I'm planning to set up a 1kW grid-tie inverter with a no-export feature to help lower my electricity consumption during the day. I want to know how this will work with my existing electrical setup. Particularly, I'm concerned about two things:
1. Is my 1kW inverter at risk if my household load is consistently around 3kW?
2. How will this system function in practice? When my inverter produces 1kW during the day, will the extra 2kW automatically be supplied from the utility without causing any issues?
3 Answers
No worries about the inverter! Anything drawn from the grid won't affect it. As for your second question, yes, the inverter will use what it generates first, and then your house will pull any extra from the grid just like normal.
Quick note: You seem to be mixing up kW and kWh. The inverter will generate up to 1kW depending on your solar setup and conditions, translating to about 1 kWh per hour of sunlight. Your energy bills will reflect kWh consumption over time, which is different from the kW rating of your inverter.
Most inverters are equipped with overload protection that should prevent damage by shutting down if there's too much load. You might want to check the manual for your specific inverter, as it usually describes its behavior under overload conditions. For instance, I recently installed an inverter that can supply 8kW but has limitations on how long it can exceed its rated output. I suggest sizing your inverter for about 100-150% of the maximum load you expect to ensure smooth operation, possibly with the addition of batteries or a bypass switch for high demand periods.