Estimate Your Off-Grid System Cost
Fill in the fields below — every value has a sensible default so you can just click Calculate to see an example first.
Going off-grid means generating and storing 100% of your home's electricity without any connection to the utility grid. That makes an off-grid system fundamentally different — and more expensive — than a standard grid-tied solar setup, because it has to work every single day, including during a week of clouds, with no grid to fall back on.
This calculator estimates the panel size, battery bank size, and total cost of a complete off-grid solar system based on your actual electricity usage and location — so you can compare configurations before talking to an installer.
What Is an Off-Grid Solar System? The Basics
An off-grid solar system generates, stores and delivers all of your electricity independently of the public utility grid. Solar panels charge a battery bank through a charge controller, and an inverter converts that stored energy into the AC power your home actually uses. Because there's no grid to draw from at night or during a stretch of bad weather, the battery bank has to be large enough to carry the whole house on its own.
A grid-tied system works differently: any surplus power it produces is sent back to the utility grid through net metering, and the grid effectively acts as a free, unlimited "battery." That's why grid-tied systems don't need batteries at all in most cases, and why they cost a fraction of an off-grid setup.
Off-grid solar makes the most sense for properties that don't have practical access to the grid — rural land, cabins, and remote parcels where running a utility line would cost tens of thousands of dollars. It can also suit homeowners who want complete energy independence and are willing to pay for it, even where grid access exists.
How the Calculator Works Methodology
The calculator above turns your inputs into a system size and a cost estimate using the same logic an installer would use when sizing a real off-grid system:
- Daily electricity usage sets the total energy your system has to produce and store every day.
- Solar panel size is calculated by dividing your daily usage by your local peak sun hours, then adding roughly 30% extra capacity to cover charging losses and cloudy days.
- Battery storage is sized for your chosen number of autonomy days, adjusted for how deeply each battery chemistry can safely be discharged — lithium batteries can use about 90% of their rated capacity, lead-acid only about 50%.
- Inverter size scales with your panel and battery capacity, since it has to handle the full output of both.
- Installation costs (wiring, mounting, labor and permits) are estimated as a percentage of total equipment cost, which is how most installer quotes are structured.
- Backup generator cost is added only if you select it, since it's optional but strongly recommended for extended low-sun periods.
The result is a realistic cost range, not a fixed quote — actual pricing varies by installer, region, and equipment brand, so treat this as a planning number to bring into conversations with solar contractors.
Factors That Affect Off-Grid Solar Cost What Moves the Price
Average Off-Grid Solar Costs By System Size
These are approximate all-in ranges, including panels, battery bank, inverter, charge controller and standard installation. Actual pricing varies by region, equipment brand and installer.
| System Size | Estimated Cost | Typical Use |
|---|---|---|
| 3 kW | $8,000 – $15,000 | Small cabin, tiny home, RV |
| 5 kW | $15,000 – $25,000 | Small to mid-size home |
| 8 kW | $22,000 – $40,000 | Full-size family home |
| 10 kW | $30,000 – $50,000+ | Large home, EV charging, workshop |
These figures are gross costs before incentives. In the U.S., the 30% federal solar Investment Tax Credit applies to panels, batteries, inverters and labor for off-grid systems — see the U.S. Department of Energy's federal solar tax credit guide for current eligibility rules.
Example Calculation Walk-Through
A home using 25 kWh per day, located somewhere that averages 5 peak sun hours, wanting 2 days of battery autonomy on a lithium battery bank, with no backup generator.
A home using less energy per day, or located somewhere with more sun hours, needs a smaller array and a smaller battery bank — which is why entering your own numbers in the calculator above gives a far more useful estimate than a single average figure.
Benefits of Going Off-Grid Why People Do It
- Energy independence. Your power supply doesn't depend on a utility company, rate changes, or grid infrastructure.
- No monthly utility bills. Once installed, your electricity cost is maintenance and eventual battery replacement — not a monthly charge.
- Reliable backup during outages. An off-grid system keeps running through blackouts that would otherwise leave a grid-connected home without power.
- Practical for remote locations. For land far from existing power lines, off-grid solar is often cheaper than paying for a new utility connection.
- 100% renewable electricity. Every kWh you use comes from the sun rather than a fossil-fuel-powered grid mix.
Ways to Reduce Off-Grid Solar Costs Save Money
- Improve energy efficiency first. LED lighting, efficient appliances and a heat pump reduce your daily kWh usage — which shrinks both the panel array and the battery bank you need.
- Compare multiple installer quotes. Off-grid pricing varies more between installers than grid-tied pricing. Getting 3+ quotes can meaningfully lower your total cost.
- Choose the right battery capacity. Oversizing your battery bank for "just in case" scenarios adds thousands of dollars. Size for realistic autonomy needs and lean on a backup generator for rare extended outages.
- Take advantage of available incentives. The federal ITC applies to batteries as well as panels. Some states and utilities offer additional rebates — check what's available in your area before you buy.
Frequently Asked Questions FAQ
Try our other solar calculators
Estimate financing, payback period, and total installation cost for a grid-tied system too — see which option actually saves you more.