With a grid tie solar system, your electrical demand will be satisfied first and foremost by your solar panels. When your panels can't meet your demand (at night or during heavy overcast weather), electricity from the grid will be used instead - seamlessly and without the need for you to do anything. This means that in most grid-tied solar systems, the electrical grid replaces the battery backup portion of a system that would be required for off grid solar setups.
Shop for grid tie solar system components individually.
A grid-tie inverter interfaces the varying DC output from solar panels, converting their power into standard AC power that is useful for home and industry.
Primarily for reducing your electric bill, a grid-tie inverter simply sends as much power as it can - as much as is available from the solar array - into the grid. When you're using more than it's generating, you're buying power. When it's generating more, your meter's going backwards and you're getting credit for the surplus. Most utilities allow you to bank this surplus power and use it later. You can use it at night or in the winter (since it's likely you'll generate a surplus in the day and in the summer). The energy isn't actually stored, but from your point of view it is because you can use it later (and the electrical grid is far more effective and efficient than batteries). For this reason, you always want to utilize the grid when it's available to avoid the need for expensive batteries (with a finite lifespan). If you think you want to get off-grid, check out our off-grid inverter/chargers.
Yes. Grid-tie inverters are designed to shut of when they sense the power grid is down. This is to prevent your solar power from traveling through the grid on potentially damaged equipment and from presenting a safety hazard to the people making repairs on grid infrastructure.
However, if your system includes batteries or an inverter with a UPS (uninterrupted power supply) or SPS (secure power supply) feature, you will not lose power.
Yes, although the vast majority of grid-tied PV system owners choose not to due to the significant cost increase batteries add to the system.
When shopping for solar panels and grid-tie inverters, think in terms of kilowatt-hours (kWh); this is how your utility bills you for electricity. You can find your daily and/or monthly kWh usage on your monthly electricity bills, or you can estimate your daily Watt-hours using our Solar Load Calculator (divide your total Watt-hours per day by 1000 to get kWh per day).
Our Solar Techs have answers! Contact them at 800-919-2400 or [email protected]
Solar Tech Erik Frye explains the Secure Power Supply feature found in many grid tie inverters from SMA.