El Hierro end 2016 performance update

Because of generally low wind strengths the Gorona del Viento (GdV) plant achieved only 28.2% renewables generation in November and December 2016. Percent total renewables generation since full operations began in June 2015 stands at 37.7% at the end of 2016, down slightly from 38.7% at the end of October 2016. Renewables generation for the calendar year 2016 was 41.1%. Minor improvements are apparently being made in wind turbine performance but hydro generation remains negligible overall. Data on GdV plant layout, operation and capacities are given in the September 2015 review. Previous posts on GdV are accessible through the El Hierro portal.

Figure 1 shows daily mean percent renewables generation since June 27, 2015 (data from Red Eléctrica de España (REE). The 100% renewables target remains as elusive as ever:

Figure 1: Daily average percentages of diesel & renewables (wind plus hydro) sent to the El Hierro grid. The month scale is not exact

The Table below updates the monthly grid statistics since startup on June 27, 2015 through December 31, 2016, a total of 18 months of operation. The “percent of El Hierro total energy demand” numbers are again based on El Hierro obtaining 23% of its total energy needs from electricity and are italicized to signify uncertainty because the 23% estimate is not verified.

Figure 2 plots the REE 10-minute generation data for November and December. The renewables percentage for these months exceeds 20% because of three periods of stronger winds – between November 7 and 12, December 15 and 18 and December 29 and 31. Wind generation was minimal for most of the rest of the time, as was hydro – there was in fact no renewables generation at all for 202 hours during the two months. This was, however, partially offset by a 30-hour, 100% renewables test conducted on November 12 and 13.

Figure 2: Generation by source, November & December 2016

The grid failures on December 30 are also of note. These occurred during a period of very strong winds and began with an abrupt decrease in the amount of wind power sent to the grid, suggesting that the turbines had to be feathered. Grid restart was achieved using hydro alone. Figure 3 shows details:

Figure 3: Details of December 30, 2016 grid outages


While it’s hard to pick any positive trends out of the GdV data there is one area in which some progress is being made – wind curtailment during high wind periods. We have usually cited 7.5MW as the curtailment level for GdV’s Enercon turbines, but as shown in Figure 4 maximum wind generation has gradually been creeping up, reaching a high of 8.8MW in December. There is also a visible correlation between percent renewables and maximum wind generation which although weak (R squared = 0.25) suggests that the increase in wind generation may be having a positive impact on renewables percentages:

Figure 4: Percent renewables generation vs. maximum wind generation by month since project startup.

This impact, however, is unlikely to add more than a percentage point or two to GdV’s output because it increases wind generation during high wind periods when wind generation often exceeds demand (and therefore has to be wasted anyway) but does nothing to increase it during low-wind periods when the extra power is needed. And the problems with the hydro system, which now seems to be incapable of delivering more than a few tens of MWh of uninterrupted power before shutting down, remain.

The REE grid data:

The daily 10 minute REE grid data for El Hierro between project startup on June 27 and December 31 2016 have been combined into a continuous data series that is now accessible on the El Hierro portal. Variables are date/time, demand, diesel generation, wind generation and hydro generation. Users are reminded that total generation is diesel + wind + hydro and that the hydro value is the sum of hydro generation and energy used to pump water uphill, meaning that it is not possible to derive individual hydro and pumping values from it. Hydro is commonly negative because uphill pumping usually exceeds hydro generation.

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42 Responses to El Hierro end 2016 performance update

  1. Rainer says:

    Really excellent like allways.
    The REE-Data does help me a lot.

  2. Stefan says:

    @Roger: Thank you for your excellent work. It is an eye opener. The local Canary island press does not report these figures.

    You got the share of electric consumption of the total energy demand on El Hierro wrong. On El Hierro island 64,10% of all hydrocarbon imports went into the production of electricity in 2012 prior to the start of Gorona del Viento.

    You cannot use the overall Canary island ratio for El Hierro because the overwhelming part of hydrocarbon consumption in Tenerife and Gran Canaria is tourism related and consumed by the international airports and the rental cars there. El Hierro does not have an international airports and tourism is very low compared to the overall Canary island average.

    Here are the dates for 2012 (they do not take into account the fact that the daily ship between Tenerife and El Hierro and the airplanes between El Hierro and Tenerife are buying their fuel in Tenerife – half of this energy should be accounted for El Hierro – but I assume this error be minor)

    (1) http://www.gobiernodecanarias.org/industria/publicaciones/ANUARIO_ENERGeTICO_DE_CANARIAS_2012.pdf
    table 2.3.1, page 19

    (2) https://de.wikipedia.org/wiki/Heizwert

    El Hierro fossile energy consumption

    Butane 313 t * 49,50 MJ/kg = 15,494 TJ
    Fuel 95/98 octanes 1997 t * 43,45 MJ/kg = 86,770 TJ
    Gasoil I.V.P. 3458 t * 45,40 MJ/kg = 156,993 TJ
    Electric Diesel 10198 t * 45,40 MJ/kg = 462,990 TJ

    SUM: 722,247 TJ

    ratio electric diesel / total:
    462,990 TJ / 722,247 TJ = 64,10%

    • Stefan: And thank you for a very valuable piece of information. I’ve modified the report table so that 64% rather than 23% of El Hierro’s total energy consumption goes for electricity generation and here are the results. They show that GdV supplies El Hierro with about a quarter rather than a tenth of its total energy, but this still isn’t very encouraging:

      “The local Canary island press does not report these figures.” They have in fact done so in these articles:




      But while the message is being read it isn’t getting through, as shown in this recent (attempted) rebuttal from Tomas Padron Hernandez, one of the originators of the project:


    • Rainer says:

      That are valuable info you gave.
      Think we should not under estimate the fossil use of the ferry and the planes en El Hierro.
      Could you estimate it???

      • Stefan says:

        Just to get an idea of the order of magintude:

        Tourists from Europe (excluding Spain) to El Hierro in 2015 (source: http://www.turismodecanarias.com/) 3655 persons

        Tourists from mainland Spain: 2444 persons (may contain some contamination from tourists changing the plane in Madrid)

        If we estimate 3500 km travel distance for european tourists and 1700 km travel distance (one-way) for tourists from the Spanish mainland, and take 4 kg fuel/100 km for air travel, we have:

        3655 * 4 kg / 100 km * 3500 km * 45 MJ/kg = 23 TJ for tourists from EU (minus ES)

        2444 * 4 kg / 100 km * 1700 km * 45 MJ/kg = 7 TJ for tourists from ES (minus Canary Islands)

        = 30 TJ for long distance tourists (one way), that is 4% of the El Hierro total annual energy consumption. Most of these 30 TJ do not show up in the balance sheet of El Hierro but in the balance sheets of Tenerife, or Madrid.

        • Rainer says:

          fine calculation!!!
          But: the tourists are the minor traffic.
          The people of El Hierro have to go also by plane / ferry for a lot of things:
          Shopping trips. medical treatment in big hospitals. Only one basic hospital does exist here.
          Elderly people travel there with companion.
          Even for sport and cultural events the groups have to use the plane or the ferry.

          Nearly all merchandising is coming in by ferry.
          All export is done by ferry.
          Just an island……

          Maybe you also have a idea of a calculation of cargo and persons.

        • Rainer says:

          Here a base of calculation of energia de flights to El Hierro:
          El Hierro, 156.439 passengers in 2016

          • Rainer says:

            here my calculation.
            please verify:
            A calculation by myself in the way Stefan showed:

            passengers 2016: 156.439
            tourists: 6000

            Valverde -TFN : 170 km
            Valverde – Las Palmas Grand Canaria: 240 km

            (156439-60000) * 4 kg / 100 km * 170 km * 45 MJ/kg = 46 TJ

            It is for sure more then 4kg/100km with short distance flights
            some flights are also to Grand Canaria a distance of 240 km one distance
            so i estimate 50 TJ

            tourists -Stefans calculation-:

            one way: 30 TJ = 4%
            two ways: 60 TJ or 8%

            50 TJ + 60 TJ = 90 TJ

            ratio electric diesel / total:
            First statistics 23% : like en all Canarias
            second statistics 64%: energy without flights and ferry

            My prilamary calculation:
            flights: 90 TJ

            So now we have to look that the base of energy
            722,247 TJ calculation of Stefan
            + 90 TJ flights

            462 TJ / 772 TJ +90 TJ = 57%

            missing still:
            main cargo and persons also: daily ferry

            For sure all this is not the main problem but shows :
            All statics have the potential of faking if you do not look really close.

  3. oldfossil says:

    I like the picture of the tree flattened by the wind. If wind power can’t make it here it can’t make it anywhere (h/t Frank Sinatra).

    • The tree is a garoé, El Hierro’s sacred tree. It’s widely used as a symbol of how strong the wind on El Hierro is, but the wind isn’t that strong. There are in fact only a handful of garoés on the island that are bent over like this (most of the photos you see are all of the same tree). The other trees on El Hierro grow straight up.

    • The bushes along the coast of northern Norway hug the ground in a similar fashion. And few trees grow in the wild – except in the gullies..

      Shame it is so far away from consumers. 🙂

  4. gweberbv says:

    A 5 MW PV plant would save money from day 1 (assuming diesel-generated electricity costs of above 15 Eurocents/kWh). It would also significantly lift up the RE penetration ratio, so there would also a PR windfall profit.

    I don’t get why this route is not persued. O&M costs of the wind farm will rise as the turbines are getting older. In contrast a PV plant can be maintained by a local electrician.

  5. climanrecon says:

    100% renewables is impossible without batteries if the fuel supply is intermittent wind and sunshine, even if they never go to zero at times of peak demand. The wind/solar generators will always shift the times of peak demand on other sources to wind/solar lulls, a phenomenon seen already in places like South Australia:


  6. Rainer says:

    Update in “Cloud”
    Field-studies-2017-01-06.txt ca 13:10 – ca 14:20
    All pictures now also with seconds in the name


    made pictures with more pixels
    Try to show same tube with cable to little control case like in upper storage.

    lower storage: Roger please verify with your metering
    more pixels in most pictures….

    Observations -ca 13:49
    water coming in at the far right side of input
    Peltons ??????
    Pumps working

    still not clear if the meter belongs to GDV ….
    meter not running
    2144−2105=39 qm since 2016-12-20

    Upper storage:

    storage more then 2016-12-20
    Roger please verify with your metering

    Meter-posts: Mark every 10 cm ???
    Try to show more details of tube with cable to little control case.

    water meter first running later not
    two pictures short one after the other: ca 120qm/h

    202725−169663=33062 qm

    33062 qm since 2016-12-20
    33062 qm/283h = 62 qm/h

    second water input:
    water running in storage is visible

  7. Rainer says:

    2017-01-10 20:40 till
    2017-01-10 20:50
    9.0 MW Eólica.
    New max??

  8. Rainer says:

    Sorry. Math. 0 points:
    50 TJ + 60 TJ = 110 TJ

    462 / (722+110) =55 %

  9. Rainer says:

    the speed is really empressing, but not a sea travel to enjoy!

    Distance Los Christianos to Valverde: 121 km
    Travel time: 2,5 h or even faster if the ferry is late…
    the speed is aprx 50 km/h or 27 knots.
    Both directions seven times a weak.

    The cargo is really used, passengers depends.

    So the engines are running at least 5 hours daily consuming how much????

    Hope that basic data does help you to estimate the used energy.

  10. Rainer says:

    OK than i try it myself again:
    Please verify

    Stefans Calculation was:

    ratio electric diesel / total:
    462,990 TJ / 722,247 TJ = 64,10%

    My calculation or estimate is:
    ferry energy consumption:

    maximum. 4 x 7,2 MW
    running 365 days 5 hours daily ==> 365 4 x 7,2 MW x 5h = 52560 MWh = 189 TJ

    462 TJ / (772 + 110 flights +(189 ferry engines ÷2 factor for not running full speat ÷0,4 factor input fossil to output ))TJ =41%

    There we are in the middle between first basic of 23% all canary and the 64% of the statistics without the traffic energy.

    I know it is more an estimate and i am not a well educated person for things like this.
    I still take that basic 23% more near to facts than the 64% of a statistics without the the use of flights and ferry energy.

  11. Stefan says:


    you should only account half of the fuel spent to El Hierro, the other half goes to Tenerife.
    Or do some weighting depending the goods interchanged between the islands. But accounting all navigation fuel to El Hierro is the same error as accounting everything to Tenerife.

    According to my experience the fast ferry does not travel at maximum speed for passenger comfort and for saving fuel (my experience from La Palma island – here the fast ferry travels at 42-44 km/h instead of the theoric maximum of 88 km/h – assuming a square law this means the motors use 1/4 of their maximum power). Actually the El Hierro boat takes 2h 45min for the trip which translates to 44 km/h average speed.

    As I understand there are these key errors in the Gorona del Viento project:

    1) Lack of transparency in the planning and operation phase (typical for all Canary Islands projects, with only a half free press which completely depends on getting advertizing from the overwhelming public sector)

    2) Solar was not considered (here on La Palma I get for my weather station 2400 kWh/m²/year sun radiation)

    3) Battery storage was not considered

    4) It would have been wiser to execute the project in phases: first the wind generators / solar cells, then the water/battery part

    5) All wind generators were put at the same spot – this means that they operate only when the trade winds (North-West direction) are present

    6) The upper reservoir was constructed directly above the diesel plant: A reservoir failure like in Barlovento on La Palma would spell catastrophe to the diesel plant below

    7) As Mr. Flocard pointed out the economic contract of GdV does not incentive actually using GdV for energy production (they get paid for peak power, but for a lot lesser degree for delivered energy), instead GdV seems now more like a means of squeezing out Spanish and EU taxpayers as a hidden subvention for some El Hierro nomenclatura.

    The failure of GdV does not mean that wind/solar on other islands is not viable because of the multiple errors in GdV planning and execution and lack of transparency.

    • Rainer says:

      thanks to put together the points.
      Allow me to respond to “According to my experience the fast ferry does not travel at maximum speed”
      For sure not.
      I also know that the El Hierro boat takes 2h 45miutes.
      To make ist easy for my estimate did remeber the time of going out of harbor and in harbour so i could calc with 2,5 h.
      So i took the speed of aprx 50 km/h or 27 knots.
      For sure it is an estimate of me.

      Also why take half of the Energy to Tenerife? All the benefits and all reason is the that remote island El Hierro. Without El Hierros beeing no flights and no ferries.
      But again: Just an estimate of mine.

      I really agree with your list of errors and also with the last sentence:
      “The failure of GdV does not mean that wind/solar on other islands is not viable because of the multiple errors in GdV planning and execution and lack of transparency.”

      It remembers me at the time when in Germany a big Company, i think it was RWE did build the GROWIAN, a big wind converter, with the aim to proof the impossibility of that technology. And nowadays RWE will get broke with old technology.

      It is just a shame for El Hierro and a shame for all people working in the future of men kind and i take it personally.
      There are also a lot of other projects en the island which put me as part time El Hierro citizen just shame in my face.

      Keep your eyes open in future too.

  12. Rainer says:

    The link to this Blog is not present in:

  13. Rainer says:


    There are a lot of places in the world with a lot of wind where no trees at all are growing.
    Like at a lot rims in the world the trees take a windy form at El Hierro too…..
    Build your own opinion.

    Field-studies-2017-01-24.txt ca 14:09 – ca 14:40

    lower storage:
    Roger please verify with your metering

    Observations -ca 14:10
    water coming in
    Peltons working
    Pumps NOT working

    still not clear if the meter belongs to GDV ….
    meter not running
    2159-2144=15 qm since 2017-01-06

    windpark E70:
    Only 4 of 5 are working.
    One in parking position

    Upper storage:

    storage less then 2017-01-06
    Roger please verify with your metering

    water meter not running
    210078-202725=7353 qm

    7353 qm since 2017-01-06
    7353 qm/552h = 13 qm/h

    second water input:
    NO water running

  14. Thanks for the pictures Rainer. I’ll discuss them in the next update. But it seems that nothing much has changed. GdV is still working with only about 100,000 cu m of water in the reservoirs.

    At 14.10 we had diesel = 3.3MW, wind = 1.2MW and hydro = 1.2MW, so the pumps wouldn’t have been running.

  15. Rainer says:

    Field-studies-2017-01-31.txt ca 16:18 – ca 17:54
    Field-studies-2017-01-31 may be there a little later at mid day 2017-02-01

    lower storage:
    new max??
    Roger please verify with your metering

    Observations -ca 14:10
    water coming in
    Peltons working
    Pumps working

    still not clear if the meter belongs to GDV ….
    meter not running
    2164-2159=5 cum since 2017-01-24

    windpark E70:
    Only 4 of 5 are working.
    One in parking position
    -other one then last observation 2017-01-24
    -Last in row-

    Upper storage:

    storage nearly empty
    Roger please verify with your metering

    water meter not running
    210078-210078=0 cum

    0 cum since 2017-01-24
    second water input:
    NO water running

    • Thanks Rainer.

      The lower reservoir seems to be about 2/3 full – i.e. about 100,000cu m – and the upper reservoir effectively empty. So it seems there’s been no significant addition of water. More in the next update.

  16. Rainer says:

    Google translation:
    “Electricity demand increased by 3.7% in El Hierro in 2016, compared to the previous year, while the Canary Islands average reached 1.3%. In the comparison with the data of the Archipelago it is noticed that El Hierro was the island in which the electrical demand increased more during 2016.”
    Could this 2% extra be caused by producing a part of the 152 701 cum GDV storage water???
    The rest was produced in 2017??

  17. Rainer says:

    Field-studies-2017-02-07.txt ca 14:14 – ca 14:47

    lower storage:
    Roger please verify with your metering

    Observations -ca 14:14
    water coming in
    Peltons working
    Pumps working

    still not clear if the meter belongs to GDV ….
    meter not running
    2169-2164=5 cum since 2017-01-31

    windpark E70:
    5 of 5 are working.
    One in parking position

    Upper storage:

    storage nearly empty
    Roger please verify with your metering

    water meter not running
    210078-210078=0 cum
    0 cum since 2017-01-31

    second water input:
    NO water running

  18. Rainer says:

    2017-02-17 21:40
    9,2 Eólica -Wind-
    new max ??

  19. Rainer says:

    2017-02-18 20:40
    9,5 MW -Wind-
    new max

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