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Decarbonisation Pathways - What are the best options?
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The biggest single emitters in electric cars is in isolating the elements used to make them, and eventually in disposing of the electrolyte in dead batteries and in chemicals used to recover elements.Anyone who thinks an electric car is more efficient when they use coal-fired electricity is wrong too. As an aside, you have to include the efficiency of the battery. These leak power as well.
Ian wrote: "The biggest single emitters in electric cars is in isolating the elements used to make them, and eventually in disposing of the electrolyte in dead batteries and in chemicals used to recover elemen..."Plus power lost as heat during transmission through the grid.
J. wrote: "Philip wrote: "Pro electric cars - no other nasty emissions from exhausts and the climate cost of refining the fuel from drilling to distributionCon electric cars - infrastructures and power gener..."
I'm aware of that, however I meant at the point of use. If all power generation was nuclear or renewable then at least that carbon emission would be reduced although hearing more about issue for coal in other furnaces still being required.
In UN leaked report the use of Carbon Capture at the point of emission (Power stations) was being pushed by the main fossil fuel proponents. This looks like another good idea to delay reductions in use but lacking in actual implementation. The cost for such energy generation would increase as an additional process.
I’ve always blindly accepted that EVs are more environmentally friendly than petrol but when you think about the production process and electricity generation mentioned by J and Ian above, well…
In terms of practicality, I can’t see every home being fitted with a charging point because of cost; if charging stations were to replace petrol stations there would have to be a complete transformation in terms of charging speed; and major infrastructure projects like systems to charge moving or parked vehicles would cost the sort of money that governments don’t have.
Hydrogen (or other) fuel cells seems a more likely way forward, although my gut feeling is that the era of widespread car ownership is coming to an end. Could this be a second age of the train?
On an aside, the planet is clearly heating up but not all scientists believe it is manmade. Just saying.
In terms of practicality, I can’t see every home being fitted with a charging point because of cost; if charging stations were to replace petrol stations there would have to be a complete transformation in terms of charging speed; and major infrastructure projects like systems to charge moving or parked vehicles would cost the sort of money that governments don’t have.
Hydrogen (or other) fuel cells seems a more likely way forward, although my gut feeling is that the era of widespread car ownership is coming to an end. Could this be a second age of the train?
On an aside, the planet is clearly heating up but not all scientists believe it is manmade. Just saying.
As for electric vehicles, the charging is supposed to be done overnight, and all you need is a standard power point in your garage. If your house does not have off-street enclosed parking, it won't work, and the environmentalists here want to build such houses to persuade people not to have cars.In one of my novels, the plot involves a major reorganization of living, where everyone has to live within walking distance of work. That cuts down transport loads during "ruch hour" significantly.
My personal view is that some combustion engines could remain, using biofuel, although that would be somewhat more expensive thasn current fuel. At one stage during one of the "energy crises" of the 1970s I showed that every person here produced enough rubbish to produce 8 litres of hydrocarbon fuel per week, or 32 litresd for the average family of four. For sewage treatment, you can grow huge amounts of microalgae, and again you can convert that to hydrocarbons in about 25% yield, as well as get the raw materials for new bioplastics. The petrol cuts have a research octane number of about 140, and the diesel cut has a cetane rating about 70, and a little hydrogenation would bring it up to approaching 100, so a lot of other stuff could be blended.
Unfortunately, a lot of development work is required. A proposal ws made to build a 50 t/d plant in the US but it never went ahead when OPEC collapsed their prices and I suspect the relevant engineering design has been lost and the engineers are probably either dead or close to it so it is start again time.
So are we saying that electric vehicles are currently charged by electricity that is generated by fossil fuels? In that case, is there less carbon pollution doing it that way than by cars running on fossil fuels? I'm not clear on that. Or on the possible environmental damage when batteries are disposed of. Sorry for being so dense, but I'm still not clear on the answers to these questions.
If the electricity is generated by burning coal, it is probably worse for electric vehicles. For gas-fired electricity, it depends on how far away the generator is (i.e. how much is lost in transmission). For wind or solar, electric wins although the emissions in building the generators has to be taken into account, and since most electric vehicles will recharge overnight, solar is unlikely to be helpful.If the electricity is from nuclear, a big reduction in emissions, although we still have to process the wastes. My view is molten salt reactors would be best, but of course yo9u can't make bombs from the waste.
Scout wrote: "So are we saying that electric vehicles are currently charged by electricity that is generated by fossil fuels? In that case, is there less carbon pollution doing it that way than by cars running o..."There's a further issue brought about by grid usage. We don't use electricity at a constant rate. Usage hits its peak in the afternoon, when everyone is running around doing stuff. And it hits minimum usage in the wee hours of the morning, when most of us are asleep. You can roughly picture this pattern as a sine wave, with the peaks in the afternoon and the valleys in the early mornings. (We'll ignore the weekends) No matter what, the grid needs power at peak usage, and it can't overload (burn down the town) at minimal usage.
Solar doesn't work at night. So it won't burn down the town. But it also won't charge your EV for the morning commute. (Also applies to rainy days)
Wind is throttled by forces beyond our control. A steady breeze is great so long as that is all of the power you need. If you need more, or the wind slows...
Hydro is scalable and can be throttled. It also drowns thousands of acres beneath the reservoir. And in periods of prolonged drought (Australia, Southwestern US, India, etc.) you have to choose between electricity, irrigation, and drinking water.
Geothermal is scalable and can be slowly throttled. But it is most effective in areas that are seismically active. So they don't work well everywhere. Oh, and they can cause micro-quakes which are mostly harmless, except for freaking out people and livestock. They may also damage buildings over time, but you were already in a seismically active area.
Nuclear is scalable, but it can only be throttled within a specific power band. Reactors are designed to put out a set amount of constant power. If you drop its output below that window, then it develops Xenon poisoning and dies.
https://youtu.be/RZQwL-2WTgA
Most reactors are designed to resist pushing above their power bands. The most notable exceptions to this are Soviet RBMKs, AKA Chernobyl. This inability to throttle means that nuclear can easily handle your minimum need, but it isn't well suited for the peak.
And that brings us to fossil fuels. The single best thing about these power plants is that they have a wide power band which can be throttled through quickly. They can run at a low idle in the wee hours. And they can roar into life in the afternoon. We know the drawbacks.
What mix of these options covers our needs and has enough elasticity to handle the occasional crisis?
The point J makes about load management is critical. You need base load generation that can run continuously, and nuclear is fine for that, but you also need something to manage the rest. Unfortunately, I disagree with J's timing, at least here. What we find is there is a sharp peak early in the morning when people get up and get ready to go to work (showering, cooking breakfast, etc and starting up non-shift commerce, like getting buildings warm in winter) then there is the daily load that is tolerably even, then another spike in the evening when everyone comes home and cooks. These end-day spikes are wrong for solar.We are fortunate in that over about 75% of our power is generated by hydro and that can be quickly switched, but as J says, unless you have suitable terrain and lots of rain that doesn't work very well. The one big advantage of electric vehicles is they can charge during the low usage night-time, which lifts the amount of base power used, which means something like nuclear can work well. So what we also need is some form of intermittent demand that can be used at otherwise low demand periods. Generation of hydrogen would work, but that raises other problems.
Ian wrote: "The point J makes about load management is critical. You need base load generation that can run continuously, and nuclear is fine for that, but you also need something to manage the rest. Unfortuna..."I was trying to simplify load variation by describing an average. Actual load variation plots look like graphs of bipolar stock prices. There is also the fun of trying to balance load across the grid throughout the day.
Before signing off on nuclear as your constant source, you should consider that in a crisis nukes are at best a wash, and at worst a nightmare. Remember reactors cannot be throttled. So if the grid gets taken out by a hurricane/typhoon, tornado, nor-easter, etc. the reactor has to be shutdown. Provided that the back-up systems keep water moving through the core following the SCRAM, it will be a minimum of three days before the reactor can be brought back on-line. If the back-ups fail...
https://youtu.be/ryI4TTaA7qM
So how often does an act of god take down the grid in your area?
I appreciate the load varies wildly - my examples were mainly to point out that there are load spikes at times when there is very little sunlight, at the ends of the day, so solar doesn't really work. Wind is just plain erratic in many places. My region is as windy as most, if not more so, but looking out the window now there is almost no wind at all. In this sense, NZ is lucky because over 75% of its electricity comes from hydro, and that can literally be turned on and off very quickly by just opening/closing inlet gates.Acts of God taking down our grid in a major way are very rare here, but local outages are not that uncommon - usually a tree falling on a line. Of course I also live about 30 meters from a major plate boundary so sooner or later a major outage will occur.
Aa for nuclear, I rather fancy the molten salt reactor. It is somewhat easier to control (in theory, anyway) and would need crass incompetence to have a major problem. Of course the same could be said for other reactors and stupidities happen.
In summary we haveGeneration
Storage of generated to cover spikes or non-generation
Distribution
Waste - all aspects
Decarbonisation of existing issues
There are potential technical issues and resolutions for all plus the time taken to change e.g. build new plant remove waste. e.g. time to build or with nuclear time to dispose
The steampunk fans would likely advocate for returning to you know what :)
Philip wrote: "In summary we haveGeneration
Storage of generated to cover spikes or non-generation
Distribution
Waste - all aspects
Decarbonisation of existing issues
There are potential technical issues and r..."
Who pays for it? And how do they pay for it?
Ultimately the consumer. If it is not done, everyone who owns property that is submerged by sea level rise or whose lifestyle is changed by adverse weather events. This situation is governed by the laws of physics and politicians can rant all they want and people can put heads in sand all they want, but the laws of physics have no compassion and no means of evading them. The laws of thermodynamics permit no exceptions.
Con electric cars - infrastructures and power generation needed fo..."
Electric cars don't have "nasty emissions from exhausts"?
Yes, they do. You just don't notice it because the exhaust pipe is miles away, at the power plant. Google what your local power plant runs on and that's what your electric car runs on. If I had an electric car it would be running on natural gas. Others have coal fired Teslas. And don't forget those nuclear powered Fiskers.