Perspectives for solar thermal applications in Taiwan

doi:10.1016/j.enpol.2016.03.033

Energy Policy

Volume 94, July 2016, Pages 25-28

https://doi.org/10.1016/j.enpol.2016.03.033 Get rights and content

Highlights

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The long-term subsidization for solar water heaters has lost effectiveness.
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Solar thermal applications include BIST, PV/T and industrial heating process.
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A performance-based subsidy policy should be implemented.

Abstract

Taiwan has long depended on imported fossil energy. The government is thus actively promoting the use of renewable energy. Since 2000, domestic installations of solar water heaters have increased substantially because of the long-term subsidies provided for such systems. However, data on the annual installation area of solar collectors in recent years indicated that the solar thermal industry in Taiwan has reached a bottleneck. The long-term policy providing subsidies must thus be revised. It is proposed that future thermal applications in Taiwan should focus on building-integrated solar thermal, photovoltaic/thermal, and industrial heating processes. Regarding building-integrated solar thermal systems, the current subsidy model can be continued (according to area of solar collectors); nevertheless, the application of photovoltaic/thermal and industrial heating systems must be determined according to the thermal output of such systems.

Introduction

In 2015, Taiwan passed the “Greenhouse Gas Emission Reduction and Management Act,” in response to global warming which stipulates that by 2050, the total carbon emission must be reduced to less than 50% of the total emission in 2005 (approximately 245 million metric tons). However, Taiwan has long depended on large quantities of fossil energy for power generation, transportation, factories, and the agricultural industry; renewable energy (municipal waste, biomass, solar PV, solar thermal and wind), which accounts only for 1.73% of the total energy production in 2014 (BEMOEA, 2015), is one of the vital options for achieving the carbon emission reduction target. Statistics released by the International Energy Agency revealed that the 2013 total global capacity in operation for solar thermal energy was 374.7 GW_th and the energy produced was 314 TWh (Mauthner et al., 2015). Taiwan lies across the Tropic of Cancer and receives abundant sunlight, rendering it a suitable region for promoting solar thermal systems. According to the “Renewable Energy Development Bill” of 2010, the Taiwan government has established the “Regulations for Incentive Subsidy for Renewable Heating” to promote the development of the solar thermal industry (Chang et al., 2011). Notably, the Energy Research Center at National Cheng Kung University has been authorized by the BEMOEA to organize an operation unit for the subsidy program since 2000.

Solar thermal applications in Taiwan are mostly concentrated in low-temperature systems, mainly solar water heaters (SWHs). Such systems do not track the sun and have temperatures less than 100 °C. Fig. 1 illustrates the annual installation area of solar collectors in the period of 1982–2015. During this period, the annual installation area of solar collectors from the year 2000 onwards reached 110,000–120,000 m² because of the subsidy policy implemented by the Taiwan government and several local governments, as shown in Table 1. Notably, the peak value in 2010 corresponds to a local subsidy program that was offered by Kaohsiung city government. From 2000 to 2014, the total area of installed solar collectors was approximately 1.5 million m². If the lifetime of a SWH is assumed to be 15 years, then 0.3 million SWHs are currently in use; the yearly saving is estimated to be 0.101 million kiloliters of oil equivalent, corresponding to a carbon dioxide emission reduction of 0.326 million metric tons. Chang et al. (2013) reported that 93% of SWHs were intended for domestic use and that 7% of systems were intended for commercial or industrial use (e.g., hospitals, motels, swimming pools, and factories). Furthermore, medium- or high-temperature solar thermal systems have a broad scope of application and such systems typically require designs that facilitate sunlight concentration and large solar collector areas. Taiwan is densely populated with high land cost and it is characterized by a maritime climate with excessive suspended particulate matter in the air because of industrial development; therefore, high solar diffusion has affected the utilization of medium- or high-temperature solar thermal systems (Kao and Chang, 2015).

From the historical data, the current subsidy policy does not positively influence the expansion of the solar thermal industry in recent years (Chang et al., 2013). Regarding the future development, traditional SWHs are not ideal for use in metropolitan areas with high-rise buildings because such systems can be mainly installed on townhouses. To increase the domestic use of solar thermal systems, building-integrated solar thermal (BIST) systems should be developed. Photovoltaic/thermal (PV/T) modules are also an alternative. Furthermore, the solar thermal industry should target businesses and industries that require large quantity of heat energy. The results of this study can serve as a reference for the energy bureau in revising the solar thermal subsidy and for other countries in promoting solar thermal energy.

Section snippets

Solar thermal applications

Imposing regulations that require new buildings to employ a certain ratio of renewable energy is a common international development trend (Lau et al., 2012, Timilsina et al., 2012, Pablo-Romero et al., 2013, Abu-Baker et al., 2014). The U.S. Energy Independence and Security Act of 2007 stipulates that all new commercial buildings must reach zero net energy by 2030. From 2009, consumers purchasing SWHs certified by the Solar Rating & Certification Corporation are entitled to a subsidy greater

Building integrated solar thermal, BIST

Architectural type of buildings limits SWHs installation. In Taiwan, domestic SWHs are mostly installed on the flat roof of townhouses. Although the number of households in northern Taiwan (i.e., Taipei City, New Taipei City, and Keelung City) is one-third of the total number of households in Taiwan, the number of SWHs in this region is only 0.89% of the total number of systems installed; this is because the building patterns in this region are mostly apartments or high-rise buildings (Chang et

Conclusions and policy implications

Because of concerns such as climate change and environmental protection, energy savings and reduction of carbon emissions have been emphasized worldwide. To promote solar thermal applications, subsidies of any form can be provided to lower the acquisition cost. Since 2000, Taiwan government's subsidization toward solar thermal systems has led to the effective increase in the total installation area of solar collectors, but long-term subsidization has progressively lost effectiveness and is

Acknowledgements

This work was supported by the Bureau of Energy, Ministry of Economic Affairs (103-D0303), Taiwan, Republic of China. The authors declare no conflict of interest.

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Opinion paperPerspectives for solar thermal applications in Taiwan

Highlights

Abstract

Introduction

Section snippets

Solar thermal applications

Building integrated solar thermal, BIST

Conclusions and policy implications

Acknowledgements

Energy Policy

Energy Policy

Energy Policy

Appl. Energy

J. Wind Eng. Ind. Aerodyn.

Appl. Therm. Eng.

Energy Sustain. Dev.

Technol. Forecast. Social. Chang.

Renew. Sustain. Energy Rev.

Renew. Sustain. Energy Rev.

Renew. Sustain. Energy Rev.

Renew. Sustain. Energy Rev.

Case Studies Thermal Energy

Renew. Sustain. Energy Rev.

Renew. Sustain. Energy Rev.

Opinion paper
Perspectives for solar thermal applications in Taiwan