15KW Solar Packages

Two thousand kWh per month is well above what a modest off-grid cabin typically uses, but it is realistic for a full-time family home with normal household habits. A three-bedroom home with a washer and dryer, full kitchen, well pump, home office, and one or two mini-split systems can easily use between 1,800 and 2,200 kWh per month.

Usage can climb beyond that range with electric water heating, central air conditioning in a hot climate, a large workshop, or several family members using appliances and electronics throughout the day.

The 15.4 kW array is estimated to produce approximately 69,300 Wh per day under good sun conditions, giving the system useful margin above the 2,000 kWh monthly baseline. Based on our experience designing off-grid systems, that extra production can reduce generator use during spring and fall.

Each 550W bifacial panel is approximately 7.5 feet tall by 3.5 feet wide, providing roughly 26 square feet of panel area. With 28 panels, the array uses approximately 730 square feet before accounting for spacing between rows.

For a ground mount, proper row spacing is necessary to reduce self-shading. In practice, the full installation will typically require approximately 1,200 to 1,500 square feet of open, unobstructed land with a favorable southern orientation.

For a roof mount, the usable roof plane must accommodate all 28 panels. Dormers, skylights, chimneys, vents, and HVAC equipment can significantly reduce the available space.

Based on trends we have observed from support requests, customers who measure their available roof area before ordering are less likely to encounter layout problems. Contact us before ordering if you are unsure whether your roof can accommodate the full array.

The Ultimate is the highest-equipped configuration in the 15 kW collection. In addition to the standard 15.4 kW solar array and Sol-Ark 18K inverter, it includes an OMO 32 kWh Freedom Series battery, a Kubota generator, an EMP Shield, and a Sinclair ground mount.

It is designed as a more complete off-grid power system rather than a basic package that requires customers to source major backup and protection components separately.

The Kubota generator provides a professional-grade backup power source intended for long-term use. The EMP Shield is designed to help protect the inverter and connected electronics from damaging electrical surges and electromagnetic events.

From what we see in real customer installations, The Ultimate is best suited for permanent off-grid homes where reliability, backup power, system protection, and redundancy are priorities from the beginning.

MPPT stands for maximum power point tracking. Each MPPT channel operates as an independent solar input that continuously identifies the best voltage and current for the group of panels connected to it.

Having three separate MPPT channels allows panels with different orientations, tilt angles, or shading conditions to operate independently. This prevents one lower-producing string from reducing the output of the others.

On a 28-panel array, this flexibility can be especially useful for roofs with two or three different faces or for systems that combine a roof-mounted array with additional ground-mounted panels.

The Sol-Ark 18K supports up to 28.8 kW of DC-coupled solar across its three MPPTs, so the included 15.4 kW array leaves substantial room for future panel expansion.

For certain off-grid homes, 96 kWh of battery storage is practical rather than excessive. A household using approximately 2,000 kWh per month averages around 67 kWh of energy consumption per day.

A 96 kWh battery bank may not eliminate generator use throughout an extended storm, but it can provide several days of useful autonomy when household loads are managed carefully. This can significantly reduce how often the generator needs to run.

This level of storage is particularly valuable in northern climates with long cloudy periods, locations where generator fuel is expensive or difficult to obtain, and homes with higher-than-average electrical loads.

Customers can also begin with one 32 kWh Freedom Series battery and add a second or third unit later. The Sol-Ark 18K supports up to 350A of continuous battery current, allowing a larger battery bank to be charged efficiently from solar or generator power as the system expands.