Do You need a 3-Phase or Bi-Directional Power Inverter?

Categories: Equipment, Inverters, Solar Power

Even though solar power is a basic concept, there are some aspects that require meticulous attention. Now, we’ve covered the basic inverters in a previous article, along with the differences between pure and modified sine waves, but now something else is rearing its head – bi-directional and 3-phase power inverter. There are certain conditions where you’ll be needing either one of these models, but these conditions are rare. Here is a look at what you need to know and tips on when to use them.

Bi-Directional Power Inverter

Without getting too complicated, it’s important to realize the basic flow of energy in a solar power system. A basic inverter only has one direction, meaning it gets fed DC energy from the panels, which it converts to AC energy and sends it to a battery kit or directly into your home. This direction can’t be changed when the batteries are fully charged or if you’re not using electricity.

A bi-directional inverter works on the same principle as grid-tied inverter. Basically, it allows you to send excess energy back into the grid and reverse the reading on the meter. Unfortunately South Africans have only one motivating factor to feed energy back into the grid, which is to save on their electric bill. In many countries this feedback is compensated, but this isn’t an option. In other words, the only time you’ll need a bi-directional inverter is if you want to stay tied to the grid and reverse the meter.

3-Phase Power Inverter

Power inverterThe first thing you have to know about 3-phase inverters is that they cost more than the rest. Based on this substantial cost difference you want to make sure it’s the type of inverter you need. A single phase inverter feeds all the power through one phase into the home. Now, this shouldn’t normally be a problem, but there are situations when it’s not the best choice.

Within a home it’s not really necessary for a 3-phase power inverter, but when it come to commercial and industrial use it’s best to consider this option. The best analogy to explain the difference between a single phase and a 3-phase is to imagine a man in a canoe. If the guy’s paddle hits the water it’s a surge of energy, but the moment the paddle isn’t in the water the energy stops. With a 3-phase inverter you can put 3 guys in that canoe, and as one paddle leaves the water another dips in. If your home requires more than a 5kw inverter then you can start looking at the 3-phase model, but this is hardly the case. Most homes are more than happy with single phase converters.

If you can get past the price, it’s interesting to note that 3-phase inverters don’t over-exert themselves like single phase models. The overall power gets divided and released in equal amounts, making it less likely to cut out. It’s also more efficient for some equipment in the commercial and industrial sector.

So, the only time you’ll actually be needing a 3-phase inverter is when you run a business where heavy equipment is used. If it’s a home-based solar system a single phase should work perfectly. In case you were wondering how much they cost, the smaller models start at around R5000.00 and can go up to R200 000.00.