{"id":10684,"date":"2024-08-24T06:20:02","date_gmt":"2024-08-24T04:20:02","guid":{"rendered":"https:\/\/reuniwatt.com\/en\/?page_id=10684"},"modified":"2025-11-26T06:17:23","modified_gmt":"2025-11-26T05:17:23","slug":"backtests-hindcasts-historic-solar-and-wind-power-forecasts","status":"publish","type":"page","link":"https:\/\/reuniwatt.com\/en\/products-and-services\/backtests-hindcasts-historic-solar-and-wind-power-forecasts\/","title":{"rendered":"Backtests: Historic solar and wind power forecasts"},"content":{"rendered":"

Backtests or Hindcasts <\/strong>are historic solar or wind power forecasts. They are used to get a glimpse of the expected forecasting accuracy on a specific site. Past data is used to generate historical day-ahead or intra-day forecasts. These simulations enable to determine solar plant parameters in the early planning phase, and evaluate the accuracy of forecasts for a specific site.<\/p>\n<\/div>

\"Reuniwatt<\/span><\/div>
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Determine wind or solar plant parameters<\/h2><\/div><\/div>

Determine wind or solar plant parameters<\/h3>\n

Historic solar and wind forecasts enable the user to determine power plant parameters in the early planning phase, and evaluate the accuracy of forecasts for a specific site.<\/p>\n<\/div><\/div><\/div><\/div><\/div>

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Worldwide availability<\/h2><\/div><\/div>

Worldwide availability<\/h3>\n

Backtests can be performed for any location on Earth. We rely on numerical weather prediction and satellite imagery.<\/p>\n<\/div><\/div><\/div><\/div><\/div>

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Finetune decision-making processes<\/h2><\/div><\/div>

Finetune decision-making processes<\/h3>\n

Backtests or hindcasts can be integrated in simulations during the detailed design process. For example, they can be fed into the Energy Management System (EMS) and\/or the control system of a power plant to fine-tune the decision-making processes in relation to weather conditions.<\/p>\n<\/div><\/div><\/div><\/div><\/div><\/div><\/div><\/div>

<\/i>Methodology
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A hindcast or backtest is a forecast computed in the present, but for dates in the past. For a given site and a determined time period, real-time conditions are simulated (e.g. using our SunSat™ Time Series<\/strong><\/a> for solar power plants or using reanalysis data for wind speed and direction) to determine the historical weather conditions. Historic forecasts are then calculated based on our HourCast™<\/strong><\/a> and DayCast™<\/a><\/strong> algorithms.<\/p>\n

Hindcasts are available worldwide based on robust data from multiple geostationary meteorogical satellites and numerical weather prediction models. They give a clear indication of what to expect in terms of forecasting performance. Hindcasts can prove useful to refine decision-making processes related to weather, and provide realistic revenue estimates for<\/p>\n