[sweet nasturtium]

We had mini-quiches and smoked salmon for tea! :roll:

[DD.]

But the great thing about veg oil fuel is that, if you really need to, you can also use it as food.  You can't eat diesel.

I think you are muddying the water here.  I will use a thousand times as many litres of fuel in a year than I will consume as food.

Maybe someone can do the arithmetic : how many hectares of rape seed would be needed to grow the 2500 litres of fuel which I will use each year?

According to this site..

http://journeytoforever.org/biodiesel_yield.html#alph

One hectare will produce 1190 litres of oil.

2.1 Hectares required to produce yearly consumption.

That equals 21,000 sq metres, which equates to 70 of my 300 sq m allotment!

[gobs]

Even a bit more area required as it also says, biodiesel= oilx0.8, approx.

Does not really matter though, because the highest yielding plants are tropical, all forests go, and even then the mighty palm oil would only answer two persons such consumption per ha.

I got depressed now. Isn't then using vegetable oil for running your cars supporting such markets and de-forestation? :?

[Selkie]

Isn't rape grown in the UK? (though I don't know whether that ends up as animal feed or vegetable oil) -- I guess you could check for a country of origin on your big bottle of vegetable oil....

[WG.]

Thanks for stats DD.

 Isn't then using vegetable oil for running your cars supporting such markets and de-forestation? :?

That's what I was saying on http://www.chat.allotment-garden.org/viewtopic.php?p=138057#138057

It may be better than burning mineral diesel but burning LESS of anything is the best solution.  Roll on the hydrogen cell.

[gobs]

Where do we get the hydrogen from, just what I was hinting on, water- we don't seem to have much, burning fossil fuels or from biodiesels, run a whole circle there, didn't we?

Less, is good point, don't know how much would be adequate.

[DD.]

Electrolysis of water produces two hydrogen atoms & one oxygen.

Burning hydrogen recombines two hydrogen atoms with one oxgen to produce water as a by-product.

No net loss.

If the electrolysis of water is done using renewable energy sources - job done.

That's the BASIC theory. Now the practice..........................

[gobs]

Electrolysis of water produces two hydrogen atoms & one oxygen.

Burning hydrogen recombines two hydrogen atoms with one oxgen to produce water as a by-product.

No net loss.

If the electrolysis of water is done using renewable energy sources - job done.

That's the BASIC theory. Now the practice..........................

I think you spot on their. As far as I know, most of production as of current is done by burning some fuels...

[WG.]

most of production as of current is done by burning some fuels...

Electricity can come from renewables too, as DD says.  Even if it doesn't, the consumption of hydrocarbon fuel is greatly reduced.

And remember that electric cars can charge their batteries when braking too !!!

[sweet nasturtium]

But it's got to be better than burning fossil fuels - provided there is no deforestation.

The stuff has to grow in order to produce the oil, and the growing process will consume co2 in the atmosphere, which is a good thing.

Also, it can be produced locally and so reduces the need for transportation of oil, including environmental accidents.

And when times are hard, it can be used to feed people as well.

I think it also produces less carbon dioxide when combusted (but don't quote me).

But well done DD for your calculations - 300 allotment plots I can understand!

[WG.]

It is the scale of the problem that is scary.

19 million vehicles on British roads on the Friday before Christmas.  Let's assume that the average journey on that SINGLE DAY used 50 litres.

950,000,000 litres of biodiesel would occupy approx a million hectares (33,263,305 allotments) for a whole year to grow enough rape seed oil for one day's consumption.  Add to that that rape is cruciferous and is therefore susceptible to clubroot.  Normal rotation would mean growing in one year out of 5 or even 7.

One million hectares is approx 10% of the TOTAL agricultural area in England.

[sweet nasturtium]

It is the scale of the problem that is scary.

19 million vehicles on British roads on the Friday before Christmas.  Let's assume that the average journey on that SINGLE DAY used 50 litres.

950,000,000 litres of biodiesel would occupy approx a million hectares (33,263,305 allotments) for a whole year to grow enough rape seed oil for one day's consumption.  Add to that that rape is cruciferous and is therefore susceptible to clubroot.  Normal rotation would mean growing in one year out of 5 or even 7.

One million hectares is approx 10% of the TOTAL agricultural area in England.

Hold up - since when does one use 50 litres on an average journey???

[WG.]

Hold up - since when does one use 50 litres on an average journey???

Going home for Christmas?  Remember trucks will burn one litre every couple of minutes.

Okay - if you want to be picky, then you can play around with my figures to show that England could grow enough rape to fuel all its diesel vehicles for a whole WEEK.    :?  

[sweet nasturtium]

So that's one million hectares for 50 days supply (assuming av. 10 mile car journey - we're not talking trucks at the mo and don't argue :roll: )

1million hectares being 10% of England's agricultural growing area.
so we could provide 350 days worth per year and only be using up 70% of England's agricultural space.

That leaves the whole of Scotland for growing the biodiesel for the trucks.  (for getting the pine wood down South to build Ruby's ecovillage ).

[WG.]

Think you can post late and not have me notice, huh!

All I can say is ... agreed.      and good night.