a bibliometric analysis based review on wind power … bibliometric analysis based review on wind...

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A bibliometric analysis based review on wind

power price

2016-02-14

Mei Sun

Center for Energy Development and Environmental Protection, Jiangsu University

Authors: Cuixia Gao1, Mei Sun*,1, Yong Geng*,2, Rui Wu3,4

1 Center for Energy Development and Environmental Protection, Jiangsu University, Zhenjiang, China 2 School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai, China 3 Key Lab of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Shenyang, China 4 University of Chinese Academy of Sciences, Beijing, China

Outline

Background 1

Data and methods 2

Results and discussions 3

Looking forward 4

Conclusions 5

Background

Renewable power generation has been globally promoted.

With the increasing negative effects of fossil fuel combustion on the environment in addition to

limited stock of fossil fuel, many countries have paid more attention on supporting environmentally

friendly energy generation, particularly for solar power and wind power.

1

Among all the renewable energy

sources, wind power experienced

the fast increase.

The wind power capacity at the

end of 2014 was 369.6GW,

representing cumulative market

growth of more than 16%, which is

lower than the average growth rate

over the last 19 years (1996-2014) of

almost 25%.

Fig. 1. Global annual new added installed capacity of wind

generation (MW) during 1997-2014.

Background

By the end of 2014, Six countries had more than 10,000MW of installed capacity.

1

Background

However, the rapid development of wind power also faces a problem, namely

relatively higher price, which is now one of the main barriers affecting further

development of wind power industry. Consequently, how to establish a reasonable pricing

mechanism has become an urgent problem.

Wind power price (WPP) mechanisms can be mainly divided into three categories in the

world.

• Fixed price, implemented in Germany, Denmark, Portugal and Spain.

• Tender price, implemented in the United Kingdom, Canada, Ireland, and France. This

means that the lowest price will win through the project bidding according to the

government’s plan of wind power installation capacity.

• Renewable energy quota system, implemented in Japan. It is an indirect measure to

support wind power which requires remaining a certain percentage of renewable energy in

the total electricity mix.

1

Background

We try to provide a systemic and quantitative image about the evolution of

WPP related studies. All the relevant researchers can better understand the research

progresses and hotpots, so that they can identify the appropriate directions for their

future study.

1

Data and methods

Scopus provides a comprehensive and standardized exporting data and has been widely

used by academia.

The keywords “wind power price” and “wind electricity price” were used to search the

related publications published during the period of 1997 to 2014.

As a result, 2359 publications were obtained. Of all publications retrieved from Scopus,

peer-reviewed research articles account for 49.08%, followed by conference papers (38.88%),

review papers (4.3%), and others (e.g. book chapter, conference reviews, notes, short surveys,

business articles, articles in press, books, letters and reports). Similarly, English (92.65%) is the

most frequently used language for such a search, followed by Chinese (2.97%), German

(2.49%) and others.

In order to provide an international perspective, only research articles, conference papers

and review papers published in English are further analyzed. Finally, a total of 1994 documents

were found that related to WPP.

2

Data:

Data and methods

Network analysis serves as a lens on the

insights underlying a network of nodes and links

through which information or social relationships

travel.

Here, network analysis is conducted in order

to establish a network with the nodes that

represented articles, keywords, or countries. Such a

network can help evaluate the importance and

influence of a node by measuring the centrality of

the nodes.

Among various software tools, Gephi is used

frequently for the visualization of networks.

2

Methods:

Social network analysis——Gephi Bioliometric——Bibexcel

Bibexcel is another software tool to

perform bibliometric and network analysis.

Here, the complex network analysis is

undertaken to analyze the academic

collaboration among different countries and

articles using Bibexcel combining with

Gephi.

• Persson, O., R. Danell, and J. Wiborg Schneider. How to use Bibexcel for various types of bibliometric analysis. In

celebrating scholarly communication studies: A festschrift for Olle Person at his 60th birthday. Copenhagen: ISSI. 2009.

• Darvish H. The impact of the latent semantic analysis on science and technology: a bibliometric analysis. In: Proceedings of

the 12th world multi-conference on systems, cybernetics and informatics 2008; 5: 224-28.

3

3.1 Analysis of review publications

Results and discussions

Among 1994 publications, 91 papers are review papers, accounting for 4.3% of the total.

The majority of review papers were published in Renewable and Sustainable Energy Reviews

(with an amount of 36 papers), accounting for 40% of the total amount of such papers. The rest 51

papers were published in 45 kinds of different journals.

Most review papers focus on renewable energy price and policies. For example, Salo and Syri

reviewed the existing knowledge of offshore wind costs in Finland and obtained a reasonable tariff

price of 115 €/MWh which is higher than the current price level (83.5 €/MWh). Zhao et al. reviewed

the costs and benefits of renewable energy power subsidy in China; Ahmed reviewed the production

costs of electricity combined with wind power density to estimate the price of each kWh electricity

from the wind farms in Egypt.

However, no review papers provide a holistic and quantitative overview on WPP related

publications by means of bibliometric analysis and complex network analysis.

3

3.2 The performances of related publications


Fig. 2. Numbers of NO, TC and ACPP during the period of 1997-2014.

Note: Countries in blue, green and red respectively correspond to the annual first, second and third largest published

countries.

• The articles published in the last 9 years accounted for 91% of the total published articles.

• The annual top 3 largest publication countries include the U.S., Denmark, United Kingdom, Germany,

Australia, Iran, Greece, Spain, Sweden, Norway, India, Italy, Iceland, Japan, Netherlands, Canada, and China.

• The NO experienced two substantial increases in 2006 and 2012 due to the meeting of G7 countries and a

wide adjustments of renewable energy policies, respectively.

NO: number of articles

TC: total citations of articles

ACPP: average citations per year per article

3

3.3 Journal’s performances


Table 1 The top 20 journals or related conferences.

Journals/Conferences TP 2 % 3 IF 4

Energy Policy 144 7.25 2.575

Renewable and Sustainable Energy Reviews 65 3.27 5.901

Renewable Energy 60 3.02 3.476

IEEE Transactions on Power Systems 51 2.57 2.814

Energy 47 2.37 4.844

Applied Energy 35 1.76 5.613

IEEE Power and Energy Society General Meeting, PES 2012 1 24 1.21 -

Energy Economics 24 1.21 2.708

IEEE Transactions on Sustainable Energy 20 1.01 3.656

Power 20 1.01 0.048

IEEE Transactions on Smart Grid 18 0.91 4.252

European Wind Energy Conference and Exhibition, EWEC 2010 1 16 0.81 -


International Journal of Hydrogen Energy 15 0.75 3.313


Energy Conversion and Management 15 0.75 4.380

Wind Engineering 15 0.75 1.414

International Journal of Electrical Power and Energy Systems 12 0.60 3.432

IET Renewable Power Generation 12 0.60 1.904

Electric Power Systems Research 11 0.55 1.749 1 Conferences or Meetings organized for specific research issues. 2 The total publications in that journal during 1997-2014. 3 The percentage of the related publications in that journal. 4 The journal’s impact factor for 2014.

All the searched 1994

articles were published in a

total of 857 journals (or

conferences).

It indicates the breadth of

publication distributions as

well as the broad interests on

WPP related research from

various perspectives.

Energy Policy is the most

influential journal with a

number of 144 (7.25%)

articles.

The top academic

conference related with WPP

is the international

conference of IEEE Power

and Energy Society

General Meeting (PES).

3

3.4 Countries’ characteristics


Fig. 3. The top 15 most productive countries.

The number of publications for

one country reflects their attentions and

overall strengths in the related research

fields.

The top 15 countries published a total of

1343 articles, accounting for 74.69% of

the total publications.

3

3.4 Countries’ characteristics


Fig. 4. The academic collaborative relationships

among 49 countries.

The top 10 countries with more collaboration are

the US, United Kingdom, Germany, Spain,

Canada, China, Australia, Norway and

Netherlands.

The US scholars have published most cooperative

publications with their partners in China, UK,

Canada, Netherlands, Denmark and Australia.

Major European countries, including Germany,

UK, Denmark, Spain, have more mutual

collaboration due to their geographical and culture

proximity and active promotion of wind power.

China is the top 1 Asian country in this field and

the Chinese scholars have more collaboration

activities with the US, UK, Australia, Hong Kong

(as one region), and Singapore.

3

3.5 Institutions’ performances


Table 2 The top 15 most productive institutions on WPP during the period of 1997-2014.

Rank Institutions Country Articles

1 Technical University of Denmark Denmark 42

2 North China Electric Power University China 26

3 Islamic Azad University Iran 26

4 Aalborg University Denmark 26

5 Carnegie Mellon University USA 23

6 IEEE - 23

7 National Renewable Energy Laboratory USA 22

8 University of Waterloo Canada 18

9 Stanford University USA 16

10 University of California USA 16

11 Argonne National Laboratory USA 16

12 Cornell University USA 16

13 University College Dublin Ireland 16

14 University of New South Wales Australia 15

15 Norwegian University of Science and Technology Norway 15

6 institutions locate in the US.

Technical University of Denmark

ranked the 1st since Denmark is the No.1

country in terms of the share of wind

power in the overall energy supply.

The North China Electric Power

University is the only one from China

although it is the second productive

institution in the world.

Only one institution is from Iran, namely,

Islamic Azad University, indicating that

the developing world still need to further

support the related studies.

3

3.6 The most cited articles


The citation counts for most

high quality papers reached the

peak within five years of their

publication, mainly due to fast

academic development.

The second most cited articles

are more relevant with WPP

than the most cited articles

according to the keywords.

The most cited articles focus on

WPP more from the perspective

of renewable electricity, while

the second most cited articles

focus on the cost-benefit

analysis of wind power.

3

3.6. The most cited articles


The top 2 most cited articles related with WPP in each year are illustrated. However, these

articles do not have complete representativeness.

For example, the citation counts of the first most cited article published in 2000 was less than

that of the third most cited article published in 2009.

Thus, a further analysis for the top 60 articles (their citation counts over 65) during 1997-2014

is necessary. The top 60 cited articles can touch the heart of WPP while the co-citing intensity reflect

their relationships between each other. Co-citing intensity between two articles is represented by the

number of same references. The more same references of two articles, the more similar their

research contents are.

Meanwhile, it has been observed that many real networks exhibit a concentration of links

within certain groups of nodes called communities (or clusters). The detection of the community

structure of a given network could help discover some hidden features of its topological

architecture.

3

3.6. The most cited articles


Community 2Cost; Risk; Policy

Community 3Integration; Storage;

Management

Community 4Energy Security;

Sustainability

Community 1Hybrid Energy System;

Modeling; Optimization

Fig. 7. The academic co-citing network among top 60 cited articles during 1997-2014.

Note: The node size is determined by that article’s total citations. The line between two

articles means that they have at least one same reference. The thicker the line is, the

stronger the correlation is.

There are 4 communities in

the academic co-citing network

according to their co-citing

intensity relationships.

There are obvious disparity in

the research field.

However, the researches on

WPP cannot leave cost, risk,

carbon emission reduction and

environmental efficiency,

which is a comprehensive

background. A hybrid model

considering various factors is

needed.

3

3.7. Research hot point analysis


Keywords’ performances

Subject 1

Subject 2

Method

Field

Purpose

Renewable Energy, 295

Electricity, 226

Solar Energy/PV, 111

Hydrogen, 53

Hydro,Huclear,Biomass, 42

Wind Energy, 224

Wind Power, 286

Wind Turbine, 73

Wind Farm, 31

Offshore Wind, 30

Energy Storage, 110

Economics, 99

Risk/Uncertainty, 86

Climate Change, 85

Electricity Price, 117

Bidding Strategy, 39

Real Time Pricing, 29

Locational Marginal

Price, 29

Feed-in Tariff, 22

Energy Security, 18 Sustainable

Development, 15

Energy Efficiency, 14

Energy Policy, 45

Environmental Policy, 27

Optimization, 162

Programming, 59

Forecasting, 51

Simulation, 46 Others, 172

Day-ahead

Electricity Market,

84

Distributed

Generation, 77

Demand Response,

65

Wind Power

Integration, 63

Smart Grid, 44

Micro Grid, 39

Electric Vehicles, 44

Fig. 9. Distributions of keywords.

Subject 1 refers to different types of

energy resource, including renewable

energy, electricity, wind energy, solar

energy and hydro energy.

Subject 2 refers to electricity market types,

including distributed power generation,

smart grid, demand response, small scaled

grid, electric vehicles , wind power

integration and day-ahead electricity

market

It demonstrates that WPP research adopts

several mainstream methods, and novel or

hybrid models are needed.

The subject of price mainly focuses on

electricity price while keywords bidding

strategy, real time pricing, and feed-in

tariff occupy have less frequency of

occurrence. However, it is inadequate with

the emerging of smart grid in new energy

policy. So, the research of wind grid-

connected for improving absorptive

capacity of wind power makes sense.

3

3.7. Research hot point analysis


Keywords’ performances

Fig. 8. The power distribution between the frequencies and ranks of keywords.

The frequency of author

keywords and their ranks follow

the power law distribution. It

is clear that most keywords

were seldom used and several

keywords were frequently used.

2599 keywords only appeared

once, accounting for 77.37% of

the entire 3359 keywords.

However, the top 4 (0.12%)

most used keywords appeared

950 times

Other keywords appeared more

than 50 times include day-ahead

electricity market, optimization,

wind turbine, energy storage,

demand response and electric

vehicles.

4 Looking forward

First, changes in the international renewable energy policy determine direction and depth

of WPP research.

Since 2011, countries with wide application of wind power, such as Germany, the

US, France, UK, Denmark, and China have signed a series of renewable energy policies,

such as renewable energy act, key funding for renewable energy investment plan, and the

renewable energy roadmap, which proposed the future requirements for smart grid,

technologies, wind power grid-connected and offshore wind in the future. Because, the

rapid development of smart grid technologies provide a seamless and excellent technical

support for wind grid-connected. It becomes a hot issue that how to solve the deviation

between frequency and voltage caused by wind power output fluctuation in a more secure

grid-connected way. Overall, future research on WPP should focus on large-scale wind

energy generation and smart grid access technology to break through its intermittent. In

the meantime, establishing a market-oriented pricing mechanism for wind power grid-

connected and incentives policies simultaneously, promotes clean energy transformation.

In addition, considering the regulation among hydropower, thermal power and wind

power in the area of wind energy generation, and establishing wind power-hydropower

complementary system and wind power-solar power complementary system are

significant for wind power consumption.

4

Second, offshore wind power has enormous potential.

As for the weakness of unbalanced wind resource distribution, large land occupation,

and generating volatility on onshore wind energy, offshore wind power developed

rapidly for its avoiding these shortcomings. The development of offshore wind power

has become the consensus of the world. But the output on offshore wind is less

according to the distribution of keywords in Fig.9. Research on wind power for

technology advances, changes in project cost, price level, market access and feed-in

tariff have great potential.

Third, China’s wind power industry drives global growth.

During 2012-2013, China’s wind power downturn, inevitably, the global wind power

grew slowly. In the year of 2014, the global wind market recovered along with the

historical high of China’s wind power installed capacity. And, the global wind power

development broke out of its slump driven by China’s wind power. Thus, It becomes a

hot issue of research on China’s wind energy generation technology, feed-in tariff,

subsidy, big data analysis and internet of energy.

Looking forward

4

Fourth, strengthen the technology exchanges and cooperation among countries.

The academic cooperative literatures research on WPP is currently limited on the

US. The cooperation between other countries, such as China, Denmark, Germany,

Spain, UK and Japan, is significance for promoting their wind power development.

Fifth, integration and innovation on research methods.

Based on the results above, optimization, dynamic planning and forecasting are the

main methods on WPP. Innovation and combination of various methods, including

considering capital cost, risk assessment, carbon emission reduction and

environmental efficiency is needed.

Looking forward

Conclusions

With fast development of wind power, more academic efforts have been

made in the field of WPP recently. Under such a circumstance, it is critical to

review the most recent progress on WPP related studies.

Based on bibliometric analysis, this study presents the current

development status of WPP through content analysis involving countries,

affiliations, the most cited articles and keywords. It provides a comprehensive

review on WPP and points out future research directions.

5

Conclusions

Overall, this study could help understand the past trajectory of wind

power price research, and how the world/nations are contributing to this

research field. Combined with knowledge from experienced researchers, this

study could help them identify research gaps in the current research as well as

help guide them in establishing future research directions including integration

and innovation on research methods, strengthen the technology exchanges

and cooperation among countries, and a comprehensive study on offshore

wind power pricing, wind power grid-connected, feed-in tariff and big data

analysis.

5

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a bibliometric analysis based review on wind power … bibliometric analysis based review on wind...

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