Bishop Hill Driving into the future?
Oct 18, 2012 Energy: electric cars From Today's Moderator
An article by Andrew English on the future of hydrogen fuel-cell electric cars appeared in the Telegraph yesterday.
In January, the Government unveiled its latest hydrogen initiative which, according to Mark Prisk, the business minister, will “ensure the UK is well positioned for the commercial roll out of hydrogen fuel-cell electric vehicles.”
The 2007 Department of Energy white paper, Meeting the Energy Challenge, concluded that “fuel cells and hydrogen technologies face significant technical and economic challenges… A huge international effort (both public and private) is being devoted to overcoming them. This will require fundamental and applied research, development and demonstration.”
In 2008, Professor Peter P Edwards wrote in the government-commissioned study, Hydrogen and fuel cells: towards a sustainable energy future: “together, hydrogen and fuel cells have the capability of producing a green revolution in transportation by removing CO² emissions completely.”
Will it really? Three government departments (Business, Innovation and Skills, Transport and Energy and Climate Change) are involved, but have any of them ever read any of their own publications?
Reader Comments (76)
Read the post about the Cella Energy system, now being commercialised. These a polymer pellets that flow like a fluid and are used to transport the hydrogen as a hydride to the fuel tank and are then pumped out to be re-used.
This IS the technology of the future. Battery cars a re a dead end technology now dying as fast as the stupid politicians made them grow.
If hydrogen fuel cell is the answer then we are asking the wrong question.
It may solve two "problems", oil reserve depletion and carbon dioxide emissions.
I have 1973 Hillman Imp. I can take the engine out, the petrol tank, fuel pump, anything I like. No safety certificates, no trade qualifications.
Has anyone considered what will happen with fuel cell cars after 4-5 years of use? Basically you will either have to throw them away or have the extreme expense of maintaining them. It will require specialist gear, specialist technicians and specialist testing. The slightest issue will mean things are replaced, expensive things using expensive labour and kit.
Look at the gas regulations in the UK for a simple domestic house. So 5000 psi, 10000 psi with an explosive gas?
From an engineering viewpoint (which also means future costs) mass adoption does not make sense.
It is trying to solve a problem that might not exist. A simple electric assist/powered personal/cargo bicycle/tricycle, if brought down in price from the current GBP 1500-2000, could actually cover a large percentage of the journeys these fuel cell vehicles would cover.
Also, people may still want the personal freedom of a car, but building the infrastructural to realise it does not make sense in this instance, and there are other ways to achieve that freedom.
Isn't water vapour a green house gas?
The best way to utilise hydrogen in a vehicle might be to produce a compound of H2 with carbon which will be liquid at normal temperatures and will pack a large amount of energy into a small volume as hydrogen alone does not. It would also be transportable in usable form by tanker or pipeline requiring no expensive transitions between production and use, as hydrogen alone does not. I claim a car could go four to six hundred miles on a tankful, while that tank would bulk out at only a few gallons rather than the uncompromisable bulk of hydrogen which corrupts the entire design of the vehicle. If we were really lucky we might find that such a liquid was freely available in geological deposits, requiring only processing.
Just a crazy pipedream.
And where does the hydrogen come from? From hydrocarbons with the by-product being CO2!
Or is there now another viable process?
Sinclair C5. The future looks bright.
Electrolysis of water using nuclear generated electricity. Or, if you believe fairy stories, from wind/solar generated electricity.
From the economist..
http://www.economist.com/blogs/babbage/2012/10/nitrogen-cycle
JS: The Cella Energy system is much lower pressure than the pressurised gas. It's a nano-engineered polymer with controlled absorption energy and high carrying capacity.
It looks to be the answer, certainly better than the La intermetallic hydride systems uses in the past.
I posted this yesterday in WUWT's tips and notes, funny thing is when Goverments try to pick winners they ALWAYS lose. Another multi million pound green dream down the drain in the US. They make car batterys for electric cars.
http://www.zerohedge.com/news/2012-10-16/another-blow-green-industry-a123-files-bankruptcy-after-collecting-hundreds-millions
Martin,
310,000 electric assist bikes were sold in Germany last year as opposed to 11,500 electric cars. A 55% increase in the last year. In Europe as a whole 700.000. Pedal assist bikes are still too expensive for a cycling ignorant country like the UK, but there is a major shift in transport approach that the UK media will not pick up on.
Last year I cycled my unassisted tadpole trike 3,500 km from the UK to Bucharest. I understand better than many the arguments about using lower riding contraptions like the C5. I have driven a pedal assist tadpole trike at 45 km/h. The C5 was not the solution to anything.
The issue is just mass. The more people "cycle" the safer is becomes. And using unusual lower riding machines as part of a greater increase in bicycles will not be an issue.
Many of the excuses, sorry arguments, for not cycling in the UK fall away with pedal assist.
Sorry correction, 11,500 electric cars sold in Western Europe not just Germany.
Hydrogen economy? There is a way it could work. Solar to electrolyse water, store the H2, run it through a fuel cell. You can also use the fuel cell itself to do the electrolysis if you want to be really clever.
The question is can you make the equipment cheap enough to overcome the inefficiency of the process? It's just the usual capital cost v. running cost thing. I would argue that yes, in a decade or two, we will be able to.
Start with multijunction solar cells. 40% or so efficiency. Electrolysis using solid oxide fuel cells. Storage of H2. Run that through solid oxide fuel cell to produce 'leccie when required. You could, potentially, also use the H2 in a car (either a fuel cell one or ICE is possible). And your fuel cell would be combined heat and power of course to increase efficiency.
The question is, could you get the combined cost of all that kit down to £15k or below? Maybe £10k if you assume a 10 year lifespan? For a household style system?
I would argue that you can. I would note that I'm marginally involved in this (certain of those solid oxide fuel cell makers use materials that I supply). so you could say I'm talking my own book. But I don't really see any good reason why the combined kit cost couldn't come down to this sort of level. Note the SOFCs do not use platinum, they are zirconia based, doped with a bit of rare earths. Multijunction fuel cells are silicon (basically boiled sand) doped with In, Ge and Ga.
There's no inherent reason why such a system shouldn't be in time cheap enough. They're all subject to drops in manufacturing costs akin to Moore's Law (not exactly the same, but akin to it). The raw materials are either cheap enough or can be made so with a bit of expansion of the mining sector. For example, the Ga and Sc needed are already in the stuff we throw away from processing bauxite for aluminium.
NB: I do not say that this is definitely workable. Nor do I say that I know exactly how to do this. Only that I think it is possible, to get the cost of the equipment down far enough that it makes up for the inefficiencies of the process and thus produces energy at prices comparable or below today's. And there really isn't any shortage of sunlight to power our civilisation.
@Jiminy Cricket
You writing about your tadpole trike reminded me of this one:
http://www.youtube.com/watch?v=WKAMus3oSdw
That is what I call electric assist!!
regards
P
Shevva: Marxist apparatchiks like Obama and Brown backed battery cars because they foolishly and with no professional engineering input assumed that the batteries could be used to store wind energy.
The fact is this was never on because the return efficiency can be as low as 20% and the lifetime is halved. The latter means that for your small car, the battery replacement cost goes from £1500 - 3000 per year if you buy them, or the rent rockets.
Total stupidity from Brown and Miliband, but what do you expect from morons?
Tim, that's very interesting if it all can be made to work. There's nothing wrong with any solution (if we actually had a problem) which works. The problem is pushing tech that does not work in terms of economics and needs subsidy or compulsion as a pre-requisite to adoption. As I am sure you realise. When they build something which competes with a petroleum car on a level playing field and does not require major infrastructure investement, be it sunbeams from cucumbers or magic fairy dust, normal market forces will prevail.
There was a major practical experiment in Japan on the hydrogen economy, involving switching an isalnd entirely to hydrogen. Anyone have the inside scoop on how it worked out?
Martin A: "Electrolysis of water using nuclear generated electricity."
Hydrogen;
Nuclear 1KWh > after electrolosis: 0.65KWh equivalent > after compression: 0.45KWh equivalent.
Electricity;
Nuclear 1KWh > after grid transmission losses: 0.95 KWh.
Build 2x more nukes?
One thing slightly concerns me, other than driving a vehicle & sitting on top of the most volatile & explosive element in the known Universe, & that is the pressures being talked of. 700Bar = 700kPa = 700 kN/m²! Considering 7.5 kN/m² is what I would design a workshop/plant/boiler room floor to carry, using reinforced concrete, getting on for around 300mm thick or thereabouts, is worrying somewhat!
To put all this in context, the supposed end of Arctic ice from CO2-AGW has had an unexpected setback. Arctic Ice freezing near an all time record: ocean.dmi.dk/arctic/icecover.uk.php
The explanation is simple thermodynamics. The August cyclone mixed fresh surface water with stratified salt water down to 500 feet. The partial molar heat of mixing is strongly negative and the lack of ice meant radiation to space was also very high. So, the ice is freezing from above and below. Expect soon record ice extent and alarmists claiming the very cold northern winter is extreme weather!
The forecast temperatures in mid-winter UK are -18 °C: http://www.metro.co.uk/news/915233-winter-to-be-colder-than-normal-as-chances-of-white-christmas-increase#ixzz29bESwTtX
Buy winter tyres if you commute by car.
Grumpy Granddad, thanks I have seen that before, 0 to 70mph in 3.9 seconds. You would do it just to p*** off the guy in the Audi/Porsche/Prius at the lights. I did 30 mph in traffic and it was fun.
On my degree course we did transport engineering, and the lecturer used to work for a maker of trolley/trams/buses (when we had such an industry.) He told the story of a "project". They converted a bus to electric power and made sure they could take the limiters off (infinite torque). They then used to go out burning people off.
Anyway the point is, the simplest engineering solution is often the best. We create more weight and complexity to carry more weight and complexity.
I still say many of these "hydrogen" ideas are trying to solve the wrong the problem.
PS, a word of explanation about the pressure needed to store hydrogen. The GE technology uses 700Bar. The ideal technology has an energy density about the same as petrol and is stored at ambient pressure.
The cella beads desorb hydrogen from ammonia borane NH3BH3 at ~85 °C and are stored in a normal fuel tank: http://www.cellaenergy.com/uploads/pdf/FCHEA_Prof_Bennington_Washington_14_Feb_11.pdf
The only high pressure is a small buffer tank just prior to use in the fuel cell
Oct 18, 2012 at 10:22 AM | ssat
Comparison is not fair. You forget distribution losses, battery charge/discharge losses and an enormous pile of dead batteries as waste. Better build more nukes (fast nukes, of course).
Albert Stienstra: "You forget distribution losses, battery charge/discharge losses and an enormous pile of dead batteries as waste."
Not at all Albert. My point is why convert baseload electricity into a portable form as the losses are huge. That together with the current viable technology to produce hydrogen neither conserving hydrocarbons nor reducing CO2 makes the entire idea a non-starter if your ambitions are green.
Now if a windmill can produce hydrogen at a viable price then that may be worth investigating as it turns an intermittent instantaneous source into an energy reservoir. Then there are other developments, some of which are mentioned above. However,at the moment hydrogen solves no (perceived by some) problem. On a green level, investing in methods to consume hydrogen fuel is daft until the problems of its production are overcome.
I rather liked the sentence in the article that said "compress air down to minus 196C to liquify it". Very funny that, BOC used to compress air but that just warmed it up so they let it expand rapidly, that did the cooling. Basic physics known for years and they got it wrong. What a joke!
ssat; the hydrogen economy will be developed using cheap methane. Indeed, the metal ceramic SOFCs are now fitted with in-situ catalysts to reform the methane to hydrogen in the fuel cell.
The alternative, electrolysis, can be 50% efficient and is a way to store windmill energy. However, I suspect it will never happen because frankly speaking, the windmills are a dead loss economically and in green terms, unless used in small numbers for remote local grids where traditional power costs more.
History will look at them as equivalent to the Easter Island Statues, a monument to an oppressive elite intent on destroying their civilisation to justify their hubris. Go long on piano wire and lamp posts.
AlecM,
That's very interesting & even encouraging.
However, nowhere in the cella-energy presentation can I see a proper formulation of the chemical reactions in the charge/discharge cycle, which was and still is my main concern.
Amine:Borane complexes do not readily release hydrogen thermally in my experience [adding water/acids to decompose such compounds is par for the course], and not reversibly either in the absence of a novel catalyst. What is the by-product produced by the claimed thermal desorption and how does this re-absorb hydrogen?
The ability to efficiently go round the chemical cycle is key to processes using borane chemistry. If the chemical problem has been solved, then they and their shareholders will become very rich, but I can't see it in that presentation.
Michael Hart; we're dealing with nano-engineered materials which form a surface compound. this is shown by the reduction of the decomposition temperature from ~120 °C to ~85 °C.
This means the carrier is reusable.
Honda knows a thing or two about hydrogen cars -- enough that they are not producing them in quantity yet.
http://automobiles.honda.com/fcx-clarity/
A few years ago, hydrogen fuel cells were shown and discussed by several manufacturers at the major car shows. That's the past. Now it's electric and plug-in hybrid. Hydrogen has dropped off the map.
Hydrogen fuel cells are used in several specialty applications such as materials handling.
http://www.airproducts.com/company/news-center/2012/10/1008-air-products-hydrogen-technology-onstream-at-mercedes-alabama-plant.aspx
Speed; you are a bit behind the times. Battery cars are being dumped as a dead end technology by the major manufacturers. The latest is Toyota. The Nissan leaf has low mileage in hot climates and you can't use the heater in cold.
As for hybrids, they have inferior fuel consumption to the ICE and the technology is morphing into an add-on to recover over-run power loss with a single motor in line with the output of the drive-train.
Most manufacturers have fuel cell vehicles as a possible future. The problem has been the refilling stations and the Cella technology appears to be the solution.
AlecM: "We're dealing with nano-engineered materials which form a surface compound. this is shown by the reduction of the decomposition temperature from ~120 °C to ~85 °C.
This means the carrier is reusable."
Reusable as a storage method for borane or the ammonia:borane complex NH3:BH3, maybe. But not hydrogen. You only get the hydrogen out by irreversibly destroying that compound, leaving you with what? A sticky mess of aqueous ammonium borate if done with water.
If they are claiming a novel compound ?? of Nitrogen and Boron that efficiently and reversibly reacts with molecular hydrogen at ~85°C, or even ~120°C, then I am seriously out of touch with all the recent Nobel Chemistry Awards.
I suggest what they have, is not what they led the venture-capitalists to think they have.
Hydrogen fuel cells just move the CO2 generation from the vehicle to the electricity source for the hydrolysis.
rhoda is correct that hydrogen is a silly way to store energy in a vehicle for energy density reasons. If you can find a reasonably efficient way to produce synthetic petrol then that's much better. The CO2 released in burning it is exactly offset by the CO2 used in the synthesis, so it's also carbon-neutral, if you care about that.
If full on petrol is too hard then methanol or ethanol will do fine and still far better than hydrogen even if not quite as good as petrol.
Petrol synthesis goes back to WWII with a lot of work done in Germany then, and later in I think South Africa.
Here in New Zealand, a factory at Motunui opened in 1986 produced methanol from natural gas, and then converted the methanol to petrol.
At the time, it was capable of producing 50% of NZ's petrol needs.
I don't know what the end to end efficiency was. I seem to recall it was expected to be profitable with oil at $50 a barrel or more, which was expected at the time but never eventuated.
http://www.ipenz.org.nz/heritage/itemdetail.cfm?itemid=68
http://www.teara.govt.nz/en/oil-and-gas/5/4
Bruce Hoult: "Here in New Zealand, a factory at Motunui opened in 1986 produced methanol from natural gas, and then converted the methanol to petrol......I don't know what the end to end efficiency was. I seem to recall it was expected to be profitable with oil at $50 a barrel or more, which was expected at the time but never eventuated."
I expect it was not very efficient, Bruce. At about the time I was doing my higher Chemistry degree [in the late 1990's] some touted a catalyst for the efficient oxidation of methane to methanol as the greatest unclaimed prize in Chemistry [stopping only at methanol being the problem].
It's not like oil companies etc. haven't tried. Chemical feed-stocks and fuels promise great riches to those that can do it cleanly and efficiently.
Speaking of which, I wonder whatever happened to the methanol fuel-cells for use in mobile phones?
Rhoda is brilliant! :-)
I have had a bumper sticker on my gas-guzzling SUV for the last 6 years that says-
"This Vehicle Powered By Hydrogen-Loaded Nanorods".
It is framed with a nice color photo of the Earth, a big green oak tree and a Dinosaur.
I was in a venture capital meeting in 1999, where they were discussing their investment in Ballard Power, a pioneer in polymer membrane fuel cells. The stock price graph had a logarithmic y axis. Their experts were predicting 1,000,000 FC vehicles on the road by 2005...
Back in 1997, a NY company was ready to commercialize a natural gas powered fuel cell residential furnace, to provide both heat and electricity. Their experts were predicting huge market penetration in 5 years...
AlecM; I am neither ahead nor behind the times. I'm just reporting what I've seen at major US car shows over the last decade. BMW, Mini, Mercedes Benz, Audi, Smart, VW, Ford and others are showing and/or selling electrics. I don't recall seeing any fuel cell cars this year. If there were some they certainly weren't promoted very well.
My personal view is that hydrogen in some form is the most likely end point if the current race to remove hydrocarbons from directly powering personal transportation devices continues.
JC -
I remember when the C5 was launched. It quickly became apparent that it had never been ridden in heavy traffic - a TV interview of its marketing manager asked the question "is it safe in traffic?". He swallowed hard and had no choice but to go pedalling off among the lorries and buses - I think everyone was a bit surprised that he survived the ride.
My girlfriend has an electric assist bike. It pretty well finished off joint bike rides. Instead of both dismounting on slopes, she'd soar effortlessly up the gradients, wanting to chat, while my lungs were working at the limit, pedalling my 1950's Carlton lightweight, my legs delivering their full 30 W output.
Cycling is much more dangerous then most people think. Published statistics, so far as I can see, grossly understate the injury rate.
I spent four nights in hospital, the first two unconscious, after being (apparently) hit on a straight stretch of the Bristol ring road cycle track by a cyclist who turned right, crossing my path. I was not entered in any count of cycling accident statistics, so far as I know. Most cycling friends have had 'no other vehicle involved' injuries - handlebar fatigue fracture at speed, front wheel collapsed for no apparent reason, and so on. I doubt that any of these got counted in the statistics.
I still ride, but I don't kid myself it's safe.
ssat -
I was not saying it was a good idea (neither was I saying it was a bad one). But that's how you can make H2 without at the same time making CO2.
Speed: Toyota has dumped its battery car. The thermal management of the batteries is the key issue because the failure rate accelerates. It's not a viable technology with Li-ion, too touvchy because of manufacturing tolerances of the intercalation anode.
Tim Worstall says-
"Start with multijunction solar cells. 40% or so efficiency. Electrolysis using solid oxide fuel cells. Storage of H2. Run that through solid oxide fuel cell to produce 'leccie when required. "
40% efficient solar PV panels do not exist, yet. Individual cells, yes, but very expensive.
Solid oxide FC runs at high temperature, 500 - 1000 C. Solar output will have a daily cycle (if you are lucky enough to have a sunny day every day), so a big portion of the solar power output will be consumed just getting the FC up to operating temperature every day. The electrolyzed hydrogen must be compressed to be stored, adding more round-trip losses. This parasitic energy loss gets much worse as the FC size is reduced to residential size.
It has been an interesting challenge to overcome all of the issues with this idea, ever since SOFC's and solar PV cells were developed...in the 1960's.
"40% efficient solar PV panels do not exist, yet. Individual cells, yes, but very expensive."
Agreed, but I do expect this to be subject to something like Moore's Law. It is, after all, a matter of getting a circuit onto a wafer (yes, more complex than that but we still would expect exponential improvements in price).
"Solid oxide FC runs at high temperature, 500 - 1000 C."
Indeed, that's why I'm involved, to get the 600 oC ones you need scandium which is what I supply....
"It has been an interesting challenge to overcome all of the issues with this idea, ever since SOFC's and solar PV cells were developed...in the 1960's."
Indeed. I know, it's horribly inefficient. But inefficiency doesn't matter if you can make the equipment cheaply enough.
Just as an example, Bloom Energy is making SOFC systems. At least until two years ago they were still handpainting the anodes and cathodes onto the zirconia plates (might still be now). There's a very long way to go in making these things a helluva lot cheaper. Thin film tech for example.
chris y: I agree, Worstall is unrealistic about the engineering issues. I midwifed one SOFC technology 20 years' ago. Hydrogen will continue be made from methane, as it is now, for a century at least. I also developed my first solar cell technology 30 years ago: It's now buried in the biggest Chinese Producer, as bankrupt as the rest!
AlecM said, "Toyota has dumped its battery car."
I count 55 Toyota dealers in California that are selling the Toyota RAV4 EV -- an "All electric, All SUV."
http://www.toyota.com/rav4ev/index.html
And then there's the Scion iQ EV ...
DENVER, Oct. 17, 2012 /PRNewswire/ -- Toyota Motor Sales (TMS), USA, Inc. today announced the arrival of the 2013 Scion iQ EV in the U.S. The iQ EV is a battery- electric 4-seater city commuter car designed for car-sharing programs, in urban and campus environments.
"Toyota believes battery-electric vehicles have the potential to play a role in future mobility strategies," says Chris Hostetter, group vice president of strategic planning at Toyota Motor Sales, USA, Inc."
http://www.bizjournals.com/prnewswire/press_releases/2012/10/17/LA94682
Hi Speed; the 2nd generation RAV4 is sold in Ca only: initial production is 2600 vehicles [Wikipedia].
The reason why the big manufacturers like Toyota are discontinuing battery only vehicles is because they do not see the technology evolving further, having spent a lot of money on battery chemistry development.
Ni-meH works and the original RAV4 EV was a success technologically. However, China has embargoed La so you can't continue those batteries, and the replacement Li-ion has a serious problem with thermal management. Toyota had a Mg battery in development but it seems not to have worked.
AlexM: "metal ceramic SOFCs"
My understanding is that Bloom boxes are the SOFC du jour.
And they produce way more VOC's (volatile organic compounds) than a modern gas power plant and the gas power plant produces more electricity from the NG than the bloom box.
SOFC's so far are dirtier and less efficient.
Electric, hybrid and fuels cell cars are all solutions to a non existent problem as a number of people have already said. In addition as a customer I am a motorist and a petrol head and I do not want any of these products, I am more than happy with my petrol engined car (but not the taxes). Judging by the sales figures for electric and hybrid cars I am not alone in my views.
Peter Mandelson paid the motor manufacturers in the UK billions of pounds to invest in electric and hybrid technology that nobody wanted or needed. The petrol engine now has a long history of development and refinement and it works just fine. I guess that many of us are of an age that means we have been through all the problems of unreliability; not starting when its cold, overheating when its hot, bits falling off, replacement clutches, batteries, alternators, gearboxes and even engines! Petrol engined cars get better every year they do exactly what we need them to do and are extremely reliable. In addition the world is stuffed with oil and will be for generations and so once again this all comes back to CO2.
It has been several years, but a neighbor of my brother worked for the Dept of Energy and during a discussion stated that hydrogen fueled vehicles were a pipe dream.
Reason? Distribution system. The existing infrastructure for transporting fuel to distribution points and storing it there will not work for hydrogen. It would have to be ripped out and replaced.
Oct 18, 2012 at 11:47 AM | ssat
"Now if a windmill can produce hydrogen at a viable price then that may be worth investigating as it turns an intermittent instantaneous source into an energy reservoir."
The windmills still remain expensive intermittent sources, even if they would produce hydrogen. Apparently people think: "the wind is free so that may cost a lot extra". If the nation would use wind energy for transport, via hydrogen or any other means, it would be necessary to build windmills all over the place.
Electricity production by nuclear plants is much more reliable, cheaper and safer. With fast reactors the amount of waste is reduced significantly. If all the money thrown towards green electricity would have been used for nuclear development we would be in a much better position.
Germany is taking a step backwards by building a lot of new coal plants to safeguard their electricity supply. As they continue to build more and more windmills it will become increasingly difficult to accomodate the wind energy on the grid, since even modern coal plants cannot be ramped up very quickly. A better plan would be to build more nukes and switch off all wind and solar plants.
Nothing to add technically, just saying thanks for the discussions so far.
Sandy
Commercial use of hydrogen as an energy carrier for vehicles is a pipe dream. Excuse the pun.
Check out the performance of Ballard Power Systems of Vancouver.
In the hayday of the hydrogen hype they were promoted as the global leaders in fuel cell technology. They had multi-million dollar research agreements with Mercedes and other automotive manufacturers. Their share price reached just shy of $200 Cdn in 2001, today they trade below $1Cdn. They trade on the Toronto exchange, TSX, under the symbol BLD.
Tim Worstall: "[I]nefficiency doesn't matter if you can make the equipment cheaply enough."
It will still matter because, at bottom, one has to account for area-based costs such as land, and fixed costs. Willis Eschenbach discussed some of these here; while his discussion concerned a PV power plant rather than PV electrolysis, some of the points remain relevant here. Inefficiency means that fixed costs will amortized over a smaller output. Alternately, a larger array is required to support fixed costs, and this larger array will impose additional cost.
I'm not saying that PV-based energy generation *can't* work. But I'm not convinced that it's just around the corner. Here's a question: is there significant investigation into the technologies involved which is *not* subsidised by government? To me, that's a better indicator of likelihood. While venture capitalists and corporations make plenty of investments which don't pan out, they're more likely to be sniffing about in the right places.
Jiminy - glad to hear you have an Imp. I built a kit car with Imp mechanicals years ago, and I think I lifted the engine into place manually! To your wider point, cars that you can maintain are far less draining of resources than ever more complicated designs that require specialist attention, especially when that involves items like Lithium batteries that are hard to manufacture and recycle, and are designed to fit only one model.
I suspect that keeping old cars running (thus deferring the need to consume the resources needed to make new ones) is relatively 'green', but governments and manufacturers don't like it, using scare tactics like emissions to persuade us otherwise. I drive a 15-year old Mazda that works perfectly well, but I can't see many Priuses or Leafs (leaves?) appearing on the banger market!
BTW, who is 'today's moderator'? Is he/she after Bish's job..?