Supply side solar tie-in setups occur when the solar inverter is tied in directly to the mains. To display consumption and generation readings correctly in this setup, the Neurio sensor needs to be specially configured on the sensor settings page while at sensor.neur.io. The channel and CT settings should match the image below.
For firmware 1.0.6
For firmware 1.1.0 (and later): Go to Sensor Settings Basic View & Choose "Supply Side Tie-In"