Wind farms - ugly truths

fclauson · 24-10-2014 11:43pm

Capt'n Midnight wrote: »

Maybe it's magic ?

or maybe there's interconnectors and hydro and pumped storage
or maybe the energy was stored as pressure in the boilers of the steam turbines
or maybe the grid is limited to 50% asynch generation and so can't use all the wind available so they have to take some off line

BTW look up the rules for spinning reserve sometime, we'd have needed a lot more than 200MW of spinning reserve to cover the conventional generators and that's before you take into account the inertia and regional rules

See the comment in my post from SEAI - they have to keep spinning the equivalent of the largest failable unit at all times.

Interconnectors create C02 (just not in the country

) - so is that set at zero or not
Hydro is my bet - zero C02 and dispatchable very quickly

pressure would not have lasted for the length of time they took the hit I don;t think

And yes the grid is limited to 50% of asynch power - which questions why we need more turbines until this issue is resolved.

to quote an email I recently received on the topic

This whole non-synchronous generation/frequency response centres around what is know as RoCoF - Rate of Change of Frequency. Wind turbine and interconnectors do not contribute to system inertia and that is why there is an operational limit on the system.
Eirgrid pushed the coventional plant to accept a RoCof at 2Hz/s back in 2012 (http://www.eirgrid.com/media/MPID229RoCoFDefinitionProposal.pdf) from the original 0.5Hz/s.

The RoCoF Problem (from Eirgrid) - FoR is the Facilitation of Renewables Study

The nominal system frequency is 50Hz. This is maintained by the synchronous machines on the system adjusting their power output so that supply and demand remains in balance. The
rotational inertia of the machines tends to keep the frequency steady, though some fluctuation in frequency is allowed and expected. When a generator trips off the system,
there is an instantaneous energy imbalance in the system. The speed of the synchronous rotating machines reduces to maintain the energy balance, resulting in a decrease in
frequency. The rate of change of frequency is a measure of how rapidly the speed of the machines, and thus the system frequency, slows down. The FoR study found that for the loss
of the largest generator on the system, RoCoF values in excess of 0.5Hz/s could occur.

Separately, the FoR study found that if a fault led to a voltage dip, and this voltage dip affected a cluster of windfarms, then much higher RoCoF values could be experienced. These
large RoCoF values (>1 Hz/s) were due to the significant energy imbalances caused by the windfarms reducing their output for hundreds of milliseconds following such a fault
clearance. This was estimated in the highest wind scenario to be up to 1400MW for a three phase fault on Tarbert-Prospect 220 kV cable. In turn, this significant energy imbalance
could adversely interact with other units that were incapable of riding through RoCoF in excess of 0.5 Hz/s leading to a cascade collapse.

Where RoCoF settings are used for loss-of-mains and they are set at levels which can be experienced following the largest single credible contingency, then there is a risk of cascade
tripping on the power system, potentially leading to a blackout.

They have now backed down with a proposal to 1Hz/s but with a lot of additional requirements such as "parking of generators" and other infrastructure costs (= more costs to consumers) see http://www.eirgrid.com/media/RoCoF_Alternative_Solutions_Project_Possible_Solutions_and_Assessment_Criteria.pdf

However it is still unknown if conventional plant can operate at this range. I attended an EPRI conference a number of years ago where Siemens stated that none of the existing machines can withstand this frequency change. You can see the backlash from conventional operators at page 33 http://www.eirgrid.com/media/DS3_Advisory_Council_Presentations_20140520.pdf

This is turning out to be one very expensive and dangerous experiment for the Irish Consumer.

fclauson · 25-10-2014 12:13am

Answer it was great Island No 4 Gas Turbine which came on line from 0 to 200Mw at around 2:30pm

ted1 · 27-10-2014 9:43am

fclauson wrote: »

Answer it was great Island No 4 Gas Turbine which came on line from 0 to 200Mw at around 2:30pm

There was some testing being carried out, so some wind was curtailed.

fclauson · 27-10-2014 4:49pm

Are you sure - was it that Wind + Inteconnector reached 50% of total so they had to pull back some wind to ensure frequency balance - which then gave the the opportunity to play with a new toy

It will be interesting to watch what happens next time we get to 50%

Also - why no increase in C02 amount or intensity - was this because it was on test and hence not factored in ?

ted1 · 27-10-2014 8:29pm

fclauson wrote: »

Are you sure - was it that Wind + Inteconnector reached 50% of total so they had to pull back some wind to ensure frequency balance - which then gave the the opportunity to play with a new toy

It will be interesting to watch what happens next time we get to 50%

Also - why no increase in C02 amount or intensity - was this because it was on test and hence not factored in ?

There's a shift change in the control system at 14:30( this is often when events happen ). Another CCGT could have come on replacing a peat/ coal plant or the EWIC could have ramped up?
The graph you have for the 18th doesn't indicate if it's for the Republic or All island, the moyle interconnector and what we supply to NI also affects the stats.

fclauson · 27-10-2014 8:34pm

May be ted but wind dropped 200Mw - great Island came on line 200Mw

but no change in C02 or intensity

look back at my post about 8 ago with the attached PDF

Just wondering what happened

Fabo · 29-10-2014 10:59pm

The EIS for Tarbert provides some good insight into the ugly truths of wind

http://www.tarbertpowerproject.com/environmental-impact-statement.html

CER decision paper “Proposed Direction on Conventional Offer Issuance Criteria” (July 2009), a paper that
is specifically associated with Gate 3 connection direction, compliments the Government White Paper with
the following statement in relation to the requirement for additional conventional generation:

“Consequently, in order to protect electricity security of supply, it is necessary to ensure that a mix of
energy sources (other then wind on its own) is connected to the network. This means that conventional
generation, which is a predictable form of generation output, is required in order to maintain security of
supply, i.e. “keep the lights on”. As noted in section 4, one of the Commission’s statutory duties is to
ensure that security of supply is protected by taking such measures as are necessary to do so. In
accordance with this duty and the Commission’s objectives for this process, the Commission considers that
processing a number of conventional applications alongside renewable generation in Gate 3 is therefore
required in order to protect long term security of supply”.

The operational installed wind capacity on the island of Ireland, as of March 2009, was 1,356 MW. In
Direction CER/08/260 Criteria for Gate 3 Renewable Generator Offers & Related Matters: Direction to the
the System Operators (16 December 2008) the CER indicates that 3,900 MW of wind generation will be
issued connection offers under the Gate 3 grid application group processing scheme.

While the increasing levels of wind penetration will make a valuable contribution to fuel diversity,
sustainability and emissions reduction, there are issues surrounding the reliability of supply resulting from
wind generated electricity and the amount of the actual wind generation i.e. capacity credit into the
transmission system. The intermittent nature of wind means that the contribution of wind power to
generation adequacy is significantly less than its installed capacity.

When considering the generation adequacy of wind as an energy source, wind is given a lower “capacity
credit” than conventional thermal generation, primarily because of its intermittent nature. This capacity
credit is used by the system operator, EirGrid, when assessing the adequacy of overall generation capacity
to meet the predicted demand. The capacity credit curve for wind used by EirGrid in the Generation
Adequacy Report 2009 – 2015 (2008)(GAR 2009 – 2015), is presented in Figure 2.6.

As illustrated in Figure 2.6, the capacity credit attributable to wind declines with increasing installed wind
capacity. The capacity credit for Wind Power Generation (WPG) is predicted by EirGrid to decrease from
19% in 2009 to 12% by 2015 as illustrated Table 2.1 below.

The following comment in the GAR 2009 – 2015 should be noted “Although the expected large growth of
installed renewable capacity will increase portfolio diversity, it will only offer a limited contribution to
generation adequacy.”

As a consequence, even though up to approximately 6,000 MW of non-fully-dispatchable wind capacity (i.e.
capacity cannot be relied upon to generate electricity as and when required) may be installed on the grid by
2020, a considerable amount of fully-dispatchable conventional thermal generating plant will also be
required. This is necessary to provide efficient system reserve and backup capacity for periods of low
output from wind generators and for retirement and non-availability of the existing fully-dispatchable plant,
in order to maintain an adequate security of supply standard.

Therefore whilst there are not generation adequacy shortfalls in the region in the short term, there is a need
for fully dispatchable flexible generation to compliment regional wind generation.

Old diesel · 03-11-2014 1:17pm

@Fabo - seen a blog post yesterday which alluded to similar points to what you've mentioned on the C02 reduction of large scale wind.

Although it was looking at how C02 DIDNT decrease between 2010 and 2013 INSPITE of 2013 apparently being a good year for wind - and wind obviously increasing during that time.

Obviously the pro wind people will put it down to lack of infrastructure - and that - this is why we NEED pylons*

*yet most of us who are critical of wind are ALREADY aware of THIS

Old diesel · 03-11-2014 1:37pm

If you take the view as many do - that renewables IN GENERAL are a good concept - winds flaws not withstanding.

I wonder what we make of the reality that if ALL your renewable energy is heavily focused towards wind only - should one not be thinking (in general) about the reality that if wind is off line due to insufficient wind - you are NOT using renewable energy for your power.

It raises the question - SHOULD some of our constantly available power sources - also be renewable - so have SOME biomass for example and see how and if one could develop a sound sustainable biomass supply chain.

There is also the obvious reality that reducing our energy use by greater energy efficiency in homes is good - and theres considerable merit I think in looking towards a concept of a home producing SOME of its own energy needs.

quentingargan · 08-11-2014 1:12am

Old diesel wrote: »

theres considerable merit I think in looking towards a concept of a home producing SOME of its own energy needs.

Yes - and in that regard, it is a huge disappointment that the Electric Ireland microgeneration pilot scheme has been ended without being replaced, because any home generation, be it solar, CHP or micro-wind really needs to be able to export its surplus to be viable. So just when other countries are looking at microgeneration and self-consumption, we've shut that option down, missing out on a chance for really interesting tech development. We do need to be more than a one-trick pony where renewables are concerned.

Old diesel · 09-11-2014 1:25am

quentingargan wrote: »

Yes - and in that regard, it is a huge disappointment that the Electric Ireland microgeneration pilot scheme has been ended without being replaced, because any home generation, be it solar, CHP or micro-wind really needs to be able to export its surplus to be viable. So just when other countries are looking at microgeneration and self-consumption, we've shut that option down, missing out on a chance for really interesting tech development. We do need to be more than a one-trick pony where renewables are concerned.

Yes it is a disappointing decision - in fact a woeful one.

Microgen has two important roles from where I am sitting.

Firstly and vitally - it actually reduces demand for electricity from the grid - because some of the electricity in the home is produced from the microgeneration.

Secondly - if LOTS of homes, buildings and businesses were able to produce SOME of their own energy on site - then if they produce excess electricity to sell to the grid - it helps make a potential contribution to our renewable targets.

I think though - its important to BELIEVE that decisions like this COULD be overturned.

Markcheese · 09-11-2014 12:20pm

How do the economics of exporting micro generated power stack up ... With a low uptake (and high tariff) it's just esb customers handing a nice little earner for little benefit , and with a high uptake it's expensive and disruptive to the grid ...
I can see the worth of it when combined with smart meters and export tariffs connected to demand ,( and contracted supply )
Might be well worth having lots of micro supplied in one area to stabilize the grid and not so worth while In another ..
Also with new batteries coming on stream would offices and business' who invest in micro generation be better off putting in a battery system as well rather than dumping onto the grid ...

Jim Martin · 09-11-2014 12:27pm

Also, with micro-generation, it stands to reason that it is more efficient as there is not the massive transmission loss as with the grid!

Old diesel · 09-11-2014 1:24pm

Markcheese wrote: »

How do the economics of exporting micro generated power stack up ... With a low uptake (and high tariff) it's just esb customers handing a nice little earner for little benefit , and with a high uptake it's expensive and disruptive to the grid ...
I can see the worth of it when combined with smart meters and export tariffs connected to demand ,( and contracted supply )
Might be well worth having lots of micro supplied in one area to stabilize the grid and not so worth while In another ..
Also with new batteries coming on stream would offices and business' who invest in micro generation be better off putting in a battery system as well rather than dumping onto the grid ...

We are already looking at building extra infrastructure to handle the demands of wind power.

You could argue the case that if LOTS of people had microgen - and the grid was set up to handle this - does one - a) have less need for the big scale wind power - I say LESS not none. - and b) Microgen should reduce in LESS demand on the grid when its producing power.

Mind you we do need to look at how to handle it coming onto the grid at lots of locations.

Are there countries that do LOTS of microgen - and how do they manage it is probably a fine question to focus on

Someone on twitter posted a link the other day about small grids - or island grids - where you could have smaller grids

Mind you there is merit in looking at battery storage - so if your 6 kw solar PV is running flat out on a good day - the power stored can be used in your home when solar is offline - at night for example.

This results in less demand on the grid during the year overall - but does raise the question - how do you monitor how much power you produce in this way so that it counts towards our renewable targets....

Will post the link that was on twitter later - but im testing the patience of people here waiting for me to come to the dinner table by typing this - so later hopefully

Capt'n Midnight · 09-11-2014 2:03pm

Price of leccy during the day
http://www.sem-o.com/Pages/default.aspx

Most of the time the wholesale cost is less than rate paid for microgen.
We could argue until the cows come home about the infrastructure costs / future value of money etc. that determine the real economics.

For wind and thermal there are unquestionable economies of scale that microgen will never match. Sticking turbines on every home in County Leitrim would only replace two large turbines in nameplate capacity but still fail miserably to match the power output due to being closer to the ground at worse sites.

Thermal is interesting though if you are already paying for heat, calor already have a 1KW generator on the market. BUT it's early days and to get that 1KW you need to be burning 6KW of gas in a ?28KW? burner. It's not remotely cheap. To break even you really need to be a retirement home or hospital with heating on 24/7/365. And out of that 1KW you are probably loosing in the order of 100W on the pump.

I have hopes for the future whereby they can use cheap to manufacture semiconductor thermal thingies like Peltiers to generate electricity from heating systems at very cheap prices without any moving parts.

and of course the holy grail is cheap energy storage

a close second would be intelligent devices / meters where you could rely on well insulated homes and water tanks to advance or retard heating loads by hours to load balance.

Charging electric cars when everyone arrives home from work just isn't worth considering until later on in the evening.

is the ESB right ? should eirgrid pass the costs of paying for micro renewables on to all operators

Old diesel · 09-11-2014 2:31pm

http://www.sciencedaily.com/releases/2014/11/141105101100.htm

Heres the link I referred to earlier.

@ Captn Midnight - Microgen is more about producing power for say the home itself, a business - or perhaps meeting SOME of a communities wider needs.

Being able to produce some electricity on site to meet SOME of the site or homes OWN needs is the goal - which reduces demand from the grid.

Even the irish wind energy association whose members think they own the country - are suggesting consideration of it

http://www.clarechampion.ie/wind-microgeneration-offers-great-benefits/

Is it perfect - no - but it is worth looking at in terms of being able to meet SOME of a home or a businesses electricity production.

fclauson · 03-12-2014 11:17pm

Interesting blog on why wind is INCREASING C02 in certain circumstances

http://irishenergyblog.blogspot.ie/2014/11/dublin-electricity-generation-analysis_27.html

Grudaire · 04-12-2014 9:05am

fclauson wrote: »

Interesting blog on why wind is INCREASING C02 in certain circumstances

http://irishenergyblog.blogspot.ie/2014/11/dublin-electricity-generation-analysis_27.html

I could be convinced by this argument if it was made better. I remain unconvinced that more energy is spent for lower outputs..

The blog seems to be based on questionable extrapolation from the gas plant efficiency chart, which it doesn't even link to a source (rather a website).. Is there better backup for the basis of the blogs argument?

djpbarry · 04-12-2014 2:52pm

fclauson wrote: »

Interesting blog on why wind is INCREASING C02 in certain circumstances

http://irishenergyblog.blogspot.ie/2014/11/dublin-electricity-generation-analysis_27.html

Surely what matters is what happens on average, rather than "in certain circumstances"?

Old diesel · 04-12-2014 3:40pm

The argument the Irish energy blog person seems to be making is that as you reduce the output of the gas plant - the amount of fuel needed to produce a Megawatt of power is more then if the plant is running flat out.

this is from the same blog http://irishenergyblog.blogspot.ie/2014/11/no-co2-emissions-savings-since-2011.html and he or she is claiming they got that info from Eirgrid.

Grudaire · 04-12-2014 3:54pm

Old diesel wrote: »

The argument the Irish energy blog person seems to be making is that as you reduce the output of the gas plant - the amount of fuel needed to produce a Megawatt of power is more then if the plant is running flat out.

That is not an unreasonable claim, what confuses me is where he came to the conclusion that when the output is reduced the inputs required actually increase!

Also, does it reflect poorly on the 'anti-wind' folks here are relying on a free blogspot blog from an unnamed author as a basis for arguments.. ye wouldn't let any 'pro-wind' types get away with using such a questionable source!

djpbarry · 04-12-2014 5:16pm

Old diesel wrote: »

The argument the Irish energy blog person seems to be making is that as you reduce the output of the gas plant - the amount of fuel needed to produce a Megawatt of power is more then if the plant is running flat out.

I'm perfectly prepared to accept that there's a certain generation capacity associated with a CCGT plant that results in maximum efficiency.

However, in the context the discussion, I question the value of a poorly-referenced blog post that is attempting to emphasise CO2 production over a very short period of time, under a very specific set of circumstances, and contains bizarre statements such as the following:

Before I proceed, a little explanation on the operation of CCGT (combined cycle gas turbine) is required. This type of plant is the most efficient for converting gas into electricity. It is basically a gas turbine, such as what is in an airplane. But unlike the gas generators of old where the steam is released into the sky through a stack, the CCGT converts the steam into electricity aswell.

Whoever put that post together doesn't have a bloody clue what they're talking about.

Old diesel · 04-12-2014 5:49pm

A wider question is though - what is a good outcome for the resident who ends up with wind turbine near their home - I don't mean no turbines - I mean how can we achieve a good outcome the resident can live happily with - even if they don't particularly love wind turbines.

If the house is in the wrong place - in other words the one off house planning in Ireland means houses were built where they shouldn't have being or in too high numbers in the country side - how do we develop solutions that ensure good living solutions for the resident - albeit possibly not in their current home - while doing what we NEED to do on renewables.

The norm in other industries like cars - is to develop products that work well in their intended environment - so a Micra type car for city driving - a Landcruiser to do farming type duties.

A resident I feel needs the confidence to plan their living - and their living needs planning for - BUT we also need to address climate change.

So I feel the way forward - is that you plan important things - energy - how and WHERE we will live in the future and other important issues TOGETHER

Fabo · 04-12-2014 6:35pm

djpbarry wrote: »

I'm perfectly prepared to accept that there's a certain generation capacity associated with a CCGT plant that results in maximum efficiency.

However, in the context the discussion, I question the value of a poorly-referenced blog post that is attempting to emphasise CO2 production over a very short period of time, under a very specific set of circumstances, and contains bizarre statements such as the following:
Whoever put that post together doesn't have a bloody clue what they're talking about.

it is poorly worded in places but the general thrust is right. Once you run a CCGT plant on low loads the fuel / electricity generated ratio goes up.

The question is is the 20% efficiency right for Poolbeg at 25% load. According to EPA he is right on the lower efficiency of Poolbeg.

Fabo · 04-12-2014 9:05pm

Grudaire wrote: »

That is not an unreasonable claim, what confuses me is where he came to the conclusion that when the output is reduced the inputs required actually increase!

Also, does it reflect poorly on the 'anti-wind' folks here are relying on a free blogspot blog from an unnamed author as a basis for arguments.. ye wouldn't let any 'pro-wind' types get away with using such a questionable source!

Lets be honest here, SEAI own the monopoly on misleading reports and investigations into energy policy in this country. SEAI have an audience of a couple of million, including the people who make the actual decisions in this country. This blogger has an audience of probably 50-100 max.

Speaking of which, i see our blogger nailed it in relation to SEAIs accounting method for reserves:

http://irishenergyblog.blogspot.ie/2014/12/seais-quantifying-savings-from.html

Grudaire · 05-12-2014 1:49am

Fabo wrote: »

Lets be honest here, SEAI own the monopoly on misleading reports and investigations into energy policy in this country. SEAI have an audience of a couple of million, including the people who make the actual decisions in this country. This blogger has an audience of probably 50-100 max.

Speaking of which, i see our blogger nailed it in relation to SEAIs accounting method for reserves:

http://irishenergyblog.blogspot.ie/2014/12/seais-quantifying-savings-from.html

The sad thing is that I'm convincible, and that blog post says things but doesn't seem to have any backup or substance...
If anything it's a sad reflection on the anti wind side that this is the best that they have

Fabo · 05-12-2014 10:03am

Grudaire wrote: »

The sad thing is that I'm convincible, and that blog post says things but doesn't seem to have any backup or substance...
If anything it's a sad reflection on the anti wind side that this is the best that they have

I doubt that. You are prepared to believe the lies from a multi billion euro industry as opposed to someone who doesnt stand to gain.

Then again subsidy junkies require plenty of fools without which they crumble

Grudaire · 05-12-2014 10:33am

Fabo wrote: »

I doubt that. You are prepared to believe the lies from a multi billion euro industry as opposed to someone who doesnt stand to gain.

Then again subsidy junkies require plenty of fools without which they crumble

It could be the CEO of BP writing that blog for all we know!

Fabo · 05-12-2014 10:40am

Grudaire wrote: »

It could be the CEO of BP writing that blog for all we know!

Sure !

http://www.bp.com/en/global/alternative-energy/our-businesses/wind-power.html

Old diesel · 05-12-2014 10:44am

My big concern isn't so much how good wind is at dealing with C02.

But how we plan it to work well in the community setting - its all very well to bang on about one off houses - yes we have too many of them. We have too many of lots of things - too many people homeless, too many people on trolleys in hospitals.

But the way I see it is - we need to plan how and where we will live in the future - AND our energy policy and other aspects like tourism, future of communities, horse industry and many other thigs TOGETHER.

We do need to change - but a big flaw in our wind and overall energy planning is we seem as a country to be planning it - in complete isolation from EVERYTHING else.

That's arguable an even more serious issue then the turbines themselves

Wind farms - ugly truths

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