Do you have solar panels?

sptrawler said:

Just had a thought Ifocus, if I was you, I would get in touch with the company installing the system and ask them if they use good quality stainless 316 bolts for the panel to rail clamps. Also I would be getting a tin of never seize, and ask the guys who put the panels on to coat the bolts, if you don't you will have a $hit of a job trying to get them off at a later date to repair or replace them with the corrosion from the surf spray.
If they are using galvanised bolts get the measurements and buy some stainless ones.
Just my opinion.

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Yes agree SP will see what turns up and hassle but no big deal to change out if not up to spec.

I logged in to the energy retailer I use and was surprised at how little power I draw from the grid. It is between 3 kWh to 5 kWh per day. This is despite the awful conditions with heat, bush fires and other impacting factors.

My off-peak power use is zero and has been since I had solar hot water installed in early August last year. The electric boost is connected to peak so that is not stunning news to me but it has been switched off day after installation when it was used allow the water to heat. Since then I have had no issues with the amount of hot water or its temperature. However, the tank is a 300 liter for a four-bedroom house and I am single so that is one cause for the outcome.

One aspect I couldn't understand for a while is why the house, when all closed down due to smoke haze, became slightly warmer later in the day. It was only after discussing it with a person who is familiar with these issues did I get some understanding. The house has double glazing. It works in reverse as well. So the heat from any electrical equipment (refrigerators, units on stand by power) and body heat will cause the temperature to rise slightly as well as the humidity. I can only assume that is the cause as I have no knowledge in such mattes but I found it interesting.

Since October last year, the house has consumed the following in peak-power:

October 19: 200.5 kWh
November 19: 128.9 kWh
December 19: 155.5 kWh
January 20 (part): 135.4 kWh

Solar exported for same periods:

October 19: 1,867.7 kWh
November 19: 2,078.9 kWh
December 19: 2,026.1 kWh
January 20 (part): 1,279.8 kWh

Belli said:

So the heat from any electrical equipment (refrigerators, units on stand by power) and body heat will cause the temperature to rise slightly as well as the humidity. I can only assume that is the cause as I have no knowledge in such mattes but I found it interesting.

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That’ll be it.

Heat is heat whether it’s coming in from outside or whether it’s from electrical appliances or humans giving off about 100 Watts each or whatever.

It’s not such an issue these days due to the lower power consumption of equipment and better air-conditioning systems but in the past places like TV studios, control rooms with a whole wall full of monitors and so on with everything giving off heat and it being impractical to have open windows were incredibly hot inside. Not unusual to find 35 degrees in a place like that when it’s 15 degrees outside and cloudy.

Factories, power stations and so on are also often incredibly hot inside for the same reason of internal heat generation from machinery.

Humid said:

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Nice pickup Humid, I will check it out when I get on the home computer and off the phone.

Bit late to the party I guess but just had a new roof put on the house and think its time to put Solar on.

Basic question …. Any recommendations on a good/best value Company and accompanying Energy provider(east coast Aus) I should be going with?

I was told by a mechanical engineer that a quality Inverter is the most important part of the equation in the long run?

Any advice/comments/suggestions from other's experience appreciated … Cheers

barney said:

Bit late to the party I guess but just had a new roof put on the house and think its time to put Solar on.

Basic question …. Any recommendations on a good/best value Company and accompanying Energy provider(east coast Aus) I should be going with?

I was told by a mechanical engineer that a quality Inverter is the most important part of the equation in the long run?

Any advice/comments/suggestions from other's experience appreciated … Cheers

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Good move barney, I guess a lot depends on how much you want to spend, if you want to add a battery, roof space limitations. You need a different inverter if you are going to install a battery.
I have had three solar systems installed, non have had the top shelf German inverters and non have failed.
I assume the German ones are better, but Im of the opinion that in 10years time whatever inverter you have, will probably need upgrading due to technical improvements and changes.
In W.A it cost $3000 for a 6.6kw system with a 5kw inverter, it was an extra $1000 to have a German inverter, I didnt bother.
But smurf will have a better idea than me with the situation on the East coast, also he has installed a battery, so probably has a hybrid inverter, which would add extra costs.
Over here in W.A you only get 7c feed in tarrif and last timd I checked you recieved no feedin tarrif if you had a battery.
Lots of variables barney, so plenty of research is the order of the day.

barney said:

I was told by a mechanical engineer that a quality Inverter is the most important part of the equation in the long run?

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Definitely agreed. The inverter, which in simple terms is the box full of electronics which converts DC (from the solar panels) into AC power (what your house uses and the grid works on). If anything's going to cause trouble then that's where it will be so you want top quality in my opinion.

The panels well personally I'm less fussy and would accept anything reasonable. Only reason to go for the latest and greatest is if you've got very limited roof space and need to maximise output per square meter since the top of the range panels do have higher output per unit of physical size. Otherwise, well paying 50% more for a panel that produces 10% more isn't the way to go - better off just adding another few panels unless physical space is a problem.

No comment on specific companies beyond noting that the vast majority of the physical work installing solar is done by small businesses. Even the large companies that do sell solar systems generally sub-contract the physical work to someone reasonably local.

Energy companies - go for whoever has the best deal unless there's some particular problem with customer service, billing etc or some reason why you just don't like a particular company. From a technical perspective well there's only one power grid and who you're paying for electricity makes zero difference there.

A few things though:

Shading - is there any shade, at all, on your roof? If so then this isn't a show stopper by any means but it does mean you need micro-inverters or optimisers on the panels. Have a good look - chimneys, TV antennas, trees, sewer vent pipes, anything that casts a shadow.

Inverter location - I strongly recommend that it's placed out of direct sunlight if at all possible. Heat is the enemy of the longevity of electronics.

How old is your switchboard? If it's old (has fuses) then it'll need replacement as part of the work. No problem if it's modern (has circuit breakers) and there's space to add the solar one and everything's in good condition. The installer will need to see it to confirm but if it's old then expect to need an upgrade.

Site inspection - if whoever's quoting won't come on site to give a firm quote then personally I'd be looking for someone who will. Site unseen, based only on Nearmap images, is good enough only for ballpark figures. It'll tell you how many panels fit on the roof but personally I'd want a site visit.

What direction(s) does the roof face?

Presumably you are on the main power grid somewhere? That is, you're not in a remote town that runs its own generators? Reason for asking is that in the case of the latter there may be different rules as to what's allowable.

sptrawler said:

But smurf will have a better idea than me with the situation on the East coast, also he has installed a battery, so probably has a hybrid inverter, which would add extra costs.

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Yep

Previous house (Tas):

4 systems totaling 6.69kW installed progressively 2009-13 on the N, E and W facing roof areas. Total of 33 panels in sizes 170W, 190W, 195W and 250W such was the progress of technology during those years.

All inverters were SMA (made in Germany) although one carried BP branding the others SMA branded. All panels were Chinese brands.

Current house (SA):

1 system comprised of 14 x 365W panels all facing North. Reason is the other roof spaces are heavily shaded by trees. These are LG panels, at the expensive end certainly, and chosen for no reason other than the physical space limit - if it wasn't for that then I'd have gone for a larger number of much cheaper 335W generic brand panels. That wasn't an option however.

Inverter is SolarEdge which by its nature means there's an optimiser on every panel so no problems with any shading of those.

Battery is DC coupled to the inverter, so yes it's a hybrid, and the battery is an LG RESU10H so that's 9.3kW active storage capacity with a maximum charge / discharge rate of 5kW (short term overload rating of 7.0kW in discharge mode).

Yes it's set up to operate as an islanded power system in the event that the grid power fails. That is, the panels still operate, so does the inverter and battery, and I'll still have power if the mains fails so long as the battery isn't discharged fully. Not all circuits are connected so as to preclude any overload situation - in short the oven and hot plates are not backed up in a blackout (but yes they will use solar power under normal circumstances, the distinction is for technical reasons due to equipment capacity limits and the huge current draw of the hot plates and oven).

System was installed in 2019 so it's all pretty new. Total energy generated thus far = 6.7 MWh. Needless to say, this arrangement was not cheap.......

barney said:

I was told by a mechanical engineer that a quality Inverter is the most important part of the equation in the long run?

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Look into micro inverters, where each panel has it's own inverter, they can increase the amount of generation you get from your panels, especially if some of your panels get a bit of shade throughout the day.

also, if your traditional inverter fails the the whole system goes down. but with micro inverters you only loose the production of the one panel, also the systems I was looking at the micro inverters came with longer warranty periods than the traditional inverters.

Value Collector said:

Look into micro inverters, where each panel has it's own inverter, they can increase the amount of generation you get from your panels, especially if some of your panels get a bit of shade throughout the day.

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Agreed - though I'll point out that properly installed optimizers on panels subject to intermittent shading are another way to achieve the same end result.

Key point there is that without adopting either approach, micro inverters or optimizers, shading one panel cuts the output of the whole lot hence the critical "is there any shade at all?" issue - it changes the design approach required for the system.

Smurf1976 said:

Otherwise, well paying 50% more for a panel that produces 10% more isn't the way to go - better off just adding another few panels unless physical space is a problem.

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Would the more expensive panels be likely to last longer ?

Rule of thumb about 1K per kw
Just installed 6.6kw system
3 Phase Fronius inverter with Longi panels
GoodWe was the other option a bit cheaper
If you get quotes be prepared to be hounded

Value Collector said:

Look into micro inverters, where each panel has it's own inverter, they can increase the amount of generation you get from your panels, especially if some of your panels get a bit of shade throughout the day.

also, if your traditional inverter fails the the whole system goes down. but with micro inverters you only loose the production of the one panel, also the systems I was looking at the micro inverters came with longer warranty periods than the traditional inverters.

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you also eliminate having high dc voltage running through your roof space

Thanks for the replies and advice gentlemen … much appreciated. The good news is I have a flat roofed house with basically no shading problems at all although a lot of it slopes SSW which I read is not ideal.

Meter box is a bit ancient so probably an upgrade needed there as well. Quote time I guess and see what eventuates. Cheers.

Try Whirlpool too you can get more local ideas

Smurf1976 said:

shading one panel cuts the output of the whole lot hence the critical "is there any shade at all?" issue - it changes the design approach required for the system.

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Could you explain what you mean by that Smurf, please. I currently have a 24 panel set-up (nearing 10 years now) in WA and in the late afternoon about 2 or 3 of the panels become shaded by the sun going behind a nearby roof. So if 3 are in the shade am I my losing more than 1/8 of what I would be getting if there was no shading?

If it's wired in series you will

bellenuit said:

Could you explain what you mean by that Smurf, please. I currently have a 24 panel set-up (nearing 10 years now) in WA and in the late afternoon about 2 or 3 of the panels become shaded by the sun going behind a nearby roof. So if 3 are in the shade am I my losing more than 1/8 of what I would be getting if there was no shading?

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https://www.infiniteenergy.com.au/shading-solar-pv-systems/

barney said:

Thanks for the replies and advice gentlemen … much appreciated. The good news is I have a flat roofed house with basically no shading problems at all although a lot of it slopes SSW which I read is not ideal.

Meter box is a bit ancient so probably an upgrade needed there as well. Quote time I guess and see what eventuates. Cheers.

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There has been some great feedback, great thread Barney.
Another thing to consider, if you can only fit a small system on the roof, check out the threshold voltage on the inverters they offer, it will make a lot of difference, as some inverters start generating at 70volts others at 110volts, so the 70 will start up earlier and shutdown later, it isn't such a big deal with large systems but can make a big difference on smaller systems.
As Humid said whirlpool is a good source of geeks and you will get good info there.