Fossil fuels, such as coal, oil, and natural gas, are non-renewable energy sources because they are formed from the remains of ancient plants and animals and take millions of years to replenish.

Hydropower is the most widely used renewable energy source worldwide, accounting for about 54% of global renewable electricity generation.

The primary economic benefit of renewable energy is reduced operating costs, as renewable energy sources such as solar and wind do not require fuel to generate electricity.

All of the above are common financing mechanisms for renewable energy projects. Power purchase agreements allow project developers to sell electricity to utilities at a fixed price, green bonds are debt instruments used to finance environmentally friendly projects, and renewable energy certificates represent the environmental benefits of renewable energy generation.

The primary challenge associated with the integration of renewable energy into the electric grid is intermittency, as renewable energy sources such as solar and wind are not always available when electricity is needed.

All of the above technologies are used to store excess electricity generated from renewable energy sources. Batteries store electricity in chemical form, pumped-storage hydroelectricity uses excess electricity to pump water uphill, and compressed air energy storage uses excess electricity to compress air in underground caverns.

All of the above are roles that government policies can play in promoting renewable energy development. Financial incentives, such as tax credits and grants, can reduce the cost of renewable energy projects. Renewable energy targets mandate that a certain percentage of electricity must come from renewable sources. Carbon pricing mechanisms, such as carbon taxes and cap-and-trade systems, increase the cost of carbon emissions, making renewable energy more competitive.

The Levelized Cost of Energy (LCOE) for a renewable energy project is the average cost of electricity generated by the project over its lifetime, including the upfront capital costs, operating and maintenance costs, and the cost of financing.

All of the above are common risks associated with investing in renewable energy projects. Technology risk refers to the risk that the technology used in the project may not perform as expected. Policy risk refers to the risk that government policies may change, making the project less profitable. Market risk refers to the risk that the price of electricity may decline, making the project less profitable.

All of the above are roles that renewable energy can play in achieving energy independence. Reducing reliance on imported energy sources can improve a country's trade balance and reduce its vulnerability to supply disruptions. Creating jobs and economic growth can stimulate the economy and create new opportunities for businesses and workers. Improving energy security can make a country less vulnerable to energy price shocks and geopolitical instability.

All of the above are common challenges associated with the development of renewable energy projects in developing countries. Lack of access to financing can make it difficult for project developers to raise the necessary capital. Lack of technical expertise can make it difficult to design and construct renewable energy projects. Lack of infrastructure can make it difficult to connect renewable energy projects to the grid and transmit electricity to consumers.

All of the above are roles that international cooperation can play in promoting renewable energy development. Sharing technology and expertise can help countries learn from each other and accelerate the development of renewable energy technologies. Providing financial assistance can help developing countries overcome the financial barriers to renewable energy development. Setting global renewable energy targets can create a sense of urgency and encourage countries to take action to develop renewable energy.

The future outlook for renewable energy is positive. Renewable energy is becoming increasingly cost-competitive with fossil fuels, and government policies are increasingly supportive of renewable energy development. As a result, renewable energy is expected to become the dominant source of electricity generation worldwide in the coming decades.

All of the above are challenges that need to be overcome to achieve a global transition to renewable energy. Cost is a challenge because renewable energy technologies are often more expensive than fossil fuel technologies. Intermittency is a challenge because renewable energy sources such as solar and wind are not always available when electricity is needed. Storage is a challenge because there is currently no cost-effective way to store large amounts of electricity from renewable energy sources.

All of the above are benefits of a global transition to renewable energy. Reduced greenhouse gas emissions can help to mitigate climate change. Improved air quality can lead to better health outcomes. Increased energy security can make countries less vulnerable to energy price shocks and geopolitical instability.