How expensive is a cheap solar inverter

4 years ago, a Mr Jones, decided to get solar panels installed on his roof hence contacted a few solar companies for quotations.

The prices of the 3kW system ranged from $2,500 to $4,000.

Now Mr Jones is a confused man with the different pricing and all companies claiming to have the best quality product. The clear winner was the cheapest price (of course!!) and upon enquiring, the salesman assured that this was their biggest seller, the price is cheaper because the solar inverter is not as expensive as the European made inverters but gave assurance that its performance is the same and it came with a 10 year warranty.

So in 2012, Mr Jones brought a 3kW system for $2,500 and thought he saved up to $1,500.

Late 2015, Mr Jones contacted me regarding his solar PV system (a friend recommended him to me). He mentioned that his system stopped working 1 year ago and the solar company who sold the system is out of business now, and he has no contact details of the installer.

To help Mr Jones, I visited the site with my electrician who checked on the system and later sent a repair quotation to him. Mr Jones was shocked with the repair cost. It was a crazy $3,400.

Well at this price, Mr Jones could purchase a brand new 2kW-3kW system but the existing faulty system needs to remain on the roof (STC t & c’s).

Of course Mr Jones wanted an explanation on why the repair cost was so high because his initial understanding was that only the inverter had to be changed.

Well, the inverter manufacturer is also no longer in business now so the 10 year inverter product warranty is of no use. The same make and model of the transformer based inverter cannot be sourced so another brand inverter needs to be installed.

Some key points during the inspections were;

The inverter is OFF, possibly component failure and would not switch ON with DC power supply;
The solar panel string voltage (open circuit) was in the acceptable range (brand of solar panel is a reputable manufacturer) so no panel fault identified;
The installation quality was very poor with cable management and all the panel leads and string cables were loose and touching the roof;
This install was done before the AS5033.2012 Standards was implemented;

The following was the cost breakdown;

$1,400 is the inverter cost – this is a European made inverter from a manufacturer that is top 3 in the global market.

$200 is for new DC isolators next to the inverter and on the roof, this system was installed before the AS5033.2012 was released hence there was no DC Isolator on the roof and the disconnectors next to the inverter was the polarised circuit breakers which cannot be used under the new standard.

$300 is for the heavy duty conduit under the roof. This requirement was not mandatory before the AS5033.2012 standards release.

$500 for the new mounting system on the roof. The electrician has to tidy up the loose solar panel cable leads hence needs to unbolt the clamps to lift the panels to manage the cables. Because the bolts & nuts of the clamps have aged, there is corrosion and a risk that it will be hard to unscrew the nuts from the bolts, and once unscrewed, the T-bolt thread and the nuts can be damaged. It’s hard to find new matching t-bolts and still have the mounting system compliant with AS1170 wind loading as the mounting system initially used does not have a brand labels.

Overall the electrician has to complete repair works and take ownership of the whole install hence becomes responsible for the whole system.

Interesting Dilemma!!!

Well, for the records, Mr Jones chose to pay the $3,400 and get the repair done instead of purchasing another system.

In trying to save $1,500 by compromising on the quality of the system, he ended up spending a total of $5,900 for a 3kW system.

eArche solar panel opens up new markets and broader applications for solar installers

eArche is a new and innovative solar panel now available to the Australian market.

Conventional solar panels use silicon cells with a glass and aluminium encapsulation. eArche panels uses the same silicon cells, but without glass and aluminium.

“Sun King” returns with ultralight, flexible PV to reshape solar market

Why will eArche panels suit your application

1. Flexibility and Suitability – the panels can be installed on a flat or curved roof. There are various installation methods from as simple as using silicone adhesive bonding to multiple mounting rail systems. Whether the roof is penetrative or non-penetrative, concrete, insulated panels, light weight, glass or simply for aesthetics reasons, we have mounting systems to suit your requirements.

2. Industry standard warranty – 10 years workmanship warranty, 25 years performance warranty. The composite material used that replaces glass, is a proven material used in the aircraft windows for decades;

3. Lightweight – 65% lighter than conventional panels. eArche 325W panel weighs 7.7kg.

Currently, an installer can move one conventional 325W panels which is 26 kg. Now replace that with 4 x eArche panels and suddenly, you are moving 1.3kW at once;

4. Weight loading on the roof – Have you comes across a job where the client didn’t pursue with solar because the roof could not handle the weight loading? A 100kW of conventional panels on the rooftop, that’s more than 8 tonnes of weight!. The equivalent eArche system will only be 2 tonnes. Conventional panels have a weight loading of 15-20kg/sqm. eArche panels are under ~4kg/sqm.

5. Packaging – the thickness of the eArche panel is only 5mm when compared with the 35mm conventional panel. A standard 2m x 1m pallet can hold 80 x 325W eArche panels. Now that’s 26kW on a pallet that sits on a solar installer’s box trailer. Compare that with conventional panels, its 7.475kW (23 x 325W conventional panels);

6. Forget 2 different sized panels (60 cell and 72 cell), we have 24 different sizes approved with the Clean Energy Council.

7. System performance – Same conventional silicon cells are used hence there is no power degradation decrease in the energy yield. The daily performance of eArche panel is similar to the conventional panels;

8. Bloomberg New Energy Finance recognised eArche as one of the most advanced product in the June 2017 report.

eArche solar panels performed at 87% performance ratio last September

eArche is a new and innovative solar panel launched into the global market by Dr Zhengrong Shi. It has passed international and local standards same as conventional panels.

How good is this panel, Let’s compare…….

A 72 cell conventional 325W solar panel, it is made up of silicon cells, tempered glass, anodised aluminium frames and weights no less than 22Kg.

Heavy, bulky, needs 2 installers to move the panel and each 40ft container can only fit 185kW.

Now use the same high efficiency silicon cells, replace glass with a composite material, remove the 35mm thick aluminium rails, the panel now weighs less than 7kg.

Lightweight and thin, now you can fit 600kW in a 40ft container and the same 2 installers can lift and move at-least 5 panels at once, that’s 1.625kW.

A composite material to replace glass. What about the product warranty?

This composite material is a proven material from the aviation industry used in the windows. The eArche panels has passed all IEC tests through the testing provider VDE. eArche panels have the same workmanship (10 years) and performance warranty (25 years) as the conventional panels.

Glass has a high refractive index hence causes light refraction and reflection which causes ~5% loss of light. The composite material on the eArche panels have much lower refractive index hence the light loss is much lower.

With various mounting methods, eArche can be installed much closer to the roof surface.

With conventional panels, due to the glass top, heat from the cells could only escape from the bottom hence there was always a gap between the panel and the roof surface for natural ventilation.

With eArche panels, the cooling of the cells occur both from the top side and the bottom hence silicon cells dissipate heat quicker and hence performs better.

Recently recorded energy yield data at one of the eArche sites in Sydney.

In the month of September when the optimum inclination of the solar panels is ~20°, eArche panels was at 5°.

There were zero rainy days in September, 21 days was above 20°C ambient temperature with 10 days well over 25°C.

The system size was 25.2kW. The irradiance recorded for 31 days was 163 kWh/m² which is ~5.26 sun peak hours.

The eArche system generated 3229kWh for the month as measured with a Class 1 meter.

The performance ratio was calculated to be 87%.

The ~13% loss accounts for temperature losses, soiling, voltage drop on cables, inverter efficiency and all losses that the PV system face in the field.

The monthly eArche performance ratio has been in the range ~ 85% – 94% for the last 8 months.

In addition to install on the normal roofs, EArche can be applied to the places whether:

· the roof purlins is not sized to take 15kg/m² of weight loading;

· the roof has a curve;

· aesthetics requirement or limited roof space;

· Panels don’t have to be installed 120mm above the roof material.

Happy to share more details and data…..