Evaluation method for the hourly average CO2eq. Intensity of the electricity mix and its application to the demand response of residential heating

This work introduces a generic methodology to determine the hourly average CO _2eq . intensity of the electricity mix of a bidding zone. The proposed method is based on the logic of input-output models and avails the balance between electricity generation and demand. The methodology also takes into account electricity trading between bidding zones and time-varying CO _2eq . intensities of the electricity traded. The paper shows that it is essential to take into account electricity imports and their varying CO _2eq . intensities for the evaluation of the CO _2eq . intensity in Scandinavian bidding zones. Generally, the average CO _2eq . intensity of the Norwegian electricity mix increases during times of electricity imports since the average CO _2eq . intensity is normally low because electricity is mainly generated from hydropower. Among other applications, the CO _2eq . intensity can be used as a penalty signal in predictive controls of building energy systems since ENTSO-E provides 72 h forecasts of electricity generation. Therefore, as a second contribution, the demand response potential for heating a single-family residential building based on the hourly average CO _2eq . intensity of six Scandinavian bidding zones is investigated. Predictive rule-based controls are implemented into a building performance simulation tool (here IDA ICE) to study the influence that the daily fluctuations of the CO _2eq . intensity signal have on the potential overall emission savings. The results show that control strategies based on the CO _2eq . intensity can achieve emission reductions, if daily fluctuations of the CO _2eq . intensity are large enough to compensate for the increased electricity use due to load shifting. Furthermore, the results reveal that price-based control strategies usually lead to increased overall emissions for the Scandinavian bidding zones as the operation is shifted to nighttime, when cheap carbon-intensive electricity is imported from the continental European power grid.