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Continuous increase of the production of photovoltaic energy requires precise forecasting to ensure grid stability. This paper presents a detailed benchmark of eight commercial forecasting solutions for intra-day solar forecasts. The comparison was carried out on a period of six months, from November to May 2021, on seven different PV plants located in different countries of the northern hemisphere. Performance evaluation metrics MAE, RMSE and MBE are used in order to analyze the forecasting precision. It is shown that forecasting solar power remains challenging, as shown by the important dispersion between the actors that we have observed.

Vertical coupling between silicon-on-insulator waveguides and optical fibers is achieved using adapted fibers with an angled facet. The proposed coupling scheme is demonstrated for waveguides containing uniform one-dimensional grating couplers. A coupling efficiency of 32% and a 1 dB bandwidth of 32 nm are measured at a wavelength of 1550 nm. We demonstrate single-step fabrication of these fibers using a simple molding technique. OCIS codes: 130.0130, 050.2770.

In 2018, the production of hydrogen from fossil fuel feedstocks for industrial use emitted around 830 million tons of carbon dioxide. The development of green hydrogen production from renewable energy is a promising solution to decrease the carbon footprint caused by hydrogen production. Herein, the impact of the variability of the power output simulated from a single‐point irradiance measurement on levelized cost of hydrogen (LCOH) calculations is studied. The analysis is carried out using 7 month of 1 min power and plane‐of‐array irradiance historical data from a 36 MWp photovoltaic (PV) plant located in Brazil. LCOHs calculated using historical power production will be compared with LCOHs calculated using power production simulated by two different methods. The difference between the two methods lies in the extent to which the variability of the power output of the PV plant is considered. The focus is set on off‐grid electrolyzers directly powered by PV solar plants. [ABSTRACT FROM AUTHOR]

Compact metal grating couplers for efficient and broadband coupling between optical fibers and silicon-on-insulator waveguides are proposed and demonstrated. Simulation results for silver, gold, aluminum and copper grating couplers are presented. Using a uniform silver grating, coupling efficiencies are calculated as high as 60 % at a wavelength of 1.55 mum. Metal grating couplers require only one single etching or lift-off step and are therefore very easy to fabricate. As a proof of principle, a gold grating coupler for near-vertical fiber-to-waveguide coupling was fabricated using e-beam writing and lift-off, demonstrating 34 % coupling efficiency and a 1 dB-bandwidth of 40 nm. Measurement data and simulation results are in good agreement.