On 03/03/2019 16:47, The Natural Philosopher wrote:
On 03/03/2019 15:59, Nightjar wrote:
On 02/03/2019 18:11, Tim Streater wrote:
In article , Nightjar
wrote:

On 02/03/2019 17:14, Tim Streater wrote:
In article , Nightjar
wrote:

On 02/03/2019 16:34, harry wrote:
On Saturday, 2 March 2019 14:48:02 UTC, BroadbackÂ* wrote:
When I was a young man, a long time ago, bottles were glass and
bags
were paper. Why cant the supermarkets revert to those? Bottles were
returned and paper used to light our fires. Then we moved to gas
(mainly) central heating, Now that is a no no. Incidentally what
will
happen to the businesses that primarily sell gas appliances?
Will they
be compensated?

Domestic gas is to be banned in a few years.

If you call 30 years a few. Even so, biogas is being considered as
an acceptable alternative, so it might be more akin to the
changeover from town gas to natural gas than a complete end to gas
as a fuel.

What's so magic about biogas? How does it differ from methane?


It is renewable, uses no energy to produce it, reduces soil and
water pollution (as compared to landfill), has organic fertiliser as
a by-product and the production cycle captures methane, resulting in
a zero-emissions fuel.

Thanks for not answering my question which was, how does it differ from
methane. Are you implying that it doesn't?

If you were trying to describe how it's produced, you've not done that
either.


I did answer your question. I gave the differences that make biogas a
suitable alternative to fossil fuel gas. Those are the only relevant
differences that would affect its choice as a substitute.

However, its similarity to natural gas, in being a good source of
methane, would also make it a better choice than, say hydrogen. On
average, biogas contains slightly less methane than natural gas;
55-70% cf 60-90%. However, the gas that reaches the consumer today has
been processed to be almost pure methane and, if that can also be done
with biogas, it could result in a seamless changeover.



As usual you have simp0ly not done the sums.

The total land area of Great Britain is 209,331 km^2

The average outout of a field of best practice biomass growth in terms
of unprocessed biomass is 0.2W/sq m opr 0.2MW/sq km

So if the *whole of great britain* were laid down to biofuel - assuming
it could be grown in the scottish highlands etc -Â* would be around 40GW.

Convert that into gas and you wouldnt get anywhere near that.

The TOTAL energy consumption of the UK averages out at 256GW give or take.

THERE IS NOT ENOUGH SUNLIGHT FALLING ON THE ENTIRE UK TO GROW ENOUGH
BIOMASS TO REPLACE NMATUYRAL GAS AND FOSSIL FUELS BY A FACTOR of 6:1

BIOMASS is ten times less efficent than windmills, which are 50 times
less efficient than solar panels, in terms of ouput per unit land area,
and the only virtue is that they represent stored energy.

Why dont you go away and do some basic research before spouting your
mindless fact free fourth hand 'opinions'

You could do worse than to follow your own advice and understand what
you are commenting on before going into a full scale rant. The
government study I was referring to was about how biogas from the
digestion of organic waste could form part of the country's future
energy policy. There was nothing about growing crops to produce it and
certainly no intention of using it to replace our entire energy needs.

The motivation behind the study was the reduction of greenhouse gas
emissions. As organic waste in landfill is a significant source of those
emissions, the study looked at other long term answers. Anaerobic
digestion was considered the best option, as it produces both methane
and fertiliser. Using the methane as a substitute for natural gas is
only one option considered, others being to use it to generate
electricity or as a chemical feedstock.


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Colin Bignell