Solar thermal systems produce hot water whether the system is installed in Sweden, Germany, India, Tunisia or South America. The annual yield depends on the application (domestic hot water, pool heating, space heating), the local climatic conditions and system dimensioning (high or low solar fraction). The annual collector yield per square metre of collector area lies around 250 kWh/m2 for unglazed pool heating systems, 400 kWh/m2 for solar combi systems for hot water production and space heating in northern regions, and up to 700 kWh/m2 for installations in southern European regions used only for hot water preparation.
Domestic Hot Water and Heating
There is a wide variety of applications for solar thermal technology. The most common application is the heating of pool water, the heating of domestic hot water and space heating. Not very wide spread yet are solar cooling systems, because of the complexity of the technology and the high initial investment costs. Also, process heat applications such as in breweries or car washes, as well as in the food and textile industries, are still in their infancy. You can search for all these different kinds of applications in the filter section market sectors on the right hand side of the page.
What is the difference between vacuum tube collectors and flat plate collectors? With flat plate glazed collectors the absorbers are fitted in a box closed by a pane of glass (90 % market share in 2009 in Europe). Vacuum tube collectors – which are the dominating technology in China (96 % market share in 2008) – have the absorber coating on the outside of the inner tube in placed within an evacuated glass tube. Generally speaking, the advantage of vacuum tubes is a higher efficiency (less space required for the collector on the roof) and higher temperatures (necessary for process heat and some solar cooling technologies).
The disadvantage: The vacuum tubes produced in Europe are more expensive than the flat plate collectors but in some incentive schemes like in Germany they receive the same grants as the flat plate collectors. In China, some locally produced vacuum tube collectors have a poor quality performance, flat plate collectors are seen as high-quality products.
By far the largest solar thermal market in the world according to newly installed solar thermal capacity per year is China. In 2008, around 21 GWth (30 million m2) were sold in China, which was around 80 % of the world global solar thermal market.
In Europe, Germany – the second biggest market in the world – is dominating. With its newly installed capacity of 1.13 GWth (1,615,000 m2) in 2009, the country reached a market share of 38 % within Europe.
Position three is held by Turkey, a dynamic solar thermal market which is estimated at 785 MWth ( 1,120,000 m2).
Besides these front-runners, India, Brazil, Israel, Austria, Greece, USA, Japan, France, Italy, Spain and Australia are countries which reached a market volume of greater than 70 MWth (100,000 m2) in 2007.
Solarenergie 2007, Study by the Swiss bank Sarasin, November 2008 (Only available in German)
Solar thermal Markets in Europe. Trends and Market Statistics 2009, Study by European Solar Thermal Industry Federation (ESTIF), June 2009 (see the following link)
There are a number of mature markets like Israel, Austria, Barbados, China or Cyprus where solar thermal is used by a wide majority of people for heating the domestic hot water and sometimes for room heating.
One factor that shows the market penetration of this technology in a certain country is the total capacity installed per capita. In Cyprus there were 0.65 kWth in operation per capita at the end of 2007 followed by Israel (0.5 kWth/head), Austria (0.23 kWth/head) and Barbados (0.2 kWth/head). You find niche markets when looking at market penetrations such as in the United States with only 0.006 kWth per capita or in sunny South Africa with so far not more than 0.0036 kWth per capita. Also, there is still quite a large untouched potential worldwide in using solar thermal technology for cooling and for supplying process heat.
Further information: Solar Heat Worldwide, a study from the IEA Solar Heating & Cooling Programme, May 2009 (http://www.aee-intec.at/0uploads/dateien648.pdf)
0.7 kWth nominal solar thermal power equals 1 m2 of collector area.
Generally speaking, you can differentiate between naturally growing markets and incentive driven markets. In the former, low-cost solar water heaters are already an economic alternative for households to produce hot water instead of using fossil fuels or electricity. Some examples are: China, which is the biggest solar thermal market in the world, Cyprus which has one of the highest solar thermal capacities in operation per capita in the world, and Turkey, which is the third biggest market in the world.
In incentive driven markets like Germany, there are grants for households and companies. In Austria there is a nationwide subsidy scheme for hotels and guesthouses and there are grants at a provincial level for household customers.
A third category is markets driven by legal frameworks such as solar obligations. The most famous example is Israel, where the government – because of the oil crisis – passed an obligation applying to all new residential buildings as well as hotels, old people’s homes and boarding schools 29 years ago. Spain followed two years ago with a national solar obligation. In the meantime 15 countries more adapted renewable building laws or solar obligations. You find further news on this issues in the filter section "key pillars", then "policy" and "obligation".
Further information: “Best practise regulations for solar thermal”, Study by the European Solar Thermal Industry Federation (ESTIF), August 2007 http://www.estif.org/fileadmin/estif/content/policies
Published in January 2007, by EREC (European Renewable Energy Council), the document shows the ambitions of the European Renewable Energy Industry to reach the EU targets for 2020 for different sectors, including electricity, heating & cooling, and biofuels.
It provides roadmaps for each sector, predicting its development and the conditions under which progress can be made.
Nowadays, in the EU-25, fossil fuels contribute to almost 80 % of the primary energy demand. The target of 20% renewable energy use by 2020 seems to be quite challenging, especially if the appropriate legal framework and incentives are not put in place.
This EREC report estimates that the contribution to the total primary energy demand will only be roughly 8% in 2010, slightly more than 12% in 2020 and only 12% in 2030 which is very far away from any target set. As for the energy supply, scenarios are more positive: 21% in 2020 if the policy developments and instruments continue progressing.
If different and specific targets were set, then it would be easier to achieve the given targets. According to EREC, the Renewable Energy roadmap should consist of an overall target for 2020, followed by targets for the different sectors (electricity, heating/cooling, biofuels). Setting up individual targets for the different sectors would fasten the process, given that not all sectors are in the same stage of development.
As what regards the solar thermal market, this report estimates that more funding on R&D would enable a broader adoption of solar thermal solutions for heating, cooling and storage.
This report provides an overview of the state of the art of measuring heat delivery in larger solar systems, looking also at the costs and accuracy of the measuring systems. The present document was produced within the framework of the Intelligent Energy- Europe project Key Issues for...