How To Select Inverter－Consider 8 Technical Parameters
A solar inverter converts electricity (DC, or direct current) from solar panels into power (AC, or alternating current) that can be used by the plugs/sockets to power devices and other wired products. Solar panels do not have the capacity to create AC power by itself; they need the helping hand of a solar inverter.
Core and Extended Roles of a Solar Inverter: Inverter technologies have advanced significantly, such that in addition to converting DC to AC, they provide a number of other capabilities and services to ensure that the inverter can operate at an optimal performance level, such as:
a)Data monitoring b)Advanced utility controls c)Applications and system design engineering.
Here are 8 technical specs to consider when you choose an inverter:
1. Off-grid or grid-tied. A grid-tied inverter takes DC power from solar panels, turns it into AC, and sends it into the grid for credit. Grid-tied inverters are simpler and easier to wire since there are usually only two main components—the inverter itself and your solar panels. (Some grid-tied systems are starting to incorporate energy storage, but most don’t have any batteries at all.)But most off-grid inverters need a battery bank to function. your solar panels feed DC power into the batteries. Then your inverter takes that power and “inverts” it, creating AC power for your home. This works essentially like a miniature power grid.
2.Waveform. pure sine wave or modified sine wave. Pure sine wave inverters deliver higher quality power output, similar to (or better than) our power grid. Modified sine wave inverters are cheaper, but they deliver lower-quality power output. For this reason, modified sine wave inverters can cause issues with certain appliances. Motors, pumps, and compressors run hotter and wear out more quickly. Modified sine wave inverter application, please read: Which devices can not use the modified sine wave inverter?
3. Efficiency. This is a measure of how much power from the batteries your inverter delivers to your home when it’s operating in perfect conditions. A good peak efficiency rating is around 94% to 96%.
4. Self-consumption, or no-load current draw. How much power will your inverter consume just sitting there? Obviously you want this to be as low as possible.
5. Surge capacity. How much short-term overload can the inverter handle before it “trips?” Some appliances, like pumps or fridges, need as much as 2x–3x their running power to start up.
6. Battery charger output. Many off-grid inverters include a battery charger, which is used to recharge your batteries during the winter months with a backup generator. The battery charger will have a rating, usually measured in amps. Most decent off-grid inverters will have a battery charger in the range of 50-100 amps DC.
7. Temperature range. Inverters are sensitive to extreme heat. Pay careful attention to the temperature range if you plan on installing your system in your garage or anywhere it could be exposed to temperature extremes.
8. Warranty. Warranties start at 1 year and typically range from 3-5 years, with a few manufacturers offering a 10-year warranty extension option.
You can normally find information on all these features on the product spec sheets. Check with your solar tech for help comparing and picking the right inverter.