Battery & storage
Enter your daily excess solar production. Get a battery size to capture it, since your utility offers little or no credit for exporting it.
How it works
Step 1
Check your utility's website or ask an installer whether exported solar earns any meaningful credit.
Step 2
The self consumption calculator covers this related sizing approach in more depth.
Step 3
Without export value, every captured kWh directly offsets a grid purchase instead, the same logic behind the time of use arbitrage tool.
A utility without net metering either offers no credit at all for solar power exported back to the grid, or credits it at a wholesale or avoided-cost rate that sits well below the retail price the household would otherwise pay for that same electricity. This makes directly self-consuming solar production, or storing it in a battery for later self-consumption, far more valuable than exporting it, the same principle behind the self consumption battery size tool, and a shift in value worth weighing against battery cost with the quick financing comparison tool in our Financing category.
Under generous net metering, exported solar is credited close to retail value, which reduces the urgency of adding battery storage purely for value-capture purposes, since exporting excess production still returns meaningful money, a policy distinction tracked by the DSIRE database of state renewable energy incentives. Without that credit, every kWh of solar production not consumed directly in the home or captured by a battery is essentially lost value, making a battery sized around the charge time from solar tool's output a much stronger financial case.
Checking a utility's website for their solar or distributed generation interconnection policy, or asking directly during a solar consultation, both reveal whether net metering is offered and at what specific rate, an approach the Department of Energy's guide to grid-tied solar systems recommends before finalizing any battery sizing decision. These policies vary considerably by state and utility, and in some cases even by when a particular system was installed, since some utilities have grandfathered older systems into more favorable terms while changing policy for new installations.
Once you have a battery size aimed at capturing excess production, the time of use arbitrage tool is worth checking too, since many no-net-metering utilities pair that policy with time of use rates that create additional savings opportunities beyond just self-consumption. If EV charging is part of your daily excess solar use, the off-peak EV charging with solar battery tool in our Solar + EV Integration category covers that combined strategy.
Questions
A household with 12 kWh of daily excess solar production, the amount beyond immediate home use, needs about 14.5 kWh of nameplate battery capacity to capture nearly all of it rather than exporting it for little or no credit.
A utility without net metering either doesn't credit exported solar power at all, or credits it at a rate far below the retail electricity price, sometimes called avoided cost or wholesale rate. This makes self-consuming solar production directly, rather than exporting it, far more valuable than it would be under standard net metering.
Yes, significantly. Under generous net metering, exported solar is credited near retail value, reducing the urgency of battery storage for value capture. Without that credit, every kWh not consumed directly or stored is essentially lost value, making a larger battery sized to capture more of the daily excess a much stronger financial case.
Checking your utility's website for their solar or distributed generation interconnection policy, or asking directly during a solar consultation, both reveal whether net metering is offered and at what rate. Policies vary significantly by state, utility, and sometimes even by when a system was installed.
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