Questions to ask potential solar installers

Screwdriva

casper_gutman said:

Any major pros and cons of these items, please? Any pitfalls to be wary of?

A few questions/ thoughts:

1) What is the cost for the quoted system? Is the installer MCS Certified and with HIES or RECC? How long is the workmanship warranty?

2) DMEG is an among the lowest end of Chinese panel brands available to installers to purchase wholesale well below £50 a panel. Not a panel I would recommend to anyone. 

3) Libbi was great in 2023/24 but has been outclassed by more recent battery inverter systems. It's also limiting because the inverter is limited to 5kW and cannot scale to a 6kW or 8kW system size, potentially costing you generation/ export. 

casper_gutman

Screwdriva said:

casper_gutman said:

Any major pros and cons of these items, please? Any pitfalls to be wary of?

A few questions/ thoughts:

1) What is the cost for the quoted system? Is the installer MCS Certified and with HIES or RECC? How long is the workmanship warranty?

2) DMEG is an among the lowest end of Chinese panel brands available to installers to purchase wholesale well below £50 a panel. Not a panel I would recommend to anyone. 

3) Libbi was great in 2023/24 but has been outclassed by more recent battery inverter systems. It's also limiting because the inverter is limited to 5kW and cannot scale to a 6kW or 8kW system size, potentially costing you generation/ export. 

Thanks. Responses as follows...
1) Quoted cost is £9200 all in, including scaffolding, bird guards etc. Installer is MCS certified and is with RECC. I think they said the workmanship warranty was three years, but can't confirm that from the paperwork I have here. I'll have to check that point (and make sure I have everything in writing).
2) That's disappointing. What are the issues you'd expect from such a panel? Is it a lack of reliability, or will it also underperform in terms of output relative to higher end products?
3) The panels are split roughly 50/50 between areas of the pitched roof at an SSW orientation and a WSW orientation, so I guess this may mean the peak output will be unlikely to exceed 5kW?

Screwdriva

1) Frankly, the price is attractive - I was initially quite skeptical but then noticed that MyEnergi is selling their stock of Libbi bundles quite aggressively.

I have always had good things to share about MyEnergi, though I have not seen a single system installed since the Powerwall 3 launched. I believe this may be why they are promoting their stock? 

I would recommend going with an installer offering a 10 year workmanship warranty - you never know when you'll need them to revisit. Being a local installer is not a guarantee of good service/ equipment or business longevity. Make sure you check how long they have been trading - anything less than 7 years is best avoided.

2) The adage "you get what you pay for" couldn't be more applicable when it comes to PV kit. Panels look the same but build quality and aftersales support is not in the same league. Some experience several years without issues, others quite the opposite. I only recommend panels from Solarwatt/ AEG/ Sunpower/ Meyer Burger/ Panasonic/ REC/ REA/ Hyundai/ Q-Cells or Eurener.

If you are set on going with this installer, I would insist they quote only for any of the above panel brands - should they try to convince you there is no difference, you would be wise to select another installer. 

3) This would be somewhat true of an East/ West orientation but I have seen SSW/ SSE aspects consistently outperform. Without seeing the roof layout (which they should have shared with you along with an OpenSolar estimate of system generation), your guess is as good as mine.  

casper_gutman

Thanks @Screwdriva. I made a mistake in my previous post, btw - should have said SSE and WSW - it's a normal house with roof areas at 90° to each other on plan. I shouldn't think that makes any difference to your response though.