MODELING ENERGY FLOWS IN FLOATING IN-POND RACEWAYS UTILIZING SOLAR POWER BACK-UP

The In-pond Raceway (IPR) is a novel option for production aquaculture, depending on water moving devices to provide constant flow. Device failure may result in catastrophic fish loss, requiring power backup systems to mitigate risk in case of power outages. Because these systems must be dependable and many suitable locations are remote, off-grid solar photovoltaic (PV) systems with battery storage have been considered since they eliminate need for utility power. Such systems can be hard to size and expensive. This study modeled system requirements using an energy balance to determine whether systems could withstand varying loads based on climatological conditions. Sizing was iterative, with battery storage and panel size increasing until the model predicted continuous power was provided year-round. This study found failure events were clustered over multiple days in winter. Therefore, it determined undersized systems were suitable if there was no stocking in these months. Further work found an integrated generator backup system would decrease necessary system size. Likewise, substitution of continuous motor loadings with variable speed motors operated based on need may further decrease system demand. The presented modelling approach has broad implications for feasibility of IPR systems, providing reduced startup costs and possibilities for greater implementation of this novel technology

Energy Management for a User Interactive Smart Community: A Stackelberg Game Approach

This paper studies a three party energy management problem in a user interactive smart community that consists of a large number of residential units (RUs) with distributed energy resources (DERs), a shared facility controller (SFC) and the main grid. A Stackelberg game is formulated to benefit both the SFC and RUs, in terms of incurred cost and achieved utility respectively, from their energy trading with each other and the grid. The properties of the game are studied and it is shown that there exists a unique Stackelberg equilibrium (SE). A novel algorithm is proposed that can be implemented in a distributed fashion by both RUs and the SFC to reach the SE. The convergence of the algorithm is also proven, and shown to always reach the SE. Numerical examples are used to assess the properties and effectiveness of the proposed scheme.Comment: 6 pages, 4 figure

Feasibility of Using Discriminate Pricing Schemes for Energy Trading in Smart Grid

This paper investigates the feasibility of using a discriminate pricing scheme to offset the inconvenience that is experienced by an energy user (EU) in trading its energy with an energy controller in smart grid. The main objective is to encourage EUs with small distributed energy resources (DERs), or with high sensitivity to their inconvenience, to take part in the energy trading via providing incentive to them with relatively higher payment at the same time as reducing the total cost to the energy controller. The proposed scheme is modeled through a two-stage Stackelberg game that describes the energy trading between a shared facility authority (SFA) and EUs in a smart community. A suitable cost function is proposed for the SFA to leverage the generation of discriminate pricing according to the inconvenience experienced by each EU. It is shown that the game has a unique sub-game perfect equilibrium (SPE), under the certain condition at which the SFA's total cost is minimized, and that each EU receives its best utility according to its associated inconvenience for the given price. A backward induction technique is used to derive a closed form expression for the price function at SPE, and thus the dependency of price on an EU's different decision parameters is explained for the studied system. Numerical examples are provided to show the beneficial properties of the proposed scheme.Comment: 7 pages, 4 figures, 3 tables, conference pape

Udviklingen i departementschefrollen

Med en lidet glorværdig afstikker til Københavns Amt i 90´erne og halvandet år som divisionsdirektør i det daværende Datacentralen som eneste afbræk har jeg været knap 40 år i centraladministrationen, heraf de sidste 15 år som departementschef i Beskæftigelsesministeriet. Det er vel baggrunden for at Administrativ Debat har bedt mig reflektere over udviklingen med fokus på rollen som departementschef