Conference Paper
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Abstract

In a large-scale integration of distributed generation (DG), a hosting capacity reflects the technical limit for the adaption. Hosting capacity depends strongly on the existing electricity infrastructure and a profile of electricity demand of end-customers. Hosting capacity and economic feasibility of large-scale integration of PV relate strongly to each other. The target of the study is to illustrate what are the limits and possibilities for the large-scale solar PV integration in Finland from the electricity distribution infrastructure perspective. The study utilizes a nationwide database of buildings and roof surface areas, a case specific network data from actual distribution areas and nationwide statistics of distribution system operators. Hourly-based load and generation data are used considering geographical location and point of compass of individual buildings. The study shows that there is significant residential rooftop solar PV capacity available according to the building and electricity infrastructure information. The main outcome is that implementing this amount of solar PV in residential level does not bring significant challenges for electricity distribution system.

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... There are also variations in the estimates of technical potential of rooftop PV. It was estimated in Finland by [50] as 34 GW. Schmidt et al [48] also estimated the technical potential of rooftop PV for European countries; for Finland their estimate was significantly lower at maximum 9 TWh/a. ...
Preprint
Ammonia has been suggested as an energy vector which has enable energy storage and sector coupling in order to balance the variability of wind and solar power. This paper investigates the impact of the power-to-ammonia technology in the North European power and heat system. Three-stage model was built for the power-to-ammonia plant. A cost optimization model, targeting the year 2050, was used to optimize investments and the full-year hourly resolved operation of conversion plants, storages and the power-to-ammonia plants. We found that the investments into power-to-ammonia plants is strongly dependent on the global ammonia price. Renewable ammonia production is in balance with the energy sector consumption at price level slightly above 450 €/tonne. Regional ammonia storage of 6 million tonnes was sufficient to balance the variations in ammonia demand in the power sector.
... There are also variations in the estimates of technical potential of rooftop PV. It was estimated in Finland by [50] as 34 GW. Schmidt et al [48] also estimated the technical potential of rooftop PV for European countries; for Finland their estimate was significantly lower at maximum 9 TWh/a. ...
Preprint
Ammonia has been suggested as an energy vector which has enable energy storage and sector coupling in order to balance the variability of wind and solar power. This paper investigates the impact of the power-to-ammonia technology in the North European power and heat system. Three-stage model was built for the power-to-ammonia plant. A cost optimization model, targeting the year 2050, was used to optimize investments and the full-year hourly resolved operation of conversion plants, storages and the power-to-ammonia plants. We found that the investments into power-to-ammonia plants is strongly dependent on the global ammonia price. Renewable ammonia production is in balance with the energy sector consumption at price level slightly above 450 €/tonne. Regional ammonia storage of 6 million tonnes was sufficient to balance the variations in ammonia demand in the power sector.
... This capacity is identified by minimising the imported electricity. The available rooftop area is identified from studies made in LUT [75]. Potentially 19 million m 2 of rooftop area is available and the 240 MW of solar panels are more than easily fit into the rooftops. ...
Article
The profitability of a rooftop solar photovoltaic (PV) system depends on several factors, such as the retail price of electricity, the load profile of the building, and orientation of the solar PV modules. If there are consumption peaks in the morning, evening, or both, the solar PV modules can be oriented eastward, westward, or east–west, respectively, in order to increase self-consumption. However, the market price of electricity varies, which makes it challenging to evaluate the revenue of a solar PV system in advance. In this study, solar PV module orientation is considered based on profitability. The study uses hourly data of 13 different statistical customer class load profiles, historical electricity market price data for the years 2016–2020, and simulated solar PV yield from southern Finland. A comparison is made between single-azimuth and dual-azimuth systems, the latter of which having the orientation of half of the modules mirrored respective to the north–south axis. A single-azimuth system is usually more profitable when compensation is paid for surplus electricity. The optimal orientations are at azimuth angles of −15°–5° and at tilt angles of 35°–45° with both fixed and dynamic electricity purchase prices. However, if no compensation is paid for surplus electricity, it is usually more profitable to minimize the electricity purchase by orienting the solar PV modules in two azimuths between east and west with tilt angles of 10°–55° depending on the capacity of the solar PV system and the load profile. The revenue is not very sensitive to moderate changes in orientation.
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Domestic hot water (DHW) heating is one of the most energy-consuming activities in a typical household. Photovoltaics (PV) connected with a ground source heat pump (GSHP) offers a low-emission method for DHW heating. This paper studies four different control methods for DHW heating in a building with a GSHP and a PV system. The main control method aims to minimize DHW heating costs by utilizing Nord Pool Spot market information together with a PV production output forecast. The results of this control method, implemented with a perfect PV output forecast and assessed over three years of hourly data, indicate that annual cost savings over other methods are achievable. Results with the real-world actual PV output forecast, evaluated between June–September 2020, demonstrate DHW heating cost savings up to 36–53%, even though forecasting errors are present. The heating costs are 9–11% higher compared against the perfect forecast case. The suggested control method thereby effectively reduces the costs when compared with all other methods, and its performance is not significantly affected even when an actual imperfect forecast is implemented. The results also indicate that minimizing energy consumption does not offer the lowest cost.
Article
The amount of installed solar power in Finland is increasing as a result of decreasing photovoltaic (PV) system component prices. The growth is especially noticeable in residential systems, and ways to make PV electricity a more competitive choice for Finnish residents are studied. One of these ways is to decrease the solar PV electricity production costs by decreasing the investment costs by undersizing the inverter of the PV system. The objective of undersizing is to find the optimal array-to-inverter sizing ratio (AISR) where the ratio of the economic loss from the clipped energy to the economic gain from the decreased system investment achieved by an undersized inverter is lowest. In this paper, the economically most optimal AISRs are determined for different residential array sizes, orientations, and inclinations when operating in Finnish locations and conditions. Calculations for each inverter size are carried out by using recorded Finnish meteorological data and the current Finnish PV system cost distribution, and by analyzing existing 1-s resolution production measurement data of a Finnish PV system. It is concluded that it is necessary to use 1-s resolution data as the use of 1-h resolution production data would lead to more significant undersizing caused by the power clipping occurring within an hour. The optimal AISRs presented in this study are higher than the optimal ratios reported in previous studies for locations further south than Finland. This can be explained by the northern location of Finland, where the irradiance above Standard Test Conditions (STC) is lower than in central Europe, for example. This allows more significant undersizing as less energy is clipped even at higher ratios. In the case of south-oriented arrays in a 30° installation angle, the optimal AISRs for the 10 kW, 6 kW, and 3 kW inverters were 1.6, 1.8, and 2.08, respectively. Again, the AISRs for the southwest-southeast facade installations were 1.8, 1.9, and 2.17 for the inverters under study. They do not clip the produced energy as much as rooftop systems because their production is more evenly distributed throughout the day, yet they do not achieve as low production costs either. It is pointed out that if the PV self-consumption is optimized by using PV to heat water or batteries as a storage, limitation of the PV generation might not be the correct solution.
Technical Report
Full-text available
Technical Report "Global Energy System based on 100% Renewable Energy – Power Sector", published at the Global Renewable Energy Solutions Showcase event (GRESS), a side event of the COP23, Bonn, November 8, 2017 A global transition to 100% renewable electricity is feasible at every hour throughout the year and more cost effective than the existing system, which is largely based on fossil fuels and nuclear energy. Energy transition is no longer a question of technical feasibility or economic viability, but of political will. Existing renewable energy potential and technologies, including storage can generate sufficient and secure power to cover the entire global electricity demand by 2050 . The world population is expected to grow from 7.3 to 9.7 billion. The global electricity demand for the power sector is set to increase from 24,310 TWh in 2015 to around 48,800 TWh by 2050. Total levelised cost of electricity (LCOE) on a global average for 100% renewable electricity in 2050 is 52 €/MWh (including curtailment, storage and some grid costs), compared to 70 €/MWh in 2015. Solar PV and battery storage drive most of the 100% renewable electricity supply due to a significant decline in costs during the transition. Due to rapidly falling costs, solar PV and battery storage increasingly drive most of the electricity system, with solar PV reaching some 69%, wind energy 18%, hydropower 8% and bioenergy 2% of the total electricity mix in 2050 globally. Wind energy increases to 32% by 2030. Beyond 2030 solar PV becomes more competitive. Solar PV supply share increases from 37% in 2030 to about 69% in 2050. Batteries are the key supporting technology for solar PV. Storage output covers 31% of the total demand in 2050, 95% of which is covered by batteries alone. Battery storage provides mainly short-term (diurnal) storage, and renewable energy based gas provides seasonal storage. 100% renewables bring GHG emissions in the electricity sector down to zero, drastically reduce total losses in power generation and create 36 million jobs by 2050. Global greenhouse gas emissions significantly reduce from about 11 GtCO2eq in 2015 to zero emissions by 2050 or earlier, as the total LCOE of the power system declines. The global energy transition to a 100% renewable electricity system creates 36 million jobs by 2050 in comparison to 19 million jobs in the 2015 electricity system. Operation and maintenance jobs increase from 20% of the total direct energy jobs in 2015 to 48% of the total jobs in 2050 that implies more stable employment chances and economic growth globally. The total losses in a 100% renewable electricity system are around 26% of the total electricity demand, compared to the current system in which about 58% of the primary energy input is lost.
Conference Paper
Full-text available
The proper modeling of Photovoltaic(PV) systems is critical for their financing, design, and operation. PV LIB provides a flexible toolbox to perform advanced data analysis and research into the performance modeling and operations of PV assets, and this paper presents the extension of the PV LIB toolbox into the python programming language. PV LIB provides a common repository for the release of published modeling algorithms, and thus can also help to improve the quality and frequency of model validation and inter comparison studies. Overall, the goal of PV LIB is to accelerate the pace of innovation in the PV sector.
Conference Paper
There are several barriers to achieving an energy system based entirely on renewable energy (RE), not the least of which is doubt that high capacities of solar PV can be feasible due to long, cold and dark Finnish winters. Technologically, several energy storage options can facilitate high penetrations of solar PV (up to 29 TWhe, or 16% of annual electricity production) and other variable forms of RE. These options include electric and thermal storage systems in addition to a robust role of Power-toGas (PtG) technology. Approximately 45% of electricity produced from solar PV was used directly over the course of the year, which shows the relevance of storage. In terms of public policy, several mechanisms are available to promote various forms of RE. However, many of these are contested in Finland by actors with vested interests in maintaining the status quo rather than by those without faith in RE conversion or storage technologies. These vested interests must be overcome before a zero fossil carbon future can begin.
Conference Paper
Solar power plants have become common during last few years in the middle Europe, especially in Germany. On the other hand, solar power has not grown in the Nordic countries, in spite of Denmark after the favorable net-metering legislation in the year 2011. Finland is one of these countries that has low solar power capacity. Many Nordic countries, such as Finland, have relatively low electricity price that is supposed to cause challenges for the viability of solar power production without legislation or does it? In this paper, the potential for solar power production in Nordic conditions is studied, simulated, and measured. A large scale solar power plant is built to Lappeenranta University of Technology (LUT).
Article
During the years 2001–2005, a European solar radiation database was developed using a solar radiation model and climatic data integrated within the Photovoltaic Geographic Information System (PVGIS). The database, with a resolution of 1 km × 1 km, consists of monthly and yearly averages of global irradiation and related climatic parameters, representing the period 1981–1990. The database has been used to analyse regional and national differences of solar energy resource and to assess the photovoltaic (PV) potential in the 25 European Union member states and 5 candidate countries. The calculation of electricity generation potential by contemporary PV technology is a basic step in analysing scenarios for the future energy supply and for a rational implementation of legal and financial frameworks to support the developing industrial production of PV. Three aspects are explored within this paper: (1) the expected average annual electricity generation of a ‘standard’ 1 kWp grid-connected PV system; (2) the theoretical potential of PV electricity generation; (3) determination of required installed capacity for each country to supply 1% of the national electricity consumption from PV. The analysis shows that PV can already provide a significant contribution to a mixed renewable energy portfolio in the present and future European Union.
load and generation statistics 2015 www.fingrid.fi
  • Fingrid
Fingrid, load and generation statistics 2015 www.fingrid.fi/EN/ELECTRICITY-MARKET/LOAD- AND-GENERATION/Pages/default.aspx
Electric Heating efficiency program's final report)
  • Sähkölämmityksen Motiva
  • Tehostamisohjelma Elvari In Finnish
Motiva, Sähkölämmityksen tehostamisohjelma Elvari 2008-2015 loppuraportti, in Finnish (Electric Heating efficiency program's final report), 2015. http://www.slideshare.net/MotivaOy/elvari-loppuraportti
Sähkölämmityksen tehostamisohjelma Elvari 2008-2015 loppuraportti, in Finnish (Electric Heating efficiency program's final report
  • Motiva
Motiva, Sähkölämmityksen tehostamisohjelma Elvari 2008-2015 loppuraportti, in Finnish (Electric Heating efficiency program's final report), 2015. http://www.slideshare.net/MotivaOy/elvari-loppuraportti
Energy Market Authority, official statistics of electricity distribution companies
EMA, Energy Market Authority, official statistics of electricity distribution companies 2014.