El Hierro May 2016 update

During May Gorona del Viento (GdV), a “hybrid” wind-hydro plant designed ultimately to provide the Canary Island of El Hierro with 100% renewable energy, provided only 25.4% renewable electricity to the El Hierro grid, thereby lowering the average renewables fraction since project startup last June to 32.8%. This was a result of a change in operating procedures that resulted in even lower renewables generation than usual and which is documented in this post. (Details on GdV plant layout, operation and capacities are given in the September update. Previous posts on GdV are accessible through the El Hierro Portal.)

I hadn’t planned to write another update on GdV until the end of June, at which time the plant will have completed one year of full operation (preceded by a full year of testing). However, the change in operating procedures during May (earlier post here) has had a strongly negative impact on the percentage of renewables delivered to the El Hierro grid during the month, and this merits another update.

Figure 1 shows the percentage of diesel and renewable power delivered to the El Hierro grid since full operations began, based on daily averages of 10-minute REE grid data. There’s no sign of a decreasing trend in diesel generation:

Figure 1: Percentage of diesel and renewable power delivered to the El Hierro grid since full operations began, daily averages

The table below summarizes monthly grid statistics since full operations began. Of particular interest is the low renewables percentage for May, which was a fairly high-wind month. This was a result of the change in operating procedures.

Up to this point GdV has balanced generation against demand either by running diesel in baseload mode and following load by switching wind power between the grid and pumping, or by a combination of diesel and wind with occasional contributions from hydro. The two modes of load management are illustrated in the August 2015 generation plot shown in Figure 2, although the reasons for switching from one mode to the other are not clear:

Figure 2: August 2015 generation. The flat spots in diesel generation around 1.6 and 3.1MW show where diesel was use as baseload and wind was used to match demand. Erratic diesel generation shows where diesel, wind and occasional hydro were used to match demand. 

In May, however, a different approach was tried. Instead of using diesel as baseload and wind/hydro for load following GdV began to use wind and hydro as baseload and diesel for load-following, This resulted in the monthly generation plot shown in Figure 3. During the first two days of May the project operated in the diesel baseload mode with one short 100% renewables test on May 2:

Figure 3: May 2016 generation, REE 10-minute grid data

On May 3, however, procedures were changed to make wind and hydro the baseload sources. Figure 4 reverses the plotting order so that the change is more obvious. The test – one has to assume this is what it was – continued to May 30, since when operations seem to have returned to “normal”:

Figure 4: May 2016 generation with plotting order changed to show the wind and hydro “baseload” contribution and how diesel was used to follow load.

Both hydro and wind production remained low while the test was in progress, and as shown by the plot of daily average wind speed at El Hierro airport this wasn’t caused by lack of wind. Between May 14 and May 24 the wind blew quite strongly (the average wind speed of 11.3 m/s on May 17 was in fact among the highest recorded at the airport since January 2014). Yet combined wind and hydro averaged only 0.8MW over the test period, with the result being that most of the island’s demand had to be filled by diesel generation.

Another feature of interest is that hydro production on May 3 and from May 16-21 was preceded by uphill pumping of water from the lower to the upper reservoir, suggesting that the upper reservoir was “primed” before the hydro generation began.

How much difference did the change make? The Figure 5 XY plot compares daily wind generation from GdV (including wind used for pumping) against average daily wind speed at the airport for May 2-30 (red) and for the rest of the data since the start of operations (blue). The trend line for the rest of the data is over twice as steep as the May 2-30 trend line, indicating that the operational change cost GdV a lot of renewable energy production. How much? At the average May 2-30 wind speed of 7.0 m/s the trend lines show a difference of over a factor of two. So had GdV proceeded with normal operations the renewables percentage during May could have been as high as 50% instead of the 25% actually generated.

Figure 5: XY plot of GdV wind generation vs. daily average wind speeds at El Hierro Airport 3km away. Red dots show all the data from May 2 to May 30. Blue dots show all other data since project startup.

On other issues, it was recently reported that GdV was paid 12 million euros for its 2015 renewable energy production. With 2015 production totalling 8,700MWh this works out to 1.38 euros/kWh. This stands in stark contrast to the claim that “ El Hierro has the cheapest electricity in the Canaries, thanks to Gorona del Viento”, although with El Hierro consumers presently paying only about 0.25 euros/kWh GdV could afford to give its electricity away and still make a handsome profit.

And who paid GdV this generous sum? GdV’s contract is with the Instituto de Desarrolo y Ahorros Emergeticos, which is a branch of the Spanish Ministry of Industry, Tourism and Trade, so presumably it was the Spanish government. In short, the Spanish taxpayer footed the bill.

And what does GdV plan to do with the money? Seven million dollars of it will swell the coffers of the Island Council, which is the majority shareholder in GdV, and the remaining five million will be spent on “improvements” at GdV instead of being distributed as dividends. Exactly what improvements are planned is not specified, but if they take priority over dividends they are obviously considered important.

This entry was posted in Energy and tagged , , . Bookmark the permalink.

57 Responses to El Hierro May 2016 update

  1. pyrrhus says:

    You almost don’t have to write these articles….it’s all a scam

    • No, I don’t think its a scam. It’s just an example of what happens when the greens take a project over. In the meantime I’m trying to keep things as technical and non-judgmental as possible.

      • robertok06 says:

        Roger: you are too kind with these guys!… how can one not call it a scam, or fraud, after having read the communique’ which you have linked above?

        “Gorona del Viento cierra 2015 con 5 millones de beneficios

        “Tenemos una central con unos beneficios medioambientales indudables y de proyección internacional, con una media de incorporación a la red de renovables del 44% en su primer año de funcionamiento comercial y con una decena de hotos puntuales en los que se ha logrado el 100% de penetración de energías limpias a la red y con beneficios económicos”, resaltó Allende.”

        So… is it 44% penetration or is it much less, as you’ve shown here?

        • I calculate renewables percentages by subtracting diesel generation sent to the grid from total generation (diesel + wind + hydro). So the 32.8% number will be robust. (Hubert Flocard estimates 32.7%).

          I think one of the problems here is Juan Pedro Sanchez, who acts as liaison between GdV and the Island Council and who was one of GdV’s originators. He’s the Island Council’s source of information on GdV and he never misses an opportunity to tell them how well the project is doing. The press release above was probably written by him.

      • RDG says:

        If El Hierro isn’t a scam, then it is legitimate but flawed. In that case it offers hope which is exactly what the populace wants to support because there is nothing else for them. The natural gas public-privatization ponzi will send them to the soup lines and worse. You are not demonstrating the folly of the greens but giving them some more hopium fuel.

        Fed: Give me control of a nations currency and I care not who makes up the rules.

        China: Give me control of the worlds quality coal after peak conventional oil and I care not about other technologies.or a petro currency.

        Fed trades worthless paper to China (and others) for USA high EROEI coal.

        Those are the two entities that comprise the ‘Greens’. No wonder we are told to shut down the dirty obsolete coal plants. It aint ours anymore! They get coal, we get new age junk that doesn’t employ anyone. Modern day land for costume jewelry scam.

        Coal creates jobs…the rest of the new age energy tech junk (solar and wind) eliminates jobs.

        Who the hell cares about this nonsense called El Hierro.

        What are we to learn here that isn’t obvious? Coal or Stark Poverty? What else is there.

  2. John F. Hultquist says:

    Versus the word from 2 years ago:
    But once you’re there, there’s no need for fossil fuels at all. The ancient island off the west coast of Africa is now a model for the future, within months of running on 100 percent renewable energy, which consists of a mix of wind and hydro-power.
    NPR Link: Here

    Notice the “… at all.” part.

  3. Rainer says:

    put this post in the link of “http://euanmearns.com/el-hierro-portal” also

  4. oldfossil says:

    Seven million euros split between the ten thousand El Hierro population works out at… lemme see… a bit better than a slap in the face with a wet fish for islanders whose per capita income in 2010 was €8,000. http://go100re.net/properties/el-hierro-canary-islands/

  5. mark4asp says:

    I suppose pumped hydro alleviates the need to keep fossil fuel boilers hot? This is a practice I believe we see a lot of in Germany – to backup intermittent wind, in case weather forecasts fail to deliver planned wind. Thereby explaining much of the failure of Energiewende to make a big dent on Germany CO2 emissions. I believe pumped hydro was first created as a means of providing peaking power because hydro switches electricity into the grid faster than anything else can.

    So, I can, sort of, understand their thinking. Now it’s done we can see why the prototype fails. If only Germans had gone with prototypes first!

  6. It doesn't add up... says:

    Meanwhile, some fantasy from Bright Blue:


  7. Euan Mearns says:

    Roger, it’s fascinating following this story. But quite bewildering to try and work out what GdV are trying to achieve. Have you any idea why they might have changed the operational procedure to 75% diesel instead of 100% renewables?

    • Rainer says:

      Hello Euan,
      sure Roger wil have a better respond.
      Here is mine:
      It reminds me at the story of the GROWIAN;
      GROWIAN was a wind generator build and run by living in past time german companies to proof it does not work. And it did not. Today this big companies are nearly broke.
      Will not be surprised to find somebody responsible on payrolls very interesting.
      It is not possible for good minding persons to present GDV in such a bad form,
      A honest person does public the problems.
      A honest person does public the aims of test runs.
      AUTSCH: forgot: “Cabildo del Hierro” is running GDV. Not wondering any more….

    • That’s a hell of a good question, Euan. I was hoping that some of our El Hierro experts would show up to give us their opinions (Kees? Greg? Hubert?). But GdV’s performance has been so dismal that it seems to me that they have now reached the point where they’re prepared to try anything. After two years of operation and testing they’ve made no progress worth speaking of and desperation may have set in. (They’re messing with the system again today, cutting wind to zero and continuing with only diesel and hydro, but that isn’t working too well either.) It’s possible that the $5 million euros now earmarked for “improvements” might solve some of the grid integration problems, but according to Hubert Flocard’s calculations GdV still couldn’t generate more that 50% of EH’s annual electricity demand even if these problems were solved.

  8. Baseload change, ok.

    What I am seeing is
    1. Recognition that this time of year ha few renewable resources.
    2. Reduction in the amount of electricity sent to pumping, specifically wind.

    Figure two and similar operation modes looks like a data gathering phase so as to be able to enact a scheme like figure 4 where wind is curtailed to avoid pumping.

    Perhaps there are issues with using the wind that would have been used for pumping given the time frame? I.e. The wind that the previously sent to pumping is not able for some reason to gt onto the grid? Perhaps during the 100% renewable test, they found distribution issues?

    • This time of the year has comparatively abundant renewable resources. June and July are two of the windiest months on El Hierro.

      • Indeed but what I am asking is not whether they can generate but whether they can get it effectively and stably onto the grid. Did they find something during the 100% test to suggest there are limitations and the need for curtailment?

        • Greg Kaan says:

          The multiple grid crashes when diesel generation was greatly reduced may offer a clue..

          • Was not aware of these. Do we know when they happened?

          • Greg Kaan says:

            You can find them discussed in the comments in the previous 2 or 3 updates that Roger has done for GdV. I continue to think that the issue is the inertial emulation of the Enercon turbines having some feedback effect when operating with the peltons leading to oscillations but Kees disagrees – he totally discounts the inertial emulation from having any effect on system behavior.

          • Roger Andrews says:

            There have been four complete or partial grid crashes since project startup.

            February 18 at 3.40am
            February 18 at 10.30am
            February 19 at 2.50am
            June 1 at 14.10 pm

            You can see them on the yellow line on the daily REE graphs, which you can access via the El Hierro Live grid box.

  9. Flocard says:

    Some additional statistics after 11 months (starting July 1st)
    % time with diesel 99 % : 13 %
    Maximum achievable renewable fraction given the wind production : 49 %

    I am afraid I have no clue as to why GdV has chosen not to use the wind power that was available in way in view of the wind velocities.(what is the addresse at which one can download wind velocities)
    My only interpretation is that
    1) it is not really important for GdV tp produce electricity. Given the contract signed with the Spanish government (which by the way right now does not exist and nobody wants to be seen as harsh on renewable in election times) they are showered with money.
    2) because energy production per se (the MWhs) is not important moneywise what becomes important for the engineers is to test GdV in as many operational modes as possible.
    Between 13 and 16 May GdV has been pumping
    Between 16 and 21″st May GdV has produced about 120 MWh of hydro power in a continuous mode (even doubling hydro power for the last two days before stopping altogether). Taking into account that each MWh produced by the turbines requires that about 800 m3 of water are released from the upper reservoir, we find that close to 100 000 m3 have entered the lower reservoir whose ultimate capacity is 150 000 m3 (a value which according to Rainer’s pictures – see one of your posts – has never been approcahed.) It is clear that this operation mode had to be stopped soon.

    In my opinion, we have just witnessed a test performed in conditions which garanteed stability (Diesel was in charge of it) This stability condition (wind and hydro used as base) was probably requested by REE

    Note a near collapse of the grid on June 1st. Before the collapse wind hydro and diesel were producing. Immediately after the collapse only diesel power is used (probably, REE does not trust GdV to help when grid stability has to be regained).

    • Thanks Hubert. The critical number, I think, is 49%, which based on operating experience to date is the highest percentage of renewables GdV could have sent to the grid even if all the wind power generated had been used. It may be as close to 100% renewables as GdV ever gets.

      The airport wind speed data are at:

      I doubt the test was ordered by REE, which is responsible only for distributing the power that GdV sends it. REE might have suggested it, but exactly how GdV and REE interact isn’t clear. REE does, however, exercise veto power over what it gets sent.

      Diesel alone was used to recover from the June 1 grid crash, but wind and hydro were used after the partial (?) grid crashes on February 18th and 19th. Unfortunately we will probably never get an official explanation of what caused these crashes.

      • Flocard says:

        Thanks for the address where to get wind information.

        The figure 49 % is an upper bound given the measured wind production since July 1st 2015.
        On the other hand, it is probably not the best possible wind production.
        – Indeed over 11 months, the load factor of the El-Hierro wind turbines is only 23%. which is low.
        – At no moment the load factor was above 65 %
        – You have pointed out that in May there has been an obvious underuse of the possibilities offered by the wind.blowing over the island
        I suspect that if GdV could use the wind farm slightly more efficiently the upper bound could move above 50 % and retrieve the upper limits that have been mentionned long ago by Spanish engineers (the most optimistic I recall is 60 %)
        Note that the May modus operandi shows that the GdV engineers can control very well the wind production independently from the wind velocity. (control in the direction of reduced powers of course)

        One can also remark that
        1) if one only had tthe wind farm and the diesel (no money spent on building and operating the hydro component (which probably is responsible for the GdV 30 jobs mentionned by the Cabilde)
        2) one had required that at any moment at least 25 % of the electric demand was produced by the diesel plant,
        one would have been able to reach a 39.3 % renewable fraction and it would have been necessary to only waste (with a resistor for instance but probably just by electronic control of the wind turbines) 1/5 of the total wind production.
        In my opinion it shows that without the burden of demonstrating the usefulness of this costly and still underdimensionned hydro component and concentrating the technical efforts on the correlation of the wind farm used at its best level with the diesel plant GdV could have reached value of renewable fraction above 40 % (it is a windy island).

        In any case, the hugely expensive hydro component can only bring in few %’s improvements over a much simpler much cheaper (but also less sexy) system

        I agree that it was probably not REE that asked for the May test*. My guess is that GdV wanted to have a test with the hydraulic turbines running continuously for days. Then my point is that REE which is responsible for the stability said “fine but make sure that while you are doing a test, the wind production does not become a nuissance. Make it stay constant and at a low value so that
        1) Diesel will be operating all the time and have a margin of reaction
        2) if wind suddenly disappears (something that happens even in windy period) this disappearance can be esaily compensated by diesel.”

        * it is not its job. It is not partner in GdV. Otherwise we would not know anything about GdV operation and would have only to rely on M Sanchez’s statement

        • Hubert: Wind production is curtailed at 7-7.5MW. If we consider 7.5MW to be the capacity of the wind farm then the capacity factor increases to 35%, which is probably high but also maybe more representative than your 23%. The issue is, however, largely academic because GdV still shows no signs of being allowed to generate at its full 11.5MW capacity.

      • Jonathan Madden says:

        Thanks, Roger, for this update.

        As a brief, belated, addendum, I cannot help but notice an ironic comparison between El Hierro GdV and the new airport on St. Helena.

        Both are critically influenced by wind, sort of inversely.

        To my astonishment recent news reports suggest that the St H. airport may never open, due to excessive wind shear. Apparently wind speed measurements were conducted in the wrong place!

        So we have a pricey, UK funded, project that may become a white elephant. Could the site be converted into a wind farm?

        I wonder how accurately GdV’s performance might have been predicted by modelling before construction? I cannot remember now from your previous posts if any such research was published. But of all engineering projects subject to the weather, anticipation of the effects of wind at an airport must rank amongst the most basic and reliable.

        • Pedro J. says:

          “I wonder how accurately GdV’s performance might have been predicted by modelling before construction? I cannot remember now from your previous posts if any such research was published. ”
          I pointed to this paper in a past comment:

          Technical–economic analysis of wind-powered pumped hydrostorage systems. Part II: model application to the island of El Hierro http://www.sciencedirect.com/science/article/pii/S0038092X04002087

          Which says: “The results of the application of the model (developed in Part I) in El Hierro indicate that an annual renewable energy penetration of 68.40% can be achieved.”

          So I think all the comments saying the project is a scam because it can not achieve 100% renewables generation are misguided. The technical project never ever pretended it.

          • Jonathan Madden says:

            Thank you, Pedro, for this reference.

          • Roger Andrews says:

            Pedro: Thanks for that link. The study, dated 2005, is the first I’ve seen that predates the 2007 GdV-IDAE sales contract. (I missed it in your previous comment). Unfortunately it’s paywalled so I only have the abstract.

            Another study that postdates the contract comes up with 65%:

            2012: Realistically, however, about 65% of island’s total annual energy demand will be covered by the hybrid hydro-wind plant.

            But after the contract was signed GdV was still claiming 100% renewables generation except in “exceptional/emergency cases”:

            Some time after 2007: The operation’s philosophy is based on supplying the electrical demand of the island with renewable sources, thus guaranteeing the stability of the electrical network; the diesel engine plant will only operate in exceptional/emergency cases, when there is not enough windwater to produce the demanded energy.

            And it seems that grid and dam stability issues may also not have been studied in detail until after the GdV/IDAE contract was signed:

            2012: Study of grid stability problems (solution hasn’t worked).

            2011: I remember a reference to dam site stability studies which I can’t find now but which may have been prompted by the failure of the similar Barlovento dam on the neighboring island of La Palma in April 2011.

            The plot thickens.

          • Pedro J. says:

            “Unfortunately it’s paywalled so I only have the abstract.”

            Try sci-hub http://sci-hub.cc/10.1016/j.solener.2004.08.007

            “But after the contract was signed GdV was still claiming 100% renewables generation except in “exceptional/emergency cases”:”

            We had, Roger, this conversation before. You know that claim is just propaganda to justify the money politically. Each and every engineer in the project would be very happy reaching 50-60% of the electrical production from renewables and they would be probably satisfied with 40%.

            Proof: read what two former engineers from the project have to say [http://goo.gl/NxiDYY]

            “Ante esta manifestación tan contundente decir que, “El Hierro 100% renovable” fue un eslogan utilizado en los orígenes del proyecto para promover una idea diferenciada en un entorno singular con el fin de motivar la conciencia política y lograr la financiación del proyecto, pero que, el eslogan, que fue un éxito, nunca podrá ser una realidad técnica factible, al menos, en estos momentos y con la tecnología actualmente existente.

            En la isla se consumen cada año unos 15.150 teps⁽*⁾ en hidrocarburos (177.000 MWh aprox.) de los cuales el 23% se destina a la generación eléctrica con grupos diésel. La producción eléctrica a partir de las energías renovables es actualmente insignificante con un 0,8%.

            No hay ningún documento escrito que indique que la producción de la nueva central renovable fuera a sustituir más allá del 70 % de la energía eléctrica consumida en la isla. Sin embargo, debido a la estacionalidad del régimen de vientos en la isla, la mejor estimación de producción de la CHE no supera el 55 % de la demanda, sin entrar en ninguna otra restricción técnica para garantizar la seguridad del sistema eléctrico insular.

            ¿Qué queremos decir con esto? Que la máxima producción teórica de la CHE sería de unos 24.000 MWh al año, lo que equivaldría al 13,6% del consumo energético de la isla, porcentaje que, con una estimación incluso de 8 MWh adicionales por el coche eléctrico, alcanzaría un tope de un 15,5% de renovables. Nos podemos preguntar qué pasa con el resto. La respuesta es que seguiremos abasteciéndonos de fuentes derivadas del petróleo.

            ” I remember a reference to dam site stability studies which I can’t find now but which may have been prompted by the failure of the similar Barlovento dam on the neighboring island of La Palma in April 2011.”

            Another issue is the money. The government put out of tender a similar project for La Gomera, another small island. Due to the lack of a volcanic crater to build the dam, no one was willing to put a penny.

          • Pedro: Thanks for the link to the full paper. Maybe Kees or Greg would like to comment on it if they’re around.

            You are a mine of valuable information. Please don’t go away.

            I note that since 20.00 on June 8 GdV has gone back to using 1.6MW of diesel as baseload and balancing demand by switching wind generation between the grid and pumping. This is giving much better results – I estimate 60-70% renewables.

          • Greg Kaan says:

            I wonder if they have altered the wind turbines to only produce active power rather than providing stability support. I still think the system was largely set up as a demonstration site for Enercon to prove that their full conversion turbines could provide significant grid stabilization support.

    • That is what I am saying as well.

      • “In my opinion, we have just witnessed a test performed in conditions which garanteed stability (Diesel was in charge of it) This stability condition (wind and hydro used as base) was probably requested by REE”

        That is what I am saying as well.

  10. Roger Andrews says:

    A quote from the two ex-GdV engineers in the link supplied by Pedro J above:

    ¿Qué queremos decir con esto? Que la máxima producción teórica de la CHE sería de unos 24.000 MWh al año, lo que equivaldría al 13,6% del consumo energético de la isla, porcentaje que, con una estimación incluso de 8 MWh adicionales por el coche eléctrico, alcanzaría un tope de un 15,5% de renovables. Nos podemos preguntar qué pasa con el resto. La respuesta es que seguiremos abasteciéndonos de fuentes derivadas del petróleo.

    “What can we say about this? That the maximum theoretical production from (GdV) is 24,000MW per year, which would be equivalent to 13.6% of the energy consumption of the island, a percentage which including an estimate of 8MW for electric cars will reach a maximum of 15.5% renewables. We can ask ourselves what happens to the rest. The answer is that we will continue to supply ourselves with sources derived from petroleum”.

    I think we’ve fallen into the trap of considering only electricity. According to many reports GdV is supposed to supply all of El Hierro’s energy. Considered from this standpoint GdV is little more than a pimple on the elephant’s backside.

    • Rainer says:

      Are you starting to take GDV and the Cabildo de Hierro by word?
      words: 100% REE —-> reality under 40% electricity
      Like a friend of mine said:
      Go on dreaming you people of El Hierro and go on spending other peoples money till they stop giving it. Than you will wake up in reality. Poor El Hierro!

  11. Kees van der Pool says:

    Two significant statements from Enercon:

    (1) “In day-to-day operation, however, the WECs run at limited capacity because the variable power output triggers fluctuations of frequency and voltage in the grid that need to be compensated constantly”

    This curtailing means that extra power is available under the right wind conditions and that the Enercons could be programmed to supply extra power if the grid frequency decreases to a certain set value (usually 48.5 Hz). This way, the Enercons help in stabilizing the grid frequency by being able to add power, like any ‘normal’ generator with a governor. Irish windmills run in this mode. I have no idea if they are programmed this way @ GdV but it seems reasonable in view of the very robust 40% curtailment.

    (2)”In summer, the winds along the west coast of El Hierro are extremely strong, often with heavy turbulence”

    At the last two mishaps, windpower disappeared and the Peltons (hydro) did not kick in, as they should have, to back up diesel power. Per the rules, only the minimum number of diesels were running and could not compensate for the disappearance of windpower. Absent hydro, blackout followed.
    Disappearance of the windpower may have been caused by either the disappearance of wind or by a programmed ‘auto’ shutdown of the windfarm due to excessive turbulence. Since Enercon supplied the ‘Windfarm Control Unit’ (FCU), my bet is ‘turbulence’ – I’m pretty sure they want to prevent damage to the windmills and subsequent warranty claims.

    Given all this, I don’t think a windfarm @ 500m altitude on a cindercone in the Atlantic tradewinds is a good match for a hydro installation. Windpower is erratic, especially this time of the year, and pumping 700m^3 @ 700m head with power modulated by two independent variables (wind and grid regulation) is not very efficient. Rainer referred to the constantly changing pitch of the pumps – no wonder. On top of that, the pumps have to be shut down/spooled up under certain protocols, introducing delays. If not done right when the only power source to the pumps (wind) disappears, damage to the penstock will take place.

    All this good stuff still does not explain the Peltons going AWOL – Endesa (Spain’s National power generator entity) has acknowledged one of the blackouts, promised an investigation and is pointing the finger at ‘two diesel generators, a fixed pump and 1.1 MW of windpower’ in other words, not at the hydro generators.

    I guess we’ll see (or maybe not. . . . )

    • Kees van der Pool says:

      The Enercons are indeed programmed to start increasing power at 49.6 Hz:

      “Later studies of the frequency regulation capability of wind generators showed better behavior when a generator trip occurs, as the frequency drop was limited to 49.6 Hz in spite of the 48.5 Hz obtained simulating the wind generator as a simple negative charge. In this way, the wind generator was requested to change its power (see Figure 1 ). Plimited is the active power setting to the wind generator, and Pavailable is the available power of the wind generator at that precise moment”


      • GdV has now gone back to the wind-balancing mode and for the last three days except for a single blip has been running diesel in 1.6MW baseload mode and following load by switching wind between the grid and pumping, sending about 70% RE to the grid as a result. Wind speed at the airport has stayed fairly constant at 5-9m/s over this period. Be interesting to see what they do when the wind drops.

      • Roberto says:

        REad a bit better. The enercons start incresing power more early, the way they do it is described in the enercon data sheets. This stopped the fall of Frequency at 49,6 Hz. It simply shows with power control swithed on the wind turbines throw in more inertia than the peltons.

        • Kees van der Pool says:

          ROBerto: you wrote “REad a bit better. The enercons start incresing power more early, the way they do it is described in the enercon data sheets. This stopped the fall of Frequency at 49,6 Hz”.

          The Enercons can increase power only when they run in curtailed mode. When they run in maximum power mode they cannot. There is also an ‘inertia emulation’ mode where they use the inertia of the generator+blades to squeeze out some more power in certain cases to assist the grid but there are no indication they are programmed that way. There is plenty of inertia available at GdV with the Peltons and diesels.

          You further wrote:”It simply shows with power control swithed on the wind turbines throw in more inertia than the peltons”.

          Power control is always switched on. The Enercon inverters would not last very long without power control. Inertia cannot be ‘thrown in’. It is either present or not present. Inertia at GdV is supplied by the Peltons that run as flywheels and by the diesel generators – nothing else.
          If you carefully read the Enercon datasheets, you’ll find:
          “This is the major advantage of the annular generator. In electrical terms, it is completely decoupled from the grid”.


  12. Pedro J. In the link you quoted earlier http://sci-hub.cc/10.1016/j.solener.2004.08.007 mention was made of a four-year wind study before the project was approved. Do you know where the data might be found?

    • Pedro J. says:

      No idea. It seems that the authors gathered some meteorological data by themselves, as you can read in the paper: ” The wind measurements taken at a height of hr = 10 m in the area chosen for the installation of the wind park showed an average annual wind speed of 9 m s⁻¹. The highest intensity was in the months of July (11.0 m s⁻¹) and August (12.3 m s⁻¹), due to the greater predominance of the trade winds, typical in the Canarian Archipelago.”

      I have just found this recent congress communication in which you can realize everybody (even the GdV staff) is aware that 100% renewables is (and was) an utopia. Even with the current configuration, penetration will be decreasing over time. They (optimistically) expected to get close to 80% the first year. Now we know they failed.

      Sustainable Energy System of El Hierro Island http://www.icrepq.com/icrepq'15/232-15-godina.pdf

      • Thanks Pedro. It looks like we won’t be able to get the wind data without going to a lot of trouble, and maybe not even then.

        Average wind speed at El Hierro Airport since January 2014 has been 6.7m/s, incidentally.

        • Kees van der Pool says:

          Roger, do you have the wind-only MWhrs for the June 27 2017 through May 31 2016 timeframe handy? The Enercon ‘calculated power curve’ shows about 1.6 MW @ 6.7m/s for a 13GWh/11 months yield. This might give us a simple ratio between the average windspeed at the windfarm and the airport.

  13. Rainer says:

    2016-06-14 03:50 Diesel OFF

  14. Blackburn's with Darwin says:

    Looks like this could be quite the Green Letter Day for little old El Hierro!

    • Rainer says:

      2016-06-15 08:00 Diesel on
      REE only since July 2015:
      225h or 2,56% of 8784 yearly hours

  15. Rainer says:

    2016-06-19 13:50
    Diesel off

  16. sod says:

    Diesel still off. They could do this much longer. Why can we not figure out, why they do not do it?


Comments are closed.