Savings and payback
See how much a standard-sized system would overproduce for your low usage, what that excess is worth, and what a right-sized system would look like.
For planning purposes only, not financial or tax advice; confirm figures with a licensed installer or tax professional before making a purchase decision.
How it works
Step 1
You'll need both your retail rate and your utility's export credit rate. Compare against the high usage home calculator if your household usage varies a lot by season.
Step 2
Try a common size like 6.5 kW to see how much a standard installation would overproduce for your usage. The solar panel calculator can help if you're starting from scratch.
Step 3
The tool shows a smaller system size that would closely match your actual usage instead of overproducing.
A standard 6.5 kW system fully offsets a 5,000 kWh annual usage and exports roughly 4,490 kWh beyond that each year. That excess isn't wasted, it typically earns a net metering credit, adding about $269 a year on top of $800 in direct bill offset in this example, for $1,069 in total annual value. The US Energy Information Administration's electricity data show how retail rates have moved, which is the starting point for any savings estimate.
Not inherently. Export credits still have value, even at a lower rate than retail. But a smaller system would achieve the same 100% offset for less upfront cost, which often makes for a shorter payback period. For a 5,000 kWh annual usage, a system around 3.4 kW would closely match usage, roughly half the size of the standard example. To size the array behind this number, the system size by annual kwh usage turns your usage into a kilowatt target.
Planning for future usage growth is a common reason to size up anyway, such as an expected EV purchase, a home addition, or electrifying a gas furnace or water heater. See the EV charging savings tool for how a new load can put oversized production to good use rather than exporting it. For the official overview, the US Department of Energy's homeowner's guide to going solar covers buying, leasing, and system sizing.
This tool gives a rough right-sizing estimate based on current usage alone. The annual maintenance cost estimator in our Maintenance & Lifespan section can help you check what upkeep will cost over the life of the right-sized system, and the bill offset percentage calculator shows the offset math in more detail.
Questions
Usage below roughly 6,000 to 7,000 kWh a year is generally considered low, compared to the typical 10,000 to 11,000 kWh most US homes use. A standard 6.5 kW system fully offsets a 5,000 kWh annual usage and exports about 4,490 kWh a year beyond that.
Not necessarily. Excess production is exported to the grid and typically earns a net metering credit, adding value even if it's usually less than the retail rate. In one example, exported power added about $269 a year on top of $800 in direct bill offset.
Often yes, since a smaller system costs less upfront while still fully covering your usage. For a 5,000 kWh annual usage, a system around 3.4 kW would match your usage closely, roughly half the size of a standard 6.5 kW system.
Planning for future usage growth is the most common reason, such as an expected EV purchase, home addition, or electrification of heating. It can be more cost-effective to size up during the original installation than to add panels later.