Research Areas

The Technology Assessment group conducts interdisciplinary research in order to support the decision-making processes of its clients as well as all stakeholders involved in the public debate on energy supply options and the requirements of a sustainable development. In order to achieve a comprehensive assessment of both current and future energy systems and scenario mixes, the Technology Assessment group has five main areas of research:
  1. Life Cycle Assessment
  2. Environmental Impact and External Cost Assessment
  3. Internal Cost Analysis
  4. Risk Assessment
  5. Multi-Scenario Modeling
  6. Mobility
  7. Decision Support

Life Cycle Assessment (LCA)

Life Cycle Assessment (LCA) is the method used for quantification of complete environmental burdens of products and services. It takes into account entire value chains of products and services, i.e. manufacturing, use, and end-of-life. The term “environmental burdens” refers to impacts on human health, on ecosystem quality, and on natural resources. We use LCA primarily for comparative evaluation of the environmental performance of technologies for energy supply and transport, e.g. power generation and passenger vehicle technologies. LCA is a key element in our Environmental Impact Assessment and External Costs calculations. We also use LCA within Multi-Criteria Decision Analysis (MCDA) for covering environmental aspects in sustainability assessment and we work on the coupling of LCA and energy economic modeling in collaboration with the energy economics group. Our LCA research is supported and used by industry, administration, as well as in policy for decision support.

Environmental Impact and External Cost Assessment

Polluting activities can cause damage to people, goods, and/or nature. These burdens are often imposed on society and not fully born by the polluter. From the polluter‘s viewpoint, the damages are „external“. In general, an effect on a group of people or the environment that is caused by another group but not fully accounted for by those causing it, is called an externality. Negative externalities are called external costs, and positive externalities are called external benefits. The Impact Pathway Approach (IPA) consists of four steps: 1. Estimation of emissions. 2. Estimation of changes of pollutant concentrations. 3. Estimation of impacts on receptors like humans, animals, plants etc. 4. Valuation. The external cost method uses money in order to value the impacts.

Internal Cost Analysis

Large, complex problems are generally constrained by available resources, with solutions reflecting inherent tradeoffs. Finances are always constrained because cost is how resources are allocated in a market system. This is reflected in the 3 pillars of sustainability, where economics is balanced against environmental and social aspects. Economic metrics include internal costs paid by customers, and external costs paid by society, and their sum, or total cost, is generally calculated by PSI for comparison with multi-criteria rankings. Internal cost is thus a fundamental measure of any technology, although its uncertainty can be very significant for future (and even historic) systems. PSI’s TA group focuses on the net present value of production costs over a technology’s full life cycle, averaged over the same reference measure or unit used for life cycle or risk analysis (e.g. per kWh or person-km). The balance between capital intense technologies and those dominated by operating expenses depends upon their load factor (hours operation per year), lifetime and the assumed interest rate. The data collection of present and future costs is often problematic, with cost scaling of capital costs, consistent forecasts (e.g. fuel costs) across technologies, and a relatively consistent level of optimism across competing technologies being frequent issues of concern. In addition to calculating average net present value cost, marginal costs are generally of key concern for system dispatch or operation. As noted, costs are generally uncertain, and sensitivity analysis is a key part of PSI’s analysis to determine the relative impact of different cost factors and how their variation affects cost. It is a general goal that when possible the cost analysis model will be combined with a physical model of the technology system being analyzed, and the integrated model will provide materials and energy inputs to LCC and risk analysis, provided consistent inputs to multi-scenario modeling and tradeoff and MCDA analysis.

Risk Assessment

Risk assessment is defined as the qualitative or quantitative estimation of a risk posed by a certain hazard (or threat). Since the mid-1990s the Technology Assessment (TA) group built up a strong competence on comparative risk assessment of accidents in the energy sector with possible consequences to human health, environment, economy and society. Based on its Energy-related Severe Accident Database (ENSAD), which concentrates on comprehensively covering severe, energy-related accidents and their technical aspects, the TA group develops and applies risk assessment methods. The final aim of accident risk assessment is twofold., On the one hand in the context of comparative energy technology analysis that contributes to improve safety performance of technologies. On the other hand, it is embedded within the broader context of sustainability and energy security, and through [DecisionSupEN][Multi-Criteria Decision Analysis (MCDA)]] can support complex decision-making processes. Our risk assessment research is strongly based on state-of-the-art scientific approaches, but also aims to provide support and added value to a variety of stakeholders, including authorities, industry, international organizations, NGOs, among others.

Multi-Scenario Modeling

The impacts of complex technological systems, like the energy and transport sectors, depend upon how these systems evolve over time in their physical composition, and also very importantly upon how we choose to operate these systems. The Multi-Scenario Modeling approach analyzes many specific scenarios over time, optimizing the operation of existing and future technologies for the least cost (or some other optimization measure). Each scenario uses a fixed strategy composed of available options (e.g. new technologies, fuel choices, or demand shifts/reductions), combined with uncontrollable uncertainties (e.g. demand growth, fuel prices, or regulatory changes). Strategies for complex, constrained systems concern multiple stakeholders, so no one strategy for expansion and operation is ever optimum, because stakeholders disagree on how to balance conflicting objectives. For this reason, the Multi-Scenario Modeling method may analyze (simulate) several thousand scenarios, calculating many different indicators for multi-criteria assessment. If multi-criteria tradeoff analysis is not adequate to assist stakeholders in selecting their preferred strategies, then the technology assessment group can use multi-criteria decision analysis methods to assist stakeholders in their choices. The MSM method is therefore complementary to the Energy Economic Modeling performed by the EEM group within LEA, which models the full energy sector, optimizing system expansion strategies using a single, least-cost criterion for a limited number of future scenarios. In both cases, the key results used by other Technology Assessment efforts (like [LcaEN][Life Cycle Assessment (LCA)]]) are the total annual production (e.g. GWh of electricity or total vehicle kilometers) by each technology in the system.


The transport sector consumes 35% of total final energy and accounts for 37% of greenhouse gas (GHG) emissions in Switzerland and contributes significantly to fine particle, nitrogen oxide, and many other emissions that are harmful to human and ecosystem health (FSO 2015). The technology assessment group has a strong competence in the environmental and economic assessment of current and potential future transport technologies, with special focus on the assessment of conventional as well as battery and fuel cell electric powertrains for use in passenger cars, motorcycles, public transport and freight transport applications.

Decision Support

The sustainability of current and future power-supply technologies can be analyzed by comprehensive, interdisciplinary assessment. The evaluation may use the total-cost approach, and/or Multi-Criteria Decision Analysis (MCDA), taking into account ecological, economic and social aspects. Total costs can be controversial, but they do include the economic and environmental effects of the various energy options. Internalization of external costs increases the relative competitiveness of renewables and nuclear. Renewable technologies have the highest potential for technological improvements and thus cost reductions. Nuclear power has the lowest total costs both now and in 2030. Total costs lead to a clear ranking of technologies, but provide a limited representation of social aspects whose broader consideration may affect ranking of nuclear. Social factors are better represented in Multi-Criteria Decision Analysis. Depending on stakeholder preferences, MCDA can lead to a different technology ranking than total cost, and is therefore used to provide an alternate aggregate sustainability indicator.