In the context of renewable energy, an inverter is a device that will convert DC battery voltage to grid-type AC power.
Most medium to large scale solar power systems are designed to power everything from “inverted” main type AC voltages from the DC battery bank. The advantage this gives us is that we can buy conventional appliances from an electrical retailer. An energy efficient light globe can be a bit expensive in a 12 volt DC version and having a 24 or 48 volt lighting system makes finding a suitable bulb even more difficult.
Investor Ratings
The three qualifications you should look at when buying an inverter are:
- Continuous rating: This is the amount of power you could expect to use continuously without the inverter overheating and shutting down.
- Half hour rating: This is useful as the continuous rating may be too low to run a power tool or high-energy appliance; however, if the appliance will only be used occasionally, the half hour rating may suffice.
- Surge Rating: It takes a large surge to turn on some appliances, and once they’re up and running, they may need a lot less power to keep running. The inverter must be able to maintain its surge rating for at least 5 seconds. Televisions and refrigerators are examples of items that require only relatively low power once they are up and running, but require a high magnification to get started.
Types of investors
There are basically two types of inverters: modified sine wave (also known as modified square wave) and true sine wave. The differences between these two types of inverters are subtle but significant in the way they work.
Modified Sine Wave Inverters
A modified sine wave inverter can adequately power some electrical appliances and power tools. It’s cheaper, but can have some compromises with some loads, like computers, microwave ovens, laser printers, watches, and cordless tool chargers. Virtually all low cost inverters are “modified sine wave”. A modified sine wave is easier and cheaper to produce than a sine wave inverter.
These low-cost inverters are generally available at electrical supply stores, hardware stores, automotive stores, and electronics suppliers. They generally lack many features, such as autostart or any kind of tweaking capabilities. Devices are typically only 70% efficient, so you can expect some significant power losses if you are using a modified sine wave inverter in your system.
True Sine Wave Inverters
A true sine wave inverter is designed to replicate and even improve the quality of electricity supplied by utility companies. To operate high-end electronic equipment, a true sine wave inverter is recommended. Efficiency has reached approximately 94% and the electricity from these devices is of a higher quality than that from the power grid almost anywhere in the world.
A high-quality inverter will include:
- An automatic start system. An auto start allows an inverter to switch to a low power consumption standby state when nothing is connected and turned on. This will save you a lot of manual changes and/or wasted energy.
- retouching ability. Also useful is the ability to adjust parameters such as autostart and battery depth of discharge.
- High quality heavy duty power transformer. A heavy duty inverter generally means a high quality heavy duty power transformer.
If you use sensitive electronic equipment, don’t take any chances – get a true sine wave inverter. The additional cost will be offset in energy efficiency.