Marc Mueller-Stoffels

Improved frequency regulation in mini-grids with high wind contribution using online genetic algorithm for PID tuning

Mini-grids with high wind contribution tend to be relatively more dynamic and less stable than wind integration in large interconnected grids. This instability is primarily due to frequency fluctuations introduced from highly variable wind generation, multiple single-phase distribution branches with highly unbalanced single-phase loads, large pseudo-instantaneous changes in load, over compensation of reactive power, and lower machine inertias providing less damping. The objective of this research is to investigate the use of a genetic algorithm (GA) based proportional integral derivative (PID) diesel speed controller to improve frequency regulation in standalone high contribution wind-diesel mini-grid systems. A dynamic model of a standalone high contribution wind-diesel system was developed to study frequency regulation under variable wind and load conditions. The results using GA-based PID diesel speed control demonstrate improved frequency regulation as compared to standard diesel speed controls.

Wind power project size and component costs: An Alaska case study

Many communities in Alaska, especially along the coast, have excellent wind resources and serve as ideal laboratories for microgrids around the Arctic and the world. Wind power systems have been installed in a number of locations in Alaska, both in remote areas and along the road system. As more isolated microgrids are developed worldwide, understanding the cost and performance of wind power in these systems is of increased importance. In this review of wind power project sizes and costs in Alaska, the costs per kilowatt for the different components of wind turbine installations generally were found to decrease with increasing sizes. Capacity factors ranged from approximately 10% to 40%, with variability from rated wind speeds, wind turbine heights, and the resolution of the wind power class map. Due to the size of communities in Alaska as well as other factors, turbines installed in Alaska are smaller than the trend in the larger market. Evidence indicates that installing overcapacity wind farms, togethe...

An Alaska case study: Energy storage technologies

In the analysis of energy storage systems (ESSs) in Alaska, the most significant trend in the data considered is the increased variance in costs with time. Thus, more options are now available for ESS with “low cost per kW/high cost per kWu2009h” and vice versa, indicating a greater variety of specialized ESS for targeted applications. The data analyzed do not show any difference in the cost of energy storage in Alaska compared to such costs in the rest of the nation or world. Alaska has had relatively few energy storage technology failures, and most that occurred were caused by improper operation. It is often difficult to justify energy storage economically based on fuel savings alone. Significant work remains to quantify other possible cost savings afforded by energy storage, such as reduced fuel consumption and stress on a diesel generator by smoothing out the load. The lack of standardization and quantification of costs and benefits is the main barrier to determining the economic potential for implementat...

An Alaska case study: Electrical transmission

Electrical transmission lines in Alaska vary from overhead to submarine to underground installations. Analysis indicates that overhead transmission lines are the least expensive to build, ranging from

An Alaska case study: Diesel generator technologies

100u2009000 to

An Alaska case study: Cost estimates for integrating renewable technologies

400u2009000/mile. Cost variability is influenced by pole spacing, pole heights, line ratings, river crossings, and the amount of work on energized power lines. Submarine lines and underground lines are substantially more expensive than overhead lines, ranging from less than

Security-Constrained Design of Isolated Multi-Energy Microgrids

3u2009000u2009000 to more than

Development of kinetic energy storage systems for islanded grids

4u2009500u2009000/mile although there is some uncertainty in the datasets. When broken down by major cost components, the cost category including materials, construction, and installation comprises just over half of the total costs, with remaining costs distributed among the control system, substation, switchyard, road clearance, indirect costs, and contingencies. Operation and maintenance costs range from

Opportunities for Energy Storage to Provide Spinning Reserve in Cordova, Alaska

2800/mile to

The Value of Energy Efficiency in the Anchorage Residential Property Market

4200/mile, with an average of