kWh
A kilowatt-hour: the unit electricity is sold in. One kWh runs a kettle for about half an hour, or a fridge for a day.
Power is measured in kilowatts (kW), which is a rate. Energy is measured in kilowatt-hours (kWh), which is an amount. A 5 kW roof running flat out for one hour makes 5 kWh.
Everything on the board is priced per kWh. If the market is at $0.187 and you sell 6 kWh in a block, you have made $1.12 before the fee.