Greening the Heat Supply: Solar Heat Worldwide 2021 highlights achievements of solar heating and cooling globally

In 2020, Germany was the world’s leading solar district heating market, while China saw the largest increase in the number of industrial solar heat systems added in a single country. This year’s edition of Solar Heat Worldwide is the first to highlight the top three countries for a variety of application areas. Published annually by the IEA Solar Heating and Cooling Programme, the report has become a well-trusted source of solar thermal data and a go-to reference for international organisations such as REN21 and the International Renewable Energy Agency. The 2021 edition plus key messages are available for free on the IEA SHC website.

"Solar heating and cooling systems with 501 GWth were in operation at the end of 2020 and saved 43.8 million tons of oil and 141.3 million tons of CO2. The standout application is once again solar district heating plants and their important contribution in decarbonizing the heating sector. With Germany, Denmark and China leading the way and generating interest in other parts of the world," states Tomas Olejniczak, Chair of the IEA SHC Programme.

Solar Heat Worldwide contains multiple important chapters on the successful use of solar heat by different customer groups. The steadily growing, global PVT market is a special feature of this year’s report. The combination of solar Photovoltaic (PV) and Thermal (T) in one collector leads the trend towards hybrid solar heat solutions, experiencing a steady growth of 9 % annually on average from 2018 to 2020 and 8 % in the dominant European market. Tibet and Ghana are some of the new markets emerging outside of Europe.

Market Leaders

Solar thermal heating and cooling systems serve millions of residential, commercial, and industrial clients worldwide with a wide variety of technologies. Below are the top three countries for different market segments.

Growth Despite COVID-19

Despite the pandemic taking a heavy toll on most national economies in 2020, some large solar thermal markets grew due to increased policy support, like in Germany and the Netherlands. In Turkey and Brazil, demand for solar water heaters increased as homeowners spent more time at home and made improvements around the house.

Positive trend: Increasing sales in major solar thermal markets in 2020.  Source: Solar Heat Worldwide 2021

Positive trend: Increasing sales in major solar thermal markets in 2020.
Source: Solar Heat Worldwide 2021

Number of Multi-MW Solar District Heating Systems Keeps Growing
The leading markets related to the total number of solar district heating systems in operation are Denmark (124 systems), Germany (43), Sweden (22), Austria (19), China (18), and Poland (8). This cost-effective way of greening the heat supply of neighborhoods, towns, and even cities sparks new interest in markets like France, Switzerland, Russia, and South Africa. 

This 3.5 MWth plant feeds heat into the district heating network of the Austrian town of Münzzuschlag with 8,500 inhabitants Photo: SOLID Solar Energy Systems

This 3.5 MWth plant feeds heat into the district heating network of the Austrian town of Münzzuschlag with 8,500 inhabitants Photo: SOLID Solar Energy Systems

Targeted Energy Policies Drive Solar Heating Growth
Germany's solar thermal market confirms the impact that targeted energy policies can have. About 10 years ago, Germany was by far Europe's largest solar thermal market with 1.5 GWth of new capacity, but by 2019 it was hovering around 0.36 GWth of new capacity. But times have changed, and in 2020 Germany's solar thermal market increased by approximately 26 % compared to 2019 to around 650,000 m², corresponding to nearly 0.5 GWth of newly installed capacity. The dramatic increase in demand is largely due to the new federal subsidy for efficient buildings.

PV2heat (using PV to heat water) is a new take on hot water heating that is emerging in South Africa. These systems consist of PV modules directly connected to an electrical element that heats the water with DC power without the need for inverters. By the end of 2020, there were 11,700 PV2heat systems installed in South Africa.

Solar heat for industrial processes (SHIP) continues its global growth, with at least 74 plants added in 2020, increasing the world market to 891 projects in operation at year´s end with an overall installed collector area of 1.13 million m2. The SHIP plants are used for many applications, with the largest at an oil production plant in Oman (300 MWth), followed by a greenhouse application in Australia (36.6 MWth) and copper mine in Chile (27.5 MWth)

Solar cooling is trending toward hybrid solutions to improve efficiency and an investment advantage up to 40% to conventional solar cooling systems.

IEA Solar Heating and Cooling Programme is in a phase of strong expansion both in terms of widening the research topics and increasing regional coverage. The Programme is supported by 19 countries, the European Commission, and eight international organisations, among them the International Solar Energy Society (ISES) and the European Copper Institute (ECI) and the Global Network of Regional Sustainable Energy Centres (GN-SEC). Together, they work on a wide range of topics, from innovative compact storage tank designs to solar cooling and the integration of large-scale solar fields into district heating and cooling networks.

For more information: IEA SHC Communications: Pam Murphy, communications@iea-shc.org