Concentrated solar power plants in EU

Spain accounts for almost all of CSP capacity, and a further five EU countries, mostly Mediterranean, intend to develop the sector.

As could be expected, the recession cast long shadows over the European solar thermal market throughout 2010. For the second year
running, new installations for hot water production and space heating (collectors) decreased. According to the EurObserv’ER survey the newly-assigned surface area was 3.8 million m2 in 2010, down from 4.2 million m2 in 2009 and 4.6 million m2 in 2008.

At the same time, the European high-temperature solar sector related to electricity production has been taking shape alongside the heat-producing applications, with 638.4 MW already installed. Spain accounts for almost all of this capacity, and a further five EU countries, mostly Mediterranean, intend to develop the sector.

Up to the previous edition of EurObserver Barometer series, the solar thermal barometer provided coverage of the development of the European solar thermal sector dedicated to hot water production and heating exclusively, which includes the flat glazed collector, vacuum tube collector and unglazed collector technologies, but excludes air collectors – a technology seldom applied in the EU.

For a number of years, another solar thermal sector related to electricity production has been emerging. It is called Concentrating Solar Power, also known as thermodynamic solar plant technologies. In contrast with solar thermal collectors for hot water production, Concentrated Solar Power (CSP) plants need conditions with a high share of direct sunlight (in contrast to solar PV, which may also function well in regions with more indirect sunlight due to clouds). In the European Union viable siting is geographically restricted to a few Mediterranean countries and is currently virtually limited to developments in Spain.

From this year onwards, the barometer will report back on the development of these two major solar thermal energy technologies (low-temperature heat and high-temperature technologies for electricity generation) in the European Union.

Concentrating Solar Power (CSP) plants use all the technologies applied to transform sunlight into high-temperature heat and then convert that heat into electrical energy. The general principle of a CSP plant entails using mirrors to concentrate the sun’s rays on a fluid that vaporises. The heat from this fluid is transferred in a heat exchanger to a water-steam cycle, which drives a turbine and a generator to generate electricity.

The most widespread technology in the CSP sector is a CSP plant based on cylindroparabolic mirror technology (also called solar trough plants) with capacities ranging from 50 to 300 MW. Cylindro-parabolic mirrors concentrate the sun’s rays on an absorber tube containing a heat-transfer fluid that can be heated to temperatures of around 400°C and generate electricity based on heat transfer to a conventional water-steam cycle.

Some plants are equipped with storage systems enabling unused, surplus energy to be stored in the form of heat in molten salt or some other phase-changing material. The plant can then draw on the stored heat to generate electricity after sunset. Spain’s Andasol 1 plant, for example, currently uses this system to operate for an additional 7½ hours every day.

Alternatively, solar power is harnessed in 10 to 50 MW-capacity solar tower CSP plants that use heliostats – huge, almost flat mirrors
over 100 m2 in surface area. They are arranged in large numbers (up to hundreds) to concentrate the sun’s rays on a point at the top of a tower, heating the heat-transfer fluid (generally a salt) up to as much as 600°C.

The only two commercially operating plants of this type are PS10 (11 MW) and PS20 (20 MW), near Seville, Spain. Another solar tower CSP plant, Gemasolar (17 MW), should come on stream this year and is also sited in the Seville region. Its design storage capacity is for up to 15 hours which should support almost round-the-clock production, and enable the plant to supplement electricity generation based on fossil fuels or nuclear energy.

There are other technologies in the stage of development and demonstration that are not yet used on an industrial scale. For instance, Fresnel linear collectors that are a variant on a CSP plant based on cylindro-parabolic mirror technology, which instead of using a trough-shaped mirror, have sets of small flat mirrors arranged in parallel and longitudinally on an incline. Furthermore, the absorber tube that concentrates the rays is stationary and the mirrors follow the course of the sun.

The fluid is heated to a temperature of up to 450°C. For the time being only prototypes are operating, such as Puerto Errado 1 (1.4 MW), which has been running since 2009 in the Murcia region of Spain. A second 30-MW plant, Puerto Errado 2, is under construction and is due to come on stream in 2012 as the first commercially-run Fresnel-type plant. Development is under way on larger (150-MW and more) plants, but they are outside Europe.

Another alternative technology is the dish Stirling system, based on a dish-shaped concentrator (comprising parabolic mirrors) to capture the sunlightand focus it on a receiver at the focal point of the parabolic dish. The parabolic dish system, which tracks the sun, uses a gas (helium or hydrogen) that is heated in the receiver to temperatures in excess of 600°C to drives a Stirling engine coupled with a generator.

The capacity of these units is limited to 10–25 kW, which will meet isolated production needs. Alternatively, parabolic dish CSP plants may be built as large-scale plants whith thousands of parabolic dishes grouped together on a single site. Two projects with an aggregate capacity of 1.4 GW are under construction in the United States, but no industrial-scale ventures have been identified in Europe.

Round-up on the European Union

The 2010 year-end capacity figure for European Union CSP power plants was around 638.4 MW, which is 406 MW more than in 2009. Virtually all of this capacity, namely 632.4 MW, is located in Spain according to the IDAE, and spread across 15 plants including prototypes (12 of the cylindro-parabolic type, 2 tower plants and 1 Fresnel type plant).

Eight of the twelve 50-MW plants were commissioned in 2010, producing 742 GWh, up from 209 GWh in 2009 (a 255.2% leap) as metered by REE (Red Eléctrica de España). However, this figure is unrepresentative of the installed capacity because most of it was connected to the grid in the autumn. According to Protermosolar (the Spanish Concentrating Solar Power Industry Association), the design output of these plants is 1 851 GWh, which equates to an annual load factor of 31 % (2 712 full-load hours out of 8 760 hours in a year).

Sector build-up is following a tight schedule. At the start of this year (2011), two new 50-MW plants were connected up, raising Spanish electric Concentrating Solar Power plant capacity to 732.4 MW. Protermosolar notes that another 20 projects with an aggregate capacity of 898 MW are under construction and will be up and running between 2011 and 2012. This additional capacity should give Spain 1 630.4 MW of CSP capacity from 2012 onwards. A host of projects are close to kick-off, as 23 plants with an aggregate capacity amounting to 842 MW are awaiting approval for the preliminary assignment of remuneration register.

The procedure, which was introduced in Royal Decree 6/2009, transfers the power to grant project approval for eligibility for production aid to the central rather than regional government. The move is aimed to regulate installed capacity build-up from the national perspective, which for the CSP sector is 5 079 MW of thermodynamic solar capacity by 2020.

At the end of 2010, a change to the incentive system, reflected by Royal Decree 1614/2010 caused serious financial difficulties for operators of CSP plants. Whereas in 2010, operators could choose between the regulated FiT, set that very same year at € 0.285/kWh or a € 0.268/kWh premium in addition to the market price, they have to opt for the regulated FiT for the first year of operation from 2011 onwards. The number of operating hours eligible for the FiT has also been reduced.

The technologies used and storage capacities (that enable electricity production to continue after sunset) have little in common. Hence production ranges from 6 450 full-load hours for tower-based CSP plants technology with 15 hours of storage capability to 2 350 full-load hours for dish Stirling plants. In the case of cylindro-parabolic plants operation can vary from 2 855 hours with no energy storage system to 3 450 hours with 4 hours of storage, 3 950 with 7 hours, and 4 000 with 9 hours of storage. Fresnel plants operate for 2 450 hours per annum.

The Spanish groups Abengoa Solar, Acciona Solar power and ACS/Cobra are constructing these plants, and source their cylindro-parabolic mirrors mainly from Rioglass of Spain and Flabeg of Germany.

The French government’s enthusiasm for developing an industrial Concentrating Solar Power sector is demonstrated by its Call for Expressions of Interest (EOI). The sum of 1.35 billion Euros has been earmarked to encourage the development of innovative solar technologies such as Concentrating Solar Power (based on thermal energy conversion) and concentrated photovoltaic power (PV). This fund could be used for research and pre-industrial demonstrators and technology platforms for thermodynamic solar technologies and systems.

The government has set its sights on developing a French leading-edge innovation sector that will sell its know-how to very sunny countries such as the Mediterranean countries, Africa, the Middle-East and Australia rather than install dozens of plants in France. There are significant economic and development hurdles to be overcome before they achieve technological and business validation. The CSP capacity to be installed in France is restricted by the dearth of available land and less than ideal exposure to sunshine, so a CSP capacity target has been set at 540 MW by 2020 in the French National Renewable Energy Action Plan (NREAP).

By that date partnership agreements may be signed with some of the Maghreb countries for the construction of CSP plants connected to the European grid via Spain.

Several prototypes and demonstrators should emerge in the next few years. The CNIM group has installed a 1-MW prototype based on Fresnel mirrors at La Seyne-sur-Mer and is considering building a demonstrator in the Pyrenees Orientales. Solar Euromed also intends to site a prototype in the Pyrenees, followed by two industrial demonstrators, dubbed Alba Nova 1 and 2 in Corsica. It has announced the signing of a framework contract with the Sudan to install 2 000 MW of CSP capacity at Darfur.

The best-placed French concern appears to be Areva Solar, the solar subsidiary of the nuclear power group, which offers turnkey solutions using Fresnel-type plant technology. A 5-MW plant (Kimberlina) is the first to be installed in California for 20 years, and the first to use this technology on American soil. In April 2011, the French group also announced it had closed a contract to construct a 44-MW Fresnel-type CSP plant to be coupled to the Kogan Creek coal-fired plant in Australia (750 MW) for an estimated 104.7 million AUD, i.e. 77 million Euros. The project will kick off before the end of June 2011 and commercial operation is expected in 2013.

Italy is also committed to the CSP sector. In July 2010, Enel commissioned a 5-MW cylindro-parabolic plant near the municipality of Priolo Gargallo, Sicily. The Archimede project, as it is known, uses molten salt as the heat transfer fluid and energy storage medium.

ANEST, the Italian Association for Solar Thermodynamic Energy, reckons that the construction of between 3 000 and 5 000 MW by 2020 is feasible despite the fact that the country’s NREAP plan has only 600 MW of capacity pencilled in for that timeline.

A tantalizing sector

The future of the CSP sector is promising. The first projects installed in the United States in the 1980s have provided over 25 years of technology tweaking and maturing and resulted in commercially-viable production costs for starting large-scale industrial and commercial development in several regions across the globe – Europe, North America, North Africa, and (in the near term) the Middle-East, Asia, and Oceania.

These plants offer a number of advantages for production as it becomes predictable and even continuous during the night provided the plants are equipped with storage systems. Furthermore they can be coupled to biomass-, coal- or gas-fuelled thermal power plants. By adopting either of these two configurations grid fluctuations can be ironed out, encouraging the integration of other intermittent renewable energy sources such as photovoltaic or wind power. Costs, which have come down dramatically, are continuing to drop because of equipment and component innovations, enhanced energy efficiency, the extended operating hours yielded by increased storage capacity, the learning curve and economies of scale.

Six European Union countries have announced installation targets in their NREAPs amounting to 7 044 MW of capacity in 2020, with an intermediate stage set at 3 573 MW by 2015. In addition to the targets – already highlighted – of Spain, France and Italy already mentioned, the NREAPs envision 500 MW for Portugal, 250 MW for Greece and 75 MW for Cyprus. The electricity output provided by these plants is put at around 20 TWh in 2020 compared to just over 9 TWh in 2015. The sector’s progress is consistent with the targets
set in the NREAPs exercise, and the targets for development of the CSP technology may be met.

The European Solar Thermal Electricity Association (Estela) reckons that growth could be much faster, and forecasts 30 000 MW of installed capacity by 2020 (equivalent to output of 89.8 TWh p.a.) and 60 000 MW of installed capacity by 2030 (equivalent to output of 195 TWh p.a.). This expansion would be boosted by setting up a super grid, linking the various European countries.

If the European Union were to interconnect the European grids with those of North Africa, the whole picture would change dimension as the solar thermal sector’s development prospects in the Southern Mediterranean countries and their neighbours across the see dwarf those of the rest of Europe. If these technologies were to flourish in North Africa, production costs would come down even faster.

The setting up of the Mediterranean Solar Plan3, essentially based on solar thermal electricity, is a key element of this development. The plan could also contribute to achieving the European Union’s renewable energy objectives for 2020. Article 9 of the 2009/28/CE Directive authorises Member States to import energy from third countries. Europe’s political and economic role could be pivotal. If it decides to open up its grid, solar energy could contribute even more to securing energy supplies, at the same time quickening the pace of economic development and the installation of electrical infrastructures around the Mediterranean basin.

The above are major industrial challenges for creating wealth and employment, in a sector which so far has limited Asian competition. Such a Mediterranen Solar Plan for CSP calls for huge investments in grid infrastructures. While they will guarantee a secure power supply, customers will inevitably have to pay more for their electricity. Cooperation would also underpin security in North African countries where the rise in hydrocarbon prices could create political instability, in a region that is a neighbour of the EU.

Spain

Planta Solar 10 -Central receiver 11 MW -2007
Andasol-1 -Parabolic trough -50 MW-2008
Planta Solar 20 -Central receiver- 20 MW-2009
Ibersol Ciudad Real (Puertollano) -Parabolic trough -50 MW-2009
Puerto Errado 1 (prototype) -Linear Fresnel -1,4 MW-2009
Alvarado I La Risca -Parabolic trough -50 MW-2009
Andasol-2 -Parabolic trough -50 MW-2009
Extresol-1 -Parabolic trough -50 MW-2010
Solnova 1 -Parabolic trough- 50 MW-2010
Solnova 3 -Parabolic trough -50 MW-2010
Solnova 4 -Parabolic trough- 50 MW-2010
La Florida -Parabolic trough -50 MW-2010
Majadas -Parabolic trough -50 MW-2010
La Dehesa -Parabolic trough -50 MW-2010
Palma del Río II -Parabolic trough -50 MW-2010
Total Spain 632,4 MW

Italy

Archimede (prototype) -Parabolic trough- 5 MW-2010
Total Italy 5 MW

France

La Seyne-sur-Mer (prototype) -Linear Fresnel -1 MW-2010
Total France 1 MW

Total EU 638,4 MW

Concentrated solar power plants in construction at the beginning of 2011

Spain

Extresol-2- Parabolic trough -50 MW
Manchasol 1- Parabolic trough -50 MW
Casa del Angel -Dish Stirling- 1 MW
Puerto Errado 2 -Linear Fresnel -30 MW
Andasol 3 -Parabolic trough -50 MW
Palma del Rio 1 -Parabolic trough – 50 MW
Gemasolar -Central receiver -17 MW
Helioenergy 1 -Parabolic trough -50 MW
Helioenergy 2 -Parabolic trough -50 MW
Lebrija 1 -Parabolic trough -50 MW
Termosol-50 -Parabolic trough -50 MW
Arcosol-50 -Parabolic trough -50 MW
Aries Solar 2 -Parabolic trough -50 MW
Aries Solar 1A -Parabolic trough -50 MW
Aries Solar 1B -Parabolic trough -50 MW
Sol Guzman -Parabolic trough -50 MW
Helios 1 -Parabolic trough -50 MW
Helios 2 -Parabolic trough -50 MW
Solacor 1 -Parabolic trough -50 MW
Solacor 2 -Parabolic trough- 50 MW
Solaben 2 -Parabolic trough -50 MW
Solaben 3 -Parabolic trough -50 MW
Total Spain -998 MW

www.eurobserv-er.org/pdf/solar_thermal_barometer_2011.pdf