TECHNO-ECONOMIC FEASIBILITY ANALYSIS OF PV-WIND. HYBRID SYSTEMS FOR SWEDEN

Подпись:F. Fiedler1*, V. Pazmino1, I. Berruezo1, V. Maison1 and E. Wackelgard

1 Solar Energy Research Center SERC, Hogskolan Dalama, S-78188 Borlange, Sweden

Corresponding Author, ffi@du. se

Abstract

PV-Wind-Hybrid systems for stand-alone applications have the potential to be more cost efficient compared to PV-alone systems. The two energy sources can, to some extent, compensate each others minima. The combination of solar and wind should be especially favorable for locations at high latitudes such as Sweden with a very uneven distribution of solar radiation during the year. In this article PV-Wind-Hybrid systems have been studied for 11 locations in Sweden. These systems supply the household electricity for single family houses. The aim was to evaluate the system costs, the cost of energy generated by the PV- Wind-Hybrid systems, the effect of the load size and to what extent the combination of these two energy sources can reduce the costs compared to a PV-alone system. The study has been performed with the simulation tool HOMER developed by the National Renewable Energy Laboratory (NREL) for techno-economical feasibility studies of hybrid systems. The results from HOMER show that the net present costs (NPC) for a hybrid system designed for an annual load of 6000 kWh with a capacity shortage of 10% will vary between $48,000 and $87,000. Sizing the system for a load of 1800 kWh/year will give a NPC of $17,000 for the best and $33,000 for the worst location. PV-Wind-Hybrid systems are for all locations more cost effective compared to PV-alone systems. Using a Hybrid system is reducing the NPC for Borlange by 36% and for Lund by 64%. The cost per kWh electricity varies between $1.4 for the worst location and $0.9 for the best location if a PV-Wind-Hybrid system is used.

Keywords: Techno-economic feasibility, PV-Wind-Hybrid systems

1. Introduction

In the Nordic countries stand-alone PV systems are mainly used to supply electricity to remote weather and telecommunication stations, traffic signals/lights and for other remote applications with a relatively low power demand. Due to the extensive developed electrical grid only a few remote residential buildings for all year round usage are supplied by stand-alone systems. An obstacle for the use of stand-alone PV systems is also the uneven distribution of the solar radiation causing high costs if the system needs to be sized for a constant load throughout the year. As the example for Gothenburg in Figure 1 shows has wind power the potential to compensate at least to some extent the low irradiation during the winter. The average wind power at the most locations in Sweden is higher during the seasons with low irradiation. Another reason why the combination of PV — and wind-alone systems can be economical interesting is that the costs for PV modules per Watt peak are still higher than the cost per Watt peak of wind turbines. If there will be a cost benefit or not depends of course also on other parameters, especially on the available local wind speed.

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Fig. 1. Monthly average wind power at 10 m height and monthly average horizontal solar radiation for

Gothenburg (TMY weather data).

Studies have performed for several other locations worldwide showing often that PV-Wind-Hybrid systems can be more cost effective than PV-alone or wind-alone systems [1-5]. The results presented in this paper are based on two Master theses reports of students of the European Solar Engineering School in Borlange/Sweden [6, 7].

2. Aims

In this paper PV-Wind-Hybrid systems have been studied for 11 locations in Sweden. The aim was to evaluate the system costs, the cost of energy generated by the PV-Wind-Hybrid systems, the effect of the load size and to what extent the combination of these two energy systems can reduce the costs compared to a PV-alone system.