Posted By: WillInAberdeenI do park under a tree!

Not a lime tree I hope :)

Posted By: WillInAberdeenI think that Lime probably has similar embodied carbon to cement!

Lime trees are about the only ones resisting exotic diseases at the moment, in future they'll be all that's left to park under, even if they drop sticky goo over your thin film PV sunroof...

Their blossom is great for beekeepers though, " like turning on a honey tap " one said to me. The blossom also makes a nice herbal tea.

Something else for the team to ponder: https://xlinks.co/morocco-uk-power-project/

Posted By: djhSomething else for the team to ponder:https://xlinks.co/morocco-uk-power-project/" rel="nofollow" >https://xlinks.co/morocco-uk-power-project/

I read about this several days ago Octopus are an investor in the £8 billion project as I understand what it will cost. The 4 massive cables will cost £4billlion to manufacture. I marvel at the technology that can achieve the outcome. I wonder what the voltage drop will be would be nice to see some tech data on the technology. At the start of the video it mention HVDC presumably high voltage direct current with the inverter stuff here in the UK I would presume.

Posted By: Peter_in_HungaryThe political/terrorist risk of putting a big chunk of the UKs electricity supply in Morocco would IMO out weigh any technical advantage. Much safer and better to keep it all local.

A valid point given Euorpe was very relaxed about buying energy from Russia

Replacing carbon-fuel blast furnaces with electic arc - of course assuming renewable electricity source somehow - would that count as 'green steel'?

https://www.theguardian.com/business/2022/jul/22/tata-needs-15bn-subsidies-keep-port-talbot-steelworks-open-south-wales

If so, it's close commercially, not "demonstrated at small scale, but unlikely to take over their respective markets ... within the next few decades."

When in doubt, ask Will. Thanks. Hope the very expert ministers round the new PM's cabinet table will get that, before handing out the £1.5bn.

Posted By: fostertomHope the very expert ministers round the new PM's cabinet table will get that

Ha, ha, ha, Tom, very droll. It seems likely we'll get a worse prime minister than Boris (unless the Conservatives choose a coloured person to represent them) and any very expert potential ministers we have will run a mile until the next general election. Much as some of the potential PMs seem to have done.

That's what it means that Port Talbot will stop "primary steel making". An electric arc furnace cannot turn ore into metal.

If in future, somebody somewhere has a spare supply of cheap hydrogen-reduced iron, then it could be shipped into Port Talbot. Until then, they'll recycle scrap!

Part of the logic is that the UK now has to import all coking coal and ore, but we have plenty of scrap steel, which we presently export.

One for you Tom:
Estimated that 350GW of additional solar PV capacity will be needed to decarbonise all of the EU's steel plants - gives some scale. (UK presently has in total 13GW of PV installed)

https://www.rechargenews.com/energy-transition/green-hydrogen-average-eu-steel-plant-would-need-a-whopping-1-2gw-of-electrolysers-and-4-5gw-of-solar-to-decarbonise/2-1-1265531

Ref post at top of this page - don't think it's either/or - need to do both!

AIUI steel is already the most-recycled material, 85% of it is recycled, so there is still a marginal gain available recycling the other 15%.

But demand for steel now is vastly more than it was a couple of decades ago, so even if it were all recycled there is not enough "old" steel in the world to meet demand for "new" steel, much of which is used in construction.

Hence the need for building regs to discourage use of steel, for a few decades, until "new" steel can be manufactured at scale without carbon emissions! Ditto glass, cement/lime, etc

Entropically, it's better to Rethink, Redesign, Reduce, and Reuse before you get started on Recycling (of usable materials)! And Recovery (of raw feedstock ingredients) is worse still.

As you go down the hierarchy, each stage requires more energy (work, in the physics 2nd Law sense) to extract all the entropy and dump it someplace else.

So better to build a small 2G window in the right place, than to build a big 3G window out of techno-recycled glass and aluminium! Or in some rooms, use a lightbulb instead.

And, apart from capex, embodied energy, organisation, renewable energy can become practically 'free' so less need to worry about minimising energy input. That is, minimise energy requirement right across the board where possible thro intelligent redesign, so as to leave energy free for major strategic needs - maybe certain processes like steel, concrete, also I'd say the basic principle that lots is needed to reverse entropy as described.

Posted By: fostertomDon't you think

Posted By: WillInAberdeendon't think it's either/or - need to do both!

Absolutely!

If renewable energy ever became really free, then nothing would get recycled or conserved, as all raw material production industries are basically about applying energy to remove entropy. Free energy => more & cheaper raw materials.

The Circular Economy is predicated on materials being too valuable to waste-and-replace, IE that the costs (ultimately energy costs) of processing new materials will remain high, compared to the cost of reusing existing products and materials.


I think renewable energy won't be cost-free anytime soon, certainly not in the next few decades, because of the

capex, embodied energy, organisation

although recent events have put me off making predictions about energy prices!

That's different from energy being carbon-free - once the production of energy (and derived materials) is not damaging the shared climate, then it's more acceptable for people to use as much energy as they want or can afford.

I just read:
"The two candidates were asked what they thought the three most important things were that people could do for the environment. Sunak said his children were the experts, and cited energy efficiency, recycling, and a faith in British innovation to solve problems."
I wonder if he's been reading this GBF topic?

Posted By: WillInAberdeen1) rethink: don't build houses with grand spans that need steel beams to hold them up.

What proportion of steel used in construction is used in houses with large spans? I believe the major use is in steel framed buildings.

Posted By: WillInAberdeen2) redesign: Use laminated timber beams. Use suspended timber floors instead of reinforced concrete slabs. Use fibreglass for garage doors, plaster's mesh, appliance cases, duct.

So using what are essentially no-renewable and non-recyclable materials with potentially shorter lifespans. Despite the eco-vibes, glulam beams are not without their significant negative environmental impact, just it isn't acknowledged as much as it needs to be, like clt. Similarly with fibreglass, terrible environmental impact due to chemicals too.

Posted By: WillInAberdeen4) reuse : preserve old buildings! Reuse steel sections from previous structures instead of recycling them.

Yep, as said, stop unecessary demolition.

Unfortunately, there is cost at every level of consideration and I'm not sure they would be any better than steel if implemented on the large scale required to replace steel. I'd love to know some figures that could provide an environmental cost to each on a proper life-cycle basis. Looking at carbon for example, from the letter I linked to in the Fires thread(https://forestdefenders.eu/standing-up-for-forests-and-against-the-swedish-forestry-model-a-letter-to-ec-policymakers/), it states regarding the Swedish forest industry:

"High logging rates lead to decreased carbon sinks, so even though Sweden to a large extent consists of forest land, its total net uptake is as low as 35.5 million tons of CO2 equivalent. To compare, the annual emissions from forest harvest including the combustion of bioenergy in paper mills and heating plants alone, amount to about 80 million tons of CO2."

If we were to attempt to replace steel with so much wood, we first wouldn't have the resources for many decades, secondly we'd be destroying more established forests, and thirdly, the net CO2 contribution would be pretty unpalatable.

In my mind, the rethink always comes back to the basic idea of consumption and how unfortunately complex and stretched our material systems have become.