The Alternative Green Energy Thread

Pile_o_stone

Cardew said:

It would appear that a fallen conifer will take 57 to 124 years to decompose.

And it provides habitat for insects and small animals and a food source for various fungi. 

joefizz

JKenH said:

No but if a tree does fall down is it better from a climate change point of view to burn the wood (once it has seasoned) or leave it to rot?

Believe it or not I asked three different scientists this very same question over Christmas (2 chemists, biologist). I got three different answers (yes, no, depends). So Im none the wiser.

The depends was the most interesting answer (biologist) as it depended on the wood and growth and coppicing and management and and and...

I dont think any of them argued it was worse than oil or gas if it was your own local wood. A case of lesser of three evils...

ABrass

Not all wood decomposes, some persists and becomes peat or eventually coal or oil. So if a tree falls in the right place it can be carbon negative.

JKenH

I have been following the argument on another thread of saving emissions by switching from fossil fuels to ethanol. While I can see the arguments on both sides burning ethanol still emits CO2 probably (but not necessarily) in similar quantities to burning FF. I believe one of the biggest sources of bio-ethanol is from sugar cane grown in Brazil. Is this encouraging deforestation which is bad for AGW. Producing ethanol also uses resources as this paper demonstrates. https://watermark.silverchair.com/55-7-593.pdf?token=AQECAHi208BE49Ooan9kkhW_Ercy7Dm3ZL_9Cf3qfKAc485ysgAAAn8wggJ7BgkqhkiG9w0BBwagggJsMIICaAIBADCCAmEGCSqGSIb3DQEHATAeBglghkgBZQMEAS4wEQQM7G_ebY7daSSFKnjpAgEQgIICMoLnUTySzakrhsAyfj1QdSiJr3i-m4HOS4uj3pT-18mu_VMz2JweLwBsh8sJCf5tjrXlWqN1ra2uI_d0HLjZZXFNtq3zVU2VPg_KpGGhX0_vm6TCbfPQxOO2WQI332XKXKReMfbwhikxnTNZ7cR-RfjpKtK3K5ZBYmijE0o3Tg1wwmNhv5lTjgQ0IV7mEGSB4ypjuoiIukwstTYgreVMKcRCAxoJnTthmvhZKZnUEt-PO7B5VbebEbS7wS5AEJ7QbEqNMIyDayEw1w30D7MDTQg3m9cR7QRuqMCFb8IG50rVSPcFd3K3PE2TFOvmYk4RtcYnyJ5EGcNFXyeJoyT-iZbWVnCBQXuo9aRfzk6PdYNk0jHRGRMLxQqleU5LO6eTc4_T65G2dJFcR24ky6JxIDTJr0zgkFrNxKLFHGcV4xlu_0KgmAiOoa2SXmSSbgfq7LBj80ScNyPY_Ztz4t7ydd95c32311lEQD-bUzG9kG2l9no7Q4nAnnElZWC98PnRqGc7gtmbcduvjCxTpRagAGh2zbf1QuJUfb013_q71CHE6jcNKPyU4tJF1_smZ-b9C73LJMWquACH9quyu_MQLHOv2KVOFxvkQVY-4l8NS7UkdOcwHkgnT4BKyaZL2ZryVEr91GHhmTbs4L0wHAn8TS8M8_eC8luUhrDxwy-RqSVtNdsA4kd4xrBlqg49ezPAZBKC7K5_HApXPmXGv7B2FUAkUakBDCa9d9l9YHxpZAJGyX8

How one sees the situation depends on whether one uses green maths or brown maths; things aren’t always black or white.

While we can use growing crops to capture CO2 and then make ethanol from them I thought if this is so environmentally friendly why don’t we just make loads and loads of ethanol to get the CO2 out of the atmosphere and then just store it rather than burn it. 

Then I thought why waste valuable farming land and chop down the Amazon rainforest when in fact it is possible to make ethanol direct from CO2 in the atmosphere?https://www.greencarcongress.com/2019/03/20190308-reactwell.html

EricMears

https://www.greencarcongress.com/2019/03/20190308-reactwell.html
Thanks JKenH !

A much 'greener' way of producing ethanol than either 'synthetic' (from Oil)  or 'bio' processes.  Indeed, using "a catalyst made of carbon, copper and nitrogen" also avoids  the usual criticisms of catalysts made of Platinum or 'Rare Earths' which are extremely environmentally unfriendly to extract.

No doubt the process would be horrendously expensive at the moment but given a few years of development and economies of scale it will get cheaper.  Maybe even to the point where 'aerial ethanol' could be used as a fuel in its own right to save those otherwise redundant oil burners from the scrapheap ?

joefizz

Brown stuff is hitting the fan with oil prices.... Might see market meltdown as soon as it opens this coming week.

Will directly impact future scale of renewables if it stays this low (it wont) and as I mentioned in a previous post will have enormous effects to prices in a few years time when all the ripple effects from the blood in the water this next few weeks play out.

All the talk of greener ways of producing ethanol all require fossil fuels (currently) and thats going to have serious effects further down the line.

Wonder if this week will be the tipping point between battery and hydrogen power for cars? Theres certainly going to be a lot less personal transport about, although love the idea of the new wee citroen battery car. The future of personal local transport?

Cardew

joefizz said:

Wonder if this week will be the tipping point between battery and hydrogen power for cars? Theres certainly going to be a lot less personal transport about, although love the idea of the new wee citroen battery car. The future of personal local transport?

How far in the future?

Unless the prices of second hand electric cars fall drastically it makes no sense(in financial terms) as 'personal local transport' for many motorists. I had a look on Autotrader today and the cheapest 2011 24kW Nissan Leafs with 70,000-80,000 miles were listed at between £5,000 and £6,000.

Many petrol cars of that age/mileage can be bought for £2,000.

EVandPV

Cardew said:

joefizz said:

Wonder if this week will be the tipping point between battery and hydrogen power for cars? Theres certainly going to be a lot less personal transport about, although love the idea of the new wee citroen battery car. The future of personal local transport?

How far in the future?

Unless the prices of second hand electric cars fall drastically it makes no sense(in financial terms) as 'personal local transport' for many motorists. I had a look on Autotrader today and the cheapest 2011 24kW Nissan Leafs with 70,000-80,000 miles were listed at between £5,000 and £6,000.

Many petrol cars of that age/mileage can be bought for £2,000.

I think it makes a lot of sense. Even at just 6000 miles a year, I would save around £800 a year between petrol and road tax so a £5k Leaf would pay for itself in 6 years.
That's without factoring in cheaper servicing due to less use of brakes, no exhaust, no coolant or oil.

JKenH

EVandPV said:

Cardew said:

joefizz said:

Wonder if this week will be the tipping point between battery and hydrogen power for cars? Theres certainly going to be a lot less personal transport about, although love the idea of the new wee citroen battery car. The future of personal local transport?

How far in the future?

Unless the prices of second hand electric cars fall drastically it makes no sense(in financial terms) as 'personal local transport' for many motorists. I had a look on Autotrader today and the cheapest 2011 24kW Nissan Leafs with 70,000-80,000 miles were listed at between £5,000 and £6,000.

Many petrol cars of that age/mileage can be bought for £2,000.

I think it makes a lot of sense. Even at just 6000 miles a year, I would save around £800 a year between petrol and road tax so a £5k Leaf would pay for itself in 6 years.
That's without factoring in cheaper servicing due to less use of brakes, no exhaust, no coolant or oil.

Now don’t misunderstand me (I am a big EV fan and have ben trying to convince my wife to replace her Picanto with an EV) but you have to appreciate that for people who can only afford to spend £2k on a car the maths might not stack up, let alone be sufficient to overcome their perceptions about the impracticality of EVs. It is a bit like telling someone who is just getting by that they should buy a house not rent. It makes perfect sense if like most of us on here you have the money to do it but not everyone can or is prepared to commit that sort of money however much it makes sense. Look how long it took Mart to get round to buying his first EV. 

EricMears

Cardew said:

How far in the future?

Unless the prices of second hand electric cars fall drastically it makes no sense(in financial terms) as 'personal local transport' for many motorists. I had a look on Autotrader today and the cheapest 2011 24kW Nissan Leafs with 70,000-80,000 miles were listed at between £5,000 and £6,000.

Many petrol cars of that age/mileage can be bought for £2,000.

Everything depends on your definition of  'personal local transport'  !  And of course what sort of car you'd get for £2000.  Most of the cheapest 9 year old cars seem to be 'gas guzzlers' i.e. smaller, more economical cars are probably holding their value better than larger, less economical ones.

An EV - with charging on a suitable tariff can have fuel costs as low as 2p / mile.  Even a modern economical petrol car (like the Seat Ibiza my son has just swapped in favour of an EV)  will struggle to get below 12ppm.  A heavy 2 litre petrol engined car with a worn fuel system is probably going to have fuel costs of 17ppm or more.  Fuel savings of at least 10ppm (and probably 15ppm or more) will result from swapping. Road tax could easily save another £200/year (my Volvo diesel would be that).  Other costs such as insurance & tyres would be unaffected.

Agreed, a couple of thousand miles per year is not going to justify switching to an EV although at that sort of usage it might even be economic to consider using taxis.  I believe 'average car use' (if there's really any such meaningful concept !) is around 8000 miles/y  which would be saving £800 - £1200 per year on fuel or £1,000 - £1400 in total.  The car owner's existing car must surely be worth something - and probably not far short of the £2,000 Cardew can 'afford'  so 'his' Leaf would probably only cost £3,000 and pay for itself in 2 to 3 years -  and be likely to last longer after that 2-3 year break-even period than the clapped out old banger it replaced was going to.

A possible downside  might be the deterioration of the battery.  In fact it seems to be the case that EV batteries don't actually deteriorate at quite the rate once feared and in any case they don't actually stop working - the car's range is just reduced and that's really not a problem with low daily usage.