Steel takes about 4.750 kw-hours to produce per kg.[1]

A 450W solar panel will make roughly 562 kwh a year in California.[2]

So one panel running for one year offsets 140kg of steel production, roughly.

Thats an I-beam based structure so it's weight efficient and a heck of a lot more then 1 solar panel are going to fit on it.

Judging from a local steel supplier[3] and some span tables it looks like you'd need about a 360mm or so I-beam to bridge a 115 ft (30m) channel (the structure looks more efficient then that though) so call it 50kg per meter. So one span is probably ballpark 1500kg of steel.

A 450W solar panel is about 0.7m wide, the structure is fully covered so call it 42 panels per span offsetting the energy production of a little over 5900kg of steel per year (and it doesn't look like we're putting one solid I-beam per row of solar panels either since I see lightweight spanning channel in there).

[1] https://solar.lowtechmagazine.com/2009/06/how-much-energy-do...

[2] https://www.cahomesolar.com/feeds/blog/solar-panel-energy-pr...

[3] https://www.mascotsteel.com.au/wp-content/uploads/2018/10/st...

▲

pixl97 a day ago | parent [-]

Furthermore at the end of the steel structures lifespan it will be recycled in a manner that is far more energy efficient, requiring only 25% of the total energy. And that's in the case it wasn't from recycled materials in the first place.

▲

Maxion 20 hours ago | parent [-]

The fact that HN is filled with so many who are weirdly against renewable energy is baffling.

Yo! Wake up sheep! Solar and wind energy are the two cheapest and least polluting ways we have of producing energy!

▲

rsynnott 15 hours ago | parent [-]

HN is kinda ground-zero for i-am-very-smart contrarians, so it's not _that_ surprising.

(Also, in the US, "solar panels take more energy to make than they produce" is a popular, although entirely false, talking point in right-wing media, so propaganda plays a part too. This claim has also been made about wind, and, bafflingly, _nuclear_.)

	▲	swiftcoder 5 hours ago \| parent [-]
		> "solar panels take more energy to make than they produce" is a popular, although entirely false, talking point in right-wing media Along with their perennial favourite, "EV batteries are more polluting than fossil fuels"