Climate Change and Renewable Energy News and Discussion

broadsword

broadsword

Brigadier
AndrewS said:
I think the answer is to buy a heavy duty blender from a bigger Chinese brand.

For home appliances, Midea or Haier should be fine, as they started out as contract manufacturers and do work for Japanese brands like Panasonic.
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I inquired with a number of manufacturers on Alibaba. None of them was confident I could grind peanuts without adding some liquid without damaging the machine.

Since Chinese companies started to replace Japanese companies as OEM for Western companies, it was relegated to making 'legacy products'. They don't make airfryers or electric pressure cookers. As long as the major Chinese white goods makers dominate in the manufacturing, there's no worry about the quality.

But if it is the small players dominating, then you see more one stars on Amazon.
 
FairAndUnbiased

FairAndUnbiased

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The western United States is, famously, in the grips of its worst megadrought in a millennium. The Colorado River, which supplies water to more than 40 million Americans and supports food production for the rest of the country, is in imminent peril. The levels in the nation’s largest freshwater reservoir, Lake Mead, behind the Hoover Dam and a fulcrum of the Colorado River basin, have dropped to around 25% of capacity. The Bureau of Reclamation, which governs lakes Mead and Powell and water distribution for the southern end of the river, has issued an ultimatum: The seven states that draw from the Colorado must find ways to cut their consumption — by as much as 40% — or the federal government will do it for them. Last week those states failed to agree on new conservation measures by deadline. Meanwhile, next door, California, which draws from the Colorado, faces its own additional crises, with snowpack and water levels in both its reservoirs and aquifers all experiencing a steady, historic and climate-driven decline. It’s a national emergency, but not a surprise, as scientists and leaders have been warning for a generation that warming plus overuse of water in a fast-growing West would lead those states to run out.
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A

AndrewS

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@9dashline
@FairAndUnbiased
@Nutrient

Critique of EROEI

EROEI doesn’t consider how the usefulness of each type of energy.
For example, 1 KWh of electricity has the same nominal energy of 1 KWh of Petrol.
But electricity has far more useful output.

Here are some key examples

Scenario 1 - Cars
When electricity is used in an electric vehicle motor, over 80% of the energy is converted into motion.
But when petrol is burned in a car petrol engine, only 40% of the energy is converted into motion.
So 1 KWh of electricity is equal to 2 KWh of petrol, when used in a car.

Scenario 2 – Heating - hot water for showers, central heating, etc
When petrol (or another hydrocarbon) is burned in a boiler, almost 100% is converted to heat.
But when electricity is combined with a ground-source heat pump, 1 unit of electricity generates 4 units of heat.
So 1 KWh of electricity is equal to 4 KWh of petrol, when used for heating.

So EROEI cannot be used to compare electricity to hydrocarbons.

---
NB. So if I look at the latest EROEI figures for Solar Panels, I get a figure of around 27.
For heating purposes, coal and oil would need an EROEI of 108 to match the solar panel.
For vehicle purposes, oil would would need an EROEI of 54 to match the solar panel.
But coal and oil have EROEI figures of only 30.

But of course, the problem is that solar electricity is generated only when the sun shines.
 
j17wang

j17wang

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Interesting table of CO2 emissions per capita. The US is insane, while Europe does quite well. It is completely reasonable to state that the reason lives in the world will be cut short or people face climate hardship over the next 50 years due to unilateral actions of the united states. This is fact.

Naturally the question remains, does it make sense to initiate proactive kinetic action against US assets specifically related to disproportionate sources of CO2? Was that not what was done by domestic actors in the US in the 70's? What are assets that could be specifically targeted by non-state actors, I'm guessing oil storage facilities and gas lines?

To be clear, this should not be done by states, but rather non-governmental groups/alliances.
 
FairAndUnbiased

FairAndUnbiased

Brigadier
Registered Member
AndrewS said:
@9dashline
@FairAndUnbiased
@Nutrient

Critique of EROEI

EROEI doesn’t consider how the usefulness of each type of energy.
For example, 1 KWh of electricity has the same nominal energy of 1 KWh of Petrol.
But electricity has far more useful output.

Here are some key examples

Scenario 1 - Cars
When electricity is used in an electric vehicle motor, over 80% of the energy is converted into motion.
But when petrol is burned in a car petrol engine, only 40% of the energy is converted into motion.
So 1 KWh of electricity is equal to 2 KWh of petrol, when used in a car.

Scenario 2 – Heating - hot water for showers, central heating, etc
When petrol (or another hydrocarbon) is burned in a boiler, almost 100% is converted to heat.
But when electricity is combined with a ground-source heat pump, 1 unit of electricity generates 4 units of heat.
So 1 KWh of electricity is equal to 4 KWh of petrol, when used for heating.

So EROEI cannot be used to compare electricity to hydrocarbons.

---
NB. So if I look at the latest EROEI figures for Solar Panels, I get a figure of around 27.
For heating purposes, coal and oil would need an EROEI of 108 to match the solar panel.
For vehicle purposes, oil would would need an EROEI of 54 to match the solar panel.
But coal and oil have EROEI figures of only 30.

But of course, the problem is that solar electricity is generated only when the sun shines.
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yeah so this is completely unsourced, until you get some sources I'm not interested in this.

one thing that's fairly obvious that you miss is that electricity is not a source of energy, only a transmission medium.
 
A

AndrewS

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Registered Member
FairAndUnbiased said:
yeah so this is completely unsourced, until you get some sources I'm not interested in this.

one thing that's fairly obvious that you miss is that electricity is not a source of energy, only a transmission medium.
Click to expand...

You assert EROEI is a valid measure, whilst I think it is nonsense.

I have pointed out the flaws in EROEI, and the figures I use are all publicly available.

Therefore the onus is on you to prove EROEI is valid.
But good luck with that because EROEI is regarded as a measure that doesn't make sense.

---

As for references, I was under the impression you had an engineering background and that you would already know these figures are roughly accurate.

But here's a statement from EDF, who are the state-owned electricity company for France.
edfenergy.com/for-home/energywise/why-EVs-are-efficient

As for how heat pumps work and their efficiency, here's the wiki page which goes into detail
en.wikipedia.org/wiki/Ground_source_heat_pump

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I use electricity as a shorthand, because I don't want to confuse the issue by talking about how the electromagnetic field is the energy transmission medium. So it's not actually the electrons that transmit energy. Otherwise how the heck would induction charging ever work?

Anyway, I am truly done here with EROEI
 
tphuang

tphuang

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A couple of things that's kind of cool
https://twitter.com/i/web/status/1566425598033297408
China looking to peak emissions in steel industry by 2025. Another important part is looking to get over 60% of iron ore demand from domestic production, steel scraps and oversea equities. Got for China, bad for Australia. Be curious how much of the remaining can be imported from Russia and Brazil.

https://twitter.com/i/web/status/1567161891159506947
Cement industry is also looking to peak in carbon level before 2023. With reduced real estate development from completion of urbanization, these are two of the major sources of Chinese emissions that will be peaking.

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I guess this is the best way for Sinopec to transition off carbon. It will need a whole lot of wind/solar farms to have more of these green hydrogen production facilities.
 
A

AndrewS

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Registered Member
@FairAndUnbiased
@9dashline
@Nutrient

Energy Payback Times for Maxeon Solar Panels for various places (Frankfurt, Tokyo, Shanghai, Washington DC, San Francisco, Marseille , Sydney, Rome, New Delhi, Dubai)

Utility. 0.13-0.45 years for Energy Payback
Residential. 0.27-0.92 years for Energy Payback

---

With their 40 year performance guarantee, that works out as

Utility. 84-269x Total energy payback (EROEI)
Residential. 41-139x Total energy payback (EROEI)

There is no shortage of solar power and solar panels generate far more energy than is used to make them.
However, the issue of energy storage remains.

Sources below

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FairAndUnbiased

FairAndUnbiased

Brigadier
Registered Member
AndrewS said:
@FairAndUnbiased
@9dashline
@Nutrient

Energy Payback Times for Maxeon Solar Panels for various places (Frankfurt, Tokyo, Shanghai, Washington DC, San Francisco, Marseille , Sydney, Rome, New Delhi, Dubai)

Utility. 0.13-0.45 years for Energy Payback
Residential. 0.27-0.92 years for Energy Payback

---

With their 40 year performance guarantee, that works out as

Utility. 84-269x Total energy payback (EROEI)
Residential. 41-139x Total energy payback (EROEI)

There is no shortage of solar power and solar panels generate far more energy than is used to make them.
However, the issue of energy storage remains.

Sources below

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interesting, I have a German report from 2022 that claims 1 year energy payback which is very good already, and they used only Chinese panels (for relevance and because SunPower uses CdTe which is more expensive to set up, has materials processing issues and may encounter regulatory and RoHS restrictions in Europe and Asia).

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So EROEI is OK, still not at thermal power levels though. Also scale is limiting the scale of PV deployment at ~5 GW per year for all of Germany vs. a single gas fired plant that can produce 1 GW, plus the capacity factor of ~10% vs ~60% for gas making 5 GW electricity of solar equal to 1 GW electricity of gas.

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S

sndef888

Captain
Registered Member
How viable would it be for China to go completely renewable by 2050?

Solar and wind are definitely the gamechangers here. If their adoption grows fast enough the world might simply give up on nuclear and fusion all together.

A China with a grid of distributed solar + sodium battery banks for peak loads would be invincible in terms of energy security
 
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