Demand Respond and Algorithm for Energy Management System in Island Mode from Renewable Energy

Abstract

This article suggested about algorithm management for energy management system in Island Mode from renewable energy of operating buildings at Kamphaeng Phet Rajabhat University by relied on Demand Response (DR). The demand response principles are to respond needs in electricity usage between load and energy sources appropriately and reduce energy consumption during the peak period efficiently. This could be resulted in costs reduction for supplying of energy storage as battery in the period. This energy supply is called a triple hybrid system because there required essentially the energy sources from solar, wind and diesel. Building energy management system (BEMS) is to bring information technology (IT) to analyze the electricity usage for planning, supervising and controlling the electricity distribution automatically with electronic controller sets for inner-building loads. The loads consisted of lighting system, steam fans, instructional speaker sets, projectors, computer and refrigerators. According to an analysis of usage load in the buildings, it is found that, in a day, the electricity usage is approximately 12.33 kWh as the average power of 0.51 kW per day. Eight-hour electricity needed periods mostly happened between 8.00 a.m.-12.00 p.m. and  1.00 p.m.-5.00 p.m. that the maximum load usage was 1.06 kW while the least three-hour electricity needed periods observingly happened between 6.00 p.m.-8.00 p.m. and 12.00 p.m. -1.00 p.m. that the minimum load usage was 0.07 kW. Energy supply used from renewable energy sources as solar and wind that was 2.4 and 0.68 kW, respectively along with battery (energy storage). In addition, supplementary of fossil energy was also 2 kW by using diesel engines. In order to distribute electricity for the building loads, energy management of renewable energy sources is somewhat not stable due to the daily weather condition. In case of the more load usage, priority of energy supply was continuously distributed from solar, wind, discharged battery and diesel engine, respectively. On the other hand, In case of the less load, both of solar and wind energy will be charged and supplied into the battery. Nevertheless, a diesel generator will especially operate to supplement in insufficient energy when overloads usage. The expected result might be the energy management system could lead to the reduction of energy consumption from the diesel generator at 5-15%.