ImpRES – Impact of Renewable Energy Sources

The expansion of renewable energies (RE) has impacts on several sectors and actors in the national economy. The project ImpRES (Impact of Renewable Energy Sources) aimed to make a comprehensive and systemic analysis of these different impacts.

The impacts are divided into three categories:

  • System-related costs and benefits include all the direct and indirect costs of RE expansion associated with direct or indirect resource consumption. The direct costs cover the resources needed to construct and operate an installation, while the indirect costs represent the costs of integration, especially infrastructure costs such as grids and storage. The system-related costs and benefits of renewable energies are always weighed up in comparison with an energy supply without forced RE expansion and determined independently of which actors will have to bear the costs of this. They can be aggregated in one figure and compared with the benefits. Benefits result especially from conserving resources and avoiding environmental damages.

  • Distributional and price effects do not represent macroeconomic resource consumption in themselves, but show, for example, the costs of RE expansion to be borne by individual actors. Distributional effects can be illustrated as debits or credits for individual groups of actors or the state, but they cannot simply be summed up to an overall figure. These remaining costs are also referred to as the microeconomic cost increases or decreases of RE utilization. In addition, price effects can occur from using renewable energies to generate electricity and heat.

  • Macroeconomic effects concern macroeconomic indicators such as the gross domestic product and its components as well as any change in sectoral and macroeconomic employment. These changes can be measured over time or in comparison to different possible future developments (scenarios). Investments, turnover, imports or sectoral employment are defined as gross effects because they are mostly analysed based on one sector and do not consider macroeconomic adaptation effects – for instance in the wake of price changes or declining investments in other sectors. Macroeconomic net effects can only be derived from comparing two future developments, where one contains RE expansion and the other does not. This is why macroeconomic models which illustrate the varied, economic interrelations between actors and economic branches as comprehensively as possible are needed to estimate the macroeconomic net effects of RE expansion alongside statistics and company surveys.

© Fraunhofer ISI
Systematic illustration of the different impacts of RE expansion

Because the increased deployment of RE is mainly being driven by politics at present, the analysis of distributional effects is essential. This is where the project’s focus layed.

ImpRES covered a period from 2012 to 2016 and was sponsored by the German Federal Ministry for Economic Affairs and Energy (BMWi). The partners in this joint project were the Fraunhofer Institute for Systems and Innovation Research ISI, the German Institute of Economic Research (DIW Berlin), the Institute of Economic Structures Research (GWS mbH) and IZES gGmbH (Institut für ZukunftsEnergieSysteme gGmbH).

The expansion of renewable energies (RE) is being pushed so that, in the long term, renewable energies are able to take over the main share of energy supply. This requires a transformation of the energy system, in which market and system integration play an important role. RE deployment is mainly being driven politically. For its political legitimization and societal acceptance as well as for designing the support policy in the future, the different effects of the politically forced expansion have to be analysed systematically and in detail.

With regard to acceptance aspects, mainly distributional effects are to be analysed; the positive (reliefs or credits) and negative (burdens or debits) effects for different actors. Alongside the current effects of using RE, future effects will also be considered. In addition, attention will also be paid to the technological, economic and instrumental interactions between RE use in the fields of power, heat and transport.

The project built on the results obtained in the BMU KNEE project “Economic evaluation of costs and benefit effects of RE expansion in the German electricity and heat sector” – and should help to further develop the methods by considering overlapping effects or aspects previously not taken into account in detail and, at the same time, guarantee a monitoring of previously quantified effects. Dynamic aspects are especially relevant when assessing RE expansion. 

The project had five work packages:

  1. Benefits: Development and application of methods to estimate other benefits of RE expansion, for example innovation effects and security of supply.
  2. Distributional effects: Development of methods for a differentiated estimation of the price and distributional effects of policy design in the power, heat and transport sectors, differentiated by actor groups (for example by household type, income group, industrial sector, region)
  3. Interactions: Examining the interactions between electric mobility and renewable energies
  4. Macroeconomic model: Integration of the distributional effects and interactions in a macroeconomic model to estimate the impact of forced RE expansion on growth and employment, differentiated by income group and industrial sector at the level of the economy as a whole and at a regional level
  5. Monitoring: Annual monitoring of the costs and benefits of RE expansion


Project results are listed in: