In recent decades, the welfare of human being is seriously threatened by climate change. As a result, numerous energy regulations have been put in place to encourage the expansion of investments in renewable energy. In this context, open questions remain regarding the impacts that these policies may have on generation expansion planning (GEP). This paper addresses this issue by applying three of the most widely adopted energy strategies, namely quota obligation, feed-in tariffs, and emission trade system, to the GEP problem, resulting in an integrated renewable-conventional generation expansion planning (IRCGEP) model with a properly modified cost function and extra constraints. To achieve this aim, first, the IRCGEP model is solved using general algebraic modeling system from a generation company (GENCO) perspective. Afterward, according to the obtained optimized expansion strategies, the policies impact on the social welfare terms including consumer surplus, GENCO profit, and environmental damages cost are investigated, while they are included on the Bergson-Samuelson social welfare function. Moreover, to assess the financing mechanism effect of the policies on consumer surplus, a suitable attribute known as the "virtual price" is put forth. Numerical studies shed light on the reactions of investment decisions and the social welfare to the energy policies.

The world is on the brink of a significant transformation in the energy sector. Rising concerns about climate change and the depletion of fossil fuel resources have accelerated the transition towards renewable energy sources. This study focuses on examining the global upward trend in adopting renewable technologies such as solar, wind, and hydropower. Findings indicate significant progress in the production and increased share of renewable energy in the global energy mix, attributed in part to domestic and international regulations and commitments to sustainable energy provision, as well as a growing trend in demand. Several critical factors influence this transition, including government support policies, investments, and technological innovations, which play a substantial role in creating economic opportunities, generating employment, and impacting the environment and local communities. However, despite these significant advances, challenges such as financial, technological, regulatory, and policy limitations persist, requiring targeted planning and special attention.

energy plays an active role in sustainable development in Iran, both in the sustainable and the development aspects. This study aims to estimate the nexus of economic growth and the renewable energy in Iran during 1981-2012. We employ the Auto-Regressive Distributed Lag (ARDL) model to estimate a log-linear equation. The results suggest that renewable energy consumption is an insignificant driver to economic growth in Iran, accepting the neutrality hypothesis, despite the significantly corresponding effects of capital and labor force. Although Iran concentrates mainly on the non-renewable energies such as oil and gas, it has a high spare-capacity in the renewable energy field. It can be rooted in the focus of governors on the fossil fuel energies rather than the renewable ones. It leads to the negligible nexus of renewable energy and economic growth. In Iran, renewable energy has a passive role in economic growth both quantitatively and qualitatively. The governors should promote this kind of energy to assign a large part of total energy consumption to it.