On the Profitability of Large-scale PV Plants in Sweden : Site Selection, Grid Connection and Design

Abstract: The market for large scale PV plants in Sweden is growing, with six PV plants of 1 MWp or more beinginstalled today. The size of the newly installed plants has increased from 1 MWp to 5.5 MWp during thelast 5 years. As the market and size of the plants continue to grow, larger investments, risks and possibleprots will be built into the project. The site selection will aect the project in terms of power production,grid connection, plant design, land lease, among many things. This report focuses on how these early choicesin the development of the project aect the protability of the PV plant.A literature study has been conducted for in-depth knowledge of PV plants as well as the most importantaspects of a pre-feasibility study. The literature study has a specic focus on the components and designof a PV plant, the grid connection, economy and future changes of the electricity price in Sweden. Oneimportant conclusion from the literature study is that the company which develops a new PV plant shouldcontact the grid company in the area of interest as soon as possible, due to the time-consuming process ofgetting an approval for the new connection as well as that a major reinforcement of the grid may ruin theprospect of the PV plant project. Another conclusion is that the site should be selected to maximize thesolar irradiation, meanwhile minimizing the costs for upgrading or reinforcing the power grid. The economiccase of a PV plant project can generally be improved by choosing a site in the southern part of Sweden.Benets are gained from both higher solar irradiation compared to the northern part of Sweden as well ascompensations from the grid company for reducing losses in the power grid. The land should preferably havea dual purpose, meaning that the same land can be used for both the PV plant and another purpose suchas a wind farm, airport, landll or feeding small lively stocks of sheep, etc.A case study has been conducted at three sites in the southern part of Sweden, located on Oland, Skurup,and Stenungsund. The sites are compared by evaluating the prospect of two dierent sizes of PV plants. ThePV plant performance is evaluated by a model developed in the program MATLAB. Hourly data of the solarirradiation is gatherer for the three sites for 2017 and 2018, using the system STRANG which is given bythe Swedish Meteorological and Hydrological Institute (SMHI). Hourly data of the temperature is gatheredfrom the closest weather station to the site, also from SMHI. The sites are compared by power productionand resulting LCOE values, including specic grid taris, land leasing costs and typical investment costs forPV plants. The investment costs are gathered from recent reports, cross-checked with costs for the largestPV plants built in Sweden.The case study results in the conclusions of the solar irradiation having a high impact on the power productionfrom the PV plants, however lower than a 1:1 ratio of the power production and solar irradiation. The PVplants can have the same designed for similar sites, except for the distance between the rows which dependson the latitude of the site. Two dierent aspects of a possible future were investigated, the rst one beinghighly uctuating electricity prices with a low or zero price during midday. The investigation focuses oncomparing if the PV plants would be more economically protable with an east-west orientation instead ofbeing oriented due south. The results showed that even with a four hour long period of a zero price duringmidday, the PV plants oriented due south were still more protable. In the second future scenario, PV plantsare protable when selling electricity to the spot market in Sweden. The investigation focuses on how muchthe spot prices need to increase and/or the investment cost for the PV plants decrease. The results dependon assumptions of how much the spot price will increase during the lifetime of the PV plant. If the spotmarket could meet an LCOE value of 0.5 SEK/kWh, the investment cost would need to be reduced to 5000SEK/kWp.