Solar Energy Systems - Research

Research: Systems Analysis and Environmental Impact

The North American power grid has been described as the largest and most complex machine that has ever been devised by mankind. Like a drop of water rippling through a pond, a change in one part of the grid, can impact the entire system. The grid must instantaneously respond to any change in electricity loads such as the turning on or off a light bulb. Likewise the grid will respond to any variations in power injections into the system. It is in this realm that systems analysis is used to quantify not only grid impacts on time scales that range from fractions of a second to decades, but also implications for natural resource consumption, financial viability, economics, and the environment. Renewable power resources that have variable and intermittent production levels such as solar are particularly challenging to assess, especially as the penetration of these technologies comprise a significant percentage of supply-side resources.

Since each solar technology has a unique set of properties and attributes, technology impacts on energy, economics, and the environment are not all identical. For example, photovoltaic technologies generate different amounts of electricity based on efficiency levels under different sunlight conditions. Also, some concentrated solar technologies can store a limited amount of thermal energy that can be used to produce electricity after sunset, while other technologies only produce power when the sun is shining. As solar power production fluctuates over time, the grid will instantaneously have an equal but opposite reaction reducing the need for generation from other technologies, most of which are fired by fossil fuels. In general, this reduces depletable fossil-fuel consumption, air emissions, and water consumed by power plants.

The deployment of solar technologies will not only reduce generation from other power sources; it will also lessen the amount of new generating capacity that must be built to replace old generating units that are retired and to satisfy load growth. Estimating the amount of new capacity displaced by solar technologies is a complex process that involves an analysis of technology characterization, location/orientation, meteorological conditions, load profiles, the transmission system topology and the existing inventory of power generators in the system.

Like any electricity generating technology, solar technologies come with a price tag including capital costs, operating and maintenance expenses and grid integration costs. Solar technologies will affect the market price of electricity and consumer electricity bills. In addition to economic and financial costs, there are also environmental cost associated with the production of solar equipment, technology deployment, and land issues. Therefore, it is important that systemic analyses be performed to estimate both the positive and negative consequences of solar energy as it relates to alternative grid development pathways.

Argonne staff have decades of experience in both developing and applying numerous operational, economic, and financial tools to solve diverse energy and environmental systems problems. Using analysis techniques that link process together in a systemic framework, Argonne staff use modeling tools to uncover potential consequences that are beyond our current conceptualization of the problem, unravel complexities and reveal system interactions that would otherwise not have been discovered.

March 2011