The potential for solar process heat in the European Union
The results of the potential studies for different European countries are reported in the figure and the table below. The potential solar process heat estimated in the PROMISE study for Austria [5] reaches 5.4 PJ/year, while the Iberian Peninsula (Spain and Portugal, [6]) and the Italian studies [7] show a potential of 21 PJ/year and 32 PJ/year respectively.
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Figure 4. Solar process heat potential in selected European countries (PJ/year). |
The study carried out for the Netherlands shows a quite lower potential (<2 PJ/year). The reason for this is because the hot water production up to only 60 °C was assessed in twelve industry branches, thereby limiting the scope of the analysis.
In Table 1, the potential for the use of solar thermal in the industrial sector in different countries is reported in terms of delivered energy (PJ/year), capacity (GWth) and collector area (Mio m2). These potential figures are also compared to the corresponding industrial heat demand, in order to obtain the share of heat demand that could be covered by using solar thermal.
The results reported show that solar thermal systems could provide the industrial sector with 3^4% of its heat demand in Austria, Italy, Portugal, Netherlands and Spain.
Extrapolating this result to the European Union (EU 25), considering an average share of 3.8%, the potential for solar thermal applications in industry reaches a value for heat production of 258 PJ/year. The corresponding potential figures in terms of capacity and area have been calculated taking into account two possible yield values for the solar plants: 400 kWh/m2 year and 500 kWh/m2 year.
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Table 1. Industrial heat demand and solar process heat potential for selected countries and for EU25.
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Even though solar thermal is used today mainly for providing hot water to households and pools, the conducted survey clearly highlights that, given its relevance in total final energy consumption, the industrial sector cannot be ignored.
Moreover, a remarkable share of its heat demand is needed in the low and medium temperature range, and this is true particularly for certain industrial sectors (food - including wine and beverage, textile, transport equipment, metal and plastic treatment, chemical) and for several processes (cleaning, drying, evaporation and distillation, blanching, pasteurisation, sterilisation, cooking, painting, surface treatment).
Studies based on both industry statistics and on case studies performed for assessing the solar thermal potential in industrial applications came to consistent outcomes regarding the share of low and medium temperature heat required by the industrial branches noted above.
The analysis of the surveyed country potential studies also shows that, even though using quite different methodologies, the obtained figures are quite similar and that solar thermal could provide the industrial sector with 3^4% of its heat demand.
This result allows the extrapolation of the national figures to the European level: solar thermal could provide 258 PJ/year of thermal energy to the EU25 industrial sector, which means an installed capacity of 100-125 GWth (143^180 Mio m2).
The most ambitious target for solar thermal, developed by ESTIF (European Solar Thermal Industry Federation), is to reach a level of 320 GWth installed in 2020, meaning about 1 m2 per capita and 19.7 Mtoe/year of energy delivered [8].
According to the European Solar Thermal Technology Platform (ESTTP), the goal for 2030 is to have installed a total capacity of 960 GWth by 2030.
Assuming that 10% of the calculated potential for solar heat in industrial applications were to be actually implemented within 2020, a total capacity between 10 and 12 GWth in industrial applications would give a contribution of 3^4% to the overall target of 320 GWth.
Following these assumptions, the industrial use of solar thermal energy could assure a market volume of 1,000 MWth/year, which would mean a 50% growth with respect to the current European annual solar market volume, that equalled 2,100 MWth (almost 3,000,000 m2) installed in 2006.
By exploiting this potential, 10,000-15,000 new jobs could be created by 2020. This figure represents a relevant share of the occupational target for the overall solar thermal sector, which according to the European Solar Thermal Technology Platform will be able to offer 224,000 full time jobs by 2020.
Even assuming a quite conservative scenario for the penetration of solar thermal use in the industrial sector, its contribution for reaching the EU set targets for 2020 is significant.
Finally, regarding future improvements of this analysis, new and more complete studies are needed within the EU framework to assess the detailed potential at national and EU levels in the different industrial sector and expand the current data available to solar thermal companies and policy makers.
[1] W. Weiss, I. Bergmann, G. Faninger, Solar Heat Worldwide - Markets and contribution to the energy supply 2005, International Energy Agency 2007.
[2] Data for 2004, based on EUROSTAT statistics.
[3] ECOHEATCOOL (IEE ALTENER Project), The European Heat Market, WP 1, Final report, Published by Euroheat & Power. www. ecoheatcool. org.
[4] D. Jaehnig, W. Weiss (AEE INTEC), Design Guidelines - Solar Space Heating of Factory Building with Underfloor Heating Systems, IEA Task 33/IV, 2007. Downloadable from www. iea- shc. org/task33/publications/index. html
[5] Muller, T. et al., PROMISE - Produzieren mit Sonnenenergie, Potenzialstudie zur thermischen Solarenergienutzung in osterreichischen Gewerbe - und Industriebetrieben within the Fabrik der Zukunft (BMVIT) Subprogram, Final report 2004.
[6] H. Schweiger et al., POSHIP (Project No. NNE5-1999-0308), The Potential of Solar Heat for Industrial Processes, Final Report.
[7] Solar thermal potential study for process heat in Italy, IEA Task 33/IV.
[8] European Solar Thermal Industry Federation, “Solar Thermal Action Plan for Europe”, www. estif. org.
