Batteriespeicher in Haushalten unter Berücksichtigung von Photovoltaik, Elektrofahrzeugen und Nachfragesteuerung

In dieser Dissertation wird die Wirtschaftlichkeit von stationären Batteriespeicher-Systemen (SBS) in Kombination mit einer Photovoltaik-Anlage (PVA) und unter Berücksichtigung von Elektro-Pkw in Haushalten untersucht. Dabei wird auch das Potenzial für Lastverlagerung von E-Pkw und SBS betrachtet sowie die Auswirkungen von verschiedenen Stromtarifen oder Rahmenbedingungen evaluiert. Hierfür wurde ein Optimierungsmodell als gemischt-ganzzahliges lineares Programm entwickelt, welches modellendogen die Anlagengrößen von PVA und SBS bestimmt sowie deren Kapitalwert maximiert

Batteriespeicher in Haushalten unter Berücksichtigung von Photovoltaik, Elektrofahrzeugen und Nachfragesteuerung

In dieser Arbeit wird die Wirtschaftlichkeit von stationären Batteriespeicher-Systemen (SBS) in Kombination mit einer Photovoltaik-Anlage (PVA) und unter Berücksichtigung von E-Pkw in Haushalten untersucht. Die Anlagengrößen von PVA und SBS werden dabei im Optimierungsmodell modellendogen bestimmt sowie deren Kapitalwert maximiert. Der Kapitalwert wird stark beeinflusst durch Lastverlagerungspotenziale von E-Pkw und SBS, Stromtarifdesign und weiteren Rahmenbedingungen

Interdependencies of Home Energy Storage between Electric Vehicle and Stationary Battery

Decentralized power generation in private homes, especially by photovoltaic systems, is already common in Germany. The developments of batteries, both for electric vehicles (EV) and for stationary storage might lead to a mass market for those batteries. In this paper we evaluate the economy of stationary battery storage with photovoltaic system at home in the context of available EV and its integration level into the home. Therefore, we use an optimization model with one year detailed operation planning and maximize the net present value of the storage investment. We integrate restriction functions for the technical parameters of the storage systems and limit EV availability and usage on the basis of German mobility studies for single vehicles. The results show, that an investment in a stationary battery system in combination with a photovoltaic system is profitable in Germany under the assumptions considered. The observed high numbers of battery cycles lead to strong requirements for battery lifetime, i. e. cycle stability and long calendar life time. Therewith, Li-ion batteries are a promising technology. In combination with an EV, the net present value of the stationary battery system is smaller when the EV is integrated into the home by controlled charging or the vehicle to home (V2H) concept, which allows discharging into the home system. The size of the EV battery, the availability at daytime and the load curve of the home are the main influencing factors for the profitability of the battery system

Effects of Integrating Electric Vehicles and Stationary Batteries in a Smart Urban Electricity Network

The aim of the European Union to drastically reduce greenhouse gas emissions in the following decades has a great influence on the transport and the energy sector. Electric vehicles and renewable energy sources are seen as outstanding possibilities on this way. An interrelation of these technologies seems to be a promising option. In our contribution we address some challenges, which come along with this interrelation. From a system perspective, more flexibility is needed. One option is to extend flexible demand through dynamic pricing, which timulates a demand response. Electric vehicles can contribute to this objective when the comprehensive load shifting potentials are activated. In addition, the application of local storage devices is discussed to relieve local grids and support the integration of decentralized electricity generation by renewable energy sources. In this contribution we analyze the effects of dynamic pricing for controlled and bi-directional charging of electric vehicles and the use of stationary battery systems in an urban electricity system. Therefore, we developed an optimization model for the application planning of the charging processes of electric vehicles and stationary storage systems. We demonstrate the high technical and economic potential for load shifting of the charging processes of electric vehicles with controlled charging. Furthermore, we identified positive and negative effects of real time pricing and load limits concerning cost and emission reductions and effects on grid loads. Only the use of stationary battery systems at home together with a load limit has positive effects for integrating photovoltaics and foster CO2 emission reductions. With real time pricing the stationary battery systems are used for arbitrage at the day-ahead market

Flexibilisierung der Haushaltsnachfrage durch ein Photovoltaik-Batteriespeichersystem und ein Elektrofahrzeug = Flexible household load by solar energy storage and EV

Die Flexibilität der elektrischen Haushaltsnachfrage wird sich mit Photovoltaik-Batterie-speichersystem (PV-Speicher) und Elektrofahrzeug deutlich steigern und kann den Verlauf der Stromnachfrage und die Erlöse für Versorger signifikant verändern. Mit einem techno-ökonom¬ischen Optimierungsmodell solcher Haushalte zeigen wir die Wirtschaftlichkeit dieser PV-Speicher-Systeme – in wenigen Jahren sogar ohne Förderung. Mit Demand Response Maßnahmen oder speziellen Tarifen lässt sich die flexible Nachfrage seitens des Energie-versorgers beeinflussen. Insbesondere gesteuertes Laden des Elektrofahrzeugs hat einen erheblichen Einfluss auf das Ergebnis

Solar energy storage in German households: profitability, load changes and flexibility

The developments of battery storage technology together with photovoltaic (PV) roof-top systems might lead to far-reaching changes in the electricity demand structures and flexibility of households. The implications are supposed to affect the generation mix of utilities, distribution grid utilization, and electricity price. Using a techno-economic optimization model of a household system, we endogenously dimension PV system and stationary battery storage (SBS). The results of the reference scenario show positive net present values (NPV) for PV systems of approx. 500-1,800 EUR/kWp and NPV for SBS of approx. 150-500 EUR/kWh. Main influences are the demand of the households, self-consumption rates, investment costs, and electricity prices. We integrate electric vehicles (EV) with different charging strategies and find increasing NPV of the PV system and self-consumption of approx. 70%. With further declining system prices for solar energy storage and increasing electricity prices, PV systems and SBS can be profitable in Germany from 2018 on even without a guaranteed feed-in tariff or subsidies. Grid utilization substantially changes by households with EV and PV-SBS. We discuss effects of different incentives and electricity tariff options (e.g. load limits or additional demand charges). Concluding, solar energy storage systems will bring substantial changes to electricity sales

How to integrate electric vehicles in the future energy system?

Main challenges within the energy system of tomorrow are more volatile, less controllable and at the same time more decentralized electricity generation. Furthermore, the increasing research and development activities on electric vehicles (EV) make a significant share of electric vehicles within the passenger car fleet in 2030 more and more likely. This will lead to a further increase of power demand during peak hours. Answers to these challenges are seen, besides measures on the electricity supply side (e. g. investing in more flexible power plants or storage plants), in (1) grid extensions, which are expensive and time consuming due to local acceptance, and in (2) influencing electricity demand by different demand side management (DSM) approaches. Automatic delayed charging of electric vehicles as one demand side management approach can help to avoid peaks in household load curves and, even more, increase the low electricity demand during the night. This facilitates integrating more volatile regenerative power sources, too. Bidirectional charging (V2G) and storing of electricity extends the possibilities to integrate electric vehicles into the grid. But, comparing electricity storage costs and availability of electric vehicles with costs and technical conditions of other technologies leads to the conclusion, that vehicle to grid (V2G) is currently not competitive - but might be competitive in the future, e. g. within the electricity reserve market. In summary, the paper gives an overview of the future electricity market with the focus on electric vehicles and argues for automatic delayed charging of electric vehicles due to economic and technical reasons

Demand Response with Smart Homes and Electric Scooters : An Experimental Study on User Acceptance

Smart technologies and electric vehicles are supposed to efficiently use renewable resources by shifting loads and storing surplus electricity. Although several field tests with smart meters, dynamic pricing or electric vehicles are conducted, hardly any consumer has experienced a combination of these components. So far, neither consumer perceptions nor the effectiveness of these demand response options are apparent. Test-residents were selected to move into KIT’s smart home for several weeks. It is equipped with smart appliances and two e-scooters. An energy management system schedules EMS) the operation time of appliances according to external price signals. Everything can be monitored on touch-screen panels provided in every room and on mobile devices. In this experimental setting demand response was tested in four phases: First, test-residents were provided with feedback. Then, different electricity-tariffs were introduced. Finally, the test-residents were able to fully use the EMS to schedule operation times of the smart appliances automatically. Electric scooters were provided for free use during the whole period. In general, the test-residents showed high interest in detailed information on their consumption. However, feedback alone had neither load-shifting nor conserving effects. These actions were realized when dynamic pricing was introduced. The willingness to shift consumption was limited to a few appliances (e.g., dishwasher) and depended on monetary savings. Charging the electric scooters was only shifted, if there was another vehicle available for emergencies. The automatic load-management ensured more convenience in shifting demand, especially in combination with dynamic electricity prices and load-limits