Promotion of building-integrated solar water heaters in urbanized areas in China: Experience, potential, and recommendations
Introduction
The building sector is a significant contributor to energy consumption and carbon emission. In China, building energy (excluding biomass energy in the rural area) was estimated to be approximately 20% of the final energy consumption in 2010 [1], [2]. This percentage is expected to grow [3], driven by rapid urbanization and the desire for better living conditions. The application of renewable energy (RE) in buildings is a promising solution to the conflict between the growing energy demand and environmental protection. Since 2006, the Ministry of Housing and Urban–Rural Development (MoHURD), in co-operation with other authorities, has promoted solar PV installation, solar thermal use, and shallow geothermal energy in buildings [4]. Among these RE sources, solar water heaters (SWHs) and ground-source heat pumps (GSHPs) are not only mature technologies, but are also economically viable for large-scale deployment in buildings.
Water heating is estimated to account for 27% and 14% of the total energy consumed in residential buildings and commercial buildings, respectively [5]. The increasing need for hot water and space heating are the principle driving forces of solar thermal use in China. In the mid- and long-term RE development plan [6] released in 2007, the Chinese government set targets for solar collectors and coal substitution capability of 300 million m2 and 60 million tons of coal equivalent (toce), respectively, to be met by 2020. On the other hand, the worldwide installation of solar collectors by 2020 is expected to reach 1.5 billion m2, including 500 million m2 in the European Union [7], 300 million m2 in the U.S., 80 million m2 in Japan, and 20 million m2 in India[8].
The Chinese government views the building sector as a vital building block in changing the country׳s energy structure. The MoHURD is leading the promotion campaign with two main objectives: an increase in building floor area with building-integrated RE systems and establishment of an infrastructure to support a national deployment. Six years have passed since the start of this promotion campaign, which has consumed billions (RMB) of the national budget. The SWH market has yet to mature. Whether the existing promotion model is sustainable and can support the next level of national deployment remains questionable. Greater challenges lie ahead: a large stock of existing buildings and diversified climatic conditions across the country. Therefore, the objective of this study was to tackle this question by analyzing lessons and experiences learned from these demonstration works and their implications for future promotion. This paper reviews the development of SWH application in urban buildings in China and the MoHURD׳s promotion policies. We summarize the experiences, barriers, SWH potential, and future policy implications based on field studies in the Changjiang River (CJR, also referred to as the Yangtze River) region during 2011.
Section snippets
Development of SWHs in China
Although low in terms of per capita installations, China is the leading country in total solar thermal use. According to the International Energy Agency [9], China installed 60% of the world׳s solar collectors in 2009. Fig. 1 shows the growth of SWH application in China based on several official sources. The National Bureau of Statistics of China has reported growth in total solar collector area in rural regions (mostly residential buildings) since 2000 [10]. The MoHURD has been tracking the
Chinese strategy of RE promotion in buildings
Effective policies for the promotion of RE sources in buildings began in the 11th five-year plan period (2006–2010). Yuan et al. [2] reviewed the development and general policies regarding various RE sources in buildings. Han et al. [16] analyzed the market performance of individual types of SWHs (mostly non-building-integrated systems), focusing on the application in Zhejiang provinces. For building-integrated application of SWHs, greater challenges exist because of the immature market. Thus
Experience and barrier: case studies in the CJR region
To understand how the city and county demonstration program has worked, we conducted field studies by making multiple trips to a number of RE demonstration cities in the CJR region during 2011. We examined the implementation progress of the demonstration tasks, incentive policies, promotion models, and barriers. First-hand data were collected through local authorities׳ reports, questionnaires, documents, and meetings with local officials, developers, project teams, and estate managers.
Energy-savings potential for domestic SWHs
In China, the solar energy in most areas in the CJR region is categorized as “usable” with moderate sunshine duration and solar radiation, which means that utilization of solar energy is economically viable. Based on the recorded weather data in 63 cities across the CJR region [30], [31], the annual solar radiation on a horizontal surface is above 3961 MJ/m2 in 75% of the cities. The solar energy is the most abundant in the west of Sichuan province, followed by Jiangsu and Anhui provinces. The
Policy implications
The coordinating effort of the central government and local governments has produced significant achievements in promoting building-integrated SWHs in the urban building sector. This progress is evident in terms of installed quantities and the establishment of a supporting institutional framework that includes a set of regulations, incentive policies, and technical standards. However, the market is still at an early stage and lacks public participation and private investment. Government support
Implications to other developing countries
Our study shows that the role of government is still critical in the progress of demonstration, even when SWHs are economically feasible. Experiences from other successful countries, such as Cyprus, Israel, Spain and other European countries, also imply that government support is a key factor[41]. Common policies include mandatory regulations and monetary incentives. Compared with other successful countries in Europe or in the Middle East, China enjoys benefits of strong domestic collector
Conclusions and recommendations
This paper reviewed Chinese policy on promoting SWH application in urban buildings and the corresponding experiences in implementing the RE demonstration city program using CJR as a study area. The joint effort of the central government and local governments in promoting the RE demonstration at a city scale has produced noticeable results: a rapid increase in the installations of building-integrated SWHs and the establishment of a supporting policy system at the level of local governments. Some
Acknowledgments
This study was financially supported by the Renewable Energy and Energy Efficiency Partnership (REEEP Grant contract 091122). We thank Fulin Zhang, Xiaolong Xu, and Caixiang Yang for their valuable comments and input.
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