Solving For Variable Renewable Energy Sources.
Two of the most common forms of variable renewable energy technology that we see being implemented today around the world are wind and solar. For solar it may be solar thermal for heating or for electricity and of course solar photo-voltaic.
Both of these energy sources are unfortunately intermittent or variable in nature.
New technologies coming online like wave, geothermal and bio-mass are not variable but rather can be considered as base load supply. You can count on it to be there 365 days a year, 24/7.
Energy storage is now a very hot area of research and development and it is easy to see why. We are rushing to install wind and solar technologies everywhere that we can which means that the percentage of variable supply is increasing.
Energy storage at the residential, commercial and grid level will allow is move completely to variable renewable energy plus base load renewables, which is where we must go if we are avoid the catastrophe that is global warming.
Most of the research for energy storage is focusing on building better batteries but there is also pumped storage where energy is stored by water at a high elevation, flywheels that store kinetic energy, compressed air storage and super-capacitors.
Advancements in home solar pv products and electricity storage are making it possible for home owners to zero out there energy usage meaning they do not need the grid. Solar shingles or conventional solar pv panels plus electricity storage systems like the Tesla Power-Wall or the Mercedes version or others is a powerful industry changing combination that completely takes the bite out of variable renewable energy tech.
In the mean time we must find ways to manage all of this renewable variable energy on our electricity grids which is the subject of new research from the National Renewable Energy Laboratory.
Models of the U.S. electricity sector are relied upon by sector stakeholders and decision makers, but the recent surge in variable renewable energy (VRE), led a team of modeling experts to examine how these models would represent scenarios with high penetrations of VRE.
Four agencies, including the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL), hosted two workshops that led to a new report where the teams identified areas of importance for modeling VRE, performed experiments to determine key assumptions, and compiled a set of recommendations for future research in this area.
“Having four nationally recognized modeling teams come together to discuss variable renewable energy modeling was tremendously valuable,” said NREL Analyst and Project Lead Wesley Cole.
Through this report, we are able to share what we learned from this collaborative exercise.
Variable Renewable Energy in Long-Term Planning Models: A Multi-Model PerspectivePDF, is a culmination of a collaboration among the capacity expansion modeling teams from the Electric Power Research Institute (EPRI), U.S. Energy Information Administration (EIA), U.S. Environmental Protection Agency (EPA), and NREL. The report shows that improvements made across a diverse group of modeling teams led to more robust representation of VRE technologies. The report also documents differences in modeling methodologies and shows how specific improvements or modeling representations led to better representation of VRE technologies.
For example, the NREL and EIA teams showed how improved temporal resolution leads to more appropriate renewable energy capacity and energy value estimations. The EPRI and EPA teams demonstrated how avoiding improper spatial resolution can lead to more robust system cost estimates.
The report also highlights 15 areas where continued research and development is needed for long-term modeling, including methods for how storage and renewable energy might interact at increased levels of penetration for each technology.
Two workshops were held by these four organizations to evaluate VRE modeling in each organization’s respective capacity expansion model. The workshops covered a wide range of VRE topics, including transmission and VRE resource data, VRE capacity value, dispatch and operational modeling, distributed generation, and temporal and spatial resolution.
The report summarizes the analyses and model “experiments” that were conducted as part of these workshops and explains how each team treats VRE in their respective model. The report also reviews the findings from the two workshops and emphasizes the areas where there is still need for additional research and development on analysis tools to incorporate VRE into long-term planning and decision-making, both for the respective agencies and for other electricity sector stakeholders.
About the Research
NREL is the U.S. Department of Energy’s primary national laboratory for renewable energy and energy efficiency research and development. NREL is operated for the Energy Department by The Alliance for Sustainable Energy, LLC.
Gordon's expertise in the area of industrial energy efficiency and alternative energy. He is an experienced electrical engineer with a Masters degree in Alternative Energy technology. He is the co-founder of several renewable energy media sites including Solar Thermal Magazine.