Electric cars-Conversions

This is the place for posts that don't fit into any other category.

Moderator: RichardW

User avatar
Mandrake
Posts: 8240
Joined: 10 Apr 2005, 17:23
x 347

Re: Electric cars/vans/bikes-Conversions/Secondhand..etc

Post by Mandrake »

The thing I think is interesting about Solar power is it is the most "direct" and pure form of power generation there is - it is capturing the sunlight directly from the sun, which after all is where ALL the energy on earth comes from in the first place.

Without the sun shining down for millions of years there would be no dinosaurs to be fossilised and turned into crude oil.... there wouldn't be any wind to power wind turbines, waves to power wave generation, rain to power hydroelectric dams, crops to generate biodiesel, pooping animals to generate methane etc...all of these are powered indirectly (and inefficiently!) by the sun in some way.

The efficiency of energy transfer from sunlight to wind for example must be vanishingly small, as wind is a result of differential heating of different landmasses and water vs land. One square metre of solar power (if the collector was 100% efficient, which it isn't, and at mid day) is about 1kW - how much wind do you generate per square metre of heated ground and how much power can that contribute to turning a wind generator ? Not much by comparison I'm guessing!

The UK isn't particularly well placed for solar generation (especially up here in Scotland) but there are large parts of some countries that are just begging for mile after mile of solar panels - look at somewhere like the Nevada desert in the US, or the outback in Australia. Thousands of square miles of uninhabited desert bathed in regular sunlight that is basically going to waste.

The big issue at the moment is that solar panel efficiency (at least of the photo-voltaic kind) is still languishing at around 17% in mass produced types, due to the quantum nature of how the panels work. (Only a narrow range of frequencies in the light spectrum are converted to electrons) I don't know enough to know whether this will ever be solved, but imagine if this efficiency could be raised to 80% or more, it would be game changing.

It may well be that focusing the light with arrays of tracking reflectors and using it to boil water and turn a steam turbine is more efficient (in fact I'm sure it is) but you then have a lot of moving parts and maintenance to deal with, whereas a silicon solar panel is more or less install it and forget it until it eventually dies...

User avatar
CitroJim
A very naughty boy
Posts: 43086
Joined: 30 Apr 2005, 23:33
x 1494

Re: Electric cars/vans/bikes-Conversions/Secondhand..etc

Post by CitroJim »

The next problem Simon, is how to export all that power generated in sunnier climes to those places less sunny...

Has any serious thought been given to that?

User avatar
Mandrake
Posts: 8240
Joined: 10 Apr 2005, 17:23
x 347

Re: Electric cars/vans/bikes-Conversions/Secondhand..etc

Post by Mandrake »

CitroJim wrote:The next problem Simon, is how to export all that power generated in sunnier climes to those places less sunny...

Has any serious thought been given to that?
Good question, to which I don't know the answer.

Somewhere like Nevada is great because you have the perfect place for solar collection, then only a couple of hundred miles away a populace place like California to deliver the power to. So traditional cross country power distribution is all that is needed there.

But I assume you mean exporting the power from one country to another. If they are nearby countries I wonder if just using the electrical grid is feasible ? We are looking at switching power provider and in the process on reading up on the UK power networks I discovered to my surprise that a large part of the electricity consumed in the UK at peak times comes from France! Presumably there is some direct grid interconnect between France and the UK to achieve this...

Of course this would only make a cloudy damp country like the UK a net energy importer, relying heavily on other countries, which is not a good thing. I guess we'll have to make do with wind, waves and hydroelectric and not so much on the Solar. :twisted:

Online
User avatar
myglaren
Forum Admin Team
Posts: 19087
Joined: 02 Mar 2008, 14:30
x 1277

Re: Electric cars/vans/bikes-Conversions/Secondhand..etc

Post by myglaren »

Ironic that we can generate the most power when we least need it and vice versa.

Hell Razor5543
NOT Alistair or Simon
Posts: 11083
Joined: 01 Apr 2012, 09:47
x 1183

Re: Electric cars/vans/bikes-Conversions/Secondhand..etc

Post by Hell Razor5543 »

Didn't Nicolai Tesla come up with a way to charge the ionosphere in such a way that would allow for wireless power transfer? I think that this caused the power generating companies some concern.

elma
Posts: 3745
Joined: 13 May 2007, 02:17
x 213

Re: Electric cars/vans/bikes-Conversions/Secondhand..etc

Post by elma »

Sort of, he was firing radio waves into the ionosphere which were coming back with more energy having interacted with the magnetic fields and existing em radiation in the ionosphere. His wireless distribution technique was similar and has only proven to work over relatively small distances compared to what he actually wished to achieve. The amount of power loss, and hugeness of magnets required for transmitting electricity in this manner is unbelievable. I've managed about 1meter with a voltage drop of about 90% using Teslas work as guidance. Of course he was a genius and his version was torn down before it was turned on, I doubt it would work myself but if anyone could've done it Mr Tesla was the man.

User avatar
white exec
Moderating Team
Posts: 6415
Joined: 21 Dec 2015, 13:46
x 1084

Re: Electric cars/vans/bikes-Conversions/Secondhand..etc

Post by white exec »

Yes, he did. High frequency energy transmission. Worth a read about him. Quite a character, who had lots of arguments with Edison (who he worked for, and was swindled by) and many others. Edison backed d.c., while Tesla did the other thing, thank goodness, but nearly got forgotten in the process.

A few years ago, a number of large German power and construction companies drew up a project to build a string of solar boilers (controlled mirror array, focussing sun's heat on to a steam-generating boiler at top of a pylon), with high-efficiency turbines/alternators in tow. These were to be build across North Africa, from Morocco to Egypt, and feed massive amounts of power into Europe, with a quantity of it made available as payment to the countries hosting the equipment. After attracting the necessary financial backing, the whole project was put on ice, following the political instability of the region.

Spain had one of these solar-steam arrays, which has been in full use for some years. At their best, at times Spain can generate about 43% of their power requirement from 'renewables'. There has been an impressive investment in wind power.

Online
User avatar
myglaren
Forum Admin Team
Posts: 19087
Joined: 02 Mar 2008, 14:30
x 1277

Re: Electric cars/vans/bikes-Conversions/Secondhand..etc

Post by myglaren »

The Spanish one is very impressive.

Hell Razor5543
NOT Alistair or Simon
Posts: 11083
Joined: 01 Apr 2012, 09:47
x 1183

Re: Electric cars/vans/bikes-Conversions/Secondhand..etc

Post by Hell Razor5543 »

I saw (on the BBC 'Click' programme) a drone that did not have any batteries, and was flying on 'beamed' energy. Part of what helped it to work was the fact they had raised the frequency a long way.

Gibbo2286
Donor 2020
Posts: 4854
Joined: 08 Jun 2011, 18:04
x 898

Re: Electric cars/vans/bikes-Conversions/Secondhand..etc

Post by Gibbo2286 »

I think come the crunch we will turn back to coal and sod the environment if we get to the position that we're held to ransom by other countries/suppliers, there's supposed to be three hundred years worth of it sitting under our feet.

User avatar
CitroJim
A very naughty boy
Posts: 43086
Joined: 30 Apr 2005, 23:33
x 1494

Re: Electric cars/vans/bikes-Conversions/Secondhand..etc

Post by CitroJim »

Mandrake wrote:
CitroJim wrote:The next problem Simon, is how to export all that power generated in sunnier climes to those places less sunny...

Has any serious thought been given to that?
But I assume you mean exporting the power from one country to another.
Yes, exactly that Simon. Say from the Sahara to the UK...

The UK and France are certainly linked and I believe the transmission is DC rather than AC. The reason being is there is no need to keep the UK AC mains synchronised with the French AC mains... Years back this system used massive Mercury Vapour Rectifiers.

I suppose by extension a link between the Sahara and the UK might pass the power to the UK via the distribution systems in each country along the way with presumably lots of DC/AC conversions along the way...

Then one has to look at how much is lost on the journey. Quite a bit I expect but then as the original energy is free maybe it hardly matters.

Maybe another method might be to use this free energy to create a fuel locally that can easily be transported to fuel power stations far away - maybe electrolysis of sea water to generate hydrogen which can then be shipped in large tankers for power generation and even filling the fuel tanks of hydrogen cars...

User avatar
Zelandeth
Donor 2016
Posts: 3741
Joined: 17 Nov 2014, 00:36
x 376

Re: Electric cars/vans/bikes-Conversions/Secondhand..etc

Post by Zelandeth »

Think you'll find that the losses Jim can be kept surprisingly low actually if you use a very high voltage DC transmission line. Obviously there are practical limits and tradeoffs and such along the way, and as you say if the energy is essentially free the overall system efficiency is slightly less critical.

Have to admit that I do like the idea of taking an old electric 106 and retrofitting it with more modern battery technology. We used to run a trio of them back when I worked at the Council, and they were lovely little things to drive. Only headache we had with them was that it was so common to find that the previous user hadn't plugged the car in when they got back.

To be honest, even in their standard form with the number of miles I tend to do these days, I'd happily have one as a second car...

User avatar
CitroJim
A very naughty boy
Posts: 43086
Joined: 30 Apr 2005, 23:33
x 1494

Re: Electric cars/vans/bikes-Conversions/Secondhand..etc

Post by CitroJim »

Zelandeth wrote: To be honest, even in their standard form with the number of miles I tend to do these days, I'd happily have one as a second car...
Given my current circumstances, one of those would be perfect for me too. Ideal for the occasional journey to work when cycling is not on and for the weekly outing to Tesco... It's generally all my cars do now barring joyrides and rallies in the Activa...

User avatar
bobins
Donor 2020
Posts: 3800
Joined: 05 Jul 2012, 18:07
x 1126

Re: Electric cars/vans/bikes-Conversions/Secondhand..etc

Post by bobins »

CitroJim wrote:
The UK and France are certainly linked and I believe the transmission is DC rather than AC. The reason being is there is no need to keep the UK AC mains synchronised with the French AC mains... Years back this system used massive Mercury Vapour Rectifiers.
I was always under the impression that one of the continental power links made landfall at Dungeness - but Wikipedia makes no reference to that.....
https://en.wikipedia.org/wiki/HVDC_Cross-Channel

Edit: To correct my own post......
"From 1961 to 1984, Dungeness power station also housed the mercury arc valves of the static inverter plant converting AC into DC for transmission on HVDC Cross-Channel, the high-voltage direct current power cable carrying electric power across the English Channel to France. In 1983, a more powerful new inverter at Sellindge replaced this facility."

User avatar
CitroJim
A very naughty boy
Posts: 43086
Joined: 30 Apr 2005, 23:33
x 1494

Re: Electric cars/vans/bikes-Conversions/Secondhand..etc

Post by CitroJim »

bobins wrote:
CitroJim wrote:
The UK and France are certainly linked and I believe the transmission is DC rather than AC. The reason being is there is no need to keep the UK AC mains synchronised with the French AC mains... Years back this system used massive Mercury Vapour Rectifiers.
I was always under the impression that one of the continental power links made landfall at Dungeness - but Wikipedia makes no reference to that.....
https://en.wikipedia.org/wiki/HVDC_Cross-Channel

Edit: To correct my own post......
"From 1961 to 1984, Dungeness power station also housed the mercury arc valves of the static inverter plant converting AC into DC for transmission on HVDC Cross-Channel, the high-voltage direct current power cable carrying electric power across the English Channel to France. In 1983, a more powerful new inverter at Sellindge replaced this facility."
Ahh, so it must have been when the new inverter came on-line they retired the old mercury vapour rectifiers...