Thomas A. Deetjen

Reduced transmission grid representation using the St. Clair curve applied to the electric reliability council of Texas

This paper applies a grid reduction method that is based on the St. Clair curve to create a transmission approximation of the Electric Reliability Council of Texas (ERCOT, the grid operator of the state of Texas, US) for use in a unit commitment and dispatch UC&D model. Comparison with known transmission limitations suggests that the approximation error might be too great for the approximation method to be used in an UC&D model. This paper discusses the method, its advantages compared to existing work in the field, its limitations and possible improvements for future usage.

Optimizing capacity extensions in power systems: A case study of Bavaria and a comparison to Texas

As the German Energiewende policy enters the latter stages of its goal to dismantle the countrys nuclear power plant fleet, the southern state of Bavaria must decide how it will replace its nuclear generation capacity. This study extends a renewable capacity expansion model that was initially developed to find optimal extensions of wind and solar generation and transmission for Texas, United States. Here, additional options for the development of the Bavarian electricity supply are added: combined-heat-and-power (CHP), improving transmission connections to the non-Bavarian German generator fleet, and constructing new natural gas combined cycle (CCGT) power plants within Bavaria. The models solution suggests that an optimal mix includes 3.5 GW of transmission to the non-Bavarian generator fleet, 6.0 to 9.5 GW of new CCGT capacity, and 8.5 to 10.0 GW of transmission capacity to the on-shore wind resources of the Schleswig-Holstein state in northern Germany, depending on the CO2 price. Compared to the model results for Texas, Bavarias system is less sensitive to a CO2 price in both the optimal system configuration and the resulting emissions. While Texas emissions can be reduced by 55% with a CO2 price increase from 10 to 100

Improving solar-induced grid-level flexibility requirements using residential central utility plants

/ton, the reduction in Bavaria is only 28% with a price increase from 0 to 100 EUR/ton.

Solar PV integration cost variation due to array orientation and geographic location in the Electric Reliability Council of Texas

This study discusses the expansion of an existing central utility plant (CUP) optimization model to analyze the effectiveness of using a residential CUP in Austin, Texas for improving the integration of solar into the grid. The CUP equipment includes a simple-cycle gas turbine (SCGT), battery, chiller plant, and chilled water storage (CHS). The analysis is accomplished by analyzing three sensitivity scenarios. Scenario 1 exposes the CUP to increasingly expensive demand charges. Scenario 2 limits the CUPs allowable ramp rate. Scenario 3 prohibits the CUP from selling electricity and requires it to provide ramping support to counteract the large ramp rates that occur in the net load during the evening when solar production diminishes but load continues to rise. The CUP effectively uses a chiller plant with chilled water storage (CHS) to change its operational behavior and provide grid-support support services. This support is limited, however, as more stringent circumstances require the CUP to invest in expensive SCGT or battery equipment, or to curtail solar generation.