The effect of weather uncertainty on the financial risk of green electricity producers under various renewable policies

In recent years, many countries have implemented policies to incentivize renewable power generation. In this paper, we analyze the variance in profits of renewable-based electricity producers due to weather uncertainty under a `feed-in tariff policy, a fixed bonus' incentive and a `renewable quota' obligation. In a first step, we discuss the price effects of fluctuations in the feed-in from renewables and their impact on the risk for green electricity producers. In a second step, we numerically solve the problem by applying a spatial stochastic equilibrium model to the European electricity market. The simulation results allow us to discuss the variance in profits under the different renewable support mechanisms and how different technologies are affected by weather uncertainty. The analysis suggests that wind producers benefit from market integration, whereas producers from biomass and solar plants face a larger variance in profits. Furthermore, the simulation indicates that highly volatile green certificate prices occur when introducing a renewable quota obligation without the option of banking and borrowing. Thus, all renewable producers face a higher variance in profits, as the price effect of weather uncertainty on green certificates overcompensates the negatively correlated fluctuations in production and prices

Prices vs. Quantities: Incentives for Renewable Power Generation - Numerical Analysis for the European Power Market

This paper outlines the effects of weather uncertainty on investment and operation decisions of electricity producers under a feed-in tariff and renewable quota obligation. Furthermore, this paper tries to quantify the sectoral welfare and investments risks under the different policies. For this purpose, a spatial stochastic equilibrium model is introduced for the European electricity market. The numerical analysis suggests that including the electricity market price in renewable policies (wholesale price + x) reduces the loss of sectoral welfare due to a renewable policy by 11-20 %. Moreover, investors face an only slightly higher risk than under fixed price compensations. However, electricity producers face a substantially larger investment risk when introducing a renewable quota obligation without the option of banking and borrowing of green certi cates. Given the scenario results, an integration of the hourly market price in renewable support mechanisms is mandatory to keep the financial burden to electricity consumers at a minimum. Additionally, following the discussion of a European renewable quota after 2020, the analysis indicates the importance of an appropriate banking and borrowing mechanism in light of stochastic wind and solar generation

Four Essays on the Economics of Renewable Power Markets

In the scope of four related essays, this thesis analyzes potential pathways to a low-carbon European electricity supply with a large share of intermittent renewables. In particular, the thesis investigates the related costs of such a transition under different economic and technical developments as well as energy policies. For this purpose, several (stochastic) optimization models and a spatial equilibrium model have been developed. These model-based analyses yield, among others, the following findings: Under cost-efficient energy policies and favorable technical and economic developments, system costs and electricity prices may not increase significantly compared to today. However, this requires a Europe-wide common energy strategy, large amounts of usable land and an open mindset surrounding feasible technology options. Moreover, the integration of intermittent renewable generation remains technically challenging. Given a large share of wind and solar power generation, regional and intraregional weather conditions play an important role in renewable power markets. Thus, simulation models neglecting weather uncertainty, which are often used in practice, underestimate system costs substantially. Furthermore, weather uncertainty induces financial risks for conventional and renewable-based electricity producers. The effect on the financial risk for green electricity producers depends on the renewable promotion scheme and the slope of the power market's supply function. It is shown that feed-in tariffs (fixed-price compensation) do not necessarily offer producers the lowest variance in profits. Moreover, the analysis shows that renewable policies not including the hourly wholesale price set inefficient incentives. For the particular case of concentrating solar plants, flat feed-in tariffs set an inefficient incentive to invest in integrated thermal energy storages in today's electricity market. The analyses in this thesis are carried out for the European electricity system. However, the results may be useful for the assessment of a transition to a low-carbon and mostly renewable-based electricity system in other regions as well

The costs of electricity systems with a high share of fluctuating renewables - a stochastic investment and dispatch optimization model for Europe

Renewable energies are meant to produce a large share of the future electricity demand. However, the availability of wind and solar power depends on local weather conditions and therefore weather characteristics must be considered when optimizing the future electricity mix. In this article we analyze the impact of the stochastic availability of wind and solar energy on the cost-minimal power plant mix and the related total system costs. To determine optimal conventional, renewable and storage capacities for different shares of renewables, we apply a stochastic investment and dispatch optimization model to the European electricity market. The model considers stochastic feed-in structures and full load hours of wind and solar technologies and different correlations between regions and technologies. Key findings include the overestimation of fluctuating renewables and underestimation of total system costs compared to deterministic investment and dispatch models. Furthermore, solar technologies are - relative to wind turbines - underestimated when neglecting negative correlations between wind speeds and solar radiation.Stochastic programming; electricity; renewable energy

The economic value of storage in renewable power systems - the case of thermal energy storage in concentrating solar plants

In this article we analyze the value of thermal energy storages in concentrated solar plants depending on the electricity generation mix. To determine the value from a system integrated view we model the whole electricty generation market of the Iberian Peninsula. Key findings for thermal energy storage units in concentrated solar plants include an increasing value in electricity systems with higher shares of fluctuating renewable generation and a potentially significant role in a transformation to a primarily renewable based electricity system. Due to the relatively high investment costs concentrated solar power plants with or without thermal energy storages are not cost efficient in todays electricity markets. However, expected cost reductions due to learning curve effects and higher fluctuating renewable generation may lead to a comparative cost advantage of concentrated solar power plants with thermal energy storages compared to other renewable technologies.Fluctuating renewables; value of storage; concentrated solar power; power plant optimization

The costs of electricity systems with a high share of fluctuating renewables - a stochastic investment and dispatch optimization model for Europe

Renewable energies are meant to produce a large share of the future electricity demand. However, the availability of wind and solar power depends on local weather conditions and therefore weather characteristics must be considered when optimizing the future electricity mix. In this article we analyze the impact of the stochastic availability of wind and solar energy on the cost-minimal power plant mix and the related total system costs. To determine optimal conventional, renewable and storage capacities for different shares of renewables, we apply a stochastic investment and dispatch optimization model to the European electricity market. The model considers stochastic feed-in structures and full load hours of wind and solar technologies and different correlations between regions and technologies. Key findings include the overestimation of fluctuating renewables and underestimation of total system costs compared to deterministic investment and dispatch models. Furthermore, solar technologies are - relative to wind turbines - underestimated when neglecting negative correlations between wind speeds and solar radiation

Optimization of power plant investments under uncertain renewable energy development paths - A multistage stochastic programming approach

Electricity generation from renewable energy sources (RES-E) is supposed to increase signi ficantly within the coming decades. However, uncertainty about the progress of necessary infrastructure investments, public acceptance and cost developments of renewable energies renders the achievement of political plans uncertain. Implementation risks of renewable energy targets are challenging for investment planning, because different RES-E shares fundamentally change the optimal mix of dispatchable power plants. Speci cally, uncertain future RES-E deployment paths induce uncertainty about the steepness of the residual load duration curve and the hourly residual load structure. In this paper, we show how uncertain future RES-E penetrations impact the electricity system and try to quantify effects for the Central European power market. We use a multi-stage stochastic investment and dispatch model to analyze effects on investment choices, electricity generation and system costs. Our main findings include that the uncertain achievement of RES-E targets significantly effects optimal investment decisions. First, a higher share of technologies with a medium capital/operating cost ratio is cost-efficient. Second, the value of storage units in systems with high RES-E penetrations might decrease. Third, in the case of the Central European power market, costs induced by the implementation risk of renewable energies seem to be rather small compared to total system costs

Scenarios for an Energy Policy Concept of the German Government

In this working paper we demonstrate how challenging greenhouse gas reduction targets of up to 95% until 2050 can be achieved in the German electricity sector. In the analysis, we focus on the main requirements to reach such challenging targets. To account for interdependencies between the electricity market and the rest of the economy, different models were used to account for feedback loops with all other sectors. We include scenarios with different runtimes and retrofit costs for existing nuclear plants to determine the effects of a prolongation of nuclear power plants in Germany. Key findings for the electricity sector include the importance of a European-wide coordinated electricity grid extension and the exploitation of regional comparative cost effects for renewable sites. Due to political restrictions, nuclear energy will not be available in Germany in 2050. However, the nuclear life time extension has a positive impact on end consumer electricity prices as well as economic growth in the medium term, if retrofit costs do not exceed certain limits.Roadmap 2050; GHG reduction; renewable energies; carbon capture and storage; power plant fleet optimization

German Nuclear Policy Reconsidered: Implications for the Electricity Market

In the aftermath of the nuclear catastrophe in Fukushima, German nuclear policy has been reconsidered. This paper demonstrates the economic effects of an accelerated nuclear phase-out on the German electricity generation sector. A detailed optimization model for European electricity markets is used to analyze two scenarios with different lifetimes for nuclear plants (phase-out vs. prolongation). Based on political targets, both scenarios assume significant electricity demand reductions and a high share of generation from renewable energy sources in Germany. Our principal findings are: First, nuclear capacities are mainly replaced by longer lifetimes of existing coal-fired plants and the construction of new gas-fired plants. Second, fossil fuel-based generation and power imports increase, while power exports are reduced in response to the lower nuclear generation. Third, despite the increased fossil generation, challenging climate protection goals can still be achieved within the framework of the considered scenarios. Finally, system costs and electricity prices are clearly higher. We conclude that the generation sector can generally cope with an accelerated nuclear phase-out under the given assumptions. Yet, we emphasize that such a policy requires a substantial and costly transformation of the supply and the demand side.Nuclear policy; climate protection; renewable energy; electricity market modeling

Decarbonizing Europe’s power sector by 2050 - Analyzing the implications of alternative decarbonization pathways

In this paper, the implications of alternative decarbonization pathways for Europe's power sector up until the year 2050 are analyzed. In speci fic, an electricity system optimization model is used to investigate the minimal costs of decarbonization under a stand-alone CO2 reduction target and to quantify the excess costs associated with renewable energy targets and politically implemented restrictions on alternative lowcarbon technologies, such as nuclear power. Our numerical simulations con firm the theoretical argumentation concerning counterproductive overlapping regulation. The decarbonization of Europe's power sector is found to be achieved at minimal costs under a stand-alone CO2 reduction target (171 bn €2010). Additionally implemented RES-E targets lead to signi cant excess costs of at least 237 bn €2010. Excess costs of a complete nuclear phase-out in Europe by 2050 are of the same order of magnitude (274 bn €2010)