Design of an off-grid renewable energy system must take into account the availability of incoming and stored energy supplies and balance them against the demands of electrical loads. Perfect reliability is impossible in any electrical system and higher reliability trades off with higher system cost. This tool allows designers and end users to readily determine what trade-offs are acceptable in system sizing and lifestyle adjustment.
This system simulates various appliance operating models against a year’s worth of hourly solar radiation data (from PV Watts) on a particular solar power system. It graphs, on an hourly basis, a day’s incoming solar energy, the hourly state of charge (SoC) of the battery bank, and the energy consumption of different categories of loads. A search function can find those days where it is expected that a particular system will deplete the batteries (blackout condition), allowing for discussion of possible options (each with different costs and benefits): accept a temporary blackout, use a backup generator, adjust demand (manually or automatically) when depletion is expected, increase generation capacity, or increase storage capacity. Excess energy generation over and above normal demand is also calculated. This excess energy, usually on the sunniest (and often hottest) days, can be used to operate fans, dehumidifiers, air conditioners, pumps, and water heaters.
This allows for a cost and benefit optimized system mix based on an informative consultation with the end user.
Data source: PV Watts CSV export file
Runs simulations based on programmable models of constant, intermittent, dispatchable, and dump electrical load models against a year of hourly solar radiation data to determine reliability of optimized off-grid solar energy system configurations. Loads CSV dataset (downloaded from PV Watts) and displays simulation results using Chart.js.