Growing population and limited energy resources have impacted energy consumption. Limited fossil fuel resources and increased pollution threaten national and human societies. These elements emphasize energy sources. Renewable energy use affects growth. All new energy sources, including renewables, are crucial for global economic growth. Economic and environmental issues have led to new approaches in international environmental law, including the green economy. This study employs structural vector auto-regression (SVAR) to compare the effects and outcomes of increasing the use of renewable energy in the context of economic growth and greenhouse gas emissions in middle income countries (MICs) and high income countries (HICs). The results show that these indicators demonstrate that the production of energy from renewable sources has positive short-term and long-term economic effects with varying contributions. However, renewable energies have a greater impact on the green economy in selected MICs than in selected HICs. Therefore, the promotion of macroeconomic indicators is viewed as one of the reasons for the development of policies to increase energy production from renewable sources in selected countries.

Compared to a photovoltaic array, a photovoltaic/thermal concentrator module can produce thermal power for various productions in downstream cycles in addition to electrical energy. In this study, the system for the combined production of electricity, heat and cooling based on a photovoltaic/thermal concentrator has been evaluated. In this triple production system, a lithium bromide-water absorption chiller with a cooling capacity of 5 kW was used. In the organic Rankine power generation cycle, the annual exergy rate of the incoming stream was almost 48 MWh, the annual production exergy rate was about 54.4 MWh and the annual exergy destruction rate was ~43.1 MWh. According to the results, the freshwater production rate of the desalination plant was approximately 56.7 m³/year; the lowest month was 3.8 m³ in November.

The main advantages of high-frequency electronic ballasts for high-intensity discharge lamps are high luminous efficacy, small size, lightweight and longer lifetime. This is why high-intensity discharge lamps operating at high frequency are widely used. This paper proposes an approach for designing resonant circuit electronic ballasts controlled by frequency variation for high-intensity discharge lamps. The proposed technique including an AC/DC rectifier, a power factor correction circuit and a DC/AC half bridge inverter. These electronic ballasts offer a wide range of dimming controls and can avoid acoustic resonance. However, under dimming, the electric and photometric characteristics of the lamp change. In order to study these effects under the process of dimming, this work studies the lamp properties by varying both lamp power and operating frequency.