Abstract

The present paper proposes a review about the energy conservation method and challenges
faced in China, which is one of the giant country in the world that consume huge amount of
energy through any sources and how they manage its process. Generally, China has entered
the “upper middle-income” stage and its rapid economic growth will promote the process of
urbanization and civilization. One of its energy-intensive which is the byproduct petroleum
refining industry also experienced rapid development and it causes the pollutant emissions
that have dramatically increase as well. Therefore, advisable alternative method to have
sufficient energy sources which are renewable are solar energy, wind energy, and
hydropower. Although the renewable energy sources are easy to be obtained, there are also
challenges that will be faced and method resolution to preserve the energy sources.

Keywords—byproduct; alternative method; challenges

1. Method

1.1 Renewable Energy Resources

Manufacturing of raw materials such as processing of petroleum, cooking and

processing of nuclear are a few example of the most energy-intensive sub-industries in the
country that consume plenty amount of energy and water.[1][2]. Therefore, renewable
energy such as solar and wind also hydropower energy are the most effective and
environment friendly to be used.

1.1.1 Solar Energy

The government aimed to build 21 new on-grid projects to reach an installed capacity
of 300 MW by 2015. For the time being, the government authorized the special
development fund of strategic emerging industry to encourage provincial renewable
energy development. In 2013, the Shubaoxiang solar power plant of the China Three
Gorge New Energy Corporation (CTGNEC) finished phase 1-3 projects. It and was put into
operation with an installed capacity of 30 MW, making it the first grid-connected
Photovoltaic (PV) power plant in Sichuan Province. By the end of 2014, the grid-connected
PV power plant in Sichuan Province had reached 60 MW, which is 20% of the planned
target. Additionally, the Yanbian PV power plant group, which is China’s biggest mountain
project with an installed capacity of 1230 MW, has already been started. After it begins
production, it will help Sichuan become the environment friendly energy demonstration
province. Prior to the distributed PV power projects in Sichuan have got certain
development influenced by incentives from central government. By the end of 2014, the
rooftop project successfully put into operation in Pan Zhihua and Ghuangyuan equalled 10
MW, and the total installed capacity of distributed PV power projects is expert to exceed
15 MW by 2015. By installing solar panel, China will expand renewable and alternative
energy use to ease fuel burdens, implement an effective electrical pricing policy, and take
advantage of the opportunities to optimize its industrial structure in the future[3]. Different
solar PV maximum power point tracking techniques have been comprehensively reviewed
in [9][10].
 Figure. 1 The distribution of solar resources in Sichuan

1.1.2 Wind Energy

With a motivation to enhance environmental performance and promote green

economic development, China has passed legislation and adopted policies in the past few
years to fund wind energy research, to develop wind energy, and to elevate the
contribution of wind in the power generation portfolio. Studies have been conducted to
examine the passage and outcomes of the wind energy policies passed by the central
government with case studies and quantitative regression analyses. Both central and
provincial governments in China have employed various renewable energy policies,
especially wind policies. Studies on provincial policies are relatively rare, and they
primarily draw conclusions from case studies, which are difficult to generalize. While most
of the extant research has paid much attention to the design, implementation, and
effectiveness of the wind energy policy instruments adopted by the central government,
few studies have investigated the nuanced rules, policies, regulations, and subsidies
adopted at the provincial government level. As shown in Yi and Liu [7], provincial policies
are significant drivers of the green energy economy at the local level, and the
implementation of such local policies is instrumental in achieving renewable energy policy
outcomes. Such gaps in extant research call for more serious attention to the role of
provincial wind energy policies in stimulating the deployment of wind energy.
 Figure 2. Geographical distribution of cumulative Installed Wind Capacity in 2012

1.1.3 Hydropower

Water resource is relatively abundant in China with per capita quantity taking up
55.1% of that in the world. It is a clean and renewable energy, as well as a superior energy
source for power generation. Hydropower generation is a kind of potential energy
generation by using endless water flow of rivers and differences in water heads, and is a
physical process of transforming primary energy to electricity. Hydropower is a clean
energy without consuming a single cubic meter of water, causing a single cubic meter of
pollution and producing a single cubic meter of hazard gas and a single kilogram of solid
waste in its power generation process. Furthermore, water resource is a permanent and
renewable energy source so long as water keeps circulating on the earth and rivers are
not dried up. Quantity of electricity obtained from hydropower generation will never lead to
any decrease in the total quantity of water resources. Therefore all countries in the world
give high priority to the development of water energy. Statistics show that there are 24
countries that depend upon hydropower to deliver 90% of their total power supply, such as
Brazil and Norway, and 55 countries with hydropower making up more than 50% of the
total power supply, such as Canada, Switzerland and Sweden. In China, the hydropower
installed capacity accounts for about 24% of the total power capacity with an annual
generation making up 14.8% of the total. However the development of hydropower will
inevitably change original conditions of rivers. More importantly, part of land will be
submerged by reservoirs and local residents have to be relocated. The land area will be
substituted by water area. The change of flow regime will have effect on fishes’ living
environment and sediment accumulated in reservoirs may bring about some unfavorable
effects. For this reason, a scientific and complete assessment system must be established
in the process of hydropower development, so as to make right decisions and take proper
countermeasures [16].

For the traditional electricity generation technology: there are differences in water
consumption among different power generation technologies: fossil fuel power generation
technologies are the biggest water users, nearly equaling that of irrigation in agriculture.
Hydropower power generation also consumes large quantities of water. While renewable
energy technologies have been developed to address energy shortages in many countries,
and are used to improve energy security. In the case of biomass fuels, much water is
consumed during the raw material planting stage, thus the final water use per unit of
energy production is high relative to that of many other renewable energy technologies [8].
Achieving water saving will contribute to reduce energy consumption [11].
Tt
Table 1. Hydropower distribution development in various river basin
2. Challenges

2.1. Solar Energy

2.1.1 Low grid access

The consumption of generated solar power depends to a great extent on the local
electricity demand over a period of time. However, there are two bottlenecks hindering
local renewable power consumption. First, the areas with rich solar resources are under-
developed so that local power demand is not sufficient to meet the economic requirements
of power plants. That is, the solar energy curtailment will become more serious and will
bring a certain loss to power generators. On the other hand, the local electricity supply is
almost completely reliant on the isolated grid. The stability of this grid is not good sufficient
for the intermittent power generation output from solar power plants. Given the long
construction cycle of state grids, the development and utilization model of solar energy in
Western Sichuan Plateau region has become a rising challenge for the Sichuan
government.

2.1.2 Feed in tariff

Chinese firms ventured to fulfil this global demand with support from local and
provincial governments. The local governments provided the firms with incentives such as
low interest loans to purchase equipment, land transfer price refunds, electricity price
refunds and multiple-year corporate tax reductions [5] Compared to conventional power
generation, the construction cost of solar power plants is relatively much higher. Thus, a
reasonable feed-in tariff pricing mechanism is needed to compensate the cost and profit of
solar firms. However, the break-even price varies greatly for different regions due to the
disparity in resource availability and development conditions. For instance, the bidding
price of 13 solar projects in north- west China ranged between 0.729 and 0.990 RMB/kW h
in 2010, while the price in Shanghai, Inner Mongolia, and Ningxia was set at 4 RMB/kW h
in 2008. In order to standardize the electricity market, the National Development and
Reform Commission (NDRC) promulgated a benchmark price policy in 2013. Based on the
solar resource potential and construction cost, all regions in China have been classified
into 3 categories and relative benchmark price will be implemented during the next two
decades. The price which exceeds the local desulfurizing feed-in tariff of coal-fired
generation will be compensated by China's renewable energy development fund.
According the classification, Sichuan belongs to the second category and implements the
price of 0.95 RMB/kW h[4].

2.1.3 Limitations on solar cell technology

Generally, crystalline siliconwafer technology and thin film cell technology are the two
major solar cell technologies in China but both have obvious limitations when applied to
solar power generation in Sichuan Province. National scale, crystalline silicon cells are
mature and have obtained more than 90% of the market share because of their low cost,
high photoelectric transformation efficiency, and less occupied areas.[4] Nevertheless, the
transformation efficiency of crystal- line silicon cells varies greatly when the solar radiation
intensity changes. Transformation efficiency can be heavily reduced, especially in the low
light conditions. Furthermore, the complex weather and changing environment in Sichuan
will bring certain impacts on the operation efficiency of crystalline silicon solar cells. In
comparison, the thin-film cells are handy, flexible, and light sensitive. These characteristics
 are much-needed for distributed power generation systems such as the Building
Integrated Photo- voltaic (BIPV) project. Given the marginal land shortage in Sichuan, thin-
film cell technology is considered as the best option for Sichuan's solar energy
development. Currently, the mature cell technology mainly includes CdTe cells, CIGS
cells, and amorphous silicon [30]. The CdTe cells have exhibited relatively higher growth
during the past decade. However, the technology bottlenecks of photoelectric conversion
efficiency and environmental impact still hinder the wide acceptance of thin-film cells. Take
CdTe cells for instance, the peak conversion efficiency of mass-produced CdTe cells is
12.8% (First Solar, US). This is much lower than that of mass-produced crystalline silicon
cell (20.1%, SunPower, US). Furthermore, Cd is a heavy metal with high toxicity which
could be discharged from the process of production, installation, and disassembly of CdTe
cells. Therefore, there needs to be more R&D for the improvement of transformation
efficiency and the innovation of other types of thin-filmed solar cells.

Solar energy is extremely intermittent and available only during daytimes. The output
power fluctuates due to irradiance variation caused by passing clouds. More importantly,
owing to the deployment of small scale distributed PV systems rather than a centralized
system, the controllability over generating power is limited. Voltage rise, voltage
fluctuation, voltage unbalance and harmonics are major problems created by GCPV
systems, especially small scale rooftop configurations connected to LV distribution
network[6]

2.2 Wind Energy

2.2.1 Poor transportation condition

Unlike eastern and northwestern provinces, mountains and hills make up the main
topography of wind energy resource-rich areas in Sichuan Province. For most
mountainous wind farms, there are no roads that connect to the nearest highway.
Therefore, a vast network of new roads is needed for mountainous wind turbines, which
would greatly increase the construction cost of wind farms. Furthermore, there are large
forest resources distributed in Sichuan's wind power potential areas. The construction of
wind farms and roads will inevitably occupy the forest land. Thus, the corresponding tax
and expense will impose additional construction costs for wind farms. Moreover,
accumulative influence by natural disasters (especially Wenchuan M (subscripts) 8.0
earthquake in 2008 and Lushan M (subscripts) 7.0 earthquake in 2013) [4] has resulted in
highway conditions in some areas that does not satisfy the transportation requirements for
large generation sets (e.g., turbines). Over a certain period, transportation problems will
hinder the wind energy development in Sichuan Province. primarily draw conclusions from
case studies, which are difficult to generalize it . While most of the extant research has
paid much attention to the design, implementation, and effectiveness of the wind energy
policy instruments adopted by the central government, few studies have investigated the
nuanced rules, policies, regulations, and subsidies adopted at the provincial government
level. As shown in Yi and Liu, provincial policies are significant drivers of the green energy
economy at the local level, and the implementation of such local policies is instrumental in
achieving renewable energy policy outcomes. Such gaps in extant research call for more
serious attention to the role of provincial wind energy policies in stimulating the
deployment of wind energy [7].

2.3 Hydropower Energy

2.3.1 The efficiency of pumped storage power station is low

 The construction of pumped storage power station has not achieved the expected
target and the overall operating efficiency is not high. The pumped storage power station is
flexible and economical as a large- scale energy storage device. However, the plant
operation has been affected by overcapacity, thermal power, and other causes of power
peaking in the utilization rate of decreasing storage and affect plant pumping. Therefore,
China's hydropower system can realize an extensive range of resource allocation and
consumption. To face of pumping power station cannot be effectively used, the “13th Five-
Year of power development (2016–2020)" refer to, China will enhance the peaking
capacity of construction, pumping power station will start about 600,00 MW, new
production about 17,000MW during 2016–2020. The installed capacity will reach
400,00MW until 2020[12]

3. Conclusions

The paper provides an approach to realistically assess the progress of Chinese cities
towards green growth. With reference to the worldwide debate regarding responsibilities
and standards of limiting pollutant emissions [13][14]. China is affluent in small
hydropower resources and the exploitation level is still not high. As a result, there is a
huge space for small hydropower development. has obtained great achievement in small
hydropower exploitation in the past 60 years[15]

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