Assessment of Solar Photovoltaics and Wind Energy for Increased Electrification and Grid Independent Farming

Abstract

A solution towards increased electrification and reduced greenhouse gas emissions in the agriculture is local renewable energy production. Not only is it a sustainable and environmentally positive project, but with remarkably increasing electricity prices renewable energy projects can also be economically favorable for farmers, by reducing grid dependence and hence high electricity costs. In this thesis, solar and wind conditions at a farm in Southwestern Norway are mapped with the goal of estimating potential energy production. An isolated building with a suitable consumption profile is chosen to investigate, size and design a complete on-grid PV system. Comparing energy production estimates from the proposed PV system and wind turbine with consumption data from the farm allows analyzing the economics to map the profitability of the two systems alone and as a combined Hybrid Power System, in addition to proposing ways of utilizing potential surplus energy for increased electrification of the farm’s machine park. Calculations show that a PV system on the Southwest facing rooftop of the chosen building can give an average annual energy production above 70 MWh, with maximum monthly production in the range of 12-13 MWh. Based on the estimated energy production, the building sees an energy surplus of up to 8 MWh between April and September. When looking at the total consumption of the entire farm, the PV system can cover up to 80% in the months with maximum production. Different variants of using PV energy to supply a charging station for an electric tractor are proposed, and opportunities, challenges, and outlook regarding the introduction of electric tractors discussed. Wind energy production estimates show annual production around 7 MWh, and a significantly lower specific production yield compared to the PV system. The economic analysis reveals a critical spot price of 0.13 NOK/kWh for the PV system to be a profitable project, and it shows short payback periods of 4-5 years and annual electricity savings up to 100 000 NOK with recently observed spot prices in the NO2 area. The analysis also indicates that the wind turbine is an unprofitable investment, but a combined Hybrid Power System seems profitable but highly dependent on spot prices, investment costs and energy production, with a critical spot price of 0.88 NOK/kWh. The thesis proposes progressive investments in local renewable energy at a farm and shows that this can support electrification and sustainable farming, while at the same time lead to significant long-term economic profits for the farmer.