A solar feed-in tariff (FIT) pays you a set price for every unit of electricity your solar panels send back to the grid. Unlike some other solar compensation programs, a FIT guarantees that price for a fixed number of years, giving you a predictable return on your investment. Here’s how the entire process works, from the hardware on your wall to the payment on your bill.
The Basic Mechanism
When your solar panels generate electricity, that power first flows to whatever appliances and devices are running in your home. If the panels are producing more than you’re using at that moment, the surplus flows out through your meter and onto the local electricity grid. A feed-in tariff is the rate your utility pays you for that exported electricity.
The defining feature of a FIT is the guaranteed price. Your utility or grid company is obligated to purchase your solar electricity at a predetermined rate, typically locked in for a set contract period. This is different from wholesale electricity prices, which fluctuate throughout the day. The fixed rate is designed to make your investment in solar panels financially predictable, so you can estimate your payback period before you install anything.
In some FIT programs, the utility buys all the electricity your system generates at the FIT rate, and you then purchase back everything you consume at standard retail rates. In others, you only get the FIT rate on the surplus you export after powering your own home. Which model applies depends entirely on the specific program in your area.
How Your Meter Tracks It
The key piece of hardware that makes a feed-in tariff possible is a bidirectional smart meter. This meter records electricity flowing in two directions: power you import from the grid when your panels aren’t producing enough, and power you export to the grid when they’re producing more than you need. Without this meter, there’s no way to accurately measure what you’ve sent back.
These meters (sometimes called four-quadrant meters or import/export meters) capture data in intervals rather than as a single running total. That interval data lets your utility calculate exactly how much you exported and when, which matters for billing. If your home still has an older accumulation meter, it will need to be replaced with a remotely read smart meter before you can participate in a FIT program. The upgrade is usually straightforward, and in many areas the utility or retailer handles the swap.
Advanced bidirectional meters also support time-of-use pricing, meaning the value of your exported electricity can vary depending on when you send it. Some newer tariff structures pay more for electricity exported during peak demand hours and less during midday, when the grid is already flooded with solar power.
Who Qualifies
Most FIT programs set a maximum system size and may restrict participation to certain customer types. Residential programs commonly cap systems at around 10 to 20 kilowatts, while commercial systems might be allowed up to 50 kW or more. Some programs are far more generous: Hawaii’s FIT, for example, allows systems up to 5,000 kW depending on the island.
Beyond size limits, you’ll typically need your system installed by a certified installer, and the equipment itself (panels, inverter, wiring) generally needs to meet local electrical and safety standards. Your meter must be approved for revenue-grade accuracy so the billing data holds up legally. In Australia, for instance, meters must carry National Measurement Institute pattern approval and meet specific accuracy classes for both import and export measurement.
Feed-In Tariffs vs. Net Metering
These two terms get used interchangeably, but they work quite differently. Under net metering, your meter essentially runs backward when you export solar power. At the end of your billing period, the utility calculates the net difference. If you produced more than you consumed, you get paid or credited for the surplus. If you consumed more, you pay for the net amount at standard rates. Your solar generation and your consumption are netted against each other on the same bill.
Under a feed-in tariff, those two flows are tracked separately. You sell all your generated electricity (or just the exported portion) at the FIT rate, and you buy all the electricity you consume at the standard retail rate. These are two distinct transactions. This means the FIT rate and the retail rate are usually different numbers. In some regions and time periods, FIT rates have been set higher than retail rates to encourage adoption. In others, the FIT rate is significantly lower than what you pay to buy electricity, which makes self-consumption (using your own solar power directly) more financially attractive than exporting it.
Why FIT Rates Keep Dropping
If you’ve been watching solar incentives over the past decade, you’ve likely noticed feed-in tariff rates declining in most markets. Several forces drive this trend.
The most straightforward reason is that solar panels have gotten dramatically cheaper. Early FIT rates were set high because the cost of installing solar was high, and governments wanted to make the investment worthwhile for homeowners. As panel and inverter prices dropped, those generous rates were no longer necessary to attract adoption, so regulators adjusted them downward.
Grid stability is the second factor. In countries like Australia, which leads the world in household solar adoption, so many homes now export power during the middle of the day that the grid faces operational challenges. This is known as the “duck curve,” a graph showing electricity demand plunging at midday (when solar floods the grid) and then spiking sharply in the evening (when everyone comes home and the sun sets). That midday oversupply can destabilize the grid and force conventional power plants into expensive rapid cycling.
To address this, some utilities have introduced time-varying export tariffs that pay less for midday exports and more for electricity sent to the grid during late afternoon or evening hours. Research on Australian households found that time-varying export tariffs alone reduced midday grid feed-in by 55.6% and extended solar exports past sunset, because homeowners with batteries shifted when they exported. This actively counteracts the duck curve by smoothing out the supply-demand mismatch.
There are also broader economic considerations. Studies across Europe have found that while feed-in tariffs successfully boost renewable energy deployment, their macroeconomic effects are mixed. The cost of above-market FIT payments gets passed through to all electricity customers, which can raise overall energy prices. When multiple countries implement generous FIT policies simultaneously, resource competition and inefficiencies can compound those costs.
Making the Most of a Lower FIT Rate
With FIT rates declining in most markets, the economics of solar have shifted. The biggest financial benefit now comes from self-consumption: using your own solar electricity directly rather than exporting it. Every kilowatt-hour you use from your panels is a kilowatt-hour you don’t buy from the grid at full retail price, which is almost always worth more than what you’d earn by exporting it.
This is why home batteries have become popular alongside solar panels. A battery lets you store midday surplus and use it in the evening, increasing the share of solar electricity you consume yourself. Running high-draw appliances like dishwashers, washing machines, and water heaters during peak solar hours is a simpler version of the same strategy.
If your area offers a time-varying export tariff, a battery also lets you choose when to export. Instead of sending power to the grid at noon when the rate is lowest, you can store it and export during the evening peak when the rate is highest. The combination of maximizing self-consumption and timing your exports can significantly improve your overall return, even as headline FIT rates continue to fall.