh daily (which could be where the 1-2MWh/day came from - a simple unit error)?

[0] https://www.bloomberg.com/opinion/articles/2025-03-21/heathr...

[1] I know precisely nothing about power consumption of large systems but dividing the annual figure by 365 seems plausible.

link