Analysis of the Use of Thermal Inertia and Cogeneration Optimization for Energy Supply Flexibility

2021
VPP Enerģētika projekts INGRIDO

This report contains results from most of the tasks within WP2. It contains three main chapters – one dealing specifically with the issue of thermal inertia utilization for flexibility improvement, the second devoted to cogeneration plant (CHPP) optimization, and the last one dedicated to DHS modelling issues. The first chapter contains the results of three scientific publications produced in the project. It presents three case studies regarding the use of residential building thermal inertia to optimize the daily operation of CHPPs which both supply the heating demand and participate in a liberalized electricity market. Building thermal properties are modelled in MATLAB Simulink analogous to an RC equivalent circuit, thus allowing the assessment of how changes in heat supply would affect the comfort temperature of residents, while enabling CHPP operators to participate in the electricity market more efficiently both from a technical and economical perspective. Moreover, a methodology is offered for the estimation of flexibility that could be provided by residential buildings. However, the deviations to the resident comfort temperature imposed by flexibility utilization must be compensated fairly from the additional revenue obtained by the cogeneration plants. For this, a game theoretic approach could be suitable for the distribution of the additional profit. The second chapter summarizes results published in two papers of the project. It deals with the optimization of thermal energy storage for CHPP participation in the electricity market and the use of genetic algorithms for CCGT CHPP scheduling also considering gas market situation. The third chapter includes three publications, considering the development of a DHS simulation model, pumped thermal electricity storage integration in DHS, and heating demand forecasting accuracy improvement as ways for increased energy supply efficiency. The last chapter benefits significantly from vast data of heat load timeseries collected from various Latvian DHS during the project. The most important conclusions of the report can be briefly summarized as follows. 1) Multi-apartment residential buildings in Riga have significant thermal inertia, the use of which via remote control devices could notably aid in adjusting CHPP operation to power system needs (under electricity market conditions) and reduce energy production costs. 2) Such a solution, however, calls for the development of a fair benefit sharing approach, which could be based on cooperative game theory and Shapley value. 3) Installing heat storage tanks on small CHPP premises allow to notably improve their loading in the highly efficient cogeneration mode, reducing the utilization of heat-only boilers. 4) Development of an accurate and validated DHS model enables the optimized planning of its development and improved efficiency of its operations. 5) A pumped thermal electrical energy storage integration with DHS scheme has been proposed, which could allow the use of storage for balancing both the electrical and heating energy supply systems. 6) A multiple linear regression-based heat load forecasting approach with modifications for time-of-day is proposed and validated on the actual data from Latvian DHS.

Keywords
siltumapgāde, elektroapgāde, elastīgums

Termālās inerces izmantošana un koģenerācijas optimizācija energoapgādes elastīguma palielināšanai: Valsts pētījumu programma “Enerģētika”, projekts “INGRIDO” VPP-EM-INFRA-2018/1-0006. Rīga: Rīgas Tehniskās universitāte, 2021. 68 p.

Publication language
Latvian (lv)