The United Kingdom Generates Less Electricity per Person Than in the 1970s

Re:The United Kingdom Generates Less Electricity per Person ... by Grombobulous on Tuesday October 13, 2026 @03:39PM (#50077451)

You’re leaving out the part where the sodium lights wasted a lot of their lumens by tossing them into the sky. LEDs can be dimmer because they can be directionally controlled.

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Re:The United Kingdom Generates Less Electricity per Person ... by OkayPhysicist on Tuesday October 13, 2026 @04:32PM (#50078287)

That's trivially solved with a reflective housing, which nearly all sodium lamps I've ever seen had.

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Re:The United Kingdom Generates Less Electricity per Person ... by linolevan on Tuesday October 13, 2026 @07:14PM (#50080287)

While it is definitely true that original power drops were due to lower lumens, few things:

- reflective housing is super inefficient (~70% losses on the bounced light off typical material, at the top end expensive stuff still ~23%), still better than just losing the light upwards but not as many lumens on the road as a lab test would show

- Today LEDs are more efficient than sodium

Some math: 100W HPS cobra head lamp prdouces 9.5k lumens, including ballast it draws ~133W from the wall. Lab test shows about 70% of the lamp's light leaves the fixture (with the rest being lost in the housing) leading to ~7k lumens exiting. Roughly 53 lm/W.

LED cobra head lamps get like ~125 lm/W on the low end + fade much more slowly than sodium

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Re:The United Kingdom Generates Less Electricity per Person ... by OkayPhysicist on Tuesday October 13, 2026 @07:27PM (#50080397)

Don't low-pressure sodium lamps get like >2x efficiency gains over HPS?

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Re:The United Kingdom Generates Less Electricity per Person ... by londons_explore on Wednesday October 14, 2026 @03:27AM (#50083738)

They do.

People don't like them mostly because they're orange.

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Re:The United Kingdom Generates Less Electricity per Person ... by mnw21cam on Wednesday October 14, 2026 @04:32AM (#50084284)

Astronomers definitely do like them because they're orange, and they can filter it out of their photos.

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