Potential of Photovoltaic Panels on Building Envelopes for Decentralized District Energy Systems

The expected increase of the penetration of distributed renewable energy technologies into the electricity grid is expected to lead to major challenges. As a main stakeholder, authorities often lack the appropriate tools to frame and encourage the transition and monitor the impact of energy transition policies. This paper aims at combining relatively detailed modeling of the PV generation potential on the building's envelope while retaining the energy system optimization approach. The problem is addressed as a multiobjective, mixed-integer linear programming problem. Compared to the existing literature in the field, the proposed approach combines advanced modeling of the energy generation potential from PV panels with detailed representation of the district energy systems, thus allowing an accurate representation of the interaction between the energy generation from PV and the rest of the system. The proposed approach was applied to a typical residential district in Switzerland. The results of the application of the proposed method show that the district can achieve carbon neutrality based on PV energy alone, but this requires covering all the available district's rooftops and part of the district's facades. Whereas facades are generally disregarded due to their lower generation potential, the results also allow concluding that facade PV can be economically convenient for a wide range of electricity prices, including those currently used by the Swiss grid operators. Achieving self-sufficiency at district scale is challenging: it can be achieved by covering approximately 42-100% of the available surface when the round-trip efficiency decreases from 100 to 50%. The results underline the importance of storage for achieving self-sufficiency: even with 100%, round-trip efficiency for the storage, very large capacities are required. However, energy demand reduction through renovation would allow reaching self-sufficiency with half of the PV and storage capacity required.

SCCER JA-RED - A list of possible ancillary services for enhanced grid operation and implementation of the most effective ones at the RE demo site - Deliverable 1.2.3

Lionel Benjamin Bloch, Luc Girardin, Jordan Holweger, Luise Middelhauve

There is a need by distribution system operators and power suppliers to propose ancillary services to enhanced grid operation allowing the optimal deployment of photovoltaic panels, cogeneration technologies and distributed storage. This deliverable therefore proposes and evaluates the impact of a list of possible ancillary services for the injection of local renewable energy in the future low voltage grid. The novelty of the proposed building to district and district to grid approaches lies in the ability to generate a wide range of optimal energy transition scenarios using multi-objective optimisation techniques both at building and district level. The proposed approach differs from previous work by integrating ancillary services by optimizing simultaneously both sizing and operation of the district energy technologies. This deliverable demonstrates, on the reference case (TR3716), the implementation of voltage control ancillary services to integrate more renewable energy to the low voltage grid. In particular it exposes how advanced electricity tariffs can influence energy system design and operation to decrease stress induced by high PV penetration on the grid. The proposed implementation can be deployed in control boxes developed using open-source standards, such as mikrobus. Moreover, considering the transformer’s area as a relevant scale for the implementation of ancillary services, this work pave the way to the definition of a new geographical division for territorial energy planning aiming at the integration more renewable energy resources in urban areas.

2020

SCCER JA-RED - Report on the performance of the implemented solutions with guidelines for subsequent implementation - D1.2.4

Luc Girardin, Luise Middelhauve

The foreseen important increase of the penetration of distributed renewable energies technologies into the electricity distribution grid is expected to lead to some major challenges. On the one hand, a large and synchronous production could lead in certain time periods to a surplus of production, exceeding the consumption needs and resulting in a zero or negative market value of electricity that may deter any incentive to further invest in certain sources of renewable energy. This production surplus is also expected to lead to grid congestion, transformer overloading and overvoltage situations that will critically affect grid operation. Yet, if the renewable energies technologies, storage devices, and electrified loads are exploited through coordinated control mechanisms they could also offer new opportunities for stakeholders. The JA-RED partners have therefore developed methods to evaluate the long-term implementation of decentralized solutions that could be massively deployed to decarbonize and denuclearize the Swiss energy mix, while providing economic opportunities for all stakeholders. This report takes a deeper look at the implemented decentralized energy solutions integrating heat pumps, heat storage, batteries and solar panels considering shading effect, not only on roofs, but also on facades of the district which indeed host 70% of the available PV area and near half of the generation potential. Achieving self-sufficiency at district scale is challenging: it can be achieved by covering approximately 42% to 100% of the available surface when the round trip efficiency decreases from 100% to 50%. The results underlined the importance of storage for achieving self-sufficiency: even with 100% round trip efficiency for the storage, very large capacities are required. Moreover, the grid revenues generated by the difference between retail and feed-in prices are not sufficient to pay for the storage required to make the district self-sufficient, suggesting that public funding would be crucial for supporting these developments. This arise with relatively low installed PV capacity (PV area / heated area = 0.2), when storage starts to be seasonal rather than daily. However, energy demand reduction through renovation would allow to reach self-sufficiency with half of the PV and storage capacity required for the actual building stock, and the deployment of additional long-term storage capacity could be implemented together with the development of the next 5th generation of district heating and cooling systems, realizing sector coupling with power to gas (P2G) and electro-thermal energy storage (ETES).

2021

Sensitivity of the dispatch strategy in designing grid integrated hybrid energy systems

Dasaraden Mauree, Vahid Moussavi Nik, Amarasinghage Tharindu Dasun Perera, Jean-Louis Scartezzini

Integrating renewable energy technologies based on solar PV (SPV) and wind energy in the energy system is challenging due to time dependence of the energy potential for these energy sources. Grid integrated hybrid energy systems combining SPV panels, wind turbines, battery bank and internal combustion generators (ICG) can be used in this regard specially for distributed generation. Energy-economic dispatch strategy plays a vital role in managing the energy flow of the system. However, it is difficult to design such energy system due to complexity of the energy flow because of the changes in electricity demand, solar and wind energy potential. This study evaluates the sensitivity of dispatch strategy on optimum system configuration considering Levelized Energy Cost (LEC) and Grid Integration Level (GI). Two existing dispatch strategies i.e. cycle charging (CC) and modified cycle charging (MCC) dispatch strategies are used for the analysis based on Pareto multi objective optimization of LEC and GI. Pareto-fronts obtained considering both approaches were subsequently compared for different grid curtailments. The results show that a notable difference in LEC and system configuration is observed for two different approaches with the increase of grid interactions.

Ieee2016

SCCER JA-RED - Report on the performance of the implemented solutions with guidelines for subsequent implementation - D1.2.4

Luc Girardin, Luise Middelhauve

2021