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Topic Title: Earth Hour
Topic Summary: Lights ON 8:30pm Saturday March 27th
Created On: 23 March 2010 03:17 PM
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 29 March 2010 06:45 PM
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Avatar for OMS.
OMS

Posts: 18919
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Originally posted by: rogerbryant

I think Hydroelectricity comes into a different catagory of 'renewable' energy than wind and solar.

The vital difference is that hydro electricity is predictable and controllable. I can judge how many kwh there are in my top reservoir and plan how I wish to use them.

Although the sun is also pretty predictable - we know where it will be at any time for any latitude Roger. Equally for some geographic areas the wind too is fairly predicatble - and lets not forget the tidal forces


Wind and solar are not predicable, you get energy when the sun shines or the wind blows. If you can store this energy and use it when required all well and good, but other than pumped storage (hydro in reverse) there are no large scale techniques currently avaiable. If the wind and solar generators have to be backed up by spinning reserves at thermal (fossil fuel burning) generation plants it's not as green as it's made out to be.

However, you are thinking in terms of current energy economics in a norther European context - what we need to crack is the storage of energy when it's abundant - hydrogen perhaps. If we can tanker LNG into Pembroke then tankering solar generated Hydrogen from North Africa isn't so much of a hurdle for engineers to overcome is it


There is a limit to the amount of hydroelectric power generation that can be installed due to geographical constraints, and most of the available sites in western Europe have already been used. There are other sites, but the environmental impact of flooding valleys has been classed as too great.

Start thinking world wide - and then add tidal to that equation


As ever our best way forward is to reduce our consumption, this can be aided by charging a realistic price, but how do you price a finite resource?

Well personally I'm all for an appraoch that first reduces demand (lean), uses the right fuel to meet that demand in a transition phase (clean) and then uses renewables (green)


I am not sure if wind and solar do offer a realistic way to reduce our dependance on fossil fuels. It is difficult to find data on the wholelife carbon balance for wind power, especially considering the distribution infrastructure requirements. The figures I have found seem to be based on the peak output of the system or with an unrealistically high utilisation factor and do not take into account the requirement for the distribution system to be specified for the peak power but operated at an average load of less than 20%.

Although you still seem to be thinking in terms of Northern Europe again with a focus on widpower - wind energy can only be part of a renewable generation mix. First though, we ned to perhaps think about changing how we supply electricity - should it be supply side or demand side led



One solution may be to use the inconsistent renewables for hydrogen generation, but again you end up sizing the system for peak power and runing it at and average of 20%.

Mmmm - I'm not so sure about that - the whole point of hydrogen is to provide the storage medium


As an aside from that the HSE in the UK have produced a report on the addition risks posed by the use of hydrogen fuelled road vehicles and their fuel distribution systems:

http://news.hse.gov.uk/2010/02...position-paper/


Well people once believed the hype that those dangerous high pressure steam boilers were the devils work and would kill millions - although we seem to have survived OK


Best regards

Roger


I won't be until we see the real cost of our cheap fossil fueled energy will we actually realise how finite it all is

Regards

OMS

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Failure is always an option
 29 March 2010 06:53 PM
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drhirst

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Roger, Thanks, a thoughtful and helpful comment.
I quite agree that hydro-power offers us much greater opportunities to plan and control electricity generation, but I fear it remains an uncontrolled resource, albeit on much longer timescales. About once in 7 years rainfall can be lower than usually expected, and a society dependent upon hydroelectricity faces possible scarcity. New Zealand is prone to such shortages (I think has one now), and Brazil has a major issue a few years ago. Yet it is expensive to have "standby" powerstations for use only in drought years.
So somehow we need to adapt our consumption to when the wind is blowing or not blowing. As you suggest, we have overinvest, so that we can always have enough wind, but that leaves us with a lot of electricity to spill when the wind is strong. Perhaps best would be to use hydro only when the wind is not blowing.
I think electric cars present a major opportunity to store electricity cheaply, so we need to be persuaded to charge them when the wind is blowing. This needs some sort of incentives, and a variable price seems a good one.
But could we really get used to the idea of electricity prices varying on a minute by minute (or even hour by hour) basis.
I think that is possible, but I would not trust profit oriented electricity suppliers to be open and honest about this. It presents too great an opportunity for them to overcharge us by upping the price when it wind looks a bit short. How can we prevent this?
If hydrogen is considered safe (or at least as safe as petrol), and is a sensible fuel for cars, then we could make hydrogen for the cars as well as filling batteries. It is right for HSE to alert us to the risks, but would be foolish for hydrogen to face unbalanced safety demands.
Cheers

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David Hirst
 29 March 2010 08:03 PM
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westonpa

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Originally posted by: drhirst
I think that is possible, but I would not trust profit oriented electricity suppliers to be open and honest about this. It presents too great an opportunity for them to overcharge us by upping the price when it wind looks a bit short. How can we prevent this?
Cheers

Solve the problems with human nature, that's how.....but I am reasonably confident the sun will burn out before we even get close to that utopia.

Whatever we debate here the progress towards renewable's will continue as will the efforts to better use the resources we have.....and I am all for it in a reasonable way. To be honest if ever we get a day when the wind stops we just need to stick Brown and co in front of the turbines and they will move at full speed.....that guy sends out enough hot air with his drivel to power a small town.

Even the oil, gas, nuclear and hydro energy industries needed, and received, some government support to get off the ground so I am not against a bit of investment in renewable's. Not everything works as we wish when we start out but if we do not make a start then it never will. I tend to think when 'reasonable' people do things they generally get the job done.

In my opinion we need to also concentrate on our transmission systems a bit more because overall there are enough reliable sources of renewable energy around the world and if we could transport it to the places of need then we would be ok. For example 1/2 of 1 billionth of the suns energy reaches the Earth and it has been calculated that this alone could supply 15000 times our current total energy needs.......yes it's mostly cloudy/raining in the UK but the sun is always shining somewhere! If they need someone to go sit in that place of sun to keep an eye on things I am first in the queue...

Regards.
 30 March 2010 12:30 AM
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Ipayyoursalary

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I'm all in favour of researching alternative energy sources - but before mass deployment those sources need to be economically viable and reliable. Wind and solar are neither.

I had a laugh watching the 3 chancellors on TV tonight arguing about the effect of the £6Bn National Insurance increase. This pales into insignificance beside the billions being poured into climate change: £8Bn for the solar feed-in-tarriff, £75Bn for the next round of useless windmills, £4Bn for CCS trials, £1Bn for climate research, millions for public brainwashing and child indoctrination and billions more for countless climate change bureacrats in Town halls, Whitehall and the EU. Money we can ill afford with the country close to bankruptcy.

It's a sad indictment of the main parties that no-one has the kahones to even suggest a cost-benefit review of climate change spending - or to discuss where it should sit in our economic priorities. Especially in the light of ClimateGate and the GlacierGate IPCC revelations.

Osbourne even had the arrogance to end by saying "with repsect to Vince - the only choice the electorate have is a Conservative or a Labour government". (The SouthPark 'Douche or Turd' episode comes to mind.... No Mr Osbourne - I, like millions of other climate sceptics, will be voting UKIP since they're the only party with a sane energy policy.

Edited: 30 March 2010 at 12:46 AM by Ipayyoursalary
 30 March 2010 09:43 AM
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rogerbryant

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I agree that in general we now when the sun will shine and the wind will blow, but these energy sources can be rapidly disrupted by other weather conditions such as tropical storms. It suddenly gets quite dark and the wind speed will probably rise above the operating limit for a turbine. It may well be that there are areas where the utilisation factors can approach 50%, in which case the transmission and conversion equipment needs only to be rated for twice the mean power rather than 5 times.
Tidal power is an interesting question, as is wave power. Tides are fairly predictable, but produce a varying output on an 11 hour cycle that needs to be stored or smoothed. This may be easier for an island such as the UK as the tidal peaks will vary around the coast. Wave power will have a similar profile to wind power as the waves are largely wind driven (as far as I understand). Both of these may have significant environmental impacts, costal erosion and silting spring to mind.
The hydrogen solution for energy storage and transport raises a lot of non trivial problems, starting with the very low energy density. The fact that the safety issues are being investigated at the start is a good thing and suggests that it is being taken seriously. Many people were burnt by radiation and blown up by boiler explosions in the early days of these technologies, now they are strongly controlled. If I want to run my model steam locomotive on the line in the local park I have to have a certified boiler, regular inspections and insurance. A lot of work is currently being carried out on the infrastructure problems. BMW has been working on automated refueling systems using cryogenic hydrogen (OK if you can afford a 7 series). Other research is being carried out into metal hydride storage, offering less extreme temperatures and pressures.
The bigest barrier to all this is political will. Is there enough joined up govenment in the world to build an energy collection facillity (wind, water, solar) in an unstable African nation, add a hydrogen conversion facility and a transport route to the coast?
Similar problems face nuclear power. One fuel reprocessing facility and one storage facility per continent would be sufficient, but few nations want their fuel cycle out of their control. This means multiple, underutillised facilities all requiring the same, expensive, safety and security infrastructure.

Best regards

Roger
 30 March 2010 09:57 AM
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OMS

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I, like millions of other climate sceptics, will be voting UKIP since they're the only party with a sane energy policy.


LoL - why did I just know you were going to come out with that

OMS

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Failure is always an option
 31 March 2010 01:00 PM
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westonpa

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 31 March 2010 01:48 PM
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Ipayyoursalary

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Originally posted by: westonpa
An interesting viewpoint.

">http://news.bbc.co.uk/.../hi.....8594561.stm

He's the archetypal loose cannon: Simultaneously making ridiculous predictions about climate doom while lambasting crooked CRU scientists, climate profiteers and crappy renewable energy scams. I'm prepared to overlook the former to enjoy the later Bravo Professor Lovelock.
 31 March 2010 02:45 PM
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Ipayyoursalary

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Originally posted by: rogerbryant
I agree that in general we know when the sun will shine and the wind will blow...

You can see some nice graphs of actual UK wind-power output vs the forecast at the bmreports website. The forecasts are often wrong by +-50%. Not good.

It may well be that there are areas where the utilisation factors can approach 50%, in which case the transmission and conversion equipment needs only to be rated for twice the mean power rather than 5 times.

The maximum utilisation I've seen is 35% for some offshore turbines. The average is 20%. However, when considering the cost of wind, the problem is not so much the 5x equipment overrating needed, but that power cannot be called upon when needed. It's not "on tap". On the contrary, the huge variations in wind output must be smoothed by conventional power stations. These must sit in permanent hot standby mode. This is costly - both in £ and CO2 (if you care about emissions of a harmless plant fertilising gas that is).

Tidal power is an interesting question, as is wave power. Tides are fairly predictable, but produce a varying output on an 11 hour cycle that needs to be stored or smoothed. This may be easier for an island such as the UK as the tidal peaks will vary around the coast.

Yes - the thing about wind/solar/tidal is they all require mind-boggling numbers of installations - in this case, right around the UK coast. The energy flux is just too low compared to the energy density of coal, oil or gas. The cost and environmental impact of these schemes dwarfs that of a little-itsy-bitsy gas-fired power station.

The biggest barrier to all this is political will. Is there enough joined up govenment in the world to build an energy collection facillity (wind, water, solar) in an unstable African nation, add a hydrogen conversion facility and a transport route to the coast?

Many African nations are likely to remain unstable if their economic development is stopped by such costly impractical schemes being foisted on them. We can afford to trial these schemes in the West, but if would be deeply wrong to impose them on poor people in the developing world - many of whom have no electricity atall.
 31 March 2010 03:34 PM
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OMS

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The maximum utilisation I've seen is 35% for some offshore turbines. The average is 20%. However, when considering the cost of wind, the problem is not so much the 5x equipment overrating needed, but that power cannot be called upon when needed. It's not "on tap". On the contrary, the huge variations in wind output must be smoothed by conventional power stations.


Or by other renewable sources such as stored Hydro, solar thermal etc. Wind power is only ever going to be a part of a basket of renewable technologies. When they are turning, they are generating and they are displacing fossil fuels

Yes - the thing about wind/solar/tidal is they all require mind-boggling numbers of installations - in this case, right around the UK coast.


Again you seem to be focused on the UK providing for it's own energy needs from "UK" resources - we don't do that with conventional generation - why would we with renewables. You need to stop thinking "Fog in Channel - Europe cut off"


The energy flux is just too low compared to the energy density of coal, oil or gas. The cost and environmental impact of these schemes dwarfs that of a little-itsy-bitsy gas-fired power station.


But we don't have any coal, oil or gas do we - we ship it in. There is no reason why renewable technology cannot be deployed where it is best suited and the resulting energy transferred to where it's required. hydrogen conversion or smart grids are both potential options. I would be suprised if solar, wind and hydro deployed on a global scale couldn't meet our energy demands - particularly if those demands are also declining through more sensible use and better technology. Most predictions on the Severn barrage suggest about 7% of UK energy needs - and that's just a simple wall across a river (in relative terms)

Many African nations are likely to remain unstable if their economic development is stopped by such costly impractical schemes being foisted on them. We can afford to trial these schemes in the West, but if would be deeply wrong to impose them on poor people in the developing world - many of whom have no electricity atall.


My experience suggests they become more unstable with economic growth. I think the point I was making was that of using say solar furnaces in Saharan Africa to evolve hydrogen for purchase by the west. In that way we perhaps address the thorny problem of world poverty, maybe get a grip on population growth and provide a clean renewable fuel for use.

Regards

OMS

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Failure is always an option
 31 March 2010 07:14 PM
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Ipayyoursalary

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But we don't have any coal, oil or gas do we?

Yes we do. The UK was a net exporter of gas up 'till 2005. Production is declining but new shale gas extraction technology promises to greatly boost production and supply. We still have large coal reserves (albeit currently uneconomic to mine) and substantial North Sea oil reserves.

Many African nations are likely to remain unstable if their economic development is stopped by such costly impractical schemes....

My experience suggests they become more unstable with economic growth.

Yes that's right. Having food, education, jobs, and health care always makes countries more unstable.

The point I was making was that of using say solar furnaces in Saharan Africa to evolve hydrogen for purchase by the west.

Would cost more to produce than they could sell it for - especially now shale gas is here.
 01 April 2010 12:10 PM
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OMS

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Originally posted by: Ipayyoursalary

But we don't have any coal, oil or gas do we?


Yes we do. The UK was a net exporter of gas up 'till 2005. Production is declining but new shale gas extraction technology promises to greatly boost production and supply. We still have large coal reserves (albeit currently uneconomic to mine) and substantial North Sea oil reserves.

So it was a net exporter of the easy gas - but now we have to go after the hard stuff - did I imagine the new terminal in Pembrokshire and the new pipline up to Gloucester - or are we importing marshmallow.

It would take billions to reopen many of the UK coal mines believe me - UK coal is not any easy win - it's where I started out, and teh dash for gas has limited the number of coal burners we now have available so we need to rebuild that as well

Many African nations are likely to remain unstable if their economic development is stopped by such costly impractical schemes....

My experience suggests they become more unstable with economic growth.


Yes that's right. Having food, education, jobs, and health care always makes countries more unstable.

Although the transition stages do have a habit of polarising rich(er) and poor(er) leading to all sorts of political instability

The point I was making was that of using say solar furnaces in Saharan Africa to evolve hydrogen for purchase by the west.


Would cost more to produce than they could sell it for - especially now shale gas is here.

LoL - I see, so an economic argument rather than anything else then - when the value of your beloved shale gas starts to rise exponentially then it becomes increasingly likley that we would need to turn to solar (at all levels) to meet our energy demands




Regards

OMS

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Failure is always an option
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