In the 21st century, many countries around the world are investing important efforts to reduce greenhouse gas (GHG) emissions in response to climate change, and Korea is one of those. In particular, in 2009 the Korean government decided to contribute on this climate issue by setting a 30% GHG emission reduction target by 2020. In order to achieve this ambitious goal, the Smart Grid technology has been identified as an effective solution.
Taking advantage of the experience gained with the Je-ju Smart Grid test-bench, implemented from 2009 to 2013, the Korea Electric Power Corporation, better known as KEPCO, developed a new energy business model called “Smart Grid Station”.
A Smart Grid Station (SGS) can be considered as an integrated regional-based control center for the optimal management of independent systems, connected with an existing power grid. Thus, the SGS combines the word “smart grid”, a platform to bilaterally exchange power-related information and provide various added-value services, and “station”, meaning the building or place where different services are provided (Fig. 1).
In each building of the SGS, various independent systems, such as renewable energy sources (photovoltaics and/or wind turbine), storage systems, smart devices, heating/cooling facilities, electric vehicle chargers, Distribution Automation Systems (DAS) are integrated together through a centralized Energy Management System (EMS) (Fig. 2).
In order to most efficiently manage a building’s energy consumption, the SGS has independently developed hybrid power conditioning system (PCS) and EMS. The main task of the hybrid PCS is to integrate the photovoltaics, wind and storage systems under the same control unit. The PCS converts the DC energy generated from renewable energy facilities to power the battery and provide AC electricity. It has eight different operation modes and receives orders from the EMS to operate accordingly. Hence, hybrid PCS has both an economic advantage and strong technological features. On the other hand, the EMS monitors and controls all the systems of the SGS components. The ESS charging/discharging algorithm that reflects load patterns also automatically optimizes energy usage, peak load, cooling/heating, etc. It has additional functions, such as energy source trading and load shedding during energy shortages.
In summary, the core functions of the SGS are power monitoring, power consumption analysis and prediction of the energy from renewables and demand, remote control (smart lights, outlets and heating/cooling), peak management (based on PCS scheduling), remote demand and failure management, etc.
After the pilot project of the Smart Grid Station at Guri-Namyangju District Office, KEPCO extended the SGS concept to 29 district offices in 2014. Furthermore, due to the success of the Smart Grid Station project in 2014, KEPCO decided to expand it even further in 2015, with a $13.5 million two-stage installment project of 75 KEPCO new buildings (renewable generation capacity 1.5MW, ESS 4.6MWh), two private corporations, three public institutions and one local governmental organization.
Due to the introduction of the Smart Grid Station, important results and benefits have been observed, as (Fig. 3). Consumers can reduce their electric bills due to a 10% reduction in energy consumption and 5% in peak demand, utilities can save generation, transmission, and distribution related construction costs by due to the reduction of peak demand, Demand Side Management (DSM) and load shedding during uncontrolled service disruptions.
In addition, the government is able to stabilize the supply and demand of energy due to load shedding and also reduce CO2 emissions due to the lower energy consumption. On a national level, the 5% CO2 emissions reduction is also important to responding to climate change. Furthermore, the integration of renewable energy facilities with smart grid technology, technological innovation and commercialization of EMS and PCS, and creating standard operational and procurement procedures to expand the SGS will greatly contribute to vitalizing the smart grid industry and job creation.
In conclusion, the Smart Grid Station is a great advancement in smart grid technology, developing independent hybrid power conditioning and energy management systems able to optimize the production and management of an energy mix between electricity and renewable energy sources. The constant growth of the SGS and large government investments within the last three years validate the technological and economic feasibility of the KEPCO Smart Grid Station project.