TECHNOLOGY AREAS: Ground/Sea Vehicles, Materials/Processes

ACQUISITION PROGRAM: DASN-Energy and Commander Naval Installation Command/Naval Facilities

OBJECTIVE: Develop new affordable energy storage systems to increase grid security, facilitate micro-grid development, and increase use of renewable energy technologies at shore-based facilities and for forward operating bases.

DESCRIPTION: Power grids can be adversely affected by variable power demands, weather events, accidental damage, and deliberate attack. Furthermore, the transient nature of many renewable energy technologies can cause detrimental fluctuations in power grids that lead to reliability problems. To mitigate these adverse effects, electric power companies are required to maintain spinning reserve to manage the transients imposed by variable demand, local grid damage, and fluctuating renewable energy sources (e.g. wind speeds, cloud cover, ocean wave variability, etc.). Such standby generators are usually fossil fueled and expensive to operate. To reduce the need for standby power and increase grid/micro-grid security, appropriate energy storage technologies can be used to enhance power quality management and provide additional energy capacity to meet power demands when renewable or primary power sources are off-line or inadequate. Such energy storage systems can also augment emergency backup power sources for critical facility infrastructure, thus reducing or eliminating the need for fossil fueled emergency generators.

The key parameters for grid/micro-grid energy storage technologies are power level, stored energy capacity, power and energy densities, capital and lifecycle costs, and cycle and calendar operational life. The time scale required of the technology is very broad (seconds to tens of hours) with corresponding power and energy requirements spanning multiple decades (typically kW-to-MW and kWh-to-MWh, respectively) depending on the grid size and the various power load demands. Such performance characteristics can come from a range of energy storage mechanisms, including electrochemical (e.g. batteries, flow batteries, and electrolyzer/fuel cell combinations) and mechanical (e.g. compressed air, pumped hydro and flywheels); however, the cost to implement many of these technologies is often commercially prohibitive at the required operational scales.

This STTR is focused on providing new energy storage technologies that can ultimately be implemented at affordable prices. Energy storage technologies capable of meeting both power and energy requirements, as described above, are of particular interest; however, consideration will be given to technologies addressing only one aspect of the problem: transient power management or stored energy capacity for extended backup power demand. In all cases, affordability will be considered in the selection process. While power and energy densities will be considered in the selection process, the anticipated cost of a viable technical system will weigh more heavily in the selection process. Only new energy storage technology approaches are desired; therefore, incremental improvements of existing energy storage technologies are not acceptable for this STTR topic.

PHASE I: Demonstrate proof-of-concept of the new energy storage technology at the small unit or component level. Concept demonstration may consist of a bench-scale or larger working unit or the demonstrated performance of key system components at the bench-scale or larger size. Work should include data collection and analysis, concept design of a commercial energy storage system, and cost estimate of an energy storage system employing the new technology on a power grid or micro-grid with 10kW to 100MW power range and with an energy capacity sufficient for up to 24 hours of operation.

PHASE II: Based on Phase I results, a prototype energy storage unit will be design, fabricated and tested at a size sufficient such that performance data collected can be extrapolated to provide an engineering design. Work will consist of data collection and analysis, engineering design of a commercial energy storage system, and refined cost projections for implementation of the energy storage technology on a power grid or micro-grid with 10kW to 100MW power range and with an energy capacity sufficient for 24 hours of operation.

PHASE III: Design and construct an energy storage system and demonstrate full performance at a government facility. The power level and energy storage capacity of the system will be defined at a future date and will depend on the availability and requirements of the designated test site and the performance parameters of the energy storage technology. Prepare performance purchase specifications for Navy use to replicate these systems at other facilities.

PRIVATE SECTOR COMMERCIAL POTENTIAL/DUAL-USE APPLICATIONS: This technology would be attractive for any shore-based facility, building complex, housing community, etc. The technology is required to increase commercial grid security, implement energy efficient commercial micro-grids, and increase commercial penetration of transient renewable energy sources into the main power grid. This technology will be readily adopted by the commercial power and building/construction sector.

REFERENCES:
1. Storage Boosts the Power of Renewable Energy, Lynda O’Malley, York University, World Wide Energy Conference, June 2008

2. Sandia National Laboratories ESS Publications: http://www.sandia.gov/ess/Publications/pubslist.doc

3. Bottling Electricity: Storage as a Strategic Tool for Managing Variability and Capacity Concerns in the Modern Grid: http://www.sandia.gov/ess/About/docs/BottlingElectricity.pdf

4. Study Plan for Critical Renewable Energy Storage Technology (CREST): http://www1.eere.energy.gov/solar/pdfs/crest_study_requirements.pdf

5. An Assessment of Battery and Hydrogen Energy Storage Systems Integrated with Wind Energy Resources in California": http://www.energy.ca.gov/2005publications/CEC-500-2005-136/CEC-500-2005-136

KEYWORDS: Energy Storage; Electochemical; Mechanical Engineering; Grids; Micro-grids; Batteries; Flow Batteries; Fuel Cell; Electrolyzer; Compressed Air; Pumped Hydro; Flywheel

Questions may also be submitted through DoD SBIR/STTR SITIS website.