Off-Grid System Sizing & Cost
Off-grid systems vary widely in size and cost depending on the loads that the owner desires/requires to run and the unique qualities of the site. Budget, of course, is perhaps the largest consideration in choosing the size of an off-grid power system.
The major components of a system are the solar array, the inverter, and the battery bank. These individual parts will determine how much power is generated, how much power is available in the conversion to household current, and how much power is held in reserve.
Energy efficiency is vital when designing an off-grid system. The cost of the system is determined by its size, and the size of the system is determined by the appliances the homeowner intends to power. Water pumping and refrigeration are necessities, and these appliances and their electrical consumption are considered first when building a system proposal. Next are appliances where use is more driven by choice – if an appliance generates heat such as a toaster, coffee maker, or dishwasher, it needs careful consideration because these items use a significant amount of power and will increase the size of a system. Off-grid systems are capable of providing every comfort and convenience of a “standard” home. They usually accomplish this by considering high levels of efficiency rather than making extraordinary investments in power production. We design systems that work as efficiently as possible.
The smallest systems provide DC voltage only. These systems are great for camps and cabins, providing power for simple living with lighting, DC water pumping, and even entertainment systems. These solar systems range in price from around $3500 to $5,000. Adding more solar modules increases your charging capacity. Add an inverter, and now you have AC current available like a standard household. Many inverters also include battery chargers that work with a generator to back up the solar array as your source of charging for your battery bank. The larger the inverter, the larger the charger built into it. These inverters have a built-in transfer switch allowing your AC circuits to run off the generator while your batteries are charging. Battery bank size is determined by the amount of reserve power required but also by the amount of charging capacity available. It’s important that batteries be regularly and fully recharged. We do not oversize battery banks relative to the amount of charging available. Mounting for the solar modules is another consideration that impacts the cost of the installed system. Larger systems that provide many or all conveniences of a standard, grid-tied home range in price from $13,000 to $23,000. Systems may be much larger, thereby capable of producing and storing significantly more power – the sky’s the limit and the equation is simple: more watts = more dollars!