manxmike1
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RE: Zero interest, Zero bikes
With regard to the Subaru laps, I understand that the money raised actually goes to help fund the prize money, so it serves a very useful purpose.
I must admit to being impressed that eight electric milk floats finished the "race", sadly I still can't raise any excitement about it.
I sincerely hope that no-one is still labouring under the impression that the electric bikes are in any way "green". The fossil fuel used to charge the batteries (never mind create the things) far exceeds the amount used by a similar petrol powered machine over a similar distance.
The argument is that "this is the future", well, what about hydrogen power cells? The technology has been around for a long time and powered the NASA moon flights. It is clean, it does not (unlike the battery power) produce great amounts of heat as a waste product. A hydrogen cell could be changed as quickly as a re-fuel allowing more laps, would be lighter than the batteries and eminently recyclable (is that a word?).
I wonder if the Zero rules only allow electric battery power, or is it open to alternatives? Come on Universities, you can't compete with the amount of money Honda San and Mugen San are throwing at the project so think outside the box!
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10-06-2017, 09:12 AM |
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AndyL
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RE: Zero interest, Zero bikes
(10-06-2017, 09:12 AM)manxmike1 Wrote: I sincerely hope that no-one is still labouring under the impression that the electric bikes are in any way "green". The fossil fuel used to charge the batteries (never mind create the things) far exceeds the amount used by a similar petrol powered machine over a similar distance.
Do you have a source for this? Even a coal-fired power station has better thermal efficiency than a small petrol engine. Gas ones much more so. And close to half of UK grid electricity is produced from non-fossil-carbon sources.
(10-06-2017, 09:12 AM)manxmike1 Wrote: The argument is that "this is the future", well, what about hydrogen power cells? The technology has been around for a long time and powered the NASA moon flights. It is clean, it does not (unlike the battery power) produce great amounts of heat as a waste product. A hydrogen cell could be changed as quickly as a re-fuel allowing more laps, would be lighter than the batteries and eminently recyclable (is that a word?).
I wonder if the Zero rules only allow electric battery power, or is it open to alternatives? Come on Universities, you can't compete with the amount of money Honda San and Mugen San are throwing at the project so think outside the box!
I think when the TTXGP first came in, the rules were quite broad and did allow fuel cells - and no-one attempted one. But now the TT Zero rules specify "stored electricity".
I have to say if hydrogen fuel cell technology was as easy and effective as you suggest, then the electric car and bike market probably wouldn't be entirely composed of battery-powered vehicles. Storage of hydrogen is a major problem. The NASA space applications have used liquid hydrogen at -250°C. To liquefy the hydrogen in the first place requires a large amount of energy.
And as for producing heat as a waste product, if you do a certain amount of work you'll produce a certain amount of waste heat, there's no getting away from that.
(This post was last modified: 10-06-2017, 12:15 PM by AndyL.)
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10-06-2017, 12:13 PM |
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AndyL
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RE: Zero interest, Zero bikes
(10-06-2017, 09:12 AM)manxmike1 Wrote: I sincerely hope that no-one is still labouring under the impression that the electric bikes are in any way "green". The fossil fuel used to charge the batteries (never mind create the things) far exceeds the amount used by a similar petrol powered machine over a similar distance.
Let's see if we can do a back-of-a-fag-packet calculation to work it out.
Say you want your electric bike to do 10 joules of work.
The electric drivetrain is abut 80% efficient so you need to charge it up with 12 joules of electricity.
Grid electricity nowadays is, very roughly, 50% nuclear/renewables, 30% gas, 20% coal.
So we only get 6 joules from fossil fuels - let's approximate it as 4 from gas and 2 from coal.
The gas power station is 60% efficient, so we need to burn 7 joules of gas.
The coal station is 30% efficient so we burn 7 joules of coal.
UK transmission grid losses are 8% so we need to burn another couple of joules of gas and coal to cover that, making 16 joules of fossil fuel burned.
A petrol engine in a bike is 20% efficient at best, so to do the same 10 joules of work, it burns at least 50 joules of fossil fuel. More than 3x as much as the electric bike used.
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10-06-2017, 12:49 PM |
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