The RTW is the price of power in wholesale markets, reflecting supply and demand for electricity at any given time. This market is maintained by ERCOT, who publishes the price in 15 minute intervals. This is what’s known as the “settlement price point” or SPP for short – the price the market “settled” to during that interval.

Real-time prices can spike all the way up to $5/kWh based on supply and demand in the energy market. That means that the solar power you send back to the grid can be very valuable when there’s high demand for power. You can read more about energy markets and prices here.

Because the RTW price reflects supply and demand, it signals how valuable power is at any given time. Spikes can happen in ERCOT markets due to increased demand, like a heatwave that causes people to use more air conditioning, or reduced low-cost supply, like if a large power producer that was supplying cheap electricity goes offline.

When your solar panels are producing more energy than is needed to power your home, they send the excess power back to the grid – and you get paid the best market rate for that power.

This is what’s known as solar buyback. Since real-time prices are published by ERCOT in 15-minute intervals, your solar will earn a credit equivalent to how much you sold back multiplied by what the price was during those 15 minutes.

You’ll see two line items on your monthly bill: One for the energy your home consumed from the grid (imports) and one for the excess energy your solar panels sold back to the grid (exports).

Your solar is earned at the real-time rate, and displayed on your bill as the weighted average in $/kWh for when you were exporting.