Shading issues and GivEnergy Inverter - do I need optimizers?

Hi all - thanks for reading my first post about what I need to do given the shading I will have on my system
I recently signed up for the solar together scheme and had my home survey today by the winning provider - ENVO. The scheme includes:

  • LONGi Hi-MO 5m (LR5-54HIB) panels
  • GivEnergy Hybrid Inverter

The panels will be on long west facing pitched roof with a chimney at the most southern point of this roof but on the ridge. Once it gets to midday the chimney no longer casts a shade on any part of the west side of the roof (photo from google maps of my roof attached - you can see this must have been morning with some of the chimney shading the west facing roof). My general understanding of PV is that without adaptation, the system output will all be limited when there is shading on any of the panels, meaning the key question is whether there is any shading as opposed to how many panels will be in shade. I’m unclear if this is a universal PV limitation, or whether it is dependent on the set up you have. A few questions:

  1. Can I check that this would apply in my situation given the proposed panels and inverter?
  2. Assuming it is, I guess it is a judgement call about whether the amount of shading warrants an adaptation - which in my case there will be no shading past midday, and a west facing roof will be generating most electricity in the afternoon, but is there any way I can aid this decision?
  3. If you think I should adapt the system, the Optimizers that I can choose to add to the system are called Tigo Flex MLPE (TS4-A-O) module-level PV optimizer. However, when researching online I have heard that there may be some downsides (other than the additional cost)
  4. Are there any other potential solutions that I should consider given the shading I have (e.g. I have seen a suggestion of putting the affected panels on a different string).

Really grateful for any advice you have as I have wanted PV for such a long time and would be gutted to find out after the installation that I haven’t made the system as effective as I could have, or have adapted the system unnecessarily. Many thanks, Rob

Rob, you’re right to be concerned about shading, but as you highlighted, the shading will cease around midday when the panels start receiving full sun and the output power increases. However, it will significantly reduce the solar output until the shade has passed. How close will the panels be to the roof ridgeline? Do you have an array layout diagram?

Ideally, if money wasn’t a problem, you would go with microinverters such as Enphase, as this is the only true technology which allows every panel to be fully isolated from the rest of the array. Tigo optimisers will help, but in my personal experience they have been too problematic.

If you went with microinverters (depending on your provider), then you would require an AC-coupled battery system. I’m not familiar with GivEnergy products but they do offer an AC-coupled battery similar to the Tesla Powerwall.
A SolarEdge system is also another option that will help reduce the effects of shading, however, these are also rather problematic.

If microinverters are not an option, then I would suggest an Inverter which has a shade function to help reduce the effects of shading. Fronius, SMA and Goodwe inverters all have a shade function as standard.

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Thanks Svarky, that’s really helpful. Are you able to elaborate on the problems you’ve had with Tigo? I don’t have an array layout diagram yet - should be here in a few days so will attach then.

Sadly the package when you buy through the solar together scheme is pre-defined, so the only optimizers I am able to get are Tigo Flex MLPE (TS4-A-O) module-level PV optimizer, and microinverters are not an option. The inverter is already pre-defined as well (GivEnergy Hybrid Inverter) and I can’t see any mention of a shading function on it.

I’m not sure if this link will work but it shows the specification of the system, including the battery - sadly I’m sufficiently ignorant that I don’t know if this is an AC-coupled battery

I was able to open the link. Looks good, my main concern would be the inverter brand. I’ve been in the industry for a long time and have never heard of GivEnergy. Although I’m based in Australia and GivEnergy is a UK company, I wonder who actually manufactures the inverters. :thinking: Also the 5-year warranty on the inverter is on the low side. That being said, GivEnergy seems to have generally good reviews and if you believe this is a reputable company that will support you in the long term then it’s not a big concern.

In regards to Tigo optimizers, my issues were with the first-generation Tigo units where I had a number of failures and poor support from the Tigo support team. However, the new generation Tigo’s are supposed to be more reliable so I can’t really comment too much on the new Tigo Flex series.

What size system are you getting exactly? Have you determined which size battery is best suited to your needs and got a final price for supply and installation?

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Thanks for taking the time to look at the spec Svarky. I’m waiting for them to confirm but likely 12-14 panels which are 405w each, and the smallest battery which is 4.2kWh. The initial quote was £8,675 for 13 panels, inverter, battery and installation, and just waiting to see if the quote has changed based on the survey yesterday. Will post again when I have the final quote and the array layout diagram

Does anyone else have experience of GivEnergy or the new Tigo Flex series?

I was really not impressed with the company and was able to pull out of the scheme. They tried to tell me shading only affected the power production of those panels in the shade rather than the whole system, which really made me lose faith in their advice. I have some separate questions but will start a new thread. Thanks again Svarky for your advice