Renewable Energy Test Facility Research Articles

Recent Research and Development Testing Conducted at Ohmsett – The National Oil Spill Response Research and Renewable Energy Test Facility

Abstract 2017-321 The Department of the Interior’s Bureau of Safety and Environmental Enforcement (BSEE) National Oil Spill Response Research and Renewable Energy Test Facility, Ohmsett, plays a critical role in advancing oil spill response capabilities through research, development, testing, and training. Ohmsett’s 10 million liter (l) saltwater wave tank provides an independent venue to conduct research and development with full-size response equipment using real oil, in realistic, repeatable conditions. This paper will discuss recent research and development conducted at Ohmsett, including: Remote sensing of surface oil by BSEE, the National Oceanic and Atmospheric Administration (NOAA), the United States Army, the United States Coast Guard (USCG), and the United States Environmental Protection Agency (U.S. EPA); using acoustics to measure oil slick thickness; creating large volumes of emulsions for Ohmsett tests; mechanical recovery of chemically treated, undispersed oil; skimmer testing in diminishing slick thickness; a USCG and BSEE test of a skimmer ice management system; and an autonomous skimmer development. This paper will summarize the setup and methodology used during recent testing, training, and research conducted at Ohmsett. Reports of BSEE funded oil spill response research can be found at https://www.bsee.gov/site-page/master-list-of-oil-spill-response-research.

EVALUATION OF OLEOPHILIC SKIMMER PERFORMANCE IN DIMINISHING OIL SLICK THICKNESSES

ABSTRACT 2017-086 ASTM F2709-15 “Standard Test Method for Determining a Measured Nameplate Recovery Rate of Stationary Oil Skimmer Systems” has become the standard for testing the performance of stationary skimmers. This standard specifies testing the skimmer in “ideal conditions” in order to measure a skimming system’s maximum performance. These ideal conditions are created by testing the skimmer in calm conditions and allowing the skimmer to recover either in pure oil or in a thick layer of oil on water. When testing the skimmer in oil and water, the skimmer recovers oil in a starting oil thickness of 75mm and continues recovery until the oil thickness reaches 50mm. Performance values obtained from this test include measured nameplate recovery rate (NRR) which is the maximum rate at which the skimmer system can recover and process oil under ideal conditions, and the recovery efficiency (RE) which is the percentage of oil collected to total fluid collected. In actual oil spills it cannot be assumed that a skimmer will encounter enough oil to continuously conduct recovery operations in 50–75mm of oil. As these performance values are becoming a tool used by regulators to verify the capabilities of response equipment listed in oil spill response contingency plans, it is important to understand if and how a skimmer’s performance will vary as oil slick thickness changes. To explore this question, the Bureau of Safety and Environmental Enforcement (BSEE) and Ohmsett - The National Oil Spill Response Research and Renewable Energy Test Facility, recently conducted independent performance testing of two oleophilic skimming systems to better understand the relationship between oil recovery rate, recovery efficiency, and different oil slick thicknesses. Skimmers were tested in various oil slick thicknesses ranging from 75mm down to 6mm at the Ohmsett facility. Skimmers were tested in a type I refined test oil as defined by the ASTM F631-15 “Standard Guide for Collecting Skimmer Performance Data in Controlled Environments.” Testing results suggest that reduced oil thicknesses do indeed have a significant impact on the measured recovery capabilities of a skimmer. This paper outlines the final testing results, and discusses the potential implications of using ASTM F2709-15 performance values in conjunction with various oil spill response planning standards for mechanical oil recovery equipment.

Utilisation of real‐scale renewable energy test facility for validation of generic wind turbine and wind power plant controller models

This article presents an example of application of a modern test facility conceived for experiments regarding the integration of renewable energy in the power system. The capabilities of the test facility are used to validate dynamic simulation models of wind power plants and their controllers. The models are based on standard and generic blocks. The successful validation of events related to the control of active power (control phenomena in <10 Hz range, including frequency control and power oscillation damping) is described, demonstrating the capabilities of the test facility and drawing the track for future work and improvements.

Testing of Oil Recovery Skimmers in Ice at Ohmsett The National Oil Spill Response Research &amp; Renewable Energy Test Facility

ABSTRACT The mechanical recovery of oil in ice-infested water presents unique and difficult clean-up challenges. Ice can impede the movement of spilled oil making it less available for removal by the active components of oil recovery skimmers. Ice and slush that is recovered with oil can jam the skimmer, pump inlets and hoses and can provide an environment for enhanced emulsion formation. Low temperatures increase oil viscosity, further complicating processing and pumping of recovered product. In response to these challenges, the U.S. Department of the Interior's Bureau of Safety and Environmental Enforcement (BSEE) recognized the need for comprehensive programs of testing and research in the area of oil spill response in icy waters. BSEE has supported and sponsored a number of testing and research programs at the Ohmsett facility involving oil in cold water and ice. During the winter of 2013, BSEE sponsored an oil-in-ice spill test at Ohmsett titled Skimmer Tests in Drift Ice: Ice Month 2013 at Ohmsett. The tests involved ten commercially available skimmers that represented a range of skimmer types. Testing was done in the Ohmsett test basin using a controlled test area with fabricated ice. To the best extent possible, test variables such as water temperature, oil characteristics, oil slick thickness, ice coverage and size distribution, and skimmer operations were controlled. Performance determinations were made for oil recovery rate and oil recovery efficiency as per the general principles and guidelines of ASTM F2709. Tabulated results for the same are presented. At lower ice coverage (30% ice), there was no significant mechanical impediment for most skimmers. However, ice can interfere with the flow of oil to the skimmer periodically even in this coverage. At higher ice coverage (70% ice), there was significant impediment to skimming, with most skimmers having dramatically lower rates and efficiencies. It was also observed that with longer exposure to skimming under these conditions, operators became more proficient with regard to recovery performance. This indicates the importance of training and practice for effective skimming operations.

The National Oil Spill Response and Renewable Energy Test Facility

ABSTRACT The American Society of Testing and Materials (ASTM) subcommittee on skimmers recently adopted a standard methodology for measuring I skimmer performance, F 2709 - Standard Test Method for Determining Nameplate Recovery Rate of Stationary Oil Skimmer Systems. Current industry practice allows manufacturers to label skimmers with a nameplate capacity based solely on the skimmer's offload pump capability without regard to the recovery rate as a system. Additionally there is no consideration given to the degradation in recovery performance when pumping fluids with viscosities higher than water. Typically the manufacturer's claimed value is unrealistic when estimating the oil recovery rate (ORR) of a skimming system. Integrating actual performance data into the planning and regulation process is prudent from all perspectives. In the absence of third party data, the United States Coast Guard (USCG) will de-rate a manufacturer's claimed nameplate capacity by 80% or more when calculating the Effective Daily Recovery Capacity (EDRC). The USCG uses EDRC as a key component in rating and regulating the oil spill response capability of responsible parties and oil spill response organizations (OSROs). The ASTM's new skimmer protocol has been used recently at Ohmsett to evaluate four oleophilic skimmers as potential alternatives to the skimmers currently used in Alaska's Prince William Sound (PWS) oil spill response plan. The selected skimmer has undergone a number of modifications with improvements quantified over four additional tests series. This paper focuses on the most recent test of this skimmer, conducted in cold-water conditions using both fresh and weathered Alaska North Slope (ANS) crude oil. During the latest testing, two newly introduced tests were performed: a 24-hour endurance test and a qualitative recovery test in the presence of seaweed.

Herding surfactants to contract and thicken oil spills in pack ice for in situ burning

Abstract In situ burning is an oil spill response option particularly suited to remote, ice-covered waters. The key to effective in situ burning is thick oil slicks. If ice concentrations are high, the ice can limit oil spreading and keep slicks thick enough to burn. In drift ice conditions and open water, oil spills can rapidly spread to become too thin to ignite. Fire-resistant booms can collect and keep slicks thick in open water; however, even light ice conditions make using booms challenging. A multi-year research project was initiated to study oil-herding surfactants as an alternative to booms for thickening slicks in light ice conditions for in situ burning. Small-scale laboratory experiments were completed in 2003 and 2005 to examine the idea of using herding agents to thicken oil slicks among loose pack ice for the purpose of in situ burning. Encouraging results prompted further mid-scale testing in 2006 and 2007 at the US Army Cold Regions Research and Engineering Laboratory (CRREL) in Hanover, NH; at Ohmsett, the National Oil Spill Response Research & Renewable Energy Test Facility in Leonardo, NJ; and, at the Fire Training Grounds in Prudhoe Bay, AK. The non-proprietary hydrocarbon-based herder formulation used in these experiments proved effective in considerably contracting oil slicks in brash and slush ice concentrations of up to 70% coverage. Slicks in excess of 3 mm thick, the minimum required for ignition of weathered crude oil on water, were routinely achieved. Herded slicks were ignited, and burned equally well in both brash and slush ice conditions at air temperatures as low as − 17 °C. The burn efficiencies measured for the herded slicks were only slightly less than the theoretical maximums achievable for equivalent-sized, physically contained slicks on open water. Successful meso-scale field trials of the technique were carried out in the Barents Sea off Svalbard in the spring of 2008 as one facet of a large joint industry project on oil spill response in ice co-ordinated by SINTEF. The larger field experiment involved the release of 630 L of fresh Heidrun crude onto water in a large lead. The free-drifting oil was allowed to spread for 15 min until it was far too thin to ignite (0.4 mm), and then the hydrocarbon-based herder was applied around the slick periphery. The slick contracted and thickened for approximately 10 min at which time the upwind end was ignited. A 9-minute long burn ensued that consumed an estimated 90% of the oil. From 2007 to 2009 experiments were carried out in the laboratory and at CRREL comparing the efficacy of herding agents formulated with silicone-based surfactants, herding agents formulated with second-generation fluorosurfactants, and the hydrocarbon-based herder. The results showed that the fluorosurfactant-based herders did not function better than the hydrocarbon-based herder; however, the new silicone surfactant formulations considerably outperformed the hydrocarbon-based herder. Most recently, experiments were conducted to determine if herding agents could: 1) improve skimming of spilled oil in drift ice; 2) clear oil from salt marshes; and, 3) improve the efficiency of dispersant application operations.