Events :: Workshops

Workshop on Energy Storage for Intermittent Renewable Energy Sources

 

 

Embassy Suites, Santa Clara, CA
April 29-30, 2010

About the Event

The Center for Sustainable Energy and Storage Systems (CenSEPS) in the Jack Baskin School of Engineering at UCSC and our partners hosted a two-day workshop focused on “Energy Storage Systems for Intermittent Renewable Energy Sources”. The workshop was held on April 29,30, 2010 at the Embassy Suites Hotel in Santa Clara, California.

This workshop concentrated on aspects of energy storage in the context of being able to deal with the impact of increased use of intermittent renewable energy sources. The workshop covered varying topics such as materials issues for energy storage devices (fuel cells, batteries, etc.), virtual storage systems, microgrids and storage technologies in general as they pertained to the integration of renewable energy sources to the grid. The workshop intent was to bring together researchers and practitioners from the various storage disciplines to discuss common problems and consider the needs to be addressed in order to promote an increased implementation of renewable energy sources in our energy portfolio.

Finally, it was the intent of the workshop to develop collaborations for the future.

Agenda

You can click on a speaker's name to download their presentation file.

Thursday April 29, 2010

Friday, April 30, 2010

Summary of Workshop

The aim of the workshop was to provide a venue for discussion between practitioners and researchers. Thus, there were presentations about different materials systems for advanced storage technologies that were more than a decade away from practical viability as well as presentations about those systems that may prove viable within the next five years. In addition, several presentations were concerned with system optimization using existing technologies, realizing that the existing technologies were far from optimal.

Deepak Srivistava gave a broad review of battery technology and defined the various regimes of energy storage (for power quality [<seconds], for power bridging[minutes] and for energy management [hours]). He discussed existing technologies such as Li ion batteries and those that are much further down the line such as Li air batteries, and noted that the energy density of existing systems is doubling about every 2-3 years, with no real sign of leveling off. So there appears to be room for improvement. Bin Chen gave an overview of using piezoelectric materials for energy harvesting from low frequency vibrations. Chris Guzy gave an overview of practical fuel cell systems, in particular those based upon hydrogen and noted that 40% of the cost of such systems was in the hydrolyser. He also discussed the misperception of safety issues when it comes to storing hydrogen. Also noted was the fact that fuel cells need high voltage and low current inverters, rather than the existing high voltage, high current inverters that are currently available.

In the next session on materials for storage, Vitalie Stavila discussed efforts at Sandia to develop a hydrogen storage system based upon metal hydrides and noted one of the rationales for this approach was that the hydrides took up four times less volume than compressed hydrogen gas systems. One of the big issues is reversibility and whether a system can be found that is stable at room temperature and does not take too high a temperature to decompose. The other issue is whether such a system can be produced at a reasonable cost. Yiping Zhao discussed novel deposition techniques for creating Mg/V nanostructures, which would allow for large hydrogen incorporation with minimal stress/strain in the manufacturing process.

In the session on emerging technologies, Preben Nyeng discussed new techniques for shifting energy use in time, by load rescheduling. He presented an interesting case in demonstration projects of delaying power demand as a way of getting virtual energy storage. John Rivera presented results of a novel bioreactor process that could produce a biofuel with twice the efficiency of natural gas.

Robert Jones discussed practical aspects of combining small turbine systems with storage technologies. He noted that hydrogen cannot be used in traditional gas turbines, so significant development is needed to be able to use hydrogen as turbine fuel. Finally, Jamie Patterson gave a broad overview of various storage technologies under investigation in order to meet the state of California energy goals by 2020. He described the different storage needs for the various components of power delivery from generation, to transmission, to distribution and final use. He pointed out that for energy storage to be viable (vis a vis cost), it must have multiple uses. But, regulations require that a storage system have only one use, i.e., generation or transmission, but not both. Thus, existing regulations seem to prevent the development of cost-effective energy storage systems.

In the last session of the day on applications, Claus Rasmussen described the Danish goal of 50% of the energy in Denmark coming from the wind by the next decade. He gave an overview of wind systems in Denmark and defined the storage needs for wind systems as needing capacity for 15 minutes to 4 hours. He presented a wide range of modeling results to guide the next generation of wind installations in Denmark.  Henrik Binder described the microgrid system at RISO/DTU that includes wind, photovoltaic, fuel cells and vanadium flow batteries. His presentation described the advantages and disadvantages of their initial system.  Joel Kubby presented preliminary results of the microgrid system being developed by UCSC at NASA-Ames consisting of a photovoltaic array coupled with a small wind turbine and an electric car as the storage device. He described the project as being an offshoot of a project in the California-Denmark Summer School in Renewable Energy of the previous year. Finally, David Martin described real world storage issues. He emphasized the need to develop better methods of storing hydrogen if hydrogen fuel cells are ever to become practical.

On the second day, Preben Jorgensen gave an overview of the  various programs of the Danish Council for Strategic Research with the emphasis on those relevant to the energy storage/renewable energy sector. This led to a discussion on various ways to increase collaboration between countries. The discussion centered upon various ways in which one might develop joint projects, which could exchange student/researchers across various institutions. Some of these included, for example; six-month internships, joint proposals to multinational funding agencies for real project based collaboration.

The broad range of presentations in this workshop dealt both with direct storage (e.g., batteries, fuel cells, etc.) to indirect storage (e.g., smart techniques). What became obvious through the workshop was that there is not one set of storage needs but many. In discussing the different storage technologies, the point was also brought up that the community does not do a good  job at alleviating the public perception of some of the risks of particular storage technologies, e.g. Hydrogen. Comparisons of risk associated with these new technologies should be compared with existing methods of energy storage.

In addition, there appeared to be a tendency of the various storage research communities to work somewhat in isolation of one another. In fact, on the second day of the workshop there were pleas from several speakers and participants for a better means of communication/collaboration between the storage research communities.  It was deemed important to bring the practitioners and researchers closer together and to bring together the proponents of various technologies so as to get a better handle on the long-term solution of "energy storage".

Photos

 

Event Sponsors

Aalborg University

Citris

Technical University of Denmark

Innovation Center Denmark

UC Davis

UC Merced

Center for Sustainable Energy and Storage Systems