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Tigo optimiser review

Tigo, pronounced TYGO, not TEEGO are a relatively small American company founded in 2007 that by 2016 was ranked third in the World in the Micro inverter/DC optimiser industry.

Shade is the enemy of solar, and there are multiple ways available these days to combat its power reducing effect. One of those ways, and probably the most cost effective if you already have a solar inverter or have your heart set on buying a brand that doesn't have its own optimisers (Huawei and SolarEdge), is to use Tigo optimisers.

They can be connected to any solar panel, new or old, cost $85 plus install of about $10 per panel if done during a new install (more if it's a retro fit to an existing system). The real beauty of these things is not only do they work with any solar panel, they also work with any solar inverter too.

One thing that many people expect to have once they purchase optimisers is panel level monitoring. In other words, the ability to report on the output of every optimised panel individually. Some say that without it, how do you know it's actually working? Tigo have an add-on Data Logger to do just this, and in a stroke of genius, some inverter companies who don't have an in-built optimiser solution, have started to incorporate the Tigo data logger into their inverter. Goodwe are incorporating it into all their inverters, including their hybrids in 2019 for free (or so they told us at All Energy Expo in Melbourne), and SMA, who are Tigo shareholders, are doing it too.

Why shade hurts solar

Shade on all or any part of a solar panel reduces the power output of that panel. Shade could come from a passing cloud, a leaf that has fluttered down from a tree, or the tree itself, a neighbours building, your own building, chimneys, flues, TV aerials and more.

Fitting one of these optimisers on a shaded panel won't have the slightest positive effect on its power output. If unshaded it is putting out 200W of power and shaded it drops to 75W, it will continue to do that, unshaded or not. That's not what optimisers are for.

The purpose of the optimiser is to stop the power output of all the others panels that are connected to it that aren't themselves in shade from dropping down to the level of the shaded panel. Panels are connected together in series in strings so their current remains the same but the combined voltage increases. Power = Voltage x Current

A typical scenario looks like this

8 panels connected together (blue) with their voltage current and power (watts)

If you follow the 3 step progression you will see how the total output from the 8 panels goes from 1.6kW when there is no shade down to just 0.6kW when the first panel is shaded, and then back up to 1.475kW if an optimiser is fitted to the first panel.

No shade

Volts 25V 25V 25V 25V 25V 25V 25V 25V 200V
Current 8A 8A 8A 8A 8A 8A 8A 8A 8A
Power 200W 200W 200W 200W 200W 200W 200W 200W 1.6kW

1st panel shaded with no optimisers fitted

Volts 25V 25V 25V 25V 25V 25V 25V 25V 200V
Current 3A 3A 3A 3A 3A 3A 3A 3A 3A
Power 75W 75W 75W 75W 75W 75W 75W 75W 0.6kW

1st panel shaded with optimiser fitted

Volts 9.375V 25V 25V 25V 25V 25V 25V 25V 184.375V
Current 8A 8A 8A 8A 8A 8A 8A 8A 8A
Power 75W 200W 200W 200W 200W 200W 200W 200W 1.475kW

The way the optimiser works is to adjust its voltage or current up and down so that the current for the entire string is maintained. In the 3rd example you can see that the optimiser has dropped its voltage from 25V down to 9.375V so that its current output rises to 8A and matches the rest of the string.

It can work the other way too. If the 1st panel is producing more current than the other panels (perhaps it is on a different roof orientation and has full sun on it) then it will raise its voltage so that is matches the current of the other panels, but in so doing it doesn't have to reduce its own power output.

Ideally, ALL the panels should have optimisers on them so that they each can individually raise and lower their own voltage to maximise power if a passing cloud or leaf flutters down on them too but selective deployment as pictured above on just one panel works very well indeed.


How does Tigo differ from SolarEdge, Enphase and Huawei?

Optimisers and micro inverters work in exactly the same way as far as adjusting voltages to maintain current for the string and therefore minimising power losses.

Tigo can be used on any panel and any inverter, so if you love your Fronius or SMA inverter's features but have a bit of annoying shade, you can put Tigos on just those shaded panels and keep the rest as it is.

SolarEdge require you to put their own DC optimiser on every single panel and you have to use their inverter too.

Enphase puts a micro inverter on every panel. It does the same job as the Tigo (or Huawei or SolarEdge) optimiser, but in addition it converts DC panel power to AC there on the roof and therefore doesn't have any need for a central inverter. Good on one side (no box on the wall and 240V AC cable through the roof not up to 600V of DC), bad on the other (expensive to have an inverter on every panel, and more electronics and heat generation to go wrong on an already hot and exposed roof).

Huawei provide their own optimiser that like Tigo can be selectively deployed, or put on every panel.

You can read more about shade here


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