Direct Solar Energy
For passive solar technologies, no estimates are available at this time for the installed capacity of passive solar or the energy generated or saved through this technology.
For active solar heating, the total installed capacity worldwide was about 149 GWth in 2008 and 180 GWth in 2009 (Weiss and Mauthner, 2010; REN21, 2010).
In 2008, new capacity of 29.1 GWth, corresponding to 41.5 million m2 of solar collectors, was installed worldwide (Weiss and Mauthner, 2010). In 2008, China accounted for about 79% of the installations of glazed collectors, followed by the EU with 14.5%.
The overall new installations grew by 34.9% compared to 2007. The growth rate in 2006/2007 was 18.8%. The main reasons for this growth were the high growth rates of glazed water collectors in China, Europe and the USA.
In 2008, the global market had high growth rates for evacuated-tube collectors and flat-plate collectors, compared to 2007. The market for unglazed air collectors also increased significantly, mainly due to the installation of 23.9 MWth of new systems in Canada.
Compared to 2007, the 2008 installation rates for new unglazed, glazed flat-plate, and evacuated-tube collectors were significantly up in Jordan, Cyprus, Canada, Ireland, Germany, Slovenia, Macedonia (FYROM), Tunisia, Poland, Belgium and South Africa.
New installations in China, the world’s largest market, again increased significantly in 2008 compared to 2007, reaching 21.7 GWth. After a market decline in Japan in 2007, the growth rate was once again posi- tive in 2008.
Market decreases compared to 2007 were reported for Israel, the Slovak Republic and the Chinese province of Taiwan.
The main markets for unglazed water collectors are still found in the USA (0.8 GWth), Australia (0.4 GWth), and Brazil (0.08 GWth). Notable markets are also in Austria, Canada, Mexico, The Netherlands, South Africa, Spain, Sweden and Switzerland, with values between 0.07 and 0.01 GWth of new installed unglazed water collectors in 2008.
Comparison of markets in different countries is difficult due to the wide range of designs used for different climates and different demand requirements. In Scandinavia and Germany, a solar heating system will typically be a combined water-heating and space-heating system, known as a solar combisystem, with a collector area of 10 to 20 m2. In Japan, the number of solar domestic water-heating systems is large, but most installations are simple integral preheating systems. The market in Israel is large due to a favourable climate, as well as regulations man- dating installation of solar water heaters. The largest market is in China, where there is widespread adoption of advanced evacuated-tube solar
collectors. In terms of per capita use, Cyprus is the leading country in the world, with an installed capacity of 527 kWth per 1,000 inhabitants.
The type of application of solar thermal energy varies greatly in differ- ent countries (Weiss and Mauthner, 2010). In China (88.7 GWth), Europe (20.9 GWth) and Japan (4.4 GWth), flat-plate and evacuated-tube col- lectors mainly prepare hot water and provide space heating. However, in the USA and Canada, swimming pool heating is still the dominant application, with an installed capacity of 12.9 GWth of unglazed plastic collectors.
The biggest reported solar thermal system for industrial process heat was installed in China in 2007.The 9 MWth plant produces heat for a tex- tile company. About 150 large-scale plants (>500 m2; 350 kWth)1 with a total capacity of 160 MWth are in operation in Europe. The largest plants for solar-assisted district heating are located in Denmark (13 MWth) and Sweden (7 MWth).
In Europe, the market size more than tripled between 2002 and 2008. However, even in the leading European solar thermal markets of Austria, Greece, and Germany, only a minor portion of residential homes use solar thermal. For example, in Germany, only about 5% of one- and two- family homes are using solar thermal energy.
The European market has the largest variety of different solar thermal applications, including systems for hot-water preparation, plants for space heating of single- and multi-family houses and hotels, large-scale plants for district heating, and a growing number of systems for air- conditioning, cooling and industrial applications.
Advanced applications such as solar cooling and air conditioning (Henning, 2004, 2007), industrial applications (POSHIP, 2001) and desal- ination/water treatment are in the early stages of development. Only a few hundred first-generation systems are in operation.
For PV electricity generation, newly installed capacity in 2009 was about 7.5 GW, with shipments to first point in the market at 7.9 GW (Jäger-Waldau, 2010a; Mints, 2010). This addition brought the cumu- lative installed PV capacity worldwide to about 22 GW—a capacity able to generate up to 26 TWh (93,600 TJ) per year. More than 90% of this capacity is installed in three leading markets: the EU27 with 16 GW (73%), Japan with 2.6 GW (12%), and the USA with 1.7 GW (8%) (Jäger-Waldau, 2010b). These markets are dominated by grid-connected PV systems, and growth within PV markets has been stimulated by various government programmes around the world. Examples of such programmes include feed-in tariffs in Germany and Spain, and various mechanisms in the USA, such as buy-down incentives, investment tax credits, performance-based incentives and RE quota systems. For 2010,
To enable comparison, the IEA’s Solar Heating and Cooling Programme, together with the European Solar Thermal Industry Federation and other major solar thermal trade associations, publish statistics in kWth (kilowatt thermal) and use a factor of 0.7 kWth/m2 to convert square metres of collector area into installed thermal capacity (kWth).