All sky imaging-based short-term solar irradiance forecasting with Long Short-Term Memory networks

The intermittent nature of solar irradiance, primarily due to cloud movements, leads to rapid short-term fluctuations in the power output of photovoltaic (PV) systems. These fluctuations pose a significant challenge for integrating this renewable energy source into the power grid. Accurate forecasting of solar irradiance is not only crucial but also multi-beneficial. It enables more precise grid management by allowing operators to anticipate power output fluctuations and adjust energy distribution and storage strategies accordingly. This proactive approach reduces the reliance on backup power sources, which are often less sustainable and more expensive. Furthermore, accurate forecasts enhance the overall efficiency and reliability of energy systems by minimizing the impact of power variability on the grid, thereby supporting a more stable and sustainable energy supply. Addressing this need, our study focuses on the development of a forecasting model through innovative feature engineering, systematic design of specific attributes, and optimization of sequence length. The model is tailored to perform efficiently across various weather conditions and offers predictions for a time horizon of 0 to 20 min ahead. Utilizing a Long Short-Term Memory (LSTM) model, we achieve a remarkable ramp Forecast Skill Score of 39% in sunny and 25% in partially cloudy conditions. This work not only contributes to the existing literature but also presents a pioneering methodology for solar energy integration, highlighting the importance and application of accurate short-term solar irradiance forecasting

Nanoparticles for Luminescent Solar Concentrators - A review

The leader of todays solar energy revolution is undoubtedly the silicon photovoltaic (PV) module. However, despite the immense progress in efficiency and the phenomenal drop of manufacturing and installation costs the dark blue flat panels have not found widespread use in the modern urban environment. The scarcity of available rooftop space, the high cost of land and the irregular metropolitan skyline have not allowed conventional solar technologies to supply cities with clean energy. Thus, new concepts are being investigated to integrate solar generators into new and existing buildings in the form of facades or windows. Luminescent Solar Concentrators (LSCs) offer a novel approach for the utilization of solar irradiation in the form of transparent glazing systems that have the potential to become functional elements of the building envelope. This paper highlights and compares the most recent technological advances in the field of LSC technology and the contribution of colloidal chemistry with reabsorption-free emitters offering broadband absorption and enhanced stability. Combined with a critical study of the newly emerged LSC applications in various fields this study will also attempt to give a possible glimpse of the near future of transparent solar harvesting devices

Economic benefits of combining self-consumption enhancement with frequency restoration reserves provision by photovoltaic-battery systems

Residential and commercial photovoltaic (PV) battery systems are increasingly being deployed for local storage of excess produced PV energy. However, battery systems aimed at increasing self-consumption are not constantly put to use. Additional battery storage capacity is available for a second application to improve the profitability of an energy storage system. One of these options is the provision of frequency restoration reserves (FRR) to the electricity balancing market. This provision can be either negative to compensate for excess power supply, or positive to compensate for excess demand on the power market. This study assesses the benefits for residential and commercial PV-battery systems by combining PV energy storage for higher self-consumption with provision of FRR. Six battery storage dispatch strategies were developed and assessed on the technical and economic performance of 48 residential and 42 commercial PV-battery systems. These systems were modelled over their economic lifetime with a time resolution of 5 min and with historical energy consumption measurements and market prices. FRR provision results in a small drop in the self-consumption rate of 0.5%. However annual revenues are significantly increased. Using battery storage systems only for self-consumption is not profitable with the assumptions used in this study. Provision of negative FRR substantially reduces the electricity bought with the consumption tariff and increases investment attractiveness substantially. Prioritizing the provision of FRR over self-consumption enhancement results in even higher revenues, but significantly reduces self-consumption. We recommend FRR provision to economically investment in residential battery storage systems. Commercial systems need prioritization of both positive and negative FRR provision over self-consumption for a cost-effective investment. In conclusion, combining enhancement of PV self-consumption with the provision of frequency restoration reserves leads to profitable investments

Economic benefits of combining self-consumption enhancement with frequency restoration reserves provision by photovoltaic-battery systems

Residential and commercial photovoltaic (PV) battery systems are increasingly being deployed for local storage of excess produced PV energy. However, battery systems aimed at increasing self-consumption are not constantly put to use. Additional battery storage capacity is available for a second application to improve the profitability of an energy storage system. One of these options is the provision of frequency restoration reserves (FRR) to the electricity balancing market. This provision can be either negative to compensate for excess power supply, or positive to compensate for excess demand on the power market. This study assesses the benefits for residential and commercial PV-battery systems by combining PV energy storage for higher self-consumption with provision of FRR. Six battery storage dispatch strategies were developed and assessed on the technical and economic performance of 48 residential and 42 commercial PV-battery systems. These systems were modelled over their economic lifetime with a time resolution of 5 min and with historical energy consumption measurements and market prices. FRR provision results in a small drop in the self-consumption rate of 0.5%. However annual revenues are significantly increased. Using battery storage systems only for self-consumption is not profitable with the assumptions used in this study. Provision of negative FRR substantially reduces the electricity bought with the consumption tariff and increases investment attractiveness substantially. Prioritizing the provision of FRR over self-consumption enhancement results in even higher revenues, but significantly reduces self-consumption. We recommend FRR provision to economically investment in residential battery storage systems. Commercial systems need prioritization of both positive and negative FRR provision over self-consumption for a cost-effective investment. In conclusion, combining enhancement of PV self-consumption with the provision of frequency restoration reserves leads to profitable investments

Assessment of policy based residential solar PV potential using GIS-based multicriteria decision analysis : A case study of Apeldoorn, the Netherlands

The Postal Code Rose policy is part of the 2013 Dutch Energy Agreement of the Social and Economic Council of the Netherlands, introduced to support sustainable energy growth. This paper presents a case of the Dutch Postal code Rose policy by developing a method combining geographical information systems (GIS) and multicriteria decision analysis (MCDA), which allows determining the solar photovoltaic potential when fully applying this policy. As case study, the city of Apeldoorn in the Gelderland province of the Netherlands was selected. The research evaluates the technical potential of the city and then applies it to the Postal code Rose framework by using social criteria. The social criteria comprise of the most important factors that play a role in the adoption of solar PV. The results showed that by fully applying the Post Code Rose policy ~77% of the total electricity demand of Apeldoorn could be covered by solar PV

Lowering greenhouse gas emissions in the built environment by combining ground source heat pumps, photovoltaics and battery storage

Ground source heat pumps (GSHPs) have been suggested to replace gas-based heating in urban environments to reduce greenhouse gas emissions and help to comply with the Paris Agreement. The emission reduction from GSHP depends on the carbon intensity of the electricity generation mix. Moreover, grid capacity may be limiting the introduction of these high-electricity demand GSHP systems. Photovoltaics (PV) systems help to provide additional emission reductions for residential GSHP systems. Battery energy storage systems can reduce the peak demand and allow for more GSHPs within the low voltage grid. We developed a techno-economic and environmental assessment model to quantify this impact of PV and batteries combined with residential GSHP systems. Measured demand data of 16 dwellings with GSHP and PV systems from the Netherlands were used. We show that PV can provide around 19% of the GSHP demand, while batteries enhance this by 50% and reduce the peak demand by 45%. Greenhouse gas emission of a GSHP with PV is reduced on average with 73 tCO2-eq, corresponding to a 80% reduction, over a 30-year lifetime. Dwellings with only a GSHP system have a net present values increase of around € 275 per tCO2-eq of avoided emission. This is reduced to € 230 per tCO2-eq when PV and storage is added to the system. Nevertheless, investment in GSHP systems today is not economically attractive for many dwellings. A sensitivity analysis showed that policies should focus on increasing natural gas tariffs, carbon taxation, investment subsidies or combinations of these routes to encourage sustainable heating

Assessment of forecasting methods on performance of photovoltaic-battery systems

Photovoltaic (PV) systems are increasingly deployed on buildings in urban areas, causing additional power flows and frequency fluctuation on the low voltage electricity grid. Control strategies for PV-battery energy storage systems (BESS) assist in reducing power flows to the grid and improve the self-consumption of PV generated electricity. Therefore, these control strategies require accurate forecasts of PV electricity production and electricity consumption. We developed and assessed relatively simple forecasting methods using 5 min resolution data, to predict the PV yield and to forecast electricity consumption for one year. We used these forecasts with a predictive control strategy to increase PV self-consumption, decrease curtailment losses and improve BESS revenues. Electricity demand patterns of 48 residential and 42 commercial Dutch buildings were used. PV yield forecast methods that uses predicted weather data shows the lowest forecast error. The best performing forecast method for predicting energy consumption of residential buildings requires historical energy consumption data of the previous seven days. Commercial systems require historical energy consumption of the previous weekday. Significant reduction in curtailment losses is achieved using predictive control strategies, especially in combination when clear-sky radiation data is used to forecast PV yield. Similar self-consumption rates were found for predictive control as for real-time control. This indicates that reduction of curtailment loss can be combined while maintaining the level of PV self-consumption. Revenues from battery storage are increased by forecast methods and are highly dependable on boundary condition of a PV-battery system, such as the feed-in limit (FIL) and the feed-in tariff. Therefore, we recommend customizing battery control strategies based on these system boundaries conditions to improve energy storage potential

Lowering greenhouse gas emissions in the built environment by combining ground source heat pumps, photovoltaics and battery storage

Ground source heat pumps (GSHPs) have been suggested to replace gas-based heating in urban environments to reduce greenhouse gas emissions and help to comply with the Paris Agreement. The emission reduction from GSHP depends on the carbon intensity of the electricity generation mix. Moreover, grid capacity may be limiting the introduction of these high-electricity demand GSHP systems. Photovoltaics (PV) systems help to provide additional emission reductions for residential GSHP systems. Battery energy storage systems can reduce the peak demand and allow for more GSHPs within the low voltage grid. We developed a techno-economic and environmental assessment model to quantify this impact of PV and batteries combined with residential GSHP systems. Measured demand data of 16 dwellings with GSHP and PV systems from the Netherlands were used. We show that PV can provide around 19% of the GSHP demand, while batteries enhance this by 50% and reduce the peak demand by 45%. Greenhouse gas emission of a GSHP with PV is reduced on average with 73 tCO2-eq, corresponding to a 80% reduction, over a 30-year lifetime. Dwellings with only a GSHP system have a net present values increase of around € 275 per tCO2-eq of avoided emission. This is reduced to € 230 per tCO2-eq when PV and storage is added to the system. Nevertheless, investment in GSHP systems today is not economically attractive for many dwellings. A sensitivity analysis showed that policies should focus on increasing natural gas tariffs, carbon taxation, investment subsidies or combinations of these routes to encourage sustainable heating

Nanoparticles for Luminescent Solar Concentrators - A review

The leader of todays solar energy revolution is undoubtedly the silicon photovoltaic (PV) module. However, despite the immense progress in efficiency and the phenomenal drop of manufacturing and installation costs the dark blue flat panels have not found widespread use in the modern urban environment. The scarcity of available rooftop space, the high cost of land and the irregular metropolitan skyline have not allowed conventional solar technologies to supply cities with clean energy. Thus, new concepts are being investigated to integrate solar generators into new and existing buildings in the form of facades or windows. Luminescent Solar Concentrators (LSCs) offer a novel approach for the utilization of solar irradiation in the form of transparent glazing systems that have the potential to become functional elements of the building envelope. This paper highlights and compares the most recent technological advances in the field of LSC technology and the contribution of colloidal chemistry with reabsorption-free emitters offering broadband absorption and enhanced stability. Combined with a critical study of the newly emerged LSC applications in various fields this study will also attempt to give a possible glimpse of the near future of transparent solar harvesting devices