Andasol Solar Power Station


  • Andasol 2: Andasol 2 Central Termosolar Dos, S.A
  • Andasol 3: Marquesado Solar S. L.
  • Andasol 1: 2008
  • Andasol 2: 2009
  • Andasol 3: 2011

Andasol is a complex of three solar thermal power plants in the Spanish province of Granada, whose maximum power is after the completion of approximately 3 x 50 or 150 megawatts ( MW). In mid-year, however, only 3 × 20 and total 60 MW (gross ) can be achieved overall. The power plants were initiated and developed by the 2011 bankrupt Erlanger company Solar Millennium.

The complex consists of three power plants, which in the feedback operation since mid-2009 Andasol 1, the supplying electricity to the grid in test mode Andasol 2 and the youngest of the three power plants Andasol 3, which has been in operation since September 2011.

The location of the power plant complex is located in the municipality of Aldeire and La Calahorra in the region Marquesado del Zenete. It is located 10 km south-east of Guadix in the Spanish province of Granada.


Each of the three Andasol power plants stands on an area of ​​about 1.95 square kilometers (1300 × 1500 m in north-south orientation). Access to the high-voltage network is performed by binding to a 400 - kV line at Huéneja in about 7 km away.

For the solar field, developed by Solar Millennium parabolic trough technology " Skal -ET " was used. The peak efficiency is around 70% of this technology. On an annual average, the theoretical efficiency of this technique is about 50%. Each of the three solar fields has 209,664 parabolic mirrors at a solar field size of 510 120 m² and 22,464 absorber tubes ( "Receiver " ) of each 4 meters in length, along with 624 sun sensors. The annual direct normal irradiance (DNI ) is for each of the three solar fields 2,136 kWh / ( m² * a). To implement this DNI into electrical energy is obtained for the complete system throughout the year, an average efficiency of about 15%. The average peak efficiency is about 28 %. The life expectancy of an individual asset is estimated to be at least 40 years.

The water requirement of a Andasol power plant for cooling the steam is approximately 870,000 cubic meters per year, and is sourced from groundwater, which is available due to the vicinity of the Sierra Nevada in over average by Spanish standards extent.

The predicted performance of each Andasol unit can power for 200,000 inhabitants ( EW) of Spain substitute self-reported, the operator, however, is deposited only one private household consumption of about 850 kWh per capita per year. If the total power consumption, consisting of civil, industrial, infrastructure, public transport, etc. on the individual inhabitants converted, so this gives a total consumption of about 7000 kWh per capita per year. Each Andasol plant substituted so theoretically the total electricity needs of about 23,000 PE. According to the annual report of Stadtwerke München the pro rata amount of electricity produced Andasol3 corresponded in 2012 the electricity consumption of 33,000 average households in Munich.


If the construction costs of 300 million euros and 400 million euros for Andasol1 for Andasol3 evenly distributed on the expected maturity of 40 years, result for " Andasol 1" cost of 7.5 million euros per year and at " Andasol 3" 10 million euros per year. Excluding the ongoing maintenance, personnel and other costs, this results from the forecast annual electricity production (the actual is unknown ) a predicted electricity price of 6.8 cents to 9.1 cents per kWh solely from depreciation. The expected operating costs can increase very early on about twice the price of electricity there is. In addition occur in winter on the combustion of natural gas considerable foreign energy costs for heating the store. For this purpose, up to 3 million cubic meters of natural gas, or approximately 1.5 million euros per year are forecast that will increase the price of electricity by almost 10 %. The projected production of 110 GWh / y per Andasoleinheit is something about already published production figures of U.S. parabolic trough power plants. This reach, such as SEGS I through IX in California or Nevada Solar One, only a total production of about 1.8 GWh / MW per year.

By design, the income will decline over the course of 40 years and rising maintenance costs. In " Andasol 3" is, according to the prospectus Andasol3 funds because of the constantly needed cleaning and consequent wear of the mirror surfaces a speedy and significant decrease of the theoretically possible electricity production to be expected. However, a promotional brochure of Solar Millennium said with a decrease in electricity production by a maximum of 0.3 % per year from the opposite. The maintenance costs are expected to rise significantly due to corrosion and wear, within the forty -year period.

In 2013, it was announced that the largest shareholder, Stadtwerke München, previously already had to write off 64 million euros on the plant. Rhine energy than other shareholders, had to write off 17 million euros. RWE Innogy and Ferrostaal AG Report also "significant" losses. Despite these losses, which are due to government regulations, the pantograph Spain, declared the Stadtwerke München in a press release that Andasol 3 but still can be operated economically, since the project can generate a multiple of the running costs. Actual numbers on the balance sheet (production, cost, etc. ) of Andasol3 are not mentioned in this press release.


The three power plants Andasol series are almost identical. For the conversion of incident solar radiation, the parabolic trough technology is used in all Andasol power plants. Here, the sunlight is focused by mirrors onto an absorber tube. The synthetic heat transfer oil contained therein is heated by the concentrated solar radiation to 400 ° C. This oil then produced over a heat exchanger steam which drives the turbine power plant.

Thus, the power plant at night supplies energy, the heat transfer oil may alternatively be conducted through a salt reservoir. This thermal storage system comprises 28,500 tons of salt, its capacity can full load for 7.5 hours out. Used a liquid salt mixture consisting of 60 % sodium nitrate ( NaNO3 ) and 40% potassium nitrate ( KNO3 ). This salt supply must constantly get in the molten state to stay ( range of 250 ° to 350 °). If the temperature drops below 240 ° Celsius, the salt is fixed and the system is irreparably destroyed. Molten salt storage of this magnitude are a novelty, the reference object Solar Two in Barstow (California ) was significantly smaller. The memory size was there only about 15% of the Andasol memory. The provider of the Andasol 3 funds had this problem out explicitly. In case of early and final termination of the operation of the power plants therefore is an overall " loss of deposits " is possible.

The salt storage each Andasol power plant is located in two tanks with different temperatures of 14 m height and 36 m in diameter. In the salt storage, the oil is added through a heat exchanger from its heat to the liquid molten salt. With the heated liquid salt may be heated if required on the same heat exchanger, the oil again. With the hot oil, in turn, steam is generated, which drives a turbine-generator set as in a thermal power plant. In essence, with the use of ground water from wells at the site of the steam with the help of cooling towers is cooled by evaporation.

If the irradiation is not sufficient to prevent impending salt rigidity in the memory, the memory can be heated with natural gas. This natural gas consumption is about 15 % of the total energy production of Andasol calculated (specified in the agreement on the feed-in tariff ). The Andasol unit must therefore only be used for the storage heater approximately 25,000 MWh annually, or approximately 3 million m3 of natural gas.

The turbine cycle of the power plant has the following performance data: The turbine power is at a maximum of 49.9 MW Andasol 1. With projected annual 2,200 hours of operation at full load results in an annual gross electricity generation of 110 GWh, which corresponds to an average turbine power output of 20 MW. The turbine cycle operates in the implementation of the stored heat into electrical energy with a peak efficiency of about 40%, or 30% of the annual average.

Water consumption

For cooling the steam in the generator circuit around 870,000 m³ of water at each Andasol power plant per year consumed ( evaporated). Due to the proximity of the mountains of the Sierra Nevada, this is easy replaceable at this location, even though water shortages in southern Spain. The amount of water consumed corresponds according to the operator about the amount of water that needs a town of 20,000 inhabitants or for the production of wheat on such a surface in the same period are needed. Here, however, is to note that wheat often rainwater, Andasol but only uses higher quality groundwater. Water use by northern European power plants is approximately 1.9 to 2.6 l / kWh ( exception: nuclear power plants with 3.2 l / kWh).

At the location of the Andasol plant prevail other meteorological conditions (ambient temperature and humidity ) than in more northern locations of conventional plants with lower water consumption. The warmer and drier are the environmental conditions, the higher the cooling water consumption of a thermal power plant by evaporation of water.

The consumption of water by evaporation is in the power plant Andasol has about 7.9 l / kWh (calculated from data above, 870,000 m³ / 110 GWh ) is significantly higher than in northern European power plants, as only cooling is possible through evaporation. The power plants in North Europe, however, consumption by cooling in a continuous process ( heating water flow without evaporation) is possible. The provider of the Andasol3 funds paid into this cooling water problem out explicitly. In case of early and final termination of the operation of the equipment therefore is an overall " loss of deposits " is possible.

Land Use

Andasol overbuilt per unit of about 2 km ² of agricultural land (including access roads ). Converted substituted to the approximately 20,000 inhabitants (EW ), whose power through each Andasoleinheit is (counting the actual total power consumption and not the purely private ), which would be about 2.5 % of agricultural land, which is this population of Spain theoretically available. For comparison, photovoltaic requires about 60 % of this area (PV - average yield in southern Spain about 1.6 kWh / a · Wp or 1600 full load hours ), nine wind turbines of the type E-126 ( Enercon 7.5 MW) also produce electricity for 20,000 EW as a Andasoleinheit and require approximately 0.5 ha per plant (of which about 500m ² for the plant itself ) has little or no agricultural land as storage devices for electricity (usually pumped storage KW) to be built in more remote mountainous area.


Solar Millennium was awarded for the initiation and development of the Andasol power plants in May 2008 with the Energy Globe Award in the category " Fire". With the Energy Globe Award in this category innovative projects for environmentally- friendly energy will be awarded.


Andasol -1 production since early 2009. Andasol -2 has completed the end of 2009 the test phase and Andasol 3 in September 2011. Production figures have not been published yet.

The three power plants in detail

Andasol 1

Andasol 1 is the first completed solar thermal power plant Andasol the series; it went on line in December 2008 and was officially inaugurated on 1 July 2009. It is the first solar power plant in Europe with 510,000 square meters of collector area on an area of ​​1300 m × 1500 m currently the largest solar power plant in the world.

For the project development of Andasol 1, the Erlangen-based company Solar Millennium was responsible. The investment costs were estimated at 300 million euros. Partner of Solar Millennium for the construction of the power plant is the Spanish construction group Grupo Cobra, a subsidiary of the construction and telecommunications company Grupo ACS. The Grupo Cobra responsible for the construction of the power plant and holds 75 % of shares in power plant company Andasol 1 SA The technology company Flagsol GmbH, a wholly owned subsidiary of Solar Millennium, took over the technical planning, including design, construction supervision and control for the solar field.

The groundbreaking ceremony took place on 20 July 2006. The site is located on the plateau of Guadix in the province of Granada. After a construction period of about two years, the test operations began in October 2008. In December 2008, the connection to the power grid; the regular operation started in early 2009, the test phase was not officially completed.

The power plant Andasol 1 is the property of the Andasol 1 power plant company Central Termosolar Uno, SA based in Aldeire in Spain. This company is an equity share of 75 % in the possession of Sistemas y Redes Cobra, SA based in the Spanish capital Madrid. Sistemas y Redes Cobra itself is a company in the ACS / Cobra Group. The remaining 25 % stake in the power plant company held the Solar Millennium Verwaltungs GmbH, a company incorporated on 23 September 1998 a subsidiary of Solar Millennium AG, headquartered in Erlangen, Germany. On 16 July 2009, Solar Millennium has sold its remaining 25 % interest in the ACS / Cobra Group.

Andasol 2

In the immediate vicinity of Andasol 1 began the construction work for the establishment of another virtually identical parabolic trough power plant Andasol 2, the mid-2009 has started its test run in February 2007. The solar field is already completed.

The power plant Andasol 2 is the Andasol 2 Central Termosolar Dos, SA, as well as the power plant company of Andasol 1, headquartered in Aldeire. The shares of this company were for a long time to 75 % of the Cobra Sistemas y Redes, SA and 25% of the Solar Millennium Verwaltungs GmbH held until Solar Millennium and the remaining 25 % also sold on July 16, 2009 ACS / Cobra Group.

Andasol 3

The third Andasol 3 power plant was built since September 2009 in the immediate vicinity of Andasol 1 and 2, the assembly of parabolic trough collectors was completed in June 2010. The plant was commissioned in September 2011. The performance of the power plant is 50 MW.

Andasol 3 is owned by the Spanish company Marquesado Solar SL And directly involved principal shareholder, Stadtwerke München GmbH a 48.9 %. Other shareholders are: 25.1 %, the AS is maintained for 3 Beteiligungs GmbH with headquarters in Essen, a holding company, which by the shareholders RWE Innogy GmbH ( 51.0 %) and Rhein Energie AG ( 49.0 %); At 13.0%, the Ferranda GmbH (100 % subsidiary of Ferrostaal AG); and also with 13.0 %, the Andasol power plant GmbH ( part of the Andasol 3 funds, after it acquired the unit from the insolvent Solar Millennium on July 12, 2012).