# Evaluation of Investments in Wind Energy Projects, under Uncertainty. State of the Art Review
## 1 Introduction  
Approximately 80% of the world's energy demand is met with fossil fuels (IEA, 2017a), causing two thirds of the global emissions of CO\({}_{2}\) ([[https://www.un.org/es/chronicle/article/el-paper-de-los-combustibles-fosiles-en-un-sistema-energetico-sostenible](https://www.un.org/es/chronicle/article/el-paper-de-los-combustibles-fosiles-en-un-sistema-energetico-sostenible)]([https://www.un.org/es/chronicle/article/el-paper-de-los-combustibles-fosiles-en-un-sistema-energetico-sostenible](https://www.un.org/es/chronicle/article/el-paper-de-los-combustibles-fosiles-en-un-sistema-energetico-sostenible)) accessed on 19 June 2021). According to the 2019 report from the International Energy Agency (IEA) (www.eia.gov/aeo accessed on 19 June 2021), world energy consumption is projected to increase by 46.9% in 2050, going from 620 billion BTUs, produced in 2018, to 911 billion BTUs. If the sources of energy were not changed, this would generate a greater demand for fossil fuels, increasing the emission of carbon dioxide (CO\({}_{2}\)) affecting the levels of global warming and climate change, greatly risking the survival of humankind [1]. With the aim of promoting a sustainable future for the planet, global strategies been proposed, such as the 2030 Agenda, adopted by the United Nations General Assembly in September 2015, which included a global goal on sustainable energy [2]. In addition, the Paris agreement (2015) established the aim of keeping the global average temperature below 2 \({}^{\circ}\)C above pre-industrial levels, and to continue efforts to bring it to 1.5 \({}^{\circ}\)C [3]. In 2020, the UN calls for urgent action to achieve zero net greenhouse gas (GHG) emissions by 2050, which involves more than 120 countries, that contribute more than half the global GDP, alongside thousands of companies and investors, cities, regions, and universities. Countries aligned with this goal currently represent two-thirds of the global economy, and 63% of global greenhouse gas emissions. The list includes the United States, the European Union, Japan, South Korea, Canada, South Africa, and China, which have committed to meeting the target by 2060 [4]. Colombia, for its part, seeks to reduce nine million tons of CO\({}_{2}\) by 2030 [5]. Regardless, tackling climate change and the high levels of greenhouse gas emissions continue to be priority problems, meriting urgent solutions on a global scale. This need increases the use of renewable energy sources as a replacement of fossil fuels and, therefore, makes them play an important role in shaping the energy matrix of the future [6; 7; 8; 9; 10]. Within renewable energies, wind energy is one of the fastest growing in the world. From 2011 to 2020, its production capacity increased from 220 GW to 733 GW, 233% [11]. However, to achieve the 2050 goal, annual increases in wind power capacity must reach 160 GW in 2025, and rise to 280 GW by 2030, three times the level of 2020, which would give renewable energies a participation of 60% in the world energy total, with 30% coming from wind and solar energy; meaning that it would require going from an investment of 380 billion dollars in 2020 to 1.6 trillion dollars by 2030, according to the IEA [4]. In addition, the growth and development of wind energy creates new challenges and opportunities due to: (i) a greater competitiveness of the energy sector [12; 13; 14], (ii) the discontinuity that characterizes the generation of wind energy [15; 16], (iii) the need to improve operations and maintenance [17; 18], (iv) better conditions as required by the distribution system and grid integration [19; 20], (v) the need for a wind energy regulation policy [21], and (vi) the environmental impact associated with power generation [22; 23]. The barriers, which prevent a generalized use of wind energy, can be grouped into technological, economic, socio-political, and environmental dimensions, as shown in Table 1[24]. Colombia projects large investments in wind energy generation, so these barriers can be increased.