100 RENEWABLE ENERGY IN NORTH AMERICA AND THE ROLE OF SOLAR PHOTOVOLTAICS

摘要

Renewable energy (RE) has been already viewed as a minor contributor in the final energy mix of North America due to cost and intermittency constraints. However, recent dramatic cost reductions and new initiatives using RE, particularly solar PV and wind energy, as a main energy source for the future energy mix of the world pave the way for enabling this source of energy to become cost competitive and beneficial in comparison to fossil fuels. Other alternatives such as nuclear energy and coal-fired power plants with carbon capture and storage (CCS) cannot play an important role in the future of energy system, mainly due to safety and economic constraints for these technologies. Phasing out nuclear and fossil fuels is still under discussion, however the 'net zero' greenhouse gas emissions agreed at COP21 in Paris clearly guides the pathway towards sustainability. Consequently, RE would be the only trustable energy source towards a clean and sustainable world. In this study, an hourly resolved model has been developed based on linear optimization of energy system parameters under given constraints with a bright perspective of RE power generation and demand for North America. The geographical, technical and economic potential of different types of RE resources in North America, including wind energy, solar PV, hydro, geothermal and biomass energy sources enable the option to build a Super Grid connection between different North American regions' energy resources to achieve synergy effects and make a 100% RE supply possible. The North American region, including the US, Canada and Mexico in this paper, is divided into 20 sub-regions based on their population, demand, area and electricity grid structure. These sub-regions are interconnected by high voltage direct current (HVDC) power lines. The main objective of this paper is to assume a 100% RE-based system for North America in 2030 and to evaluate its results from different perspectives. Four scenarios have been evaluated according to different HVDC transmission grid development levels, including a region-wide, country-wide, area-wide and integrated scenario. The levelized cost of electricity (LCOE) is found to be 63 {EUR}/MWh_(el) in a decentralized scenario. However, it is observed that this amount decreases to 53 {EUR}/MWh_(el) in a more centralized HVDC grid connected scenario. In the integrated scenario, which consists of industrial gas production and reverse osmosis water desalination demand, integration of new sectors provides the system with required flexibility and increases the efficiency of the usage of storage technologies. Therefore, the LCOE declines to 42 {EUR}/MWh_(el) and the total electricity generation is decreased by around 6.6% in the energy system compared to the non-integrated sectors due to higher system efficiency enabled by more flexibility. The results clearly show that a 100% RE-based system is feasible and a real policy option.