Photovoltaic Systems In Germany Research Articles

Using DNPV to determine the economic viability of residential photovoltaic systems in Germany: Is the investment still worth it?

The conditions for photovoltaic investments have changed significantly in recent times. Declining subsidies and rising investment costs make these investments less attractive. In addition, electricity price uncertainty has risen sharply, making the economic benefit of using self-produced electricity from residential photovoltaic systems risky. This paper provides a novel framework to determine the financial attractiveness of such investments using the Decoupled Net Present Value (DNPV) method, which allows for a systematic and consistent consideration of the individual risks inherent in these investments. Furthermore, an extensive survey of the relevant current market parameters is performed to validate the common opinion that residential photovoltaic investments are generally advantageous. It turns out that in the current market environment in Germany, residential photovoltaic systems are not economically viable under most conditions. The system evaluated in this case study with a common size of 10 kWp leads to a negative DNPV of -1,664 €. This results in a compelling need for action for political decision-makers in order not to jeopardize the ambitious goals for the expansion of power generation from renewable energy sources.

How higher‐order personal values affect the purchase of electricity storage—Evidence from the German photovoltaic market

AbstractWhy do consumers make different decisions even when socioeconomic conditions are similar? The present article examines the effects of human values—as formulations of motivational goals—on the decision to purchase electricity storage for a photovoltaic system, a phenomenon hardly explored in prior research regarding high‐priced household investments. About 50 percent of photovoltaic‐system owners in Germany are also owners of an electricity storage. This study aims to explore the more deeply rooted motivational factors behind these different decisions to extend our understanding of consumers' decision‐making processes regarding energy‐efficiency investments. It is based on an online survey of 460 owners of residential photovoltaic systems in Germany in 2019 and focuses on the interplay between higher‐order values, purchase decisions, perceived risk, and environmental concern. The analysis of the higher‐order values showed direct effects of conservation and self‐transcendence and indirect effects of openness to change and self‐enhancement, both mediated by perceived risk.

Towards a psychology of solar energy: Analyzing the effects of the Big Five personality traits on household solar energy adoption in Germany

This research paper investigated the effect of consumers’ Big Five personality traits on the adoption of residential photovoltaic systems in Germany. To account for different types or groups of households, a multigroup structural equation model with N = 9,281 individuals was analyzed using data from a nationwide, representative household panel. It could be shown that the ways in which personality traits are mediated through environmental concern and risk propensities change depending on whether there is a single household or if additional individuals are involved in the decision-making process. In the aggregated view, direct effects of extraversion could be found for households comprising only a couple. For other households with additional members, no direct effects were found. All five personality traits were mediated by risk preference while openness, agreeableness, and neuroticism were mediated by environmental concern. On the individual level, the examination revealed that the head of household’s neuroticism and the partner’s openness and extraversion showed significant effects on the purchase of a photovoltaic system – albeit with small effect sizes. The results provide important insights into how household decisions can be better understood in order to contribute to the energy-system transformation.

Generation of Spatiotemporally Resolved Power Production Data of PV Systems in Germany

Photovoltaics, as one of the most important renewable energies in Germany, have increased significantly in recent years and cover up to 50% of the German power provision on sunny days. To investigate the manifold effects of increasing renewables, spatiotemporally disaggregated data on the power generation from photovoltaic (PV) systems are often mandatory. Due to strict data protection regulations, such information is not freely available for Germany. To close this gap, numerical simulations using publicly accessible plant and weather data can be applied to determine the required spatiotemporal electricity generation. For this, the sunlight-to-power conversion is modeled with the help of the open-access web tool of the Photovoltaic Geographical Information System (PVGIS). The presented simulations are carried out for the year 2016 and consider nearly 1.612 million PV systems in Germany, which have been aggregated into municipal areas before performing the calculations. The resulting hourly resolved time series of the entire plant ensemble are converted into a time series with daily resolution and compared with measured feed-in data to validate the numerical simulations that show a high degree of agreement. Such power production data can be used to monitor and optimize renewable energy systems on different spatiotemporal scales.

Performance of roof-top PV systems in Germany from 2012 to 2018

The photovoltaic (PV) sector is a central pillar for the global energy transition process which aims to reach the climate change mitigation goals. Roof-mounted systems in particular can make a significant contribution to greenhouse gas-free energy generation. By the end of 2018, more than 1.5 million rooftop systems have been installed in Germany. The yield data measured by monitoring systems and provided by web-based online systems from 2012 to 2018, as well as the configuration information of 23,944 PV systems, are evaluated in this publication. Long-term indicators are derived from the spatial and temporal distribution of the yield data. The yield analysis shows a typical south-north gradient in Germany. 2018 was the year with the highest yield, 2013 the year with the lowest. The annual specific yield varies between 816 kWh/kWp in 2017 at the Baltic Sea and 1049 kWh/kWp in 2018 in Bavaria. If analysis of data evaluation is narrowed to one to two years, a deviation of five percent and more from the long-term yield can be observed. In order to obtain detailed information on the quality of PV systems, at least five years of data are required. The yield data evaluation can be used by PV system operators and owners to identify an undersupply of their PV system and to initiate countermeasures.

Photovoltaic self-consumption after the support period: Will it pay off in a cross-sector perspective?

We quantify the cost savings potential of photovoltaic self-consumption by single-family houses with small-scale roof-top photovoltaic systems in Germany against the background of recent storage applications after the end of the legal support period. We analyze different systems where an already installed PV system is combined with a battery storage and/or a power-to-heat solution. A comparison is made in terms of a household’s electricity and heating costs under cost-minimizing operation of each system. For this purpose, we carry out comprehensive simulations of site-specific PV production and determine optimal self-consumption as well as optimal charging of the hot water thermal storage and the battery storage. We use 25 representative electricity load profiles, which differ only in temporal distribution of consumption, to obtain a broader picture of the cost savings potential. Results suggest that the major share of the savings potential is due to direct PV self-consumption and thus concerns electricity costs. A profitability analysis reveals that the inclusion of the thermal storage and/or the battery storage system does not pay off when juxtaposing cost savings and investment expenses, at least at current prices. However, since storage application prices are constantly falling, individual profitability is within reach for the next years.

Analysis and model-based predictions of solar PV and battery adoption in Germany: an agent-based approach

In order to tackle energy challenges faced in Germany, a Feed-in Tariff program was created in 2004 to aid the adoption of solar PhotoVoltaic (PV) systems where owners of such systems are paid a certain amount for each unit of electricity generated. Solar PV electricity generation is limited due to its intermittency but this can be managed using batteries. In this paper, we study the adoption of PV and battery (PV-battery) systems in Germany, and evaluate policies that could improve the adoption of these systems and their impact on the electric grid. To do this, we create an agent-based model that is simulated to estimate the impacts of different policies; this model is informed by an online survey with respondents from Germany. Simulating adoption over a period of 10 years, the results show that increasing electricity prices could result in improved PV-battery adoption in Germany better than reducing PV-battery system prices could. In addition, given the high level of affinity of people towards PV systems in Germany, disconnection from the grid would be a viable option within the next 10 years.

Does localized imitation drive technology adoption? A case study on rooftop photovoltaic systems in Germany

The purpose of this paper is to illuminate the spatio-temporal diffusion of rooftop household photovoltaic installations in Germany and to test whether localized imitation drives their adoption. Our study is based on a unique data set of some 576,000 household photovoltaic systems installed in Germany through 2009. We employ an epidemic diffusion model which includes a spatial dimension, and control for temporal and spatial heterogeneity. According to our results, imitative adoption behavior is highly localized and an important factor for the diffusion of household photovoltaic systems.

Economic Implications of Enhanced Forecast Accuracy: The Case of Photovoltaic Feed-In Forecasts

Forecasts are usually evaluated in terms of accuracy. With regard to application, the question arises if the most accurate forecast is also optimal in terms of forecast related costs and risks. Combining insights from research and practice, we show that this is indeed not necessarily the case. Our analysis is grounded in the dynamic field of short-term forecasting of solar electricity feed-in. A clear sky model is implemented and combined with a linear model, an autoregressive model, and an artificial neural network. These models are applied to a portfolio of ten large-scale photovoltaic systems in Germany. We compare the different models in order to quantify the connection between errors and costs. We find that apart from accuracy, correlation with market prices is an important characteristic of forecasts when economic implications are considered as important.

Revenue prospects of photovoltaic in Germany—Influence opportunities by variation of the plant orientation

The fixed feed-in tariff under the Renewable Energy Sources Act in Germany particularly encourages photovoltaic systems with the highest possible annual yield, regardless of their temporal generation profile. Consequently, a large part of the installed photovoltaic systems in Germany have a southern orientation. This paper examines how the optional German market premium scheme incentivizes the installation of photovoltaic systems with a more demand-oriented electricity production. For this purpose, the measure ‘energy yield elasticity (of market value)’ was developed and calculated by using historical market data. The results show that some of the plant orientations that are deviating from the southern reference could have led to an increase in the market value in the last few years. However, these would not have been high enough to more than compensate for the financial losses that were formed as a result of the annual energy yield declines. The merit order effect could change this situation in the future.

A high-resolution determination of the technical potential for residential-roof-mounted photovoltaic systems in Germany

In Germany the introduction of a feed-in tariff for renewable energies in the year 2000 led to a massive increase in newly constructed photovoltaic (PV) plants reaching a total installed capacity of 35GWp as of November 30th, 2013. The distribution of these plants shows a large disparity between regions, which motivates investigations of regional potentials which earlier studies of Germany have not addressed in detail. This study presents a high-resolution calculation for the technical potential of residential-roof-mounted photovoltaic systems for each municipality in Germany. Electricity load curves for municipalities were generated based on the socio-economic structure and used to draw generalized conclusions about the relationship between the (potential) supply from PV and the local demand. The total German residential-roof-mounted technical PV potential was determined as 148TWh/a with an installable capacity of 208GWp. About 30% of municipalities could become autonomous based on a yearly balance of PV electricity generation. If the daily and seasonal variations in demand and PV electricity generation were considered, only 53 of the 11,593 German municipalities could become autonomous, provided they installed a short-term storage system which would have to be sized around 57% of their daily electricity demand. Imposing the restriction that no feedback of electricity into the distribution network outside the municipality should occur, and assuming that no local storage exists, around 49% of the total technical potential, i.e. 103GWp could be installed (i.e. 90GWp additional potential since some municipalities already experience feedbacks into the distribution network). A validation of the results with municipal solar cadastres has shown that the discrepancy between them and the technical potential calculated in this study is quite consistently about 30%, which is assumed to be due to non-residential buildings not being considered here. The calculated technical potential is most sensitive to the assumptions on the module efficiency and the usable area of (slanted) roofs. A validation of building data assumptions as well as a comparison with other studies both show a good agreement.

Improved Low Voltage Grid-Integration of Photovoltaic Systems in Germany

This work discusses the technical and economical benefits of different active and reactive power control strategies for grid-connected photovoltaic systems in Germany. The aim of these control strategies is to limit the voltage rise, caused by a high local photovoltaic power feed-in and hence allow additional photovoltaic capacity to be connected to the mains. Autonomous inverter control strategies, which do not require any kind of data communication between the inverter and its environment, as well as an on-load tap changer for distribution transformers, is investigated. The technical and economical assessment of these strategies is derived from 12-month root mean square (rms) simulations, which are based on a real low voltage grid and measured dc power generation values. The results show that the provision of reactive power is an especially effective way to increase the hosting capacity of a low voltage grid for photovoltaic systems.

Fuel cell based micro-combined heat and power under different policy frameworks – An economic analysis

The residential fuel cell technology faces a list of challenges, of which some are linked to the technology through the need of cost decreases and reliability improvements. Others are linked to the political stage, where the necessary support schemes have to be in place in combination with clear political objectives on the design of the future energy system.This article takes the point of departure in the existing support schemes, most common ownership structures, energy prices, electricity demand and heating demand in Denmark, France and Portugal. For the three countries, we analyse different constellations of operational strategies, ownership structures and promotion schemes and assess the necessary support levels for residential fuel cells under these constellations.We find that the necessary support levels are not excessively high compared to the initial support levels for e.g. photovoltaic systems in Germany. Especially net metering in Denmark and price premiums for fuel cells functioning as a virtual power plant in France and Portugal seems promising. The annual number of operation hours depends strongly on the operational scheme. For thermal-led units, cold start and modulation capacity plays a certain role, whereas the fuel cell generates virtually permanently if it is part of a virtual power plant.

Grid parity analysis of solar photovoltaic systems in Germany using experience curves

The paper starts with experience curve analysis in order to find out the future prices of solar photovoltaic (PV) modules. Experience curves for 75–90% progress ratio are extrapolated with the help of estimated future growth rate for PV installation worldwide and current module price data until year 2060. A kWh PV electricity generation cost has been calculated for coming decades with the help of local market parameters and module prices data from extrapolated experience curve. Two different prices for grid electricity – wholesale electricity price and end user electricity price – are separately analyzed. Household electricity consumption profile and PV electricity generation profile for Cologne, Germany, have been analyzed to find out the possibility for PV electricity consumption at the time of its generation. This result is used to calculate the real grid parity year – which lies somewhere between grid parity years calculated for wholesale electricity price and end user electricity price.