Modeling of Photovoltaic-Thermal District Heating with Dual Thermal Modes

Anneka Kang,Ivan Korolija,Dimitrios Rovas

doi:10.1088/1742-6596/2042/1/012090

Anneka Kang, Ivan Korolija + Show 1 more

Open Access

https://doi.org/10.1088/1742-6596/2042/1/012090

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Abstract

Solar photovoltaic thermal (PVT) collectors could be a competitive addition to district heating systems, particularly in areas with high energy density since they simultaneously produce electricity and heat whilst increasing the PV efficiency through cooling. This study presents a new Modelica PVT model, which is used together with EnergyPlus in a co-simulation setup to assess the technical feasibility of solar PVT district heating in new builds. The model has been applied to a block of 12 2-bedroom terraced houses with a 184m2 PVT array on the south facing side of the roof. It was identified that well-designed seasonal PVT heating configurations and control schemes are required to maximise PVT outputs. PVT dual thermal modes occur when the PV is either connected to a load or producing at close to the maximum power point. Integrating the dual modes into a control system could be more economical if heat tariffs were higher than electrical ones when heat demand is greater than the PVT thermal output.

Highlights

Advances in building energy systems and improvement of existing/new infrastructure will play a pivotal role towards the target to reduce global emissions and avert increasing of the mean temperature over 1.5◦C above pre-industrial levels [1], which would have pernicious consequences.District Heating (DH) systems can improve energy efficiency whilst reducing emissions and running costs [2]
In summer, when DHW demands were lower than the thermal output at times, the system could operate in an open loop maximum power point (MPP) mode configuration, where the cooling effect mazimised the photovoltaic thermal (PVT) electrical output and was greater than conventional PV output
Since the PVT cell temperature was dependent on the collector mean fluid temperature, it was important for PVT DH systems to have a low DH return temperature

Summary

Introduction

District Heating (DH) systems can improve energy efficiency whilst reducing emissions and running costs [2]. In these systems, a centralised heat source is used to meet building heating demands within an area, removing the need for individual heating systems in each property. A communal heating system is of an additional benefit to urban dwellings, constituting 81.5% of the UK building stock [3], where space is at a premium. Installing a renewable energy communal heating system would allow these types of dwellings to benefit from additional space from neighbouring dwellings or communal shared areas, which otherwise would not have been feasible to install

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