Solar Thermal Heating and Cooling


Solar thermal technologies contribute significantly to hot water production in many countries, and increasingly to space heating and cooling as well as industrial processes. In 2012i, the world added 55.4 GWth (more than 79 million m2) of solar heat capacity, increasing the cumulative installed capacity of all collectortypes in operation by over 14% for a year-end total of 283.4 GWth.ii 1 An estimated 53.7 GWth (almost 97%) of the market was glazed water systems and the rest was unglazed water systems mainly for swimming pool heating (3%), as well as unglazed and glazed air collector systems (<1%).2 Glazed and unglazed water systems provided an estimated 239.7 TWh (863 PJ) of heat annually.3

The vast majority of solar heat capacity is in China, which accounts for 86% of the world market and 64% of total capacity in 2012.4 (See Figure 16.) The top countries for capacity added in 2012, including both glazed and unglazed systemsiii, were China, Turkey, India, Brazil, and Germany, and the top five for total capacity in operation remained China, the United States, Germany, Turkey, and Brazil.iv 5 (See Figure 17 and Reference Table R9.)

Most countries focus on glazed water collectors, with China primarily using evacuated tube water collectors (ETC), and other key markets relying mainly on flat plate (FPC). In the United States, the majority of systems use unglazed water collectors for pool heating. The only other markets of note for unglazed water collectors are Australia and Brazil.6

In 2013, an estimated 57.1 GWth (81.6 million m2) of gross capacity was added worldwide, bringing operating global solar thermal capacity to about 330 GWth (including 325.9 GWth of water collectors and an estimated 3.6 GWth of air collectors).7 (See Figure 18.) There was enough capacity by year's end to provide approximately 276.6 TWh (996 PJ) of heat annually.8

China was again the main demand driver in 2013, adding 46.2 GWth (up 3.3% over 2012).9 A significant share (21%) of the new collectors in China replaced existing capacity, although the replacement rate was reportedly lower than in past years; approximately 36.6 GWth of newly installed capacity was additional, bringing the country's total to 217 GWth.10 In China, solar water heaters cost far less over their lifetimes than do electric or gas water heaters—a major factor driving the market.11 China's use of solar thermal on urban apartment buildings is expanding rapidly, and it includes roof- and façade-integrated systems. The urban sector represented nearly half of the 2013 market, with growth driven largely by green building policies and solar mandates.12

The European Union (EU-28) supports a greater diversity of uses for solar thermal heat technologies than any other market.13 In 2012, Europe's total operating capacity was up 7.5% over 2011 to 30.2 GWth, but the annual market declined for the fourth consecutive year, down 5.8% to 2.3 GWth.14 In 2013, the region continued to account for a significant share of the capacity additions made outside of China. However, growth contracted again in many countries, constrained by lower construction and renovation rates (due in large part to the economic crisis), pressure from solar PV and heat pumps (particularly in Austria, Germany, and France), and the reduction of support policies for solar heating.15Germanyand Austria, the long-term EU leaders for total installations, both experienced marked declines. Germany remained Europe's largest installer in 2013, adding 0.7 MWth for a total of 12.3 GWth; but this was down 11% from 2012, following a 9.4% drop in 2011.16 The Austrian market shrank about 14% in 2013, following declines of nearly 16% in 2012 and 13% in 2011.17

Over a six-year period, Brazil's market more than doubled, with nearly 1 GWth added in 2013 for a total approaching 7 GWth.18 Demand is driven largely by the economic competitiveness of solarthermal in Brazil and by municipal building regulations and social housing programmes, such as Minha Casa, Minha Vida ("My House, My Life"), that mandate solar water heaters in new buildings for very poor families.19 Mexico is also starting to play a role, and there are very small but growing markets in Argentina, Chile, Costa Rica, and Uruguay.20

India and Japan are the largest Asian markets outside of China. India added 0.9 GWth during 2013 for a year-end total of 5.2 GWth.21 Japan's market was stable during 2012 and 2013, at about 0.1 GWth per year, but cumulative capacity is declining due to decommissioning of old systems.22 After Thailand's five years of steady growth, driven by the national incentive programme and risingfuel prices, the marketforsubsidised systems declined 28% in 2013.23 The drop is considered to be a direct result of Thailand's new solar PV programme, which drew investment away from solar heating.24

Turkey, the United States, and Australia continue to be important markets; as of publication, however, data for 2013 were not available. In 2012, Turkey added 1.1 GWth to end the year with 10.8 GWth and retain its fourth place ranking for total operating capacity.25 The market was down relative to a spike in 2011, but is generally quite stable even without government incentives.26

About 60% of all unglazed water collectors operate in the United States, where an estimated 30,000 swimming pool systems are installed annually.27 While the country continues to rank second for total collector area, with 16.2 GWth at the end of 2012 (14.3 GWth of which is unglazed), it placed sixth for additions that year (0.7 GWth).28 Some U.S. states have set solar thermal carve-outs in their renewable portfolio standards (RPS), or allow electric utilities to meet RPS requirements with solar water heating systems.29

Australia added an estimated 0.6 GWth during 2012 (71% unglazed), for a year-end total of 5.1 GWth (59% unglazed).30 A large share of Australian households heats water with solar thermal systems, with the highest number in New South Wales. By early 2013, more than 630,000 systems were in operation.31

In the Middle East, Israel leads for total capacity (with about 85% of households using solar water heaters), followed by Jordan and Lebanon.32 Solar thermal systems are used to heat water in several African countries, including Egypt, Mozambique, Tunisia, Zimbabwe, and South Africa, the most mature market in sub-Saharan Africa.33 However, markets in many developing countries are challenged by a lack of standards, leading to use of inferior products and poor installations, which have undermined solar thermal's reputation.34

i - The year 2012 is the most recent one for which firm global data and most country statistics are available.

ii - Data include air collectors. Gross (including replacements) water heating collector capacity additions in 2012 were 55.4 GWth, for a year-end total of 281.7 GWth.

iii - Starting with this edition, the GSR covers both glazed and unglazed water systems throughout. For more details, see Methodological Notes, page 142.

iv - Note that the 2012 data in Figure 18 are total installations of water collectors and include replacement capacity, which accounts for a large share of China's additions. In 2013, for example, about 21% of China's additions (9.6 GWth) were to replace existing capacity.


Figure 16. Solar Water Heating Collectors Global Capacity, Shares of Top 10 Countries, 2012

Source: See Endnote 4 for this section.

Figure 17. Solar Water Heating Collector Additions, Top 10 Countries for Capacity Added, 2012

Source: See Endnote 5 for this section.

Figure 18. Solar Water Heating Collectors Global Capacity, 2000-2013

Source: See Endnote 7 for this section.

Data are for solar water collectors only (not including air collectors).

At the end of 2012, Cyprus remained the world leader on a per capita basis considering all water collectors, with 548 kilowatts-thermal (kWth) per 1,000 inhabitants, followed by Austria (420 kWth), Israel (385 kWth), Barbados (320 kWth), and Greece (268 kWth).35

Mostsolarthermal systems are used for domestic water heating, and they typically meet 40-80% of demand.36 There is a trend towards larger domestic water heating systems for hotels, schools, multi-family homes, and other large complexes.37 The use of solar thermal systems for space heating is also gaining ground, particularly in Central Europe, where 100% solar-heated buildings have been demonstrated (although typically solar meets 15-30% of space heating demand).38 "Combi-systems," which provide water and space heating, account for about 4% of the global solar thermal heat market.39 They are most common in Europe (particularly Austria, Germany, Italy, and Poland) and represent about 40% of installed systems in Austria and Germany.40 Solar thermal heating can be combined with various back-up heat sources, and hybrid systems with heat pumps are gaining popularity in Europe.41

Domestic hot water and space heating are provided by conventional flat plate and evacuated tube collectors, which typically supply heat at temperatures below 60 °C.42 Advanced collectors can be used for solar-assisted district heating as well as industrial and commercial applications with typical operating temperatures in the 60-120 °C range; they can also drive some cooling systems.43 Concentrating systems—including parabolic trough, dish, and Fresnel collectors (smaller than their CSP relatives and adapted to specific needs)—provide heat at higher temperatures (typically 120-250 °C, and up to 400 °C) for industrial processes or to drive double- or triple-stage absorption chillers.44

An increasing number of district heating systems relies on solar thermal technology, often combined with other heat sources such as biomass.45 Although the market for such systems remains relatively small, interest has increased in recent years, particularly across Europe.46 More than 200 solar thermal district heating plants operate in about 20 EU countries, with 50 of these in Denmark (where systems are cost competitive), and over 20 each in Austria, Germany, and Sweden.47 Interest is rising beyond Europe as well, with large heat systems also operating in Canada, China, and South Africa.48 At least 17 plants bigger than 700 kWth (1,000 m2) were constructed in 2013, and the world's largest plant began operating in Denmark in early 2014.49

The still-modest global solar cooling market grew at an average annual rate exceeding 40% between 2004 and 2012, and approximately 1,050 systems of all technology types and sizes were installed by 2013.50 While most of these systems were in Europe (81%), use of solar cooling is rising in many regions with sunny dry climates, including Australia, India, Mediterranean islands, and the Middle East.51 The availability of small (<20 kW) cooling kits for residential use has increased interest in the residential sector in Central Europe and elsewhere, and large-scale systems are gaining appeal due to their more favourable economics.52 One of the market drivers for solar cooling is the potential to reduce peak electricity demand, particularly in countries with significant cooling needs.53

Solar thermal technologies are being used increasingly for industrial applications, providing heat and steam, refrigeration, and air conditioning.54 Major industrial applications include food processing, cooking, and textile manufacturing.55 In 2013, the world's largest low-temperature system was inaugurated in Chile, where it is expected to cover 85% of the heat demand of the Gaby copper mine.56 Other 2013 projects included dairies in MexicoandSwitzerland, leathertanneries in Kenya and Thailand, and a chemical manufacturing facility in Germany.57 India leads in the use of concentrating solar thermal systems with at least 145 systems producing steam, primarily for cooking.58 Rising fuel prices have driven rapid expansion and, as of early 2014, India had an estimated 40 MWth for industrial applications.59 In 2013, several countries offered funding specifically for solar process heat.60

Although interest is growing around the world, district heating networks, solar air conditioning, and solar process heat for industrial purposes account for only about 1% of global solar thermal capacity.61 There also exists a large untapped potential for new applications such as water treatment and sea water desalination.62


China maintained its multi-year lead in the global solar heating industry, producing an estimated 50.1 GWth (71.6 million m2) of collectors in 2013.63 Export activities remained negligible (1.8% in 2012, or USD 300 million) compared to the industry's total turnover, but they continued to increase.64 The market shares of Chinese vacuum tubes continued to rise in price-sensitive export markets including Poland, Turkey, and India.65

By contrast, Europe saw accelerated consolidation during 2013, with several large suppliers announcing their exit from solar thermal manufacturing.66 In two cases, management buyouts prevented abandonment of the collector technology or brand.67 However, a large number of smaller European collector manufacturers no longer considers in-house production to be economically feasible due to high price pressures and low-cost imports from outside Europe, especially from China.68 To offset decreasing domestic demand, many European companies have focussed on foreign markets through local partnerships and investments.69

South Africa's supply chain has been in a consolidation phase, with the number of commercial entities in the solar water heater market falling from a high of over 700 in 2011 to about 400 in 2013.70 Brazil had about 150 solar thermal suppliers by mid-2013.71 While most focussed on the domestic market, a small number of companies were exporting to other countries in the region.72

In 2013, industry expectations for current and future market development were brightest in India and Greece.73 Manufacturers in India expanded production capacities and integrated vertically in response to rapid market growth.74

Production costs of solar thermal heat technologies have continued to decline. In Europe, for instance, production costs of standard collectors fell about 23% for every doubling of installed capacity from 1995 to 2012, or nearly 50% over the period.75 And new technologies continue to emerge. For example, by early 2014 there were more than 130 hybrid solar thermal-heat pump systems from more than 80 companies (mostly in Europe) for combined production of domestic water and space heating.76 About 30 companies in at least 12 countries were making a variety of photovoltaic thermal (PV-T) hybrid solar collectors that combine solar PV and thermal water collectors for simultaneous production of power and heat.77

Attention to quality standards and certification continued in response to high failure rates associated with cheap tubes from China, and harmonisation of standards and certification played an important role in the industry's export strategies.78 In September, the International Standard Committee approved a global collector test standard, paving the way for a variety of new collector technologies to receive a Solar Keymark label in Europe.79 In addition, several countries are working on domestic standards.80

A growing number of manufacturers around the world specialise in concentrating collectors for industrial applications.81 Solar process heat is already competitive in many niche markets today, but the technology is not widely known.82

The cost of solar cooling kits continues to fall, declining by 45-55% (depending on system size) over the period 2007-2012.83 The variety of thermal chillers continued to increase in 2013, as did their standardisation.84 At least two European companies released new chillers for small systems down to 5 kW, and companies in Europe and Asia introduced cooling kits that include integrated heat rejection (which removes waste heat generated by the system).85 Alternative heat rejection systems are under development to reduce costs and planning time.86 In addition to new chillers, innovative technologies continue to emerge, particularly for large-scale and industrial systems.87

1 Total additions and capacity based on Franz Mauthner, AEE -Institute for Sustainable Technologies (AEE-INTEC), Gleisdorf, Austria, personal communication with REN21, March-May 2014, and on Franz Mauthnerand Werner Weiss, Solar Heat Worldwide: Markets and Contribution to the Energy Supply 2012 (Gleisdorf, Austria: International Energy Agency (IEA) Solar Heating and Cooling Programme (SHC), forthcoming May 2014). The Mauthner and Weiss report covers 58 countries and is assumed to represent 95% of the global market. Data provided were 52.7 GWth added (75.3 million m2)fora total of 269 GWth, which were adjusted upwards to 100% for the GSR to reach 55.4 GWth added (79.2 million m2)and 283.4 GWth total. Note that collector area (and respective capacity) in operation were estimated by Mauthner and Weiss based on official country reports regarding the lifetime basis used; where such reports were not available, a 25-year lifetime was assumed except in the case of China , where the Chinese Solar Thermal Industry Federation (CSTIF) considers lifetime to be below 10 years. Also, note that in 2004 the represented associations from Austria, Canada, Germany, the Netherlands, Sweden, and the United States, as well as the European Solar Thermal Industry Federation (ESTIF) and the IEA-SHC agreed to use a factor of 0.7 kWth/m2 to derive the nominal capacity from the area of installed collectors; this conversion rate is also used in the GSR.

2 Glazed water collectors accounted for a 96.8% share of the global market in 2012 (unglazed water systems accounted for about 3.0% of the global market in 2012, and glazed and unglazedair systems for less than 0.2%), and global capacity of glazed collectors added in 2012 was 51 GWth, per Mauthner, op. cit. note 1, and Mauthnerand Weiss, op. cit. note 1. The 51 GWth was adjusted upwards by REN21 from an estimated 95% of the global market to 100%, to reach 53.7 GWth.

3 Preliminary estimate from Mauthner, op. cit. note 1. Note that the estimate does not consideraircollectors.

4 Mauthner and Weiss, op. cit. note 1.Figure 16 based on data from Mauthner and Weiss, op. cit. note 1, and from Mauthner, op. cit. note 1. Global total was adjusted upwards by REN21 from an estimated 95% of the global market to 100%, and this is reflected in shares data.

5 Mauthnerand Weiss, op. cit. note 1.Figure 17 from idem and from Mauthner, op. cit. note 1.

6 Mauthner, op. cit. note 1.

7 Ibid.; Mauthner and Weiss, op. cit. note 1. Estimates for 2013 are based on available data from Austria, China, Germany, Japan, Mexico, Portugal, Spain, and the United States; data for remaining countries were estimated by Mauthner and Weiss according to their trends for the previous two years; these estimates assume 100% of the global market.Figure 18 based on data from Mauthner and Weiss, op. cit. note 1, and from Mauthner, op. cit. note 1. Data were adjusted upwards by REN21 from an estimated 95% of the global market to 100%.

8 Ibid.

9 Based on installations of an estimated 66 million m2, from Hu Runquing, CSTIF, data provided by Mauthner, op. cit. note 1.

10 An estimated 21% of newly installed capacity replaced existing collectors, and net additions were 52.3 million m2; the estimated cumulative capacity at end-2013 was based on 310 million m2, per Runquing, op. cit. note 9.

11 Solar heaters cost an estimated 3.5 times less than electric water heaters and 2.6 less than gas heaters over the system lifetime, from CSTIF, cited in Barbel Epp, "Solar Thermal Competition Heats Up in China," Renewable Energy World, 10 September 2012,, and from Barbel Epp, "Solar Thermal Shake-Out: Competition Heats Up in the Chinese Market," Renewable Energy World, July-August 2012, pp.47-49; annual market growth has increased fairly steadily year-by-year, up from 4,480 MWth in 2000, per Franz Mauthner and Werner Weiss, Solar Heat Worldwide: Markets and Contribution to the Energy Supply 2011 (Gleisdorf, Austria: EA-SHC, May 2013), http://www.iea-shc. Org/data/sites/1/publications/Solar-Heat-Worldwide-2013.pdf.

12 Epp, op. cit. note 11.

13 European Commission, European Technology Platform Renewable Heating & Cooling, Common Vision for the Renewable Heating & Cooling Sector in Europe (Brussels: European Union, 2011),

14 Mauthner, op. cit. note 1.

15 Contraction has occurred since the peak in 2008, per EurObserv'ER, Solar Thermal and Condcentrated Solar Power Barometer (Brussels: 2013),; lower construction rates and pressure from idem; pressure particularly in Germany, according to Harald Drück, University of Stuttgart, cited in Bärbel Epp and Jan Gesthuizen, "Germany: A Standstill Is Not the Answer, a System Solution Is," Solar Thermal World, 26 May 2013,; France from Barbel Epp, personal communication with REN21, 26 March 2014; see also Robin Welling, ESTIF, interviewwith Barbel Epp, "It is a groundbreaking fact that solar thermal is the only technology to be enabled to obtain the A+++ label," Solar Thermal World, 4 December 2013,; solar PV had greater appeal for investors in Austria, and reduction of support policies, from Pedro Dias, ESTIF, Brussels, personal communication with REN21, 4 May 2013.

16 Based on 1.02 million m2 of added collector area during 2013 for a total of 17.5 million m2 installed in Germany by year's end, with all data from Bundesverband Solarwirtschafte. V., "Statistiche Zahlen derdeutschen Solarwärmebranche (Solarthermie), March 2014,; decline in 2011 from ESTIF, Trends and Market Statistics 2012 (Brussels: June 2013), p.5,

17 Figure of 14% market decline in 2013, -15.9% in 2012, -12.8% in 2011, and -21.7% in 2010, from AEE-INTEC, provided by Mauthner, op. cit. note 1.

18 More than doubled based on 671,156 m2 in 2008, from Solar Heating Department (DASOL), Brazilian Association of Refrigeration, Air Conditioning, Ventilation and Heating (ABRAVA), cited in Filipa Cardoso, "Brazil: Residential Demand Drives Market," Solar Thermal World, 24 July 2013,; 2013 additions and year-end total based on 1,378.8 thousand m2of newly installed glazed and unglazed collector area and 9.8 million m2 of accumulated area, from DASOL, ABRAVA, 2014, and provided by Renata Grisoli, MGM Innova, personal communication with REN21, 29 March 2014. Note that additions were up from 1,151.3 thousand m2 in 2012, and 1,029.6 thousand m2 in 2011, from idem.

19 Drivers also include a growing awareness of sustainability issues, and are all from Cardoso, op. cit. note 18. Solar thermal is competitive in Brazil due to good solar resources/weather conditions and high electricity prices—systems can payoff in two years. See also Alejandro Diego Rosell, "Brazil: Rising Electricity Prices Put Spotlight on Solar Thermal," Solar Thermal World, Note that Minha Casa, Minha Vida has resulted in installation of only 260,000 systems since 2009.

20 Mexico added an estimated 200 MWth (285,000 m2) in 2013, although down from 210 MWth (300,000 m2) in 2012 due mainly to a crisis in the construction sector, from Daniel Garcia, Mexican renewable energy industry association FAMERAC, cited in Alejandro Diego Rosell, "Mexico: ANES to Provide National Solar Market Statistics," Solar Thermal World, 24 February 2014,, and from Alejandro Diego Rosell, "Mexico: Fight for New Incentives," Solar Thermal World, 13 September 2013,; Argentina from Eva Augsten, "Argentina: Solar Water Heaters for Rural Schools," Solar Thermal World, 29 October 2011,, and from Eva Augsten, "Argentina: ASADES' Network for Solar Energy," Solar Thermal World, 6 April 2012,; Chile has seen great success from a tax rebate scheme, approved in 2009, with 20,000 systems installed underthe programme as of mid-2013, but uncertainty aboutits extension beyond the end of 2013 caused much uncertainty in Chile's industry, per Alejandro Diego Rosell, "Chile: So Far No Government Compromise on Extending Tax Credits," Solar Thermal World, 8 July 2013,; most of Chile's systems have been installed in new social housing projects, per Alejandro Diego Rosell, "Chile: New Government to Extend Tax Credits," Solar Thermal World, 23 January 2014,; Eva Augsten, "Chile: Mining Sector May Be Solar Thermal's Future," Solar Thermal World, 24 January 2013,; Costa Rica has an annual market volume estimated at 5,000-6,000 m2 of glazed collectors, of which 30% are vacuum tubes with most imported from China, based on estimate by Stefan Frey, Swissol, cited in Bärbel Epp, "Costa Rica: Small Market but Prestigious Large-Seale Projects," Solar Thermal World, 23 July 2013,; Uruguay has seen slow growth despite government incentives due to the lack of a financing culture and inability of most people to afford high upfront costs, plus low-quality imported systems have made people wary of investing in them, per Alejandro Diego Rosell, "Uruguay: Growing at Its Own Pace," Solar Thermal World, 15 July 2013,

21 Based on 1.3 million m2 added (6.17 million m2 at end-2012) for a total of 7.47 million m2 in operation on 31 December 2013, from Government of India, Ministry of Newand Renewable Energy (MNRE), "Physical Progress (Achievements),", viewed 18 January 2014. India's market picked up in Maharashtra and Karnataka, but not in otherstates despite subsidies, perV. Rishi Kumar, "Implementation of Solar Projects Likely to Gather Paces, Says MNRE Secretary," Hindu Business Line, 1 November 2013, Note that India added 1.1 GWth for a total of 5.6 GWth, according to data from Malaviya Solar Energy Consultancy, provided by Mauthner, op. cit. note 1.

22 Japan added approximately 140 MWth in 2012 and about the same in 2013. Additions and total capacity data estimated by Institute forSustainable Energy Policies (ISEP) based on data from Solar System Development Association, cited in ISEP, Renewables Japan Status Report 2014 (Toyko: 2014) (in Japanese) and provided by Hironao Matsubara, ISEP, personal communication with REN21, 23 April 2014.

23 Steadygrowth and drivers from Yongyuth Sawatdisawanee, Thailand's Department of Alternative Energy Development and Efficiency, Ministry of Energy, interview by Stephanie Banse, "Thailand: Many Enterprises Have Become Interested in the Technology," Solar Thermal World, 6 March 2013,; Thailand added 8,000 m2 of subsidised systems in 2013, down from 11,155 m2 in 2012, from Kulwaree Buranasajjawaraporn, Thai Department of Alternative Energy Development and Efficiency (DEDE), presentation at Thai-Germany Technology Conference, Bangkok, October 2013, cited in Stephanie Banse, "Thailand: Ministry of Energy Extends Incentive Programme until 2021," Solar Thermal World, 2 February 2014,

24 Buranasajjawaraporn, cited in Banse, op. cit. note 23.

25 Mauthner and Weiss, op. cit. note 1.

26 The marketwas down about 10% (to 1,624,298 m2) in 2012 relative to 2011 (1,805,675 m2), but the 2011 marketwas considered unusually high, and demand moves up and down from year to year, based on information from A. Hakan Alaş, ezinc, provided by Mauthner, op. cit. note 1. There are still no subsidies in Turkey per Bärbel Epp, personal communication with REN21, 26 March 2014.

27 About 60% based on an estimated 14,311.4 MWth of unglazed water col lectors in operation in 2012, from Weissand Mauthner, op. cit. note 1; 30,000 annually from Beam Engineering, Solar Heating & Cooling: Energy for a Secure Future, prepared for U.S. Solar Energy Industries Association (SEIA) (Washington, DC: 2013),

28 Rankingand capacity data from Mauthnerand Weiss, op. cit. note 1. The United States added 530.2 MWth of unglazed systems and 169.2 MWth of glazed systems in 2012, for a year-end total of 14,311.4 MWth of unglazed systems and 1,935.4 MWth of glazed systems, from idem. Note that are uncertain because the U.S. Energy Information Administration no longertracks solarthermal and SEIA has notfinalised a planned survey, from Barbel Epp, "USA: GoSolar at SEIA's Birthday," Solar Thermal World, 27 January 2014,

29 See, forexample, Jennifer Runyon, "New Hampshire Sets Thermal Renewable Energy Carve Out," Renewable Energy World, 26 June 2012,; SEIA, "RPS Solar Carve Out Arizona," 12 February 2013,; SEIA, "RPS Solar Carve Out Pennsylvania," 12 February 2013, Sheet%20PA.pdf; Jennifer Runyon, "Trend: U.S. States Adding Thermal Energy to Their RPS (Part 1)," District Energy, 15 August 2012,; "Small-scale Renewables: Big Problem, Small Solution," in REW Guide to North American Renewable Energy Companies 2013, special supplement in Renewable Energy World, March-April 2013, pp.18-24. A few states also allow utilities to meet requirements under RPS laws by buying Solar Renewable Energy Emission Certificates produced by solar water heaters. See, for example, Barbel Epp, "USA: Solar Thermal SRECs Traded in Washington, D. C.and North Carolina," Solar Thermal World, 27 February 2011,, and Barbel Epp, "Maryland/USA: Solar Water Heaters Eligible for Solar Renewable Energy Credits," Solar Thermal World, 27 April 2011,

30 Based on 643.9 MWth of capacity added during 2012, of which 455 MWth was unglazed, and 5,128.2 MWth of cumulative capacity at year's end, of which 3,045 MWth was unglazed, from Mauthner and Weiss, op. cit. note 1.

31 Tim Flannery and Veena Sahajwalla, The Critical Decade: Australia's FutureSolar Energy (Climate Commission Secretariat, Australian Department of Industry, Innovation, Climate Change, Science Research and Tertiary Education, 2013),, pdf.

32 Israel, Jordan, and Lebanon rankings from Mauthner and Weiss, op. cit. note 10; 85% of households from Observatoire Méditerranéen de l'Energie (OME), Solar Thermal in the Mediterranean Region: Market Assessment Report (Nanterre, France: September 2012), p.37,; Lebanon experienced market growth averaging over 17% during 2008-2012, from Wilson Rickerson et al., Solar Water Heating Techscope Market Readiness Assessment (Paris: United Nations Environment Programme (UNEP), 2014), prepared for UNEP, Division of Technology, Industry and Economics, Global Solar Water Heating Initiative, p.67,

33 Mauthner and Weiss, op. cit. note 10. Egypt has a small market but has seen a rapid increase, particularly in the hotel sector, as solar thermal is a readily available option for reducing costly diesel consumption, from Bärbel Epp, "Egypt: Green Star Hotels 'Download' the Sun," Solar Thermal World, 9 January 2013,; thanks to a support scheme that was introduced in 2009, Tunisia had 14,000 m2 by the end of 2012, mostly in hotels, public baths, hospitals, and 30 hotels had installed systems by late 2013, from Bärbel Epp, "Tunisia Funds Solar Process Heat," Solar Thermal World, 7 October 2013,; South Africa has seen success driven greatly by rising electricity prices, fear of electricity shortages, and a national rebate programme from utility Eskom, from Frank Stier, "South Africa: High Demand from Tourism Sector," Solar Thermal World, 1 July 2013,

34 Anton Schwarzlmüller, Domestic Solar Heating, Zimbabwe, cited in "Zimbabwe: Installing 100 Locally Produced Storage Tanks in 2013 Would Be a Big Success," Solar Thermal World, 1 May 2013,; Stier, op. cit. note 33; Yaping Zhang, "Thailand: Prefabricated Container Solution Improves Quality in Tannery," Solar Thermal World, 9 April 2013,; Alejandro Diego Rosell, "Uruguay: Growing at Its Own Pace," op. cit. note 21.

35 Mauthner and Weiss, op. cit. note 1. Also among the top 10 in 2012 were Australia, Germany, Turkey, China, and Jordan.

36 European Commission, op. cit. note 13.

37 Mauthner, op. cit. note 1.

38 European Commission, op. cit. note 13.

39 Mauthner and Weiss, op. cit. note 1; Mauthner, op. cit. note 1.

40 Mauthner and Weiss, op. cit. note 1; Mauthner, op. cit. note 1; approximately two out of five systems in Germany are combi-systems, from Bundesindustrieverband Deutschland Haus-, Energie- und Umwelttechnik e. V.(BDH) and Bundesverband Solarwirtschaft (BSW), "Solarkollektorabsatz 2013 rückläufig – Solar- und Heizungsbranche fordern: Wärmewende jetzt einläuten," press release (Berlin and Cologne: 17 February 2014),; Poland also from March Czekanski, "Poland: Market in Transition," Solar Thermal World, 30 May 2013,; France and Switzerland also have a growing share of combi-systems, from European Commission, European Technology Platform on Renewable Heating and Cooling, Strategic Research and Innovation Agenda for Renewable Heating & Cooling (Brussels: European Union, 2013), p.14,; and markets are growing in Russia, particularly in areas with cold climates, per interviews with manufacturers in Russia, New Polus, Inten, and Kassol, cited in Vladislava Adamenkova, "Russia: 2014 – Year of Change and Growth," Solar Thermal World, 22 January 2014,

41 European Commission, op. cit. note 13. The trend towards hybrid systems including heat pumps is seen particularly in Austria, Germany, and Switzerland, where policies and high electricity prices create favourable conditions, per "Solar + Heat Pump Systems," Solar Updafe (IEA-SHC), January 2013, p.14,

42 Mauthner, op. cit. note 1.

43 Cooling systems include one-stage absorption chillers, adsorption chillers, and desiccant cooling systems (DEC) systems for thermal cooling, from ibid.

44 With such systems, pressurised water, steam or thermo-oil can be used as heat transfer medium, from ibid.

45 Other heat sources from Jan-Olof Dalenbäck and Sven Werner, CIT Energy Management AB, Market for Solar District Heating, supported by Intelligent Energy Europe (Gothenburg, Sweden: revised July 2012),

46 Solar District Heating, Intelligent Energy Europe Programme of the European Union, "Solar District Heating," viewed 6 March 2014,

47 Jan-Olof Dalenbäck, "An Emerging Option: Solar District Heating and Cooling," Euro Heat & Power, vol.10, no.(2013), pp.26-29; Jan-Olof Dalenbäck, Chalmers University of Technology and Solar District Heating (SDH), personal communication with REN21, 12 April 2014; cost competitive in Denmark only, from Bärbel Epp, solrico, personal communication with REN21, 29 April 2014; Rachana Raizada, "Renewables and District Heating: Eastern Europe Keeps It Warm," Renewable Energy World, 13 September 2012, Costs have come down considerably in the past five years and, in Denmark, the heat price from solar thermal is as low as USD 42.7/MWh (EUR 31/MWh), below that of gas-fired district heating, due to the large size of fields and low interest rates over expected lifetime of at least 20 years, from Søren Elisiussen, Arcon, cited in Barbel Epp, "Denmark: 'We have improved the cost/performance ratio by around 50 % over the last 5 years'," Solar Thermal World, 4 March 2014, See also Barbel Epp, "Germany/Denmark: Solar District Heating Prices between 37 and 88 EUR/MWh," Solar Thermal World, 24 March 2014,

48 Natural Resources Canada, "Canadian Solar Community Sets New World Record for Energy Efficiency and Innovation," press release (Okotoks, Alberta: 5 October 2012),; Canada also from "Solar Community Tops World Record," Solar Update (IEA-SHC), January 2013, p.16,; Government of Canada, "Drake Landing Solar Community," brochure,, viewed 29 April 2014; China's "Utopia Garden" project in Dezhou covers 10 blocks of apartment buildings with 5.025 m2 combined with seasonal storage beneath the complex, per Barbel Epp, "China: Utopia Garden Sets New Standard for Architectural Integration," Solar Thermal World, 10 April 2012,; the University of Pretoria's 672 m2 solar thermal system provides warm water for apartments for 550 students, per Stephanie Banse, "South Africa: University of Pretoria's 672 m2 Solar Thermal System," Solar Thermal World, 12 April 2012,

49 Constructed in 2013 from Dalenback, "Emerging Options...," op. cit. note 47. Dalenback, personal communication, op. cit. note 47 Most plants were in Denmark, but there were two in Austria, two in Germany, one in France, and one in Norway. See also "Busingen: First German ground-mounted solardistrict heating plant in operation," Newsletter of the Solar District Heating, Intelligent Energy Europe Programme of the European Union, 16 September 2013,; Jan Erik Nielsen, "Large Solar Heating and Cooling Systems," IEA-SHC Task 45, 2014, provided by Mauthner, op. cit. note 1. Denmark's Dronninglund Solar District Heating Plant is 26 MWth (37,000 m2 of collectors) with 60,000 m3 seasonal storage. It is expected that the field together with storage will cover about 50% of annual heat load for 1,400 connected customers, from Nielsen, op.cit.this note.

50 Uli Jakob, "Technologies and Perspectives of Solar Cooling Systems," presentation for AHK Conference, Sydney Australia, 24 March 2014, slide 29,; data from Solem Consulting/TECSOL/Green Chiller, provided by Uli Jakob, Green Chiller Verband fur Sorptionskalte e. V., personal communication with REN21, 22 April 2014. Note that roughly 600solarcooling systems were installed worldwide in 2010, per Hans-Martin Henning, "Solar Air-conditioning and Refrigeration—Achievements and Challenges," Conference Proceedings of International Conference on Solar Heating, Cooling and Buildings—EuroSun 2010, Graz, Austria, 2010,

51 Europe accounted for about 81% of installed systems worldwide as of 2013, based on data from Jakob, op. cit. note 50; Australia, Mediterranean islands, and Middle Eastfrom IEA, Technology Roadmap, Solar Heating and Cooling (Paris: OECD/IEA, 2012), p.11, r_Heating_Cooling_Roadmap_2012_WEB.pdf. Several hundred small cooling kits were sold in these countries in 2011. The Australian market hasgrown 30% annually over the past eight years, from Uli Jakob, Green Chiller and Solem Consulting, cited in Eva Augsten, "Australia: Country to Publish First Solar Air Conditioning Standard," Solar Thermal World, 17 June 2013,; in India, for example, solar thermal is used for cooling at a hospital and at Muni Seva Ashram in Gujarat state, where 100 parabolic dishes (Scheffler type) supply a 100-tonne air conditioning system, from Eva Augsten, "India: Quarterly Sun Focus Magazine Presents Concentrating Solar Heat," Solar Thermal World, 19 September 2013,; Jamaica's first solar cooling system was commissioned in an office tower in Kingston, from SOLID, "Commissioning of S.O.L.I.D.'s First Solar Cooling Plant in Jamaica," press release (Graz, Austria: 2013),

52 IEA, op. cit. note 51, p.11. Several hundred small cooling kits were sold in Australia, Mediterranean islands, and the Middle East in 2011.

53 Daniel Rowe, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Australia, personal communication with REN21, 29 April 2013.

54 Mauthner, op. cit. note 1. See also, forexample, Uli Jacob, Green Chiller, "Status and Perspective of Solar Cooling in Europe," Australian Solar Cooling 2013 Conference, Sydney, Australia, April 2013.

55 Eva Augsten, "The world of solar process heat," Sun & Wind Energy, March 2014, pp.36-45.

56 The 27.5 MWth (39,300 m2 of collector area) system is combined with 4,000 m3 of heat storage to provide heat for the remote Gaby mine of the state-owned company Codelco, per Bärbel Epp, "Chile: President Inaugurates World's Largest Solar Field with 27.5 MWth," Solar Thermal World, 13 November 2013, This field is 8% largerthan the Saudi Arabian plant inaugurated at the end of 2011 to supply heat to a women's university, per Eva Augsten, "Saudi Arabia: World's Biggest Solar Thermal Plant in Operation," Solar Thermal World, 26 January 2012,

57 Solar Heat for Industrial Processes—SHIP Database, IEA-SHC Task49/IV,, viewed 10 April 2014.

58 Jaideep Malaviya, "India: Pilgrim Sites Use Solar Energy," Solar Thermal World, 31 May 2013, At least a dozen large religious sites in India use concentrating solarthermal for community cooking; the largest (Saibaba Ashram in Shirdi, Maharashtra State) uses solar thermal concentrators (parabolic dishes) to cook for 50,000 people per day, saving 100,000 kilograms of LPG annually, from idem. By late 2013, at least 23 additional systems were underdevelopment in India, primarily to replace conventional boilers and generate steam for cooking, per Eva Augsten, "India: Quarterly Sun Focus Magazine Presents Concentrating Solar Heat," Solar Thermal World, 19 September 2013,

59 Rapid expansion and fuel prices, and an estimated 11,600 m2 of solarconcentrators installed during 2012, with a cumulative area of 28,000 m2 by year's end, all from Jaideep Malaviya, Malaviya Solar Energy Consultancy, interviewwith Franz Mauthner, information provided by Mauthner, op. cit. note 1. The figure

60 See, for example, Eva Augsten, "Germany: Solar Process Heat Support Shows First Results," Solar Thermal World, 22 January 2013,; Eva Augsten, "Germany: Solar Process Heat Cheaperthan Fossil-Fuel Heat, but Outperformed by CHP," Solar Thermal World, 4 December 2013,; Stephanie Banse, "Austria: Large-Scale Solar Plants Subsidy Scheme Shows Increase in Average System Sizes," Solar Thermal World, 3 January 2014,; Frank Stier, "Denmark: Launch of Subsidy Scheme for the Industrial Sector," Solar Thermal World, 26 September 2013,; Jaideep Malaviya, "India: 90 Process Heat Projects with Concentrating Collectors in Five Years," Solar Thermal World, 11 June 2012,

61 Interest growing from, forexample, Vladislava Adamenkova, "Russia: 2014 – Year of Change and Growth," Solar Thermal World, 22 January 2014,; Observatoire Méditerranéen de l'Energie (OME), Solar Thermal in the Mediterranean Region: Market Assessment Report (Nanterre, France: September 2012), pp.40-41, 74-75,; Bärbel Epp, "Tunisia Funds Solar Process Heat," Solar Thermal World, 7 October 2013,; Emily Hois, "US Ranchers Roundup the Power of the Sun," Renewable Energy World, 16 July 2013,; 1% from Mauthner and Weiss, op. cit. note 10, p.3.

62 European Commission, op. cit. note 13. Note that the Hyatt Regency in Aruba uses solar thermal to provide its guests with pure drinking water, from SOLID, "S.O.L.I.D. Installed a Large Solar Plant at the Hyatt Regency in Aruba," press release (Graz, Austria: 2013),; and solar thermal is being used in Oman, where it is cheaper than natural gas for powering oil recovery projects, from Wael Mahdi, "Solar Beats Natural Gas to Unlock Middle East's Heavy Oil, Says GlassPoint Solar," Bloomberg, 20 January 2014,; a pilot "tri-generation" project in Jordan, operational since 2011, uses a parabolic trough system for electricity generation, industrial steam generation, and water desalination and chilling, per Rayer Ltd., "State of the Art Tri-Generation Project,", viewed 3 May 2014.

63 Production data from Solar Alliance Network, (in Chinese), cited in Barbel Epp, "China: Flat Plate Collector Share is Growing," Solar Thermal World, 1 July 2013,

64 Epp, op. cit. note 8. China's exports were up 20% between 2010 and 2012.

65 Poland from Czekanski, op. cit. note 40; Turkey from A. Hakan Alaş, ezinc, interviewwith Bärbel Epp, "Turkey Vacuum Tubes on the Rise," SolarThermal World, 23 April 2012,; India from Jaideep Malaviya, "India: Flat Plate vs Vacuum Tube Technology," SolarThermal World, 19 November 2012,

66 Forexample, the Austrian Greiner Group announced in mid-June 2013 the closure of the former Sun Master collector production plant, and the Danish Velux Group announced the phase out of its production and sale of solar collector systems in September 2013, per Barbel Epp and Eva Augsten, "The seven year itch," Sun & Wind Energy, November-December 2013, pp.32-45.

67 Barbel Epp, "Germany: Management Buyout of Schuco's Collector Production," Solar Thermal World, 14 March 2013,; Barbel Epp, "Austria/Europe: General Solar Systems and Sonnenkraft Management Buyout," Solar Thermal World, 27 February 2014,

68 From the 12 collector manufacturers in the Czech Republic in 2007, seven have since left the solar thermal sector or plan to close in the coming months, per Barbel Epp, personal communication with REN21, 4 March 2014.

69 Foreign markets from Alejandro Diego Rosell, "Spain: 'Most of these companies will survive thanks to internationalisation'," Solar Thermal World, 16 December 2013,; local partnerships and investments from Welling, op. cit. note 15. Forexample, boiler manufacturer Bosch Thermotechnik (Germany) operated solar production facilities in five locations on fourcontinents by late 2012, from Epp and Augsten, op. cit. note 66.

70 Greencape, Green Cape Sector Development, Market Intelligence Report: Energy Efficiency & Embedded Generation, Cape Town, South Africa, January 2014, pp.7-8.

71 Carlos Alencar, DASOL, ABRAVA, cited in Cardoso, op. cit. note 18.

72 Ibid.

73 Based on the ISOL Index, an international business climate index developed and surveyed by solrico since the beginning of 2010. This point-based indicator (ranging from 0 to 100 points) shows the satisfaction of solar thermal manufacturers and system suppliers with current and expected market development, and company values are averaged to obtain country and regional indices, per The average long-term current business ISOL Index 2012/2013 for Greece was 58 points, the highest score togetherwith India, per Barbel Epp, solrico, personal communication with REN21, February 2014.

74 Jaideep Malaviya, "India: Industry Shifts to Vacuum Tube Collectors," Solar Thermal World, 1 May 2013,

75 European Technology Platform on Renewable Heating and Cooling, Strategic Research Priorities for Solar Thermal Technologies (Brussels: December 2012), p.22,

76 Werner Weiss and Pam Murphy, IEA-SHC, personal communication with REN21, March 2014.

77 Most PVT manufacturers are based in Europe, but there are also companies in China, Israel, Turkey, and the United States, from Irina Mitina, Fachhochschule Dusseldorf, Arbeitsgruppe E2- Erneuerbare Energien und Energieeffizienz, "Technology Survey: Pros and Cons of Different PVT Collectors," SMEThermal 2014, Berlin, 18 February 2014. See also Lydie Bahjejian, "France: Third Playerto Launch PVT Panel on Market," Solar Thermal World, 7 May 2013,

78 See, forexample, Stephanie Banse and Joachim Berner, "Lowering Costs, Maintaining Efficiency," Sun & Wind Energy, December 2012, pp.62-65; Epp, op. cit. note 20; Rosell, "Mexico: Fightfor New Incentives," op. cit. note 20.

79 The test standard EN ISO 9806, by ISO committees CEN/TC312and ISO TC180, includes testing methodology for a numberof new solar thermal technologies, such as solarair heating collectors and concentrating medium-temperature collectors, from Barbel Epp, "Global Collector Test Standard ncorporates New Technologies," Solar Thermal World, 24 October 2013,

80 Forexample, review of a technical quality standard in Mexico during 2012 reduced the approved system models from 250 to 40, and there are still efforts under way to create a national standard, from Rosell, "Mexico: Fight for New Incentives," op. cit. note 20; Costa Rica's Institute of Technical Standards began working on a standardisation process for solar thermal systems, from Epp, op. cit. note 20.

81 The first World Map of the Solar Process Heat Collector ndustry includes 36 companiesfrom 10 countries including 18 parabolic trough collector manufacturers, four Fresnel collector manufacturers, 1 evacuated flat-plate collector manufacturer, 8 scheffler/paraboloid dish collector manufacturers, and 4 receiver (tube) manufacturers, per Eva Augsten, "The world of solar process heat," Sun & Wind Energy, March 2014. Onlya small portion (perhaps one-third) of manufacturers is also active in the CSP field, per Barbel Epp, solrico, personal communication with REN21, 26 March 2014.

82 Based on survey with manufacturers of process heat systems, from Augsten, op. cit. note 81, pp.36-45.

83 Jakob, op. cit. note 50, slide 26.

84 Eva Augsten, "Australia: Country to Publish First Solar Air Conditioning Standard," Solar Thermal World, 17 June 2013,

85 Makatec (Germany) and Solabcool (Netherlands) released new chillers; Solabcool, Mitsubishi Plastics (Japan), and Jiangsu Huineng (China) put out new cooling kits, from Augsten, op. cit. note 84.

86 Eva Augsten, "Germany: Additional SupportforSmall Solar Cooling Systems," Solar Thermal World, 3 February 2014,

87 Daniel Mugnier, TECSOL SA, personal communication with REN21, 11 April 2014. See, for example,