Here's what we do:

1. First, we need detailed information about the system's proposed location.
   Ideally you supply a grid reference plus topographical information on the immediate area - is the site on a hill or in a valley, is it near buildings/trees?

2. Then we do the wind & solar power calculations. We take an 18 year annual ‘average’ using data supplied by an international meteorological institute. For a UK-based system, we also cross reference this against a more localised (square kilometre) wind database. We are aware that many times the wind speeds will be significantly higher than the average and this has been factored in by using a Weibull distribution curve.

3. Once the solar and wind data has been collected, we input this into the Off-grid Power Matrix.

   This shows the estimated amounts of power generated over a 12 month period. On the Off-grid Power Matrix, we show the ‘load line’ in red.  As power output is often at it's lowest during the winter months when solar irradiation levels are at their lowest, we design the system to produce enough power to accommodate the 20% safety margin.

   

4. Where power requirements are high, it may make sense to supplement the renewables with a back-up generator or methanol fuel cell. This will cover the power load for a few of the winter months and means the system isn't over-sized, keeping system costs within budget. The generator would only kick in when the battery voltage dropped to a pre-set level and would run for the minimum amount of time.

   

5. To give you complete peace of mind, you can remotely monitor and control the off-grid system. Using Victron's Cerbo GX, you can check battery status, receive alarm signals and change system settings without having to go on-site. This is an essential requirement for business critical applications.