Approaches to integrating a high penetration of solar PV and CPV onto the electrical grid

The United States has ample potential renewable energy resources, especially in wind and solar having a combined 15,000 Gigawatts of potential capacity [1,2]. For the past 30 years, California has led the nation in promoting and using energy efficiency programs and has led the nation with the most aggressive Renewable Portfolio Standard (RPS) goals. Energy efficiency and demand response programs are key strategies for addressing climate change and meeting AB 32 (California `s 33% RPS law). RPS goals have been adopted by 43 states that require on average 20% of energy delivered to customers by 2020 by from renewable resources [140]. Solar cost reductions, increasing cost of traditional resources, and Renewable Portfolio Standards have created the possibility of significant levels of distributed solar generation being installed on the grid and specifically, the distribution system [127]. Federal law requires grid modernization to enable an increased dependency on variable and distributed energy resources [143]. This means that existing market and grid control systems, based on traditional centralized resources and one-way distributed power flows, require new operational paradigms, systems architectures and market structures. California's utility rate design and the NEM program for rooftop solar will also require future changes. Land use challenges, both local and remote, may lead to new applications of installing solar PV on water. Studies performed by the California Transmission Planning Group (CTPG) have shown the proposed "high potential" transmission upgrades may be insufficient, by themselves, to allow California to meet its 33% RPS goal. Because integrating a high penetration of distributed resources on to the distribution network is evolving with its own unique challenges, a floating water-borne solar PV design is discussed to assist in bridging the gap to assist in meeting RPS goals, energy efficiency goals and the Governor's goal to achieve 12,000MW of distributed generation in California. The floating water-borne PV system is capable of installation on waste water treatment plant (WWT) settling ponds. California has more than 800 WWT plants and estimates predict floating water-borne PV on WWT ponds could potentially generate greater than 1000 MW without the need to build additional transmission