Solar power forecast
Solar power forecasts are predictions of the electrical power that one or more photovoltaic systems will generate over the next few days. They describe a process which enables the time course of the feed-in power of one or more photovoltaic systems to be determined for the following days. A combination of weather forecast and system simulation is used. The solar radiation forecast by weather models is used to calculate the performance of individual photovoltaic systems. Such predictions have long been used in the field of wind energy. They enable better integration of the weather-dependent energy sources in the electricity market.
Use
Relevance for network security
Solar power forecasts are necessary to improve the grid integration of photovoltaics (PV) into the existing energy supply structure . The energy supply companies (EVU) always try to provide exactly as much electricity as is currently being demanded by the consumers. For this purpose, the consumption and supply of electricity are planned in advance. In areas with a high proportion of PV, the availability of electricity is underestimated on sunny days, while it is overestimated on cloudy days. This can lead to voltage fluctuations in the power grid . These fluctuations have to be compensated for by expensive balancing energy. In extreme cases, this could even endanger network security. In a position paper dated January 7, 2011, the Federal Network Agency asked all distribution network operators to improve the forecasting methods for their solar power feed-in.
Legal relevance
The Renewable Energy Sources Act (EEG) stipulates that solar power should be marketed on the European Energy Exchange (EEX). Since only future electricity is traded on the exchange, a forecast is essential. That is why EEX and the four German transmission system operators (TSOs) publish nationwide solar power forecasts on a daily basis. This is intended to ensure transparency when billing the EEG.
Procedure
First of all, it must be determined how much radiation falls on the solar system. For this purpose, the global radiation determined by the weather forecast is converted to the inclined surface of all modules if necessary. With the help of the efficiency and the so-called "performance rate", the current performance is calculated. The Swiss company meteoblue, together with the solar server, offers such calculations free of charge for individual photovoltaic systems.
Web links
Individual evidence
- ↑ Position paper on the improved forecast and accounting for solar power feed-in. ( Page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. on: bundesnetzagentur.de as of January 7, 2011.
- ↑ Expected production solar. ( Memento of the original from January 17, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. at: transparency.eex.com
- ↑ Volker Quaschning: Regenerative Energy Systems. 8th edition. Hanser Verlag, Munich 2013, ISBN 978-3-446-43526-1 .
- ↑ Energy calculation ( Memento of the original dated December 28, 2010 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. on: meteoblue.com (engl.)
- ↑ Performance forecast for private solar power systems in Europe. on: solarserver.de
