Spain Wind Integration

2 articles below, Pedro Prieto and National Renewable Energy Laboratory:

Jan 14, 2015 Pedro Prieto [energyresources] Digest Number 8957 [altered slightly]

In Spain we have this mix, as of the end of 2014:


MW     %         GWH     %

  • 19893 18.4    43191   16.7     Hydro (incl. Mini/micro)
  •   7866  7.3     57179   22.1     Nuclear
  • 11482 10.6    46264   17.9     Coal
  •   3498  3.2       6620    2.6     Fuel/gas
  • 27206 25.2    25869   10.0     Combined cycle gas fired
  • 23002 21.3    51439   19.9     Wind power
  •   4672  4.3       8211     3.2    Solar PV
  •   2300  2.1       5013     1.9    Concentrated Solar Power (CSP)
  •   8212  7.6     30935   12.0    Thermal renewable & Others


Pump up hydro & Generation Consupmtion: 12663 -4.9 Exports to neighbors -3543 -1.4, TOTAL 258515 100.0 LOAD FACTOR GROSS % Hydro (incl. Mini/micro) 24.78 Nuclear 82.98 Coal 46.00 Fuel/gas 21.60 Combined cycle gas fired 10.85 Wind power 25.53 Solar PV 20.06 CSP 24.88 Thermal renewable & Others 43.0


  1. Spain has a huge excess of installed power, with daily maximum peaks of hardly 40 GW, averages of 30 GW and a total installed power of 108 GW. This is the consequence, at the end of 90s and early 2000s of belief in infinite growth and preparation to it.
  1. Spain has a reasonably good hydro system, which is an excellent buffer for pumping up to back up the intermittencies of renewables.
  1. The international exchanges (in the balance exports) are basically with France (we have a positive balance), Morocco, through the Gibraltar Strait and Portugal, a country with also some renewables that Spain sometimes helps to balance as well. But at the end, it is basically more an island (with even less connection with Europe that the UK) from the electric point of view, as you can see.
  1. Spain has a huge installed combined cycle gas fired power plants, that were built in the mentioned belief of eternal growth about 10-15 years ago and now are basically backing the renewables, as the second source, if hydro has a bad year. This is very good for the renewable system, but an economic and financial tragedy for operators who invested heavily in combined cycles and are now having a misery of 10% load factor, when they were thought and designed for at least 5,500 hours a year.
  1. CSP has a bigger load factor than solar because the law admits some 15% of gas (classified as renewable energy) to back the plants and thus avoid the molten salt deposits to solidify on cloudy days or during the nights.
  1. Self-consumption is high and pump up (5,403 GWh/year) is not only to back up renewables, but mostly to help nuclear to offload in the nights.
  1. Renewable energies represented in 2014 about 43.7% of the total yearly national demand. Exactly the same percentage of installed power, but the trick is that in Spain, renewables (except big hydro) enter first into the grid by law, so, other sources (except the non-stop nuclear) have to give way to them and besides, regulate when possible (mainly hydro and combined cycles or fuel/gas, which is installed basically in the Canary and Balearic archipelagos) , as coal or nuclear are not good to back up fast variations of renewables.
  1. Last but not least, the Control Center you have mentioned in a previous post, located in Red Eléctrica Española (REE, the responsible entity for transport high voltage power lines in our country) is a world leader in handling and managing intermittent generations. They have a very sophisticated national network of sensors and meteorological devices all around the country and in neighboring countries and sophisticated algorithms connected to the national weather system, so that they can already very accurately predict how much a given wind field or solar field is going to produce every day at almost every hour, with at least six seven hours anticipation, so that they can program the 1-2 hours warm-up or disconnection of the combined cycle plants, which are suffering from much more on/off switches than originally programmed.

Neither wind, or solar in its two modalities in Spain (PV and CSP) has the need to be added or subtracted to balance the network, as they have priority of entrance into the grid by law. So, they deliver as much as they can produce in every instant. Only in very few exceptional circumstances have they had to switch off from the grid for a while. This balancing function is reserved basically to the hydro and to the combined cycle gas fired plants, that are the ones suffering the impact,  today working 870 hours a year (10% load factor), when originally designed to work 5,500 hours/year and suffering from faster degradation in their life cycles because the much increased number of pre-warmings and post-coolings and switching on and off more than originally expected.

There has been a decline in electrical usage in Spain over the last 3 years, obviously due to the international financial and economic crisis that is impacting mainly Southern European countries, but this is not affecting to the renewable generation, but has stopped addition of new power plants.

As for the vastly overbuilt capacity, the big mistake was not only in installing renewables, that everybody knows demand overcapacity and storage or handling to provide a safe and continuous service, but also to believe in Kyoto and to install huge amounts of modern combined cycle gas fired plants (Spain has 7 regasifying ports, first in Europe in handling this gas traffic and besides two gasoducts coming from Algeria). The idea was to burn gas and dismantle coal plants to minimize or avoid penalties (see Germany today and smile). I suggest that those countries and governments believing in 2000 that economic growth could not be sustained forever, while growing like Spain at 3-4% yearly, should raise their hands. No one had foreseen this and Spain was trapped in this belief. Only a handful of people like in this forum knew that growth could not be forever.

Of course, some countries like France (+75% of electricity coming from nuclear) can presume having less installed overcapacity, because the load factors of nuclear and the policy to “warm” the country also with electricity. This may have some other enormous inconveniences in the future. Germany is another case, with plenty of coal plants and still some nuclear plants running, despite of having many more renewables than Spain (but not as high a penetration percentage). The Netherlands can also add a lot of renewables because they have an essential buffer with the neighboring countries, in case no wind/no sun exists or if it goes in excess.

But in general, people have to accept that if they want renewables, they will have to build and install a considerable amount of over-capacity, and also, and most important, a massive energy storage system which will bring costs of the so called “renewables” to prices that will always escape the so called grid parity.

Finally, the very high prices Spanish consumers are paying for the electricity are not only due to the “overbuilt capacity” of renewables, but also and mainly due to a poor, corrupted and politically biased energy policy of the government, always willing to accept what the big electric oligopolies demand to continue with their sick benefits. The well-known and publicized case of former dinosaurs of politics being appointed to the boards of the big electric or energy corporations, with insultingly high salaries, immediately after having regulated them, while in the government, those in favor of them (the so called revolving doors scandal) is a very sensitive and painful issue for the Spaniards. To such an extent that probably the traditional bipartisan system is going to explode. So we are not accepting AT ALL thise perverse system, we are just suffering them and fighting it as much as we can.


NREL. 2012. Integrating Variable Renewable Energy in Electric Power Markets: Best Practices from International Experience. National Renewable Energy Laboratory.

Appendix F. Case Study: Spain Author: David Pérez Méndez-Castrillón, Ministry of Industry, Energy, and Tourism Coordinated and Integrated Planning Policy and Planning Spain’s energy situation as well as the policies pursued in the last decades are the direct result of certain challenges: a high degree of energy dependence, a lack of sufficient interconnections (as it is almost an isolated electric system), high energy consumption per unit of gross domestic product, and high levels of greenhouse gas emissions (mostly due to a strong growth in electricity generation and to the energy demand in the transport sector).

To face these challenges, energy policy in Spain (and in other European countries) has spun round three axes: security of supply, enhancement of the competitiveness of Spain’s economy and a guarantee of sustainable economic, and social and environmental development. The RE energy policy proposed takes into account that Spain has one of the highest levels of energy dependence in Europe, and that the Iberian Peninsula makes up an electric system that is isolated from Europe.

Energy Demand Coverage: At the end of 2011, RE covered 13.2% of final energy consumption and 33% of the total electricity production in Spain. On November 6, 2011, Spain achieved a new record when wind power provided 59.6% of electricity demand; the previous peak was 54.0%. In 2010, RE covered 11.8% of final energy consumption and 33.3% of the total electricity production in Spain.

The impact of high RE levels in the production required from conventional generation implies that thermal power plants must be able to cope with the variability of RE production. When this is not feasible, the TSO must rely on imports from, and exports to, neighboring systems. However, when the level of interconnection is not enough, as it is the case of Spain, RE curtailment will be the only solution.

A main objective in the planning studies of the TSO in Spain is to propose mechanisms to minimize those RE curtailments. New pumping stations, new interconnections, and new fast response power plants (i.e., those using open-cycle gas turbine or OCGT technology) can be considered and evaluated. From an electric point of view, Spain has one of the lowest interconnection ratios in the European Union.66 This lack of sufficient interconnection capacity has prevented the Spanish system from taking advantage of cross-border exchanges for the integration of RE, as cross-border exchanges enable electricity exports when the surplus of renewable production cannot be properly dispatched in the system, thus diminishing RE curtailments and increasing the overall efficiency.

This means special attention must be paid to coordinating, aggregating, and controlling the overall production that is fed into the grid because a certain volume of non-RE units must also be dispatched to fulfill with security and technical constraints.

That RE plants tend to be far more distributed and dispersed than conventional power plants complicates this task. In response to this challenge, the system operator in Spain established a control center of special regime, the Spanish Control Centre of Renewable Energies (CECRE), whose objective is to monitor and control RE production, maximizing its production while ensuring the safety of electrical system. CECRE was established in June 2006 as wind generation started to become a relevant technology in the Spanish electrical system. It is composed of an operational desk where an operator continuously supervises RE production. Renewable energy control centers collect real-time information and channel to the CECRE. To minimize the number of points of contact dealing with the TSO, the renewable energy control center acts as the only real-time speaker with the TSO. The control center also manages the limitations established by set-points, and they are responsible for assuring than the non-manageable plants comply with them.

The Iberian Peninsula has a very low electricity interconnection capacity compared with the rest of Europe. The existing interconnections between Spain and Portugal under the MIBEL framework do not facilitate the integration of intermittent generation produced in Spain (as Portugal is not interconnected to any other country). For this reason, interconnections between Spain and the rest of Europe through France are essential. The use of information GEMAS was designed taking into account that the operator must be able to create, manage, and activate a plant rapidly as situations may arise in which returning the system to a balanced N-1 secure state as soon as possible might be necessary. Because more than 800 wind parks are installed in the Spanish peninsular system, they must be as managed as automatically as possible. The reliability of the tool is a crucial issue as the failure to deliver limitations to the RE control centers could result in a significant decrease of the security of supply.

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