Stand Alone Solar Power System Design

When designing an off grid power system, it is crucial that we determine the size and type of loads that require powering and when they require power. Variation in load demands need to be evaluated, including seasonal differences, day vs night loads, heat and cooling systems and in many off grid homes, water pumping requirements.

Off Grid Solar Power Systems are generally designed for  worse case condition, ie, Winter Periods where solar radiation drops to more than half of average summer output. Batteries play an important roll in providing power autonomy, and can be scaled up to eliminate the need for a backup generator. Generally, we design systems for 2 – 4 days of autonomy.


Victron-EasySolar-12V-Solar-PV-System-Diagram_500x359.jpgAn average sized off grid power system capable of supply loads to a modern home, will consist of 5-10kWp of solar PV panels, between 15 – 40kWh of available battery energy, and an inverter charger which can discharge between 10 – 20kWp of power.

Smaller off grid power systems can be designed for Mobile Homes, Yachts, Sheds and Villages Dwellings for as little as a few thousand dollars. Please enquire for further details.

Home Efficiency and Design Principals in relation to an Off Grid Power System

Home Design and Appliance Efficiency play a critical roll in determining the size and characteristics of the stand alone power system. Generally, the heating and cooling of a home will determine the cost and size of an off grid power system, so it is imperative that careful consideration be given to home climate control. The Green Power Company recommend the use of evaporative cooling systems in summer (for non-humid conditions) and heat pump/ fire boosted underfloor hydronic heating systems for winter.

Off Grid Solar

Back Up Generators

Stand Alone Power Systems do not have the luxury of mains power backup, so a backup generator is generally required for the worst days of the year. The supplied generator should have Two Wire Auto-start functionality, and have an output peak equal to the combined active loads of the property.

Back Up Power Generators are wired to the inverter charger for automatic startup when solar input is lacking and the available battery power is exhausted. GreenPowerCo can supply and install recommended auto-start generators upon request.

Kubota 6kVa autostart generator
Kubota 6kVa autostart generator