Reliable and affordable energy supply is the backbone of today’s societies. It comes at a cost, though: Emissions into air, water and soil pollute the environment and cause diseases among humans. For balancing benefits and drawbacks of modern power generation globally, the Ecological Systems Design group at ETH Zürich develops new assessment approaches that combine the large amounts of available data and fill the gaps.

The current research on pollution from power generation covers many important aspects. It quantifies a range of environmental exchanges, investigates the effects of these exchanges in the environment and determines the resulting impacts. One of the main weaknesses of the current research is its lack of a global systems perspective, though. Assessments are limited to certain regions, technologies or circumstances and typically do not allow to link pollution impacts to its root causes. Thus, the system-wide interactions of the energy system and the environment are not captured in detail and it becomes difficult to determine globally optimal solutions.

That is why an on-going project at the chair of Prof. Stefanie Hellweg aims at the systematic closure of this research gap. Currently, the focus of the project is on air and water-related environmental impacts. Air pollution is not only a major issue in terms of climate change, but it is also the main cause for pollution impacts to human health globally. Water, on the other hand, is a scarce resource in some regions of the world and it is indispensable for food production.

The applied methodological framework for studies on these issues is fundamentally similar (shown for the example of air pollution from coal power generation in the figure above). First, it depends on the large-scale collection of technical and operational data for the individual electricity generation sites around the world and may include upstream resource supply. This data is then in a second step combined with detailed mechanistic bottom-up models. These models allow to target operational parameters for improvement measures. In a third step, different kinds of environmental exchanges like water consumption or airborne emissions can be calculated by running the model with its input data. And finally, in a fourth step, model and data are used to derive pollution impacts and point to improvement options.

This general framework has so far been applied to several energy technologies like air pollution from coal power generation, water consumption and heat emissions from thermoelectric power plants or greenhouse gas emissions from hydropower. Up-coming research is about to combine and expand these studies to allow for an extended assessment of pollution from global power generation.

The people involved in this project are ESC member Prof. Stefanie HellwegDr. Stephan Pfister, and Christopher Oberschelp. Prof. Hellweg is head of the Ecological Systems Design group, whose research focus is to model, evaluate and improve the resource efficiency and environmental performance of products and processes, new technologies, and consumption patterns.

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