Inverters convert DC electricity into AC electricity. Solar panels (and most small wind turbines) produce DC electricity. That electricity is used to charge a battery bank in off-grid systems or sent directly to a grid tie inverter which feeds the electricity directly to the electric grid. We offer some inverters which are capable of both working as an Off-Grid and an On-grid inverter.Read more +
Since each inverter needs proper disconnects on the AC and DC side, often people choose the simplicity of one of our self contained Inverter Power Panels. By mounting one or two inverters on a power panel, that is wired with the appropriate disconnects, you have yourself a neat, pre-wired and safe inverter system. Folks often choose the pre-wired inverter systems to save time and costs of having a professional electrician going through the manual and wiring up the various components.
It must be large enough to handle the peak watts you will be using at one time. Start by listing all of the appliances, etc that you use and their wattages in our Load Calculator. This form will display the number of watt hours you use in a day. In order to properly size an inverter, consider which of those loads you will be using simultaneously and add up their wattages only. For example, if you will be using the 1500 watt microwave at the same time you will be running 100 watts of lighting and also running a refrigerator that will draw 500 watts of instantaneous power, you will need an inverter that can handle at least 2100 watts (1500 + 100 + 500). Once you have identified a minimum wattage, you will select an inverter that has the same nominal voltage as your battery bank (12, 24, or 48 VDC).
Grid Tie Inverters connect directly to the utility grid and do not require batteries. A battery-less system is much less complex (and less costly) than a system with batteries. The drawback is that a pure grid-tie solar inverter system without batteries cannot supply power to the home in the case of a power outage. For the safety of the workers working on the utility lines, the grid intertied inverter will shut down until power has been restored. If frequent power outages are not an issue, then a utility grid tied system can be an excellent, cost effective option.
Furthermore, to qualify for most state rebate programs, you must be connected to the utility grid. Sizing an on-grid inverter can be a bit more complex than sizing an inverter intended to be used with batteries. Each inverter manufacturer offers a string sizing tool that will display the acceptable configurations for your PV array based on the quantity and wattage of your solar electric panels. These string sizing tools also account for variations due to high and low temperature extremes.
Need more help understanding string sizing for inverters?
Please give us a call and let us know how many solar panels you have and their wattage, and we'll be happy to help you understand.
Off Grid Inverters Capable of Grid Tie are intended to hook directly to the utility grid and can still allow a battery bank to provide backup power in case of a blakcout or power outage. These inverters are typically at least 2500 watts and can operate with 24 or 48 volt DC battery banks. If you aren't sure which inverter to choose, give us a call and let us know how many watt hours per day you will be using and the maximum wattage you'll need at want time and we can help make product recommendations.