PVSyst Meteo Data Import with Solcast

Solcast day-ahead irradiance and power forecasts are now improved by 15% to 35%

25 May 2020

Meteonorm data as the PVSyst default choice

But look no further than the description of the meteonorm data on the PVSyst data source reference page. - "not measured, but are rather synthetic data"

As I've previously discussed in detail, there are many potential pitfalls in relying on synthetic data for your solar project.

I boiled it down to this - synthetic estimates are useful when high quality direct observational data do not exist. However, given the presence of a global fleet of high resolution weather satellites that directly image cloud cover - this is not the case!

The Meteonorm alternative for PVSyst

Solcast uses a fleet of five weather satellites that image the world’s cloud cover in high resolution, multi-spectral imagery at up to 5-minute intervals. The resolution of this data is about 1km2 resolution on average across these regions of coverage.


We've leveraged this data by applying an entirely new suite of modelling tools which very accurately detect and characterise cloud cover and directly include the impact of aerosols. This detailed, 'big data' approach means it is no longer necessary to rely on lower quality datasets based on ‘guesswork’ (e.g. synthetic data!).

Integrating Solcast Data with PVSyst

While you could choose to move ahead with solar farm modelling based on the 'default' data options in PVSyst, with just a few minutes of extra effort, you could be completing this with increased levels of rigour. Saving you pain down the track when you're financing the site or attempting to find a buyer for that asset you've devoted many hours of your team's precious time into perfecting.

Skip the Meteonorm Default Step 1 - Databases


Skip the Meteonorm Default Step 2 - Known Format


Full Guide - Just a few more steps!

You can find the full step-by-step guide for adding your own high quality data option to PVSyst in our walkthrough page here.

But of course, you'll first need some Solcast data to plug into PVSyst. Thankfully, we've thought this one through for you in great detail, and have made it easy to download our historical and tmy data in PVSyst format.

Once you've created your free API Toolkit account, you can access free TMY and Monthly Averages requests to complete your own PVSyst integration within just a few clicks.

In the API Toolkit, create a new historical data request, using our quick order form (pictured below) and choose the data type most relevant to your project design phase. Use your free historical data credits to complete the order, and you'll have access to the PVSyst format of the file within a few minutes.

Your data options meteornorm-beating-historical-data.png

Be sure to select 'PVSyst' format on the download page! pvsyst_TMY_1v1.PNG

Beat the Default and Replace Meteonorm

If you're serious about a high quality outcome from your PV modelling efforts, then you should be equally rigorous in your data input choices. As the adage goes - "garbage in, garbage out". Now, to be clear, I'm not calling Meteonorm data garbage! Far from it, they are a respectable business with a long history of supporting the solar industry, and we take our hats off to that effort! They're making their own contribution to the solar powered future, and that's the team effort we care most about at Solcast.

But what I am definitely saying is - high resolution, high quality satellite imagery and the application of our new stack of modelling tools will provide you with a more robust, more accurate outcome. Your team ain't the 'default', don't let your data choices be!

Dr. Nick Engerer

Dr. Nick Engerer

Solcast CTO • Author

Nick is an expert in the field of solar radiation and distributed solar PV modelling, and has co-founded Solcast out of a sincere desire to enable others to build the solar-powered future.

Read more about Dr. Engerer's scientific papers

Solar Power Forecasting