Diesels to be banned

[furnessvale]

3 hours ago, David Schweizer said:

I assume that observation is intended to be ironic, we have plenty of hills and water flows downhill. Memory of my schoolboy physics suggest that the height of the source is irrelevant, it is the restriction of the flow channel which increases speed.

I believe it is more to do with the volume that can be contained for storage rather than the available head.

Certainly the people in the know about such things, think the UK has just about exhausted all its available hydro sites.

George

[Murflynn]

1 hour ago, Alan de Enfield said:

 

It is crazy that we use 'potable water' to wash our clothes and flush our toilets, there should be a dual-system with rain water 'catching' as a priority for secondary uses.

 

'potable water' is treated rainwater.  water treatment is not particularly energy-hungry.

installing a dual water system in parallel with the existing mains connections to every household would certainly be energy-hungry.

nothing stopping you saving rainwater in a tank (and treating it so it doesn't grow green stuff) and using it to do your washing; if you have a water meter it may pay for itself in 20 years. 

[mross]

2 minutes ago, Murflynn said:

'potable water' is treated rainwater.

No it isn't.  Potable just means fit to drink, it can come from anywhere.

[Alan de Enfield]

5 minutes ago, Murflynn said:

'potable water' is treated rainwater.  water treatment is not particularly energy-hungry.

installing a dual water system in parallel with the existing mains connections to every household would certainly be energy-hungry.

nothing stopping you saving rainwater in a tank (and treating it so it doesn't grow green stuff) and using it to do your washing; if you have a water meter it may pay for itself in 20 years. 

I think you are misunderstanding.

There is no suggestion that a 'secondary water main' should be laid countrywide, just that all new houses (and those that want to) are built / modified such that they have their own catchment system (basically water running off the roof, into a tub, and piped into the toilet)

Not a lot of energy-cost (or financial cost) in doing that.

[Murflynn]

1 minute ago, furnessvale said:

I believe it is more to do with the volume that can be contained for storage rather than the available head.

Certainly the people in the know about such things, think the UK has just about exhausted all its available hydro sites.

George

Not quite.

the energy stored in water is provided by kinetic energy (flow) plus potential energy (mass and available head).

the amount of kinetic energy available in most English rivers is limited and nearly zero in a dry summer (like we were heading towards a month ago).

the amount of potential energy is considerable if you have a high dam that allows a large flow continuously, again a scenario not found in England in more than a handful of places.  However, pumping water uphill into a high storage dam is an excellent means of storing energy, as was done in the Dinorwic scheme in Wales, and is a partial solution that can be used to partner wind farms.

if anyone is in any doubt that wind farms will provide a huge proportion of our energy needs in the middle future, check the investments being made in the industry, particularly around the coast of the British Isles which is one of the windiest places on the planet.  Even the Gulf countries want to get involved - they would like to keep a share of the UK energy supply even when we no longer want to import their hydrocarbons.  

8 minutes ago, mross said:

No it isn't.  Potable just means fit to drink, it can come from anywhere.

I know what it means, but in the UK where it doesn't come from desalination or from glaciers, it comes from the sky.  

[David Schweizer]

11 minutes ago, furnessvale said:

I believe it is more to do with the volume that can be contained for storage rather than the available head.

Certainly the people in the know about such things, think the UK has just about exhausted all its available hydro sites.

George

That will be the case where large hydro electric dams are in place, but on rivers like the Thames, there is always a head of water feeding the weirs, the upper river stretches acting as a reservoir. The small Hydro electric systems I have seen in Switzerland are fed by constantly flowing rivers, most of which are much narrower than our larger rivers.

[mross]

Wind farms are very profitable only because they are heavily subsidised.  This is due to our governments commitment to renewable energy.

[David Schweizer]

23 minutes ago, Murflynn said:

'potable water' is treated rainwater.  water treatment is not particularly energy-hungry.

installing a dual water system in parallel with the existing mains connections to every household would certainly be energy-hungry.

nothing stopping you saving rainwater in a tank (and treating it so it doesn't grow green stuff) and using it to do your washing; if you have a water meter it may pay for itself in 20 years. 

I'm sorry but you clearly do not know what you are talking about, The tanks used in Australia cost a few hundred dollars and are installed above ground, the water is fed to the house by gravity. All mains water in Victoria State is metered, believe me if it wasn't cost effective, my son would not have installed the system in the first place,

Edited July 26, 2017 by David Schweizer

[Murflynn]

2 hours ago, mross said:

We already grow enough food to feed 11 billion people.  Unfortunately, much of it is wasted by converting it to bio fuel and animal feed.  The world population will peak at 11 billion due to declining family sizes.  This is happening all over the world as women are empowered to control their own bodies.  If you don't believe me, watch the excellent presentations from Gapminder by the famous statistician Hans Rosling.

And your point is?

I prefer to listen to David Attenbrough who concluded at the end of one of his documentary series that the sustainable human population is about 1 billion, at which level no more species need to go extinct prematurely and there would be no need to burn the rain forests or fight over water rights.

It is not all about food, it is more about the general tendency of humans to want more and more - more space, more water, more energy, more holidays, more gadgets and belongings that give people satisfaction - like narrowboats that aren't used as a residence, or oversized cars that sit in the driveway most of the week, or house extensions undertaken just to pump up the resale value.  The Chinese and the Indians are well on their way to providing themselves with all these luxuries, just wait till the Africans go the same way. 

11 billion is not sustainable, nor is 7 billion, where we are now, and we all know it.  Even 'economic migration' which powers the majority of the Libyan boat people and the Calais jungle dwellers is the result of an unsustainable population, particularly from the Indian sub-continent and in Africa.

 

[Murflynn]

18 minutes ago, Alan de Enfield said:

I think you are misunderstanding.

There is no suggestion that a 'secondary water main' should be laid countrywide, just that all new houses (and those that want to) are built / modified such that they have their own catchment system (basically water running off the roof, into a tub, and piped into the toilet)

Not a lot of energy-cost (or financial cost) in doing that.

no, I fully understand and you have confirmed the only practical way to do it.  However the current housing stock will make up most of our accommodation for a generation or so, and installing catchment tanks in new developments will only scratch the surface.  In any event, UK water availability is not a major issue, because we already have the means to use and re-use most of our river water, sometimes several times over (like the Thames).

you can be sure that in places where water is not readily available the locals already harvest all the rainwater that they can.

[Jerra]

18 minutes ago, David Schweizer said:

I'm sorry but you clearly do not know what you are talking about, The tanks used in Australia cost a few hundred dollars and are installed above ground, the water is fed to the house by gravity. All mains water in Victoria State is metered, believe me if it wasn't cost effective, my son would not have installed the system in the first place,

One thing to keep in mind is that Australia has an awful lot of a natural resource we lack .......... 

 

Land!

Many many houses in the UK wouldn't have space lots don't even have room for recycling bins.

[furnessvale]

25 minutes ago, Murflynn said:

Not quite.

the energy stored in water is provided by kinetic energy (flow) plus potential energy (mass and available head).

the amount of kinetic energy available in most English rivers is limited and nearly zero in a dry summer (like we were heading towards a month ago).

the amount of potential energy is considerable if you have a high dam that allows a large flow continuously, again a scenario not found in England in more than a handful of places.  However, pumping water uphill into a high storage dam is an excellent means of storing energy, as was done in the Dinorwic scheme in Wales, and is a partial solution that can be used to partner wind farms.

<SNIP>

 

All agreed.  Perhaps you misunderstand my comment.  I was saying the reason we do not have more hydro in the UK is that we have run out of sites where we can store the volumes required.

George

[dor]

2 hours ago, David Schweizer said:

Which is exactly what many homes in Victoria State (Australia) have. My son lives in Beechworth and has mains water for drinking, cooking etc. and collects water from the house roof in a huge tank for all other use. He is currently planning an extention to his property and will be installing a secod tank to collect the additional "free" water.

His father in law is a farmer and lives about ten miles out of town, where there is no mains water, he has a triple system. He has a series of  ponds running down the hillside behind the farm, which collect ground surface water for agricultural use, he collects water off various barn roofs into tanks, for non drinking domestic use, and has borehole pump for drinking water. He has access to so much "free" water that his farm is the rostering point for the fire and emergency services when there are bush fires. As far as I know, in his 70 years on the farm, they have never run out of water.

 

Melbourne has had a serious water problem.  Many houses only have "tank water" and no potable supply.  Melbourne had ten years of drought which put huge strains on their water supply.  To protect itself, it has built one of the largest and most efficient desalination plants (reverse osmosis) in the world to the south of the city.  It came on stream about two years ago. Since being fully commissioned it has hardly supplied any water as rainfall has been higher than normal.  It cost billions too!

[WotEver]

8 minutes ago, dor said:

Melbourne has had a serious water problem.  Many houses only have "tank water" and no potable supply.  Melbourne had ten years of drought which put huge strains on their water supply.  To protect itself, it has built one of the largest and most efficient desalination plants (reverse osmosis) in the world to the south of the city.  It came on stream about two years ago. Since being fully commissioned it has hardly supplied any water as rainfall has been higher than normal.  It cost billions too!

However, the next time there's a sustained drought they're ready for it. And by then it would cost tens of billions

[David Schweizer]

41 minutes ago, Jerra said:

One thing to keep in mind is that Australia has an awful lot of a natural resource we lack .......... 

 

Land!

Many many houses in the UK wouldn't have space lots don't even have room for recycling bins.

Very True, but some houses in the larger towns are now being squashed in like those built in the UK, In Wodonga we saw new houses with barely a metre between them.

23 minutes ago, dor said:

Melbourne has had a serious water problem.  Many houses only have "tank water" and no potable supply.  Melbourne had ten years of drought which put huge strains on their water supply.  To protect itself, it has built one of the largest and most efficient desalination plants (reverse osmosis) in the world to the south of the city.  It came on stream about two years ago. Since being fully commissioned it has hardly supplied any water as rainfall has been higher than normal.  It cost billions too!

True. When my son lived in Melbourne, he was very aware of the water shortage, and could not believe how wasteful some Australian residents were with water.

[MtB]

Getting back on topic, is it considered that the battery technology we now have is adequate? Or is the govt assuming technology will advance and ranges grow and charge times reduce? A bit of a big assumption in my view.

What sort of range do modern electric cars have and what sort of re-charge time do they require? 

[bozlite]

1 hour ago, mross said:

Wind farms are very profitable only because they are heavily subsidised.  This is due to our governments commitment to renewable energy.

Is that still the case? I read here that Germany are now commissioning subsidy-free offshore farms: http://gcaptain.com/germany-trumpets-first-subsidy-free-offshore-wind-farm/

[Alan de Enfield]

3 minutes ago, Mike the Boilerman said:

What sort of range do modern electric cars have and what sort of re-charge time do they require? 

No personal experience but I've often heard the saying "30-50 or 50-30" regarding the range.

You can do 30 miles at 50mph, or 50 miles at 30mph.

It was interesting watching Clarkson trying to do tests and the cars could never quite get to the next charging point - at one point he ended up in Lincoln with an extension lead thru someones window.

[MtB]

1 minute ago, Alan de Enfield said:

No personal experience but I've often heard the saying "30-50 or 50-30" regarding the range.

You can do 30 miles at 50mph, or 50 miles at 30mph.

It was interesting watching Clarkson trying to do tests and the cars could never quite get to the next charging point - at one point he ended up in Lincoln with an extension lead thru someones window.

 

That sounds like plain silliness for the sake of good telly. Even a 13A extension lead would take tens if not hundreds of hours to supply enough energy to recharge a car motive battery.

30 miles at 50mph is a PATHETIC range and utterly unuseable except perhaps for running the brats to skool and a bit of local shopping.  

 

[dor]

7 minutes ago, Alan de Enfield said:

No personal experience but I've often heard the saying "30-50 or 50-30" regarding the range.

You can do 30 miles at 50mph, or 50 miles at 30mph.

It was interesting watching Clarkson trying to do tests and the cars could never quite get to the next charging point - at one point he ended up in Lincoln with an extension lead thru someones window.

I think a Tesla is good for about 300 miles.  Not sure how long it would take to recharge after that!

[WotEver]

2 minutes ago, Mike the Boilerman said:

30 miles at 50mph is a PATHETIC range and utterly unuseable except perhaps for running the brats to skool and a bit of local shopping.  

There are four main obstacles to electric vehicles with today's technology. 

1. The range is pathetic. 

2. Charging times are excessive. 30 minutes for a fast boost to 80%, so now your range is only 80% of what you started off with. 

3. Vastly inferior numbers of charging stations. Maybe 1 or 2 at a motorway service station. Maybe 1 or 2 in a city centre car park etc. 

4. If 1, 2, and 3 were to be addressed we'd require several extra power stations (as already pointed out) 

3 minutes ago, dor said:

I think a Tesla is good for about 300 miles.  Not sure how long it would take to recharge after that!

A full 300-mile charge takes around 9.5 hours. Bit of a problem if you want to travel 500 miles...

[dor]

3 minutes ago, WotEver said:

A full 300-mile charge takes around 9.5 hours. Bit of a problem if you want to travel 500 miles...

One would hope there will be some very significant improvements in capacity and recharge rate over the next 20+ years.  One way round the charging would be to have swappable battery cartridges.  This would also make it easier to tax, with the option to charge untaxed from your own solar.   The alternative is being stuck with hybrids, which at the moment are a compromise and fall between two stools.  It is still going to need a huge investment in the infrastructure, both for providing the power in the first place and having recharge points.

I saw something the othe day which says we will all have solar/battery setups alongside the grid feed, and people will be rewarded for turning off their car chargers, washing machines or water heaters and other high current devices for a few minutes.  One house doing it won't mean much, but several million switching off for ten minutes here and there could give a significant reduction in generation capacity when averaged out.

[IanD]

1 hour ago, David Schweizer said:

That will be the case where large hydro electric dams are in place, but on rivers like the Thames, there is always a head of water feeding the weirs, the upper river stretches acting as a reservoir. The small Hydro electric systems I have seen in Switzerland are fed by constantly flowing rivers, most of which are much narrower than our larger rivers.

Switzerland (like Norway) has far more available hydro power then the UK, and far fewer people -- the numbers simply don't add up here. To see this I suggest you read the splendid book by David MacKay "Sustainable energy -- without the hot air" which is a free download; his estimate is that the best we could do in the UK for hydroelectricity is about 1% of the total energy demand...

[WotEver]

Just now, dor said:

One would hope there will be some very significant improvements in capacity and recharge rate over the next 20+ years.

I suspect this is the plan. I would also expect it to be true

[dor]

1 minute ago, IanD said:

Switzerland (like Norway) has far more available hydro power then the UK, and far fewer people -- the numbers simply don't add up here. To see this I suggest you read the splendid book by David MacKay "Sustainable energy -- without the hot air" which is a free download; his estimate is that the best we could do in the UK for hydroelectricity is about 1% of the total energy demand...

But what say every lock had a small generator in the bywash or sluice?  Or lots of small rivers with turbines - just drive up from Cromford to Matlock - there used to be something like 20 or more  substantial mills in just a few miles along a relatively small river.  Like our domestic solar panels, a lot of small producers could add up to a lot of power, and not require a hugely expensive investment.