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"Wind and wave energies are not renewable after all"

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    #62
    Macha
    Moderators, Science, Health & Environment Moderators Posts: 6,376 Mod ✭✭✭✭Macha


    Was there something about my post that was incorrect or untrue?


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    #63
    Heroditas
    Registered Users Posts: 9,450 ✭✭✭Heroditas


    Macha wrote: »
    Is everyone aware that standard plants are about 35% efficient? The obsession with wind's load factors is very difficult to understand in light of years of silence on the inefficiency of regular plants.


    What is a "standard plant"?
    All modern CCGT plants are in the high 50s in terms of efficiency.
    Examples in Ireland being Aghada, Whitegate and Huntstown 2.


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    #64
    Macha
    Moderators, Science, Health & Environment Moderators Posts: 6,376 Mod ✭✭✭✭Macha


    Heroditas wrote: »
    What is a "standard plant"?
    All modern CCGT plants are in the high 50s in terms of efficiency.
    Examples in Ireland being Aghada, Whitegate and Huntstown 2.
    Yes, "modern". I was referring to the deafening silence since I can remember on the efficiency of fossil fuel plants.

    People have also been using home boilers working at about 40% efficiency.


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    #65
    Heroditas
    Registered Users Posts: 9,450 ✭✭✭Heroditas


    Then why quote figures for older less efficient generating plant?


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    #66
    Macha
    Moderators, Science, Health & Environment Moderators Posts: 6,376 Mod ✭✭✭✭Macha


    Heroditas wrote: »
    Then why quote figures for older less efficient generating plant?
    Because many of them are still on stream. And I'll say it again, I am talking about the historic lack of interest in the woeful efficiency of our power plants.

    I don't see what's so difficult to understand here.

    Edit: Just checked official figures and in 2008, our electricity supply was 42.4% efficient. As recently as 1990, it was 33% efficient.


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    #67
    Heroditas
    Registered Users Posts: 9,450 ✭✭✭Heroditas


    Macha wrote: »
    Because many of them are still on stream. And I'll say it again, I am talking about the historic lack of interest in the woeful efficiency of our power plants.

    I don't see what's so difficult to understand here.



    No need to be condescending.


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    #68
    Macha
    Moderators, Science, Health & Environment Moderators Posts: 6,376 Mod ✭✭✭✭Macha


    Heroditas wrote: »
    No need to be condescending.
    I wasn't.


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    #69
    Chloe Pink
    Registered Users Posts: 804 ✭✭✭Chloe Pink


    Macha wrote: »
    Was there something about my post that was incorrect or untrue?

    In simple terms:
    'Load factor' is the output of a generator as a percentage of its total installed capacity.
    'Efficiency' is the amount of energy output as a percentage of the amount of energy input.
    To make a fair comparison, like for like should be compared.

    Wind generators are actually more efficient than 'conventional' generators.
    It's the load factor that is is particularily of note regarding wind generators i.e. on average (in the UK), wind generators have a load factor of 26% (give or take one or two percent according to the year) whereas conventional generators have a load factor of 50%.

    As mentioned, the age of a generator is relevant when looking at load factors. Again of note, on average in the UK, new wind generators will have a load factor of of 26% (give or take one or two percent according to the year) whereas new conventional generators have a load factor of 80-90%.

    So load factor is an issue with wind generators; 1000MW installed capacity of a conventional generator, can generate nearly 1000MW of output whereas 1000MW installed capacity of wind generators, can only generate 260MW of output.

    And despatchability of power from wind generators is also an issue i.e. they are not firm generators i.e. ones we can control the output from, the wind controls the output so when it's really cold and we need power and there's little or no wind, wind turbines aren't going to keep us warm - hence the need for backup and spinning reserve from conventional generators.


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    #70
    Macha
    Moderators, Science, Health & Environment Moderators Posts: 6,376 Mod ✭✭✭✭Macha


    Yes, the integration of wind is actually improving the efficiency of our electricity generation - that and the closing down of peat burning stations.

    The methods for integrating higher percentages of wind into the grid do not just include back up and spinning reserve, as suggested. Load factors have been discussed on this forum many times.


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    #71
    djpbarry
    Registered Users Posts: 13,104 ✭✭✭✭djpbarry


    Chloe Pink wrote: »
    ...1000MW installed capacity of a conventional generator, can generate nearly 1000MW of output whereas 1000MW installed capacity of wind generators, can only generate 260MW of output.
    1,000 MW of installed wind turbines can generate almost 1,000 MW of output. On average, output will be of the order of 20 – 30%.

    I’m with Macha on this – I have no idea why people continuously harp on about (and often misrepresent) the fact that wind speeds are (obviously) variable.
    Chloe Pink wrote: »
    And despatchability of power from wind generators is also an issue i.e. they are not firm generators i.e. ones we can control the output from, the wind controls the output so when it's really cold and we need power and there's little or no wind, wind turbines aren't going to keep us warm...
    And again, this has literally been done to death – who has said we should rely 100% on wind generators for our electricity?
    Chloe Pink wrote: »
    ...hence the need for backup and spinning reserve from conventional generators.
    Could you list off the thermal power stations that have been built as “back-up” in Ireland alongside the installation of wind farms?


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    #72
    Chloe Pink
    Registered Users Posts: 804 ✭✭✭Chloe Pink


    Macha wrote: »
    Yes, the integration of wind is actually improving the efficiency of our electricity generation
    Would you expand on this statement please especially in light of the fact that conventional generators are less 'efficient' when not run at peak load which is done to backup wind generators?
    Macha wrote: »
    The methods for integrating higher percentages of wind into the grid do not just include back up and spinning reserve, as suggested.
    My statement was not exclusive, as your post infers. But yes you're correct, integration of higher percentages of wind power also includes interconnectors and storage and the costs of such measures.
    And the interconnectors will more often than not just be another method of providing thermal backup i.e. bringing electricity from conventional generators in another country.


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    #73
    Chloe Pink
    Registered Users Posts: 804 ✭✭✭Chloe Pink


    djpbarry wrote: »
    1,000 MW of installed wind turbines can generate almost 1,000 MW of output. On average, output will be of the order of 20 – 30%.
    Indeed, my apologies for the lack of clarity there... whereas 1,000MW of installed (new) conventional generators can generate almost 1,00MW of output and on average, output will be in the order of 80 - 90% and higher. And they can provide electricity when we want it.

    djpbarry wrote: »
    – who has said we should rely 100% on wind generators for our electricity?
    I don't know, who has? Does that alter the load factor, the matter under discussion?
    djpbarry wrote: »
    Could you list off the thermal power stations that have been built as “back-up” in Ireland alongside the installation of wind farms?
    No but there are plenty in Germany.
    Can you list off the thermal power stations that have closed in Ireland as a direct result of the installation of wind farms?


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    #74
    Macha
    Moderators, Science, Health & Environment Moderators Posts: 6,376 Mod ✭✭✭✭Macha


    Chloe Pink wrote: »
    Would you expand on this statement please especially in light of the fact that conventional generators are less 'efficient' when not run at peak load which is done to backup wind generators?
    You said it yourself:
    Wind generators are actually more efficient than 'conventional' generators.
    Chloe Pink wrote: »
    My statement was not exclusive, as your post infers. But yes you're correct, integration of higher percentages of wind power also includes interconnectors and storage and the costs of such measures.
    And the interconnectors will more often than not just be another method of providing thermal backup i.e. bringing electricity from conventional generators in another country.
    Of course it's going to cost. The idea that we can continue to have energy at cheap prices is crazy. The grid needs to be upgraded anyway. So are we going to upgrade and future proof it or are we going to have a BAU scenario based on the continued importation of increasingly costly fossil fuels?

    There are going to be increased costs no matter what way you look at it.

    If we actually committed to creating renewable generation in this country, the interconnectors could be used for selling electricity to our neighbours. It isn't just a question of electricity but the green value of renewable electricity. Every EU member state has a renewable target they have to meet by 2020 and the Renewables Directive contains a number of flexible mechanisms to allow member states to use renewables from other MSs.

    The UK is going to start experiencing rolling blackouts as it's old coal plants start being shut down. There isn't a snowballs chance in hell we'll be importing energy from them over the medium-term.


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    #75
    Chloe Pink
    Registered Users Posts: 804 ✭✭✭Chloe Pink


    Macha wrote: »
    You said it yourself:"Wind generators are actually more efficient than 'conventional' generators."
    Yes but this has to be offset against the reduced efficiency of conventional plant when it is held in spinning reserve for the wind generators.
    Macha wrote: »
    The grid needs to be upgraded anyway. So are we going to upgrade and future proof it or are we going to have a BAU scenario based on the continued importation of increasingly costly fossil fuels?
    The grid only needs upgrading to cater for multiple, dispersed renewable generators. And we'll still need fuel for the conventional generators running in spinning reserve and then filling in for the failing wind.
    Macha wrote: »
    If we actually committed to creating renewable generation in this country, the interconnectors could be used for selling electricity to our neighbours.
    Periods of good wind (for wind turbines) tend to occur at the same time across Europe so why, when the rest of Europe is trying to balance its grids by offloading its electricity to other countries in Europe, do you think it's going to want to buy yours?
    Macha wrote: »
    It isn't just a question of electricity but the green value of renewable electricity.
    Oh and there I was thinking that all this stemmed from a need to reduce CO2 emissions to combat global warming.
    Macha wrote: »
    Every EU member state has a renewable target they have to meet by 2020
    This doesn't make the policy sensible.
    Macha wrote: »
    The UK is going to start experiencing rolling blackouts as it's old coal plants start being shut down.
    But the UK has put up lots of wind turbines!


    The point is is that effectively utilising renewables and wind turbines in particular, is complicated.
    Although now an aged submission, the principles in this report still stand http://www.publications.parliament.uk/pa/ld200708/ldselect/ldeconaf/195/8060304.htm

    and so does the following extract from it: "As has been pointed by Malcolm Keay of the Oxford Institute for Energy Studies in his 2006 book, The Dynamics of Power, the addition of large quantities of renewable generation may well have a causal influence on the technologies chosen by investors for the conventional portfolio, and it is conceivable, and perhaps probable, that the result would be a system that was less clean than it would have been if no renewables or a smaller or differently structured renewable component had been introduced. Get the renewables right, and the savings of both fuel and emissions could be welcome; get it wrong, and we may be worse off than if we had done nothing."


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    #76
    djpbarry
    Registered Users Posts: 13,104 ✭✭✭✭djpbarry


    Chloe Pink wrote: »
    I don't know, who has?
    Nobody, so pointing out that wind turbines don’t produce electricity when the wind isn’t blowing is moot (and stating the bloody obvious).
    Chloe Pink wrote: »
    Can you list off the thermal power stations that have closed in Ireland as a direct result of the installation of wind farms?
    I never suggested that any where closed. Nobody has. As has been pointed out to you several times on other threads, wind generation is intended to compliment existing thermal/nuclear generation, not replace it (at a local level, that is).


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    #77
    Chloe Pink
    Registered Users Posts: 804 ✭✭✭Chloe Pink


    djpbarry wrote: »
    Nobody, so pointing out that wind turbines don’t produce electricity when the wind isn’t blowing is moot
    Moot
    1. open to discussion or debate; debatable; doubtful: a moot point.
    2. of little or no practical value or meaning; purely academic.
    3. Chiefly Law . not actual; theoretical; hypothetical.
    "Moot" is a strange word to use to describe the intermittancy of wind turbines when its one of the biggest issues regarding integrating them into a power generating system!
    djpbarry wrote: »
    wind generation is intended to compliment existing thermal/nuclear generation, not replace it.
    So when the existing power stations are retired, others will have to be built to backup the wind turbines hence the backup is incorporated in costings.
    I'm not sure why anyone would have an issue with this; it's what any proper cost analysis would do.


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    #78
    djpbarry
    Registered Users Posts: 13,104 ✭✭✭✭djpbarry


    Chloe Pink wrote: »
    So when the existing power stations are retired, others will have to be built to backup the wind turbines hence the backup is incorporated in costings....
    ...of the entire system, not wind turbines in isolation.


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    #79
    Chloe Pink
    Registered Users Posts: 804 ✭✭✭Chloe Pink


    djpbarry wrote: »
    ...of the entire system, not wind turbines in isolation.

    Absolutely...

    If your system is made up of firm generators, you only need to count the cost of firm generators...

    And if your system is made up of wind turbines and firm generators, you need to count the cost of the wind turbines and the cost of the firm generators.

    The point to note of course is that the installed capacity is greater in the second scenario i.e. you roughly need the same amount of firm generators as in the first scenario plus the wind generators.

    So as a starting point, the second scenario, firm generators and wind turbines, is more expensive in terms of capital costs and maintenance than the first scenario which consists just of firm generators.


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    #80
    Macha
    Moderators, Science, Health & Environment Moderators Posts: 6,376 Mod ✭✭✭✭Macha


    Chloe Pink wrote: »
    Absolutely...

    If your system is made up of firm generators, you only need to count the cost of firm generators...

    And if your system is made up of wind turbines and firm generators, you need to count the cost of the wind turbines and the cost of the firm generators.

    The point to note of course is that the installed capacity is greater in the second scenario i.e. you roughly need the same amount of firm generators as in the first scenario plus the wind generators.

    So as a starting point, the second scenario, firm generators and wind turbines, is more expensive in terms of capital costs and maintenance than the first scenario which consists just of firm generators.

    What about fuel costs?


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    #81
    Chloe Pink
    Registered Users Posts: 804 ✭✭✭Chloe Pink


    Macha wrote: »
    What about fuel costs?

    Fuel costs are a valid and valuable point especially as the fuel costs for wind turbines are zero.

    This very point is made in the report I linked to earlier in this thread:
    http://www.publications.parliament.uk/pa/ld200708/ldselect/ldeconaf/195/8060304.htm

    It states:
    "However, while renewable generators are generally speaking more capital intensive, several have very low or no fuel input costs, for example wind power, and this is a real merit."

    It then goes on to say:
    "Nevertheless, to a significant degree this benefit is for most renewable technologies counterbalanced by load factors that are low even if a market is guaranteed for all energy that may be generated. The load factor for onshore wind, for example, is generally less than 30%, while even offshore wind will only be in the region of 35-40%. The exception is biomass, which is theoretically capable of load factors comparable with conventional generators, though this of course has a fuel input cost."


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    #82
    Macha
    Moderators, Science, Health & Environment Moderators Posts: 6,376 Mod ✭✭✭✭Macha


    What sort of fossil fuel price assumptions does that report make and does it include carbon costs?


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    #83
    Chloe Pink
    Registered Users Posts: 804 ✭✭✭Chloe Pink


    Macha wrote: »
    What sort of fossil fuel price assumptions does that report make and does it include carbon costs?

    Obviously that they might increase and yes it includes carbon costings - it's worth reading


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    #84
    Macha
    Moderators, Science, Health & Environment Moderators Posts: 6,376 Mod ✭✭✭✭Macha


    Thanks I will - but who wrote it?

    Edit: Nevermind, found John Constable's name

    Edit 2: No doubt that fossil fuel prices will go up. I've looked at old (eg from 2009) McKinsey MAC studies & seen $60/bbl described as low and $120/bbl described as high. Laughable now.


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    #85
    Capt'n Midnight
    Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 90,958 Mod ✭✭✭✭Capt'n Midnight


    http://cleantechnica.com/2011/03/05/how-denmark-will-integrate-50-wind-power-by-2025/

    Short version - Denmark can have 50% of it's installed capacity as wind power by using interconnectors to Norwegian Hydro and German demand.

    we too could use hydro,
    we too have a large neighbour
    our neighbour currently pays a premium to cover nuclear - so there should be enough margian
    The study found that higher prices across the border was more of a determinant for exports than lack of demand at home, with high prices were driven by variations in regional weather conditions such as the dry years reducing hydro power in Norway and Sweden.

    In order to integrate 50% onto the Danish grid, the report recommended integrating all the distributed players in the market, on both the supply and demand side, to meet future balancing needs.

    One such source of balancing is the country’s extensive heat storage capacity in the Danish district heating systems. Previous energy researchers had found that “As a rough estimate between 20 and 30 GWh energy can be stored as useful heat.”

    30 GWh of heat storage in a grid with up to 5 GW of wind capacity installed, would provide the needed sink for peaks of wind energy generation, by itself.


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    #86
    vaalea
    Closed Accounts Posts: 151 ✭✭vaalea


    With that argument NOTHING on the planet is renewable... and we know that everything renewable has an over-consumption limit ie we have a water crisis, but we always have the same quantity of water on earth… just how much is clean and consumable, and what is our consumption vs speed of purifying etc - which is why there is a need to diversify also when it comes to renewable energy sources so that we can keep a more even output of energy through changes in weather and we/business/government should be more flexible in people's choices of daily schedule lessen the peak consumption periods phenomenon.


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    #87
    Capt'n Midnight
    Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 90,958 Mod ✭✭✭✭Capt'n Midnight


    vaalea wrote: »
    With that argument NOTHING on the planet is renewable...
    The sun is not on the planet

    Then again it itsn't renewable either, we need to figure out some other power source sometime in the next 4 billion years or so


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    #88
    jill_valentine
    Registered Users Posts: 7,090 ✭✭✭jill_valentine


    Nuclear it is!


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    #89
    Scofflaw
    Registered Users Posts: 23,283 ✭✭✭✭Scofflaw


    Capt'n Midnight wrote: »
    http://cleantechnica.com/2011/03/05/how-denmark-will-integrate-50-wind-power-by-2025/

    Short version - Denmark can have 50% of it's installed capacity as wind power by using interconnectors to Norwegian Hydro and German demand.

    we too could use hydro,
    we too have a large neighbour
    our neighbour currently pays a premium to cover nuclear - so there should be enough margian

    Goodness - are you suggesting that we sell our excess wind to the UK, and buy from them when the wind isn't blowing? A market solution to energy? Outrageous!

    cordially,
    Scofflaw


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    #90
    Chloe Pink
    Registered Users Posts: 804 ✭✭✭Chloe Pink


    Scofflaw wrote: »
    Goodness - are you suggesting that we sell our excess wind to the UK, and buy from them when the wind isn't blowing? A market solution to energy? Outrageous!

    cordially,
    Scofflaw

    Generally areas of high and low pressure cover most of Europe i.e. winds are high over most European countries at the same time. This means that when the winds are good for elecricity generation with wind turbines in Ireland, they're probably good in the UK too (and the rest of Europe) meaning that everyone will be trying to export electricty to balance their grids.

    Which valleys will be flooded in Ireland to provide the hydro and / or which mountains will be hollowed out?


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    #91
    Capt'n Midnight
    Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 90,958 Mod ✭✭✭✭Capt'n Midnight


    Chloe Pink wrote: »
    Generally areas of high and low pressure cover most of Europe i.e. winds are high over most European countries at the same time. This means that when the winds are good for elecricity generation with wind turbines in Ireland, they're probably good in the UK too (and the rest of Europe) meaning that everyone will be trying to export electricty to balance their grids.
    wind moves from high pressure areas to low pressure areas
    but not in straight lines, it moves in a sprial / cyclonic way
    eye of the storm will have no wind and wind strengths will vary across the the weather front.

    when you have high winds you are already at max capacity anyway , but we don't have high winds all the time - you are taking the exception and calling it the rule.

    and they have pumped storage in wales, they have gas turbines in the UK , and I'll repeat that a grid means everyone needs less installed capacity


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