1, 1.5, 2, 3KW Solar Panel Systems

[yots]

Personally - i would be careful of a "high frequency" style grid tie inverter.
These use switchmode technology, which is extremely sensitive and prone to failure if conditions exceed limitations even marginally.

I will be getting a Rich Electric "Solarworx" grid-tie inverter with my system, since they are a low frequency inverter, and made in Taiwan, not mainland China.
Low frequency inverters use a torroidal transformer, and are faaaar more robust and capable of taking a beating - much more likely to last several years versus a made in china high frequency unit.


yes i realise i just went over the top of many people's heads there....

Whats the price difference between the two inverters?

 

[HiEquity]

Personally - i would be careful of a "high frequency" style grid tie inverter.
These use switchmode technology, which is extremely sensitive and prone to failure if conditions exceed limitations even marginally.

I will be getting a Rich Electric "Solarworx" grid-tie inverter with my system, since they are a low frequency inverter, and made in Taiwan, not mainland China.
Low frequency inverters use a torroidal transformer, and are faaaar more robust and capable of taking a beating - much more likely to last several years versus a made in china high frequency unit.


yes i realise i just went over the top of many people's heads there....

For an alternative view for the techies amongst us, high frequency inverters are state of the art power electronic technology and transformers are low tech. Power electronics are more efficient than transformers and passive devices, particularly with standing losses but also with current losses.

Power electronics are also getting cheaper - most large scale wind turbines use them to some degree and yes, theirs are made in China. High frequency inverters cause significantly fewer power quality issues due to their minimal harmonics and no need for filtering. They are often safer due to more sophisticated anti-islanding protection schemes, for example. There is no risk of them providing fault current as they saturate at 110% rated current.

High frequency IGBTs are now getting used in a multitude of mainstream high power applications. All large scale (multi MW) modern PV systems use IGBT (high frequency switchmode) inverters (SMA has over 50% of that market).

Like most things, there are inverters and there are inverters. There are good and bad passive and active ones. There are ones designed for all conditions and others designed for some conditions. The most important thing is to ensure they comply with Australian standards and are approved for use by your utility. Buying direct from overseas is usually not a good option. Secondly, it is worth doing some research on reputable, long standing brand names compared to the ones no-one has heard of before... much like solar PV panels in that respect.

 

[Witzl]

For an alternative view for the techies amongst us, high frequency inverters are state of the art power electronic technology and transformers are low tech. Power electronics are more efficient than transformers and passive devices, particularly with standing losses but also with current losses.

Actually - the Rich Electric unit that i've sourced has extremely high efficiency at not just full load, but lower loads as well.
Typcially, most high frequency switchmode devices lose their efficiency as the output load decreases.

Here is the efficiency vs Load for the GTI-2000-242 from Rich Electric (nb: it is a 2000W unit):
25% load, >86%
50% load, >88%
75% load, >90% (75% is 1500W)
100% load, >86%
... these are the results from the AS4777 test report (which i have).

Compared to the Sunnyboy SMA1700, which is a high frequency unit: efficiency - 91% at full load. Figures for lower loads not listed.

Power electronics are also getting cheaper - most large scale wind turbines use them to some degree and yes, theirs are made in China. High frequency inverters cause significantly fewer power quality issues due to their minimal harmonics and no need for filtering. They are often safer due to more sophisticated anti-islanding protection schemes, for example. There is no risk of them providing fault current as they saturate at 110% rated current.

High frequency switchmode actually causes far more electrical noise (EMI, RFI, etc) than low frequency. High frequency devices actually need significant filtration circuitry... but yeah once in a finished product, they typically have low EMI/RFI due to the well designed filtration in the product.

Like most things, there are inverters and there are inverters. There are good and bad passive and active ones. There are ones designed for all conditions and others designed for some conditions. The most important thing is to ensure they comply with Australian standards and are approved for use by your utility. Buying direct from overseas is usually not a good option. Secondly, it is worth doing some research on reputable, long standing brand names compared to the ones no-one has heard of before... much like solar PV panels in that respect.

Cant argue with that statement.

The Rich Electric Solarworx inverter was designed in Australia by an Australian who works for the Rich Electric factory. I just spent a couple of weeks travelling around australia back in march doing product training with him.
I've also personally visited the Rich Electric factory in Taiwan.... the whole thing is powered by a 275kW solar array on the roof, as well as a 45kW vertical axis wind generator... fed into their own designed and built grid-tie inverter bank (a whole room of the factory!!). So they have put their money where their mouth is, so to speak
They make 140% of their factory's power needs, and sell the rest back into the local power grid.



How's the supply of SMA's at the moment?? I hear they arent available until Aug-sept.....

 

[HiEquity]

Hi Witzl

We should probably have this discussion on another forum but just for an alternative view and the chance to have a techie discussion here...

Typcially, most high frequency switchmode devices lose their efficiency as the output load decreases.

Not from the test reports I've seen and I've spent a fair bit of time in inverter test labs. The main difference being the magnetisation losses for the transformer core in a low frequency design. Of course at zero output the efficiency of all devices is below zero percent but a good IGBT inverter beats one with a transformer across the full load range. That's why they are used for all the multi-MW inverters.

High frequency switchmode actually causes far more electrical noise (EMI, RFI, etc) than low frequency.

Incorrect. The harmonics of an IGBT inverter are all at exceptionally high frequencies and can only travel a short distance down any conductor before being removed. No filters required. It's the low frequency devices that require filtration as their harmonic frequencies are able to travel long distances into the power network.

the whole thing is powered by a 275kW solar array on the roof, as well as a 45kW vertical axis wind generator...

That wouldn't power much of a factory! I think it would be more accurate to say the grid powers the factory and the renewables contribute their respective amounts to the grid.

How's the supply of SMA's at the moment?? I hear they arent available until Aug-sept.....

I don't usually deal in the household sector. For a >1MW inverter, about 6 months, depending on the project...

 

[Witzl]

clearly you are far more educated than i in this field... im just a humble technical marketing guy, who sources products for Jaycar/Electus.

... i just know enough to be dangerous, and to sell the products and understand the markets they are sold into.

BTW - that factory IS powered by the solar/wind system. The whole factory was built from the ground up to be super energy efficient, and they mostly only do assembly, tool production, testing and R&D in that factory. All the parts/component manufacture is contracted out, like is done with most factories in the far east (that ive been to anyway)

and yeah... waay off topic for this thread now

 

[tdh78au]

tdh78au,

A quick search around on the internet says that VIC is still using NET metering

<trim>

Note - RECs are "renewable energy certificates", these are the things which give you the "rebate" for your solar power system.
See here for information - http://www.greenenergytrading.com.au/rec-faqs.html

To give you some idea of what the RECs are worth to you... each REC is worth around $42.
Go here to work out how many RECs you can create for a system in your location: http://www.greenenergytrading.com.au/solar-pv-systems-2.html

Hi Witzl,
really appreciate your detailed response and all your help here. Love your work.

On the REC's front, given that the ETS takeup by Australia is going to be delayed by few years, I'm confused on whether REC's will still apply. (In my simplistic view) if the ETS doesn't exist then Carbon Credits are not required and hence REC's are useless anyway. Is this correct?

This is one of the main reasons why I haven't moved forward with the purchase/installation just yet. All the solar companies carry clauses in their purchase/installation contracts to pass on the full costs to the consumers should the REC rebates not apply. I really don't want to end up with a surprise 10k bill just because 3k + REC's didn't work out for the solar company!!!!!

 

[HiEquity]

On the REC's front, given that the ETS takeup by Australia is going to be delayed by few years, I'm confused on whether REC's will still apply. (In my simplistic view) if the ETS doesn't exist then Carbon Credits are not required and hence REC's are useless anyway. Is this correct?

No it's not correct.

RECS are a function of the Renewable Energy (Electricity) Act, which did pass parliament last year with bipartisan support.

Carbon Credits (also known by other names) were to be a function of the CPRS legislation which didn't pass parliament. Actually, to be correct, the CPRS didn't mean there was going to be any more income for PV systems - it was meant to work by raising the price of electricity you got from your PV system and paid as an end user.

There is no problem with certainty around the existence of RECS - the only risk now is their price, which can fluctuate significantly. My personal view is there is significant upside in that price in the large scale industry, not sure about the small scale rooftop PV RECs now they are being split from the large scheme - it's not a market I follow.

 

[redsquash]

What is the opportunity cost for installing solar panels?
You need to consider this with any investment if this is your approach.
If trying to benefit the planet then just do it.

If you assume you can get a return of 7% on $20,000, perhaps the cost of a system all up, then you will need to have electricity savings of at least $1400 to break even.

Of course you will be down $20,000 as well on capital costs.
I believe in the next 5 years the costs will be significantly reduced with greater efficiencies, if not earlier( Silex, an Australian company has a subsidiary working on this now).

 

[redsquash]

I believe that a Solar HWS gives you a better bang for your buck. Followed by changing electricity usage patterns.

But I am following this keenly as I am planning to install something myself.

Cheers

Look into heat pumps as they act like an air conditioner which can help cool a house depending on the location of installation.
I have a heat pump and 2 Solar HWS.

Only Go for a closed system ,with Marine grade steel tanks to avoid a sacrificial anode, otherwise go for a heat pump would be my suggestion generally.

 

[Witzl]

Just for reference - a $20,000 grid tied PV system (before RECs) would be around 3kW in size, maybe larger. This would produce around about 13.5kWh per day.

Lets look at the numbers on that.

NET METERED:
Lets assume that your house has a daytime power consumption of around 5kWh (this is pretty large), whilst solar power is being produced.
Therefore, excess solar production is = 8.5kWh/day
Saving on energy consumed = 5kWh
If your power costs you $0.17/kWh, and your feed in tarrif is $0.60/kWh, that represents:
8.5 x 0.6 = $5.10
5.0 x 0.17 = $0.85
== $5.95/day in savings/credits.
==== $2175.75 per year.

WITH GROSS METERING:
.. all solar is fed into the grid:
13.5 x $0.60 = $8.10/day
=== $2956.50 per year

As for now many RECs you get from that system, it depends on your location:
Melb = 159
Syd = 186
Bris = 186
... each REC is worth $42 at the moment.

So if you were in sydney, and hooked up this 3kW system with GROSS metering.
Total outlay = $12,188
Savings per year = $2956.50
Total payback time = 4.12 years.
... then after 4.12 years you are saving/making $2956.50 each year.

 

[Spectre]

wonder how it would work with getting two - say one on your IP and one on your PPR.
Rebates on both properties. Wonder if the supplier could do a buy one get one free pricing scenario and then make the non deductable one very cheap as there appears to be a lot of fat in them

 

[Witzl]

talking to my electricity provider - the person who receives the feed-in credits for solar power fed back into the grid is the account holder for that property.
Hence, your tennant would receive the feed-in credits for the system on your IP.
However, you would receive the RECs for installing the system on your property.

You might want to talk to your electricity provider to see what they say

 

[Spectre]

And the update

Ok

Got the quotes etc from my guy and have attached.

I blacked out a few bits for your reference.

At this point I dont see much sense in getting the PV system mainly due to cost and I figure they'll come down over time.

Appreciate any comments/feedback.

BTW I get trade due to the side business we have so cant say its available for everyone nor make any representations you would.

Although I probably could order them for ya and we could split it.
lol

 

[Spectre]

Also

also 2 other pdfs I didnt attach for your reference.

 

[Brett IP]

Thanks for that

Good comparison point

 

[Witzl]

that isnt a very good trade price for a 1.5kW system.... that's almost full retail price actually.

there are many large companies offering 1.5kW systems installed for around $4000 after RECs.... so that $6500 is a little on the higher side IMO

 

[redsquash]

Just for reference - a $20,000 grid tied PV system (before RECs) would be around 3kW in size, maybe larger. This would produce around about 13.5kWh per day.

Lets look at the numbers on that.

NET METERED:
Lets assume that your house has a daytime power consumption of around 5kWh (this is pretty large), whilst solar power is being produced.
Therefore, excess solar production is = 8.5kWh/day
Saving on energy consumed = 5kWh
If your power costs you $0.17/kWh, and your feed in tarrif is $0.60/kWh, that represents:
8.5 x 0.6 = $5.10
5.0 x 0.17 = $0.85
== $5.95/day in savings/credits.
==== $2175.75 per year.

WITH GROSS METERING:
.. all solar is fed into the grid:
13.5 x $0.60 = $8.10/day
=== $2956.50 per year

As for now many RECs you get from that system, it depends on your location:
Melb = 159
Syd = 186
Bris = 186
... each REC is worth $42 at the moment.

So if you were in sydney, and hooked up this 3kW system with GROSS metering.
Total outlay = $12,188
Savings per year = $2956.50
Total payback time = 4.12 years.
... then after 4.12 years you are saving/making $2956.50 each year.

Witzi,you wrote in a prior post that
'If you have a pool, then your typical pool pump ALONE will chew through the power that a 1.5kW solar system will produce each day.
...................................
..............................

A typical home, without a pool, and only occasionally using aircon, will use about 20kWh per day on average'.
can you explain please.
Also is your comment based on 5 hours of usable light to get 13.5kWh ?
"Just for reference - a $20,000 grid tied PV system (before RECs) would be around 3kW in size, maybe larger. This would produce around about 13.5kWh per day."

 

[Spectre]

that isnt a very good trade price for a 1.5kW system.... that's almost full retail price actually.

there are many large companies offering 1.5kW systems installed for around $4000 after RECs.... so that $6500 is a little on the higher side IMO

didnt take that and went with the water system.

My current one is about 10 years old and not going to be hanging out for too much longer.

So I figured to get a new one would be what - @7-800 for the tank.
Take off the 2600 so the panels etc installed around 1800 and a long term thing after rebates. I can live with that

Besides I know the guy and I think if I support his business he'll help me and support mine. And that'll outweigh the total cost of doing everything well and truly

 

[BV]

Appreciate any comments/feedback.

Your solar electricity system seems very expensive
I was quoted a bit $less than $3K for a 1.5Kw system from Solar first (marketed through Bunnings)

 

[BV]

I've recently ordered a 1.5kw system from Beyond Building. They had a special on and I only paid $2k for the system, which means it will pay for itself in around 18 months.

Skater
How did you go with the order?
Did you get any other quotes?
cheers