In 20th century, the rapid growth of the US is largely owing to its providing cheap hydrocarbon dominated energy pattern. While the Americans account for 4.8% of the world's population and US’ domestic energy production accounts for 17% of the world total energy production, the US’ energy consumption takes up 29% of the world total, resulting in energy shortage under the energy development strategy [2] . In order to safeguard US’ energy safety, US government attaches greater importance to the renewable energy resources. In 2010, US solar industry grew 34% year on year, with 1.3 million kilowatts put into operation in the fourth quarter [8] . In general, in 2015, renewable energy consumption accounts for 7% of its total energy consumption and the share of solar consumption in renewables takes up 53% with year-on-year growth rate of 60.6%. However, the solar energy capacity is fairly small in total, only 4.7% (3% in 2008) [2] (Figure 1 and Figure 2).

To reduce dependency on traditional energy, US has put forward development plan of gradually increasing the green electricity, which can be achieved through wind power, photovoltaic power and biomass power generation. It is anticipated that photovoltaic power will take up 15% installed capacity increment, with accumulative solar energy installed capacity reaching 36 gigawatts, maintain its leading position in photovoltaic power technology. In the future decade, US will make 15 billion US dollars investment each year, creating 5 million jobs related with renewable energy industry [9] .

The US and European countries put a high value on exploration and exploitation of renewable energy resources with the purpose of reducing dependence on energy imports, reducing pollution and coping with global warming. By 2030, solar power will represent 12% of the total electricity production of the EU. The development and use of solar energy change current business model fundamentally and bring new opportunities and technologies for urban development [10] .

The European Union is one of the leaders in development of renewable energy. According to the BP’s statistics, the EU takes up nearly 42% of the world renewable energy consumption, with the US 23%, China 9%, and Japan 4%. During the last 15 years, EU encourages renewable energy development and takes a wide variety of measures to bring into effect the policy that the EU and each state take responsibility on a two-level basis. When it came to 2000, EU introduced a package energy related measures with its new goal to increase renewable energy production and consumption of total to 20%. Over the 2002-2011 periods, the total renewable energy production increased by 67% in EU, at an annual average of 7.4% (Figure 3).

In the solar energy industry, reduction of solar photovoltaic power cost can be reached by optimizing the production process and technology cycles. For instance, the so-called integration production which is designed and operated in Germany brings down the manufacturing cost about 10% and realized execution control operation and transportation. In 2010, energy companies from UK, Germany, France, Norway, Denmark and Sweden proposed to initiate the same program [11] . Among the EU countries, Germany makes the most prominent progress. The German government is considering making renewable energy a key factor in boosting energy safety and improving economy. In 2004, a special law was passed to promote the use of renewable energy. This act stipulates that network operators should purchase and use the electricity generated by renewable energy and energy companies will be subsidized for producing “clean” electricity by the state. The subsidies will be: 510 euros per MWH by solar power; 100 euros per MWH by biomass power; 90 euros per MWH by wind power; 70 euros per MWH by hydropower. It is EU’s plan that, by 2020 the share of renewable energy consumption will

be raised at least to 20%. The EU has spent almost 3 billion euros on supporting wind power and solar power companies so far. Figure 3 illustrates European solar photovoltaic consumption over the 2000-2015 periods, which sees an obvious upward trend.

Although the technologies are developing rapidly, most renewable energy is of little competitiveness compared with traditional energy. The first factor hindering renewable energy development is government supports on cutting. During economic crisis, the subsidy has become a heavy burden. Currently, the EU has revised the strategy for renewable energy to reduce the amount of subsidy, which will inevitably result in renewable energy use falling dramatically and thus go against previous negotiated goal and standard. The EU will rely on traditional energy imports to keep the economy going [12] .

Restricted by environmental elements, Asian countries take a keen interest in developing renewable energy; Asian takes the first place in the growth rate of renewable energy industry by now. There are several reasons contributing to the fast development of renewables. First, development of renewables will help to mitigate global warming. Second, it will raise energy self-sufficiency rate and help balance the energy diversity. Third, it is a worldwide trend in energy field. However, just like other countries, Asian countries are faced with many severe problems and challenges in the first stage, regarding development of renewable energy as a priority. In developing countries, the main obstacles to the development of renewable energy sources are: high initial investment costs, financing difficulties, low level of technology, lack of information dissemination, limited renewable energy technology suppliers, marketing and distribution inefficiency, lack of financial incentives, lack of institutional framework [5] .

In some countries, such as South Korea, Kazakhstan, Uzbekistan, Turkmenistan, Mongolia, Malaysia, Singapore, renewable energy production accounts for no more than 3% - 5% of the total energy production. That ratio in Russia is 3%, where hydropower plays an important part. Then the share of renewable energy in Pakistan, India, Indonesia and Thailand is 20% - 40%, and North Kore (12%), China (14%) and Cambodia (70%). Renewable energy production in Tajikistan and Kyrgyzstan accounts for respectively 39 and 45% of the total energy production [13] .

Currently, cooperation in the field of renewable energy is increasingly common and deeper among nations. Some Asian countries are developing renewables through development aid. Besides, national leaders work together in formulating policies related with renewable energy, which provides the foundation for rapid development of renewable energy [14] .

At present, although the development of solar energy has entered into economic and technical maturity, it still lacks competitiveness compared with traditional energy resources. However, it is only a matter of time. Over the next 10 years, it is anticipated that renewable energy will cross the break-even point. Traditional energy prices are rising, which will promote the development of renewable energy and increase competitiveness in energy market.

In the past three years, the solar industry has developed rapidly. In the United States, Japan, Germany, China and South Africa, the solar industry is supported with fiscal and financial support and tax incentives. In some countries, due to the unique geographical location and natural conditions, regard the development of solar energy industry as a priority target. Take Kazakhstan as an example, the country is endowed with sufficient solar energy resources. The potential solar energy capacity is estimated about 25 billion kWh per year. About 70% of the days are sunny all year around in Kazakhstan; sunshine time is about 2800 - 3000 hours and of sun radiation at least 19 × 10¹⁹ kcal in its territory. Therefore, the development of solar energy industry is an important factor in achieving sustainable economic development of the country.

The weather condition in Kazakhstanis conducive to the development of solar technology, which can be effectively applied to the national economy. However, in the solar energy market of Kazakhstan, impeded by economic, technological, legal and financial reasons, no large-scale application has been realized. To overcome these obstacles, well-coordinated action is required from all ministries and departments. Methods to overcome the economic obstacles, carbon tax should be levied on the traditional fossil power plant and energy consumption and tax incentives and financial subsidies should be offered to solar energy industry. Technical barriers can be overcome by introducing new energy technologies to increase competitiveness of renewable energy in the energy market, thus promote economic development. Law passed in July 2009 created favorable conditions for “supporting the matching use of renewable energy”, in order to increase the amount of renewable energy used to generate electricity and heat in Kazakhstan [15] .

Kazakhstan will be negotiating the Astana Solar LLP project in the 2017 World Expo, in an attempt to promote the development of solar energy industry, in which Kazatomprom Company has excellent performance [7] . In order to achieve effective project management, Kazakhstan plans to implement joint projects in solar energy projects, and is going to confirm “Russia and Kazakhstan will consider the possibility of establishing joint ventures” and sign memorandum of “road map” before August 1st this year. Kazakh Kazatomprom Company and Qatar Company have signed a document on development of solar energy. According to the agreement, Kazatomprom is becoming a strategic shareholder of Qatar company, and the Kazatomprom is able to expand the industrial chain from raw materials of the solar panels to solar power generation, increasing the existing production capacity [6] .

Nowadays environmental problems are standing out, having posed a serious threat to public health and economic development. In recent years, energy consumption has steadily risen. In response to environmental requirements the international trading system is increasing requirements of energy-consumed “non-green” products. Kazakhstan is a country of top ten energy intensity in the world and emissions of Kazakhstan ranked 17 in the world. In order to tackle environmental problems and realize the transformation, the government approved the “green economy” Action Plan for 2013-2020 in August. In particular, Kazakhstan should carry out industrial waste management plans, revise garbage classification rules to comply with European standards, inspect major industrial landfills, construction of infrastructure and industrial waste treatment; introduce the environmentally-friendly technologies and processes, including integrated treatment technology of persistent organic pollutants and other hazardous wastes; update emission standards (on nitrogen oxides, sulfur oxides, particulate matter, etc.), and develop modern urban solid waste management system. Currently taking “Green growth” as guidelines, Kazakhstan implements ecological protection and restoration project, through the “green” policy, optimize the use of natural resources, and introduces technologies related with renewable energy, energy efficiency to reduce damage to the environment and achieve health sustainable economic development [5] .

KazPV project began at the beginning of this year, Kazakhstan conducts in-depth cooperation with South Africa, Algeria, India, Qatar, the United Arab Emirates, Russia, China and other countries, relevant cooperation including: supply of raw materials, production and sales of products, operation of solar power plants and technical services to complement each other with advantages and achieve a win-win situation.