Pecologix Political Ecology Blotter » wind

Where is the ideal location for a US East Coast offshore grid?

A. Cherson — Fri, 30 Mar 2012 14:03:51 +0000

This paper identifies the location of an “ideal” offshore wind energy (OWE) grid on the U.S. East Coast that would (1) provide the highest overall and peak-time summer capacity factor, (2) use bottom-mounted turbine foundations (depth ≤50 m), (3) connect regional transmissions grids from New England to the Mid-Atlantic, and (4) have a smoothed power output, reduced hourly ramp rates and hours of zero power. Hourly, high-resolution mesoscale weather model data from 2006–2010 were used to approximate wind farm output. The offshore grid was located in the waters from Long Island, New York to the Georges Bank, ≈450 km east. Twelve candidate 500 MW wind farms were located randomly throughout that region. Four wind farms (2000 MW total capacity) were selected for their synergistic meteorological characteristics that reduced offshore grid variability. Sites likely to have sea breezes helped increase the grid capacity factor during peak time in the spring and summer months. Sites far offshore, dominated by powerful synoptic-scale storms, were included for their generally higher but more variable power output. By interconnecting all 4 farms via an offshore grid versus 4 individual interconnections, power was smoothed, the no-power events were reduced from 9% to 4%, and the combined capacity factor was 48% (gross). By interconnecting offshore wind energy farms ≈450 km apart, in regions with offshore wind energy resources driven by both synoptic-scale storms and mesoscale sea breezes, substantial reductions in low/no-power hours and hourly ramp rates can be made.

doi: http://dx.doi.org/10.1029/2011GL050659

Quantifying the hurricane risk to offshore wind turbines

A. Cherson — Wed, 22 Feb 2012 02:23:06 +0000

The U.S. Department of Energy has estimated that if the United States is to generate 20% of its electricity from wind, over 50 GW will be required from shallow offshore turbines. Hurricanes are a potential risk to these turbines. Turbine tower buckling has been observed in typhoons, but no offshore wind turbines have yet been built in the United States. We present a probabilistic model to estimate the number of turbines that would be destroyed by hurricanes in an offshore wind farm. We apply this model to estimate the risk to offshore wind farms in four representative locations in the Atlantic and Gulf Coastal waters of the United States. In the most vulnerable areas now being actively considered by developers, nearly half the turbines in a farm are likely to be destroyed in a 20-y period. Reasonable mitigation measures—increasing the design reference wind load, ensuring that the nacelle can be turned into rapidly changing winds, and building most wind plants in the areas with lower risk—can greatly enhance the probability that offshore wind can help to meet the United States’ electricity needs.

doi: http://dx.doi.org/10.1073/pnas.1111769109

Baseload electricity from wind via compressed air energy storage (CAES)

A. Cherson — Fri, 06 Jan 2012 14:44:53 +0000

This study investigates two methods of transforming intermittent wind electricity into firm baseload capacity: (1) using electricity from natural gas combined-cycle (NGCC) power plants and (2) using electricity from compressed air energy storage (CAES) power plants. The two wind models are compared in terms of capital and electricity costs, CO2 emissions, and fuel consumption rates. The findings indicate that the combination of wind and NGCC power plants is the lowest-cost method of transforming wind electricity into firm baseload capacity power supply at current natural gas prices (∼$6/GJ). However, the electricity supplied by wind and CAES power plants becomes economically competitive when the cost of natural gas for electric producers is $10.55/GJ or greater. In addition, the Wind-CAES system has the lowest CO2 emissions (93% and 71% lower than pulverized coal power plants and Wind-NGCC, respectively) and the lowest fuel consumption rates (9 and 4 times lower than pulverized coal power plants and Wind-NGCC, respectively). As such, the large-scale introduction of Wind-CAES systems in the U.S. appears to be the prudent long-term choice once natural gas price volatility, costs, and climate impacts are all considered.

doi:10.1016/j.rser.2011.11.009

The cost of transmission for wind energy in the United States: A review of transmission planning studies

A. Cherson — Tue, 29 Nov 2011 00:19:30 +0000

The total range in transmission costs per kW of wind implicit in the study sample is vast – ranging from $0/kW to over $1500/kW. The median cost of transmission from all scenarios in the sample is $300/kW, roughly 15–20% of the cost of building a wind project. The median cost of transmission is near the upper end of the range implied by two higher-level assessments of transmission required to provide 20% wind electricity in the U.S. by 2030.

doi:10.1016/j.rser.2011.07.131

Windtronics: Blade Tip Power System

A. Cherson — Sat, 19 Nov 2011 00:42:04 +0000

Our wind turbine is a gearless wind turbine that measures just 6 feet (1.8 m) in diameter, weighs 241 lbs (110 kgs) and produces up to 1500 kWh’s per year depending on height and location. Our Wind Turbine’s BTPS perimeter power system and unique design of multi-stage blades allows the system to react quickly to changes in wind speed. This ensures that the maximum wind energy is captured without the typical noise and vibration associated with traditional wind turbines. Our wind turbine has an increased operating span over traditional turbines with a start-up speed as low as 0.5 mph (0.2 m/s), cut in at 3 mph (1.34 m/s), with an auto shut off at 38 mph (17.0 m/s), traditional gearbox turbines require minimum wind speeds of 7.5 mph (3.5 m/s) to cut in and start generating power. Our wind turbine is designed to be installed by a licensed electrician wherever energy is consumed, turning homes and businesses from points of total consumption to distributed energy sources, in a cost effective and efficient manner.

Blade Tip Power System

GIS-based wind farm site selection using spatial multi-criteria analysis (SMCA): Evaluating the case for New York State

A. Cherson — Sat, 23 Jul 2011 16:38:12 +0000

Twenty states plus the District of Columbia now have renewable portfolio standards (RPS) in place that requires a certain percentage of energy to come from renewable sources by a specific year. With renewable energy on the verge of massive growth, much research emphasis is put on enabling the implementation of these technologies. This paper presents a novel method of site selection for wind turbine farms in New York State, based on a spatial cost–revenue optimization. The algorithm used for this is built in ESRI ArcGIS Desktop 9.3.1 software and consists of three stages. The first stage excludes sites that are infeasible for wind turbine farms, based on land use and geological constraints. The second stage identifies the best feasible sites based on the expected net present value from four major cost and revenue categories that are spatially dependent: revenue from generated electricity, costs from access roads, power lines and land clearing. The third stage assesses the ecological impacts on bird and their habitats. The proposed spatial multi-criteria methodology is then implemented in New York State and the results were compared with the locations of existing wind turbine farms. The wind farm site selection tool presented in this paper provides insights into the most feasible sites for a large geographic area based on user inputs, and can assist the planning of wind developers, utilities, ISO’s and State governments in attaining renewable portfolio standards.

doi:10.1016/j.rser.2011.04.010