Solar panels, inverters and batteries


There are three basic cost components for a solar installation:
The inverter.
The panels.
The installation.

 

The cost of panels has plunged over the past ten years to the point where, after deducting the ‘rebate’, an entire system of panels typically costs just a few hundred dollars.

Inverter quality has improved leaps and bounds, and there are fewer brands to chose from as the rubbish has been weeded out, but costs have barely moved in a decade with regular 5kW single phase inverters costing $1,200, hybrids and European made inverters $2,000 and optimised and micro inverter systems over $3,000.

 

Installation costs have gone in two directions. Increased regulation has pushed up time and labour costs, but more electricians gaining their solar accreditation has increased competition amongst sub-contractors and lowered prices available to solar sales companies who contract out their installations.

 

Solar panels
Bloomberg NEF provides investor advice on the size, and financial strength of solar manufacturers.

 

The biggest and safest are given Tier 1 status. Mostly these are Chinese firms as China dominates the solar industry both as a manufacturer and a consumer. Canadian Solar currently top the Tier 1 list, with Jinko and Trina at their heels. Smaller firms, by comparison, but still Tier 1, usually provide slightly cheaper prices to compete…ET Solar, Longi, Seraphim, Talesun, Risen and GCL as examples.

 

The price difference may seem small…$20 per panel for instance, but when multiplied by 22, 23 or 24 panels for a complete 6.6kW system, it can work out to a saving of $500 or more.

There are hundreds of even smaller Indian and Chinese solar panel manufacturers making probably perfectly OK products, usually rebadged by solar sales companies, and they may be just fine, but for a few hundred dollars savings on these no-names against Tier 1 brands, almost everyone who has done the slightest bit of intelligent research opts for a Tier 1 brand.

No point getting a 10 year warranty if its just a scrap of paper when you need it.

 

Other brands have opted for innovation and technology and the higher prices they can charge for it. REC, one of the few not made in China, were the front-runners in half-cell technology and now offer a 25 year defect warranty on their NPeak mono panels compared to the industry standard of 10 years. Q.Cells still do all their R&D in Germany and their mostly South Korean made panels consistently win awards for their design and build quality, as do those from LG and SunPower.

 

Whilst it’s common sense that a 325W panel is more efficient than a 275W panel if the physical size of the panel is the same, it doesn’t mean that you get more power from an entire system of them, in fact you often get less. In WA we have a 5kW inverter and 6.66kW of panels limit on single phase.


You can only install 20 x 325W panels = 6.5kW, against 24 x 275W = 6.6kW


The ‘perfect’ panels are those that divide neatly into 6.66kW…275W, 300W, 315W, 330W.

 

Panel performance reduces as the temperature outside goes up so finding a panel with a lower temperature coefficient means lower power losses. Monos are typically a little better than polys, and half-cell monos best of all.

 

If you have shade on some of your panels then fitting optimisers to shaded panels is the best way to maximise your system output. The panels all have diodes (3 on most panels, 6 on half-cell panels) that help a little with combatting the effects of shade, but optimisers are far better at it.

 

Inverters
Hybrid inverters have battery inputs, everything else doesn’t, which means you can only connect batteries to your solar installation if you buy a hybrid. If you buy a non hybrid then when its time for batteries you have two choices. (1) Throw out your existing inverter and buy a hybrid, or (2) connect another inverter that can run batteries. When you see cheap ads in the papers with ‘battery ready system’ emblazoned across the top of the ad, then what they actually mean is that you’ll have to fork out another $2,000+ later on to replace the inverter or add a second inverter.

 

If you have single phase power, then the largest inverter you can install is 5kW but you can go much larger if you have 3 phase supply to your home. 3 phase inverters are more expensive than their single phase counter-parts.

 

The cheapest inverters are from Growatt, with Zeversolar, Goodwe, Sungrow, and Delta not far behind. Even the cheapest 5kW inverters cost over $1,000 for single phase and $1,500 for 3 phase.


If you want European made and top quality then Fronius is the brand of choice, Austrian made, and $2000 for single phase and $2200 for three phase. However, not a single one of these above are hybrids.

 

Single phase hybrids from Huawei, Goodwe, Sungrow, Delta, SolaX cost between $1,600 and $2,200.


Three phase hybrids are available from SolaX and Fronius and cost $3,000 and $3,600 respectively, however Huawei have announced their three phase hybrids will be here by July 2019 and Goodwe even sooner and both will sell for under $2,500.

 

All inverters come with at least a 5 year parts and labour warranty. 10 years for parts but still 5 years on labour is becoming more common either free, or for $100 extra. Panels are almost indestructible and very rarely fail, but inverters have a lot inside that could go wrong so making sure you have a genuine manufacturer’s long warranty is an intelligent move.

WIFI reporting of your solar output to smartphone apps or web browsers is almost universal now and it’s usually very good. Some brands (Fronius, Huawei, SolarEdge, Enphase) also have optional energy meters often called smart meters that can be installed in your switchboard if you have the space for them, to report on your home power consumption and imports and exports through your meter. They are also needed by hybrid inverters to manage the storage or release of battery power, and to limit exports back out to the grid.

 

 

If you have shade on all of your panels during the peak of the day then don’t waste your money on solar, but if the shade is only on a few panels then fitting optimisers at the time your system is installed will cost you about $90 a panel and will stop the shaded panels from dragging down the output of all the others. Tigo optimisers can be installed with ANY inverter, Huawei and SolarEdge have their own optimisers, and Enphase have micro inverters but do the same job as optimisers for shade.  Tigo and Huawei optimisers can be selectively deployed only on the shaded panels, SolarEdge and Enphase require them on every single panel which can get quite expensive.

 

Installation
A typical 5kW inverter and 6.6kW of panels on single phase, single storey house costs about $2,000 to $2,300 with an extra $100 to cover the extra component costs for three phase.
Double storey homes take a fair bit longer, and usually cost $300-$500 more.
Smart meter installs are pretty easy and usually $50 covers it.

 

Batteries
Most people have heard of Tesla Powerwall. Version 1 came and went very quickly, Version 2 has a built-in inverter inside the big white battery box and connects to the switchboard. Costs about $11,000 if you are prepared to put yourself on the waiting list for the limited supply coming here.
This is the battery of choice for most people who have a non hybrid inverter but there are other solutions from Goodwe and SMA (and others) that allow you to buy the second inverter, and then use a variety of other batteries.

 

If you have a hybrid inverter then you don’t need the second inverter, and therefore your costs are much lower. Most of the batteries work out to be $800 per kW, so 10kW is $8,000. LG Chem are the most popular, but BYD, Pylontech, Samsung and Panasonic and others are out there too.

 

Click the blue brand name for a full review, datasheets etc

 

Panel manufacturers

 

Canadian Solar have the largest available range of panels with a variety of straight poly panels, straight mono panels, half cell polys, half cell monos, bifacial...you name it, and all supplied and supported by the local Canadian Solar Australia team.

Trina, Jinko, along with Canadian are 'the big three' Chinese brands with annual sales over $3 billion each, they top the Tier 1 list.

Talesun, ET and GCL and Seraphim are slightly further down the Tier 1 list but still giants in the industry. Smaller available range in Australia than from 'the big three', but what we do get from them has proven to be very good quality, and usually priced a little lower too.

Longi are, and have been for many years, the World No.1 monocrystalline cell manufacturer and we like their panels. Not too many others sell them, but they should. They have a well-priced really looking nice fully black panel, 300W mono. Black cells, black frame, black backing sheet.

Q.Cells. The half-cell Q.Peak Duo mono panel won this year's 'Best panel' award at Intersolar in Munich (biggest solar expo) and the year before they won with their innovative steel frame (everything else is aluminium), so it's clear the R&D and engineering in Germany for Q.Cells is as strong as ever. Well supported by their Australian office, this brand is always more expensive than the Chinese, but it's top quality.

REC panels are made in Singapore and are a good quality brand. They were early adopters of half cell technology with their Twin Peak polycrystalline range and we are now seeing REC half cell monos coming out as well. 25 year defect warranty just introduced. Awesome.

 

LG and Sunpower. Small range of top quality mono panels at significantly higher prices than average, but with 25 year warranties.

 

 

A brief description of each of these top inverter brands

Click the blue brand name for a full review, datasheets etc

Huawei FusionHome inverters are indeed a fusion of everything that is good about rivals Fronius and SolarEdge, all combined into one small and light product. Huawei are already World No.1 inverter manufacturer by revenue (20% of World market) and the new residential single phase and three phase hybrids are only going to increase their lead.

Battery interface built-in, DC optimisers for eliminating shade issues with panel level reporting, excellent WIFI and a 10 year warranty make this product very hard to go past. Huawei are 83rd on the World Fortune 500 list with sales of US$75 billion last year.

Fronius make excellent 'string inverters'. Primo range for single phase, and Symo range for three phase. All 100% European made (Austria), 10 year parts and 5 year labour warranty. Excellent reporting via inbuilt WIFI. A Hybrid version of Primo is expected before the end of 2019. Fronius have 4% of the Worldwide inverter revenue.

SolarEdge. Every solar panel has a SolarEdge power optimiser attached and in so doing, at great expense, allows every panel to operate as a law unto itself. Shading, roof orientations mean nothing to the flexibility of SolarEdge. However, a very confusing array of products, best explained by clicking on the blue SolarEdge link means that many end up with (not from us, of course) something other than what they thought they were buying. SolarEdge have 8% of the worldwide inverter revenue, and are particularly successful in the USA.

Goodwe are perhaps the surprise near the top of this list of heavyweights but it ranks highly because it is so reliable, has very detailed reporting via WIFI and the company built their name in the challenging battery inverter market. They have the most comprehensive range of Hybrid inverters, and retro fit DC and AC coupled solutions that can be used to put batteries on ANY solar installation, new or old, single or three phase.

SMA German company that still makes their smallest inverters in Germany (1.5kW and 2.5kW) but the rest are made in China. We hear the move to China saves $80 an inverter compared to making it in Germany, but in Australia, the brand name, so popular for such a long time for being German not Chinese made, was seriously damaged by the move. Nice AC Coupled battery inverter (SMA Sunny Boy Storage) that can be added to any solar install new or existing. No matter where the inverters are made, this is a top quality product range to put on the shopping list alongside Fronius, Huawei,and SolarEdge. SMA are second behind Huawei with 13% of the worldwide inverter revenue.

Enphase make an excellent micro inverter, similar in function and price to SolarEdge except there is no central inverter. The conversion from DC to AC happens on the roof with each micro attached to each solar panel. Good reporting via WIFI through a small control unit (called Envoy). We stopped doing Enphase three years ago for reasons we won't put here.

Delta

Good inverters priced a few hundred more than most other Chinese brands because they provide a full 10 year parts AND labour warranty. Now they have WIFI (finally), they are a good choice.

Sungrow
Solid range of single and three phase inverters plus a nice single phase hybrid that works with any low voltage (48V) lithium or lead acid battery. Good to see the new Sungrows have re-introduced the LCD screen on the inverter. WIFI works very well and their 18 strong office in Sydney (since 2012) provides excellent support (Telephone 1800 786 746). Sungrow have 10% of the Australian inverter market and 11% globally so certainly a very strong brand.

 

Growatt

The cheapest inverter in all categories by a couple of hundred dollars and a fair choice if on a tight budget.

Zeversolar

German SMA bought a large share of this company as a way to get into the Chinese market, but apparently things have not gone well financially for SMA with this deal. . They are often advertised as 'German' which they aren't, and the quality of a Zeversolar isn't the same as an SMA, but they seem to be on par with any other regular inverter for quality.

 


 

 

 

 

 

 

 
-->