Do you have solar panels?

[drsmith]

Stage 3 of my solar power system, adding a complete new 1.52 KW string on the NE roof face, will be a goer soon as I'm about to order the equipment.

I'm shot for any serious upgrade.

If I upgrade the inverter to a higher capacity one, I lose the feed in tariff.

 

[sptrawler]

Stage 3 of my solar power system, adding a complete new 1.52 KW string on the NE roof face, will be a goer soon as I'm about to order the equipment.

Interesting thing the other day a mate who has 1.5kw on his east roof asked me where to put an extra 3kw he was going to buy.
The suplier said put it on the east roof as more output due to temp, therefore more feed in tarrif,
I suggested, because he is a high user (air con) he would be better to have it on the west side. Thereby reducing the a/c operating cost when feed in tarrif cuts out. Also reduces afternoon sun on the roof.
I just tend to think people are more concerned about the pay back time on the system. Than installing it in a manner which reduces their consumption in an efficient manner.

 

[drsmith]

North is obviously ideal, but east is better than west, all other factors being equal, as solar panel efficiency declines with increasing panel temperature.

Another consideration is slope of the roof, east vs west.

Solar panels are generally specified at 25 DegC panel temperature (not air temperature) and decline by 0.45%/DegC.

http://www.hanwha-solarone.com/imag...odules/polycrystalline/en/sf_190_poly_IEC.pdf

 

[bellenuit]

We have a new way of ripping of the power, if you have solar panels, and you are getting more for your power from them, than you get from the grid, all you have to do is get a battery charger wired up to your solar panels, at night you turn on the battery charger.
Good one Labour.

That doesn't make sense. Assuming you are on the 47 cent FIT (WA, but I assume similar in other states), why would you direct your excess power to a battery foregoing 47 cent per kWH, when the battery operating at night will only save you 20 (approx) cents per kWH used or even less if you are using smart power. Additionally, charging a battery will always be less than 100% efficient, so you will not get back what you put in.

If you are not on the FIT, then what you are doing is perfectly valid so long as the setup is approved by the appropriate regulatory authority. You are generating the power, storing what you don't use during the day and retrieving it back at night. Who is being ripped off?

 

[kimcasablancas]

I don't, but I've considered getting them.

 

[DB008]

That doesn't make sense. Assuming you are on the 47 cent FIT (WA, but I assume similar in other states), why would you direct your excess power to a battery foregoing 47 cent per kWH, when the battery operating at night will only save you 20 (approx) cents per kWH used or even less if you are using smart power. Additionally, charging a battery will always be less than 100% efficient, so you will not get back what you put in.

If you are not on the FIT, then what you are doing is perfectly valid so long as the setup is approved by the appropriate regulatory authority. You are generating the power, storing what you don't use during the day and retrieving it back at night. Who is being ripped off?

+1
I am a little confused with pilots statement.

 

[sptrawler]

North is obviously ideal, but east is better than west, all other factors being equal, as solar panel efficiency declines with increasing panel temperature.

Another consideration is slope of the roof, east vs west.

Solar panels are generally specified at 25 DegC panel temperature (not air temperature) and decline by 0.45%/DegC.

http://www.hanwha-solarone.com/imag...odules/polycrystalline/en/sf_190_poly_IEC.pdf

The problem is Doc, when the feed in tarrif finishes. If the panels are facing east you are making power in the morning when you don't need it. When the house is hot in the afternoon and you turn on the a/c the panels won't be producing. IMO

By the way he doesn't have much north facing roof.

 

[drsmith]

The problem is Doc, when the feed in tarrif finishes.

That's why I referred to all other factors being equal.

Another consideration is the longevity of the components in terms of the return you get over a reasonable lifespan. It's OK to plan ahead, but what if the inverter packs up out of warranty but before or when the FIT ends ?

In relation to future usage, another consideration is the increasing cost of grid electricity and the reducing cost of solar components.

 

[pixel]

That's why I referred to all other factors being equal.

Another consideration is the longevity of the components in terms of the return you get over a reasonable lifespan. It's OK to plan ahead, but what if the inverter packs up out of warranty but before or when the FIT ends ?

In relation to future usage, another consideration is the increasing cost of grid electricity and the reducing cost of solar components.

In WA, the fit contracts run until 2020; by that time, our installation has been well and truly paid for and every unit produced after that will be a profit. Either in saved import (bought at ever increasing rates from Western Power) or exported into the grid at a lower wholesale price.
Should our inverter pack it in before then, it'll be replaced - either under warranty or from the Power Budget. I mean, we're not talking about a new car; the inverter is a small component of an installation that cost a few Grand in total.

 

[pilots]

+1
I am a little confused with pilots statement.

Gentlemen, no batteries needed, you have a battery charger wired in to your solar panels, at night you turn on the charger and you get 47c for the power you are supplying to the grid, you are NOT paying 47c to run the charger(way less). This little scam will be costing the power companies big bucks, how are they going to stop it????

 

[Calliope]

The daily output of my 1.5 KW system exceeded 10 KWh for the first time yesterday. I doubt it will go much higher this summer. Although the days are gettin longer, they are also getting hotter. As drsmith pointed out, panel efficiency decreases with panel temperature rises.

 

[sptrawler]

Gentlemen, no batteries needed, you have a battery charger wired in to your solar panels, at night you turn on the charger and you get 47c for the power you are supplying to the grid, you are NOT paying 47c to run the charger(way less). This little scam will be costing the power companies big bucks, how are they going to stop it????

They are not 12volt panels.

 

[pixel]

They are not 12volt panels.

no, but you can get batteries with higher voltage.
I think pilot's ruse is, he buys power at the the cheap noght rate, shoves it into a battery, then he "empties" the battery during the day, increasing the solar panels' output into the grid, selling at the subsidised 47c rate.
It may be technically possible; whether it's legal or ethical is a different matter.

 

[pilots]

They are not 12volt panels.

Is that so, tell me what are they if they are not 12v.

 

[pilots]

no, but you can get batteries with higher voltage.
I think pilot's ruse is, he buys power at the the cheap noght rate, shoves it into a battery, then he "empties" the battery during the day, increasing the solar panels' output into the grid, selling at the subsidised 47c rate.
It may be technically possible; whether it's legal or ethical is a different matter.

No battery at all, the charger feeds in to the grid at night only.

 

[DB008]

So what happens exactly.
Step by step please....
1)

 

[pixel]

The daily output of my 1.5 KW system exceeded 10 KWh for the first time yesterday. I doubt it will go much higher this summer. Although the days are gettin longer, they are also getting hotter. As drsmith pointed out, panel efficiency decreases with panel temperature rises.

Sounds about right, Calliope;
our 2KW system produces around 100 units a week and the credits from our exports are just about balancing charges for imports.
That's slightly better than what my initial feasibility study was based on. As retail rates increase over time, the balance is likely to change numerically. But then, the value of any solar-generated power that we consume ourselves will increase - so it'll all even out.

 

[pixel]

No battery at all, the charger feeds in to the grid at night only.

OK, I get it:
You run the charger with power imported from the grid, then you feed the charger's output back into the grid.
Works only if you have two meters: one to import what you need for the charger, the other to register the export. Had you hoth on the same meter, you'd be paying through the nose because you'd never export more than you import. And at least in WA, you only receive FIT credits for the net charge that you export into the grid after your own consumption.

Another flaw: The Power Company may take some time, but they surely could find out if you exported more than your solar panels can produce. I'm sure they know about efficiency, cloudy days, etc. With tools like "nearmap.com" they'd also be able to find out the size of your solar installation. You'd be busted.

 

[DocK]

The daily output of my 1.5 KW system exceeded 10 KWh for the first time yesterday. I doubt it will go much higher this summer. Although the days are gettin longer, they are also getting hotter. As drsmith pointed out, panel efficiency decreases with panel temperature rises.

Sounds about right, Calliope;
our 2KW system produces around 100 units a week and the credits from our exports are just about balancing charges for imports.
That's slightly better than what my initial feasibility study was based on. As retail rates increase over time, the balance is likely to change numerically. But then, the value of any solar-generated power that we consume ourselves will increase - so it'll all even out.

Aha! At last I get to say "mine's bigger than yours" We've had our 4kw system since mid-Feb this year and am averaging 20-23 kwh daily this week. So far, March, Sept & Oct were all similar at 510, 522 & 515 kwh respectively. I'm located Gold Coast so agree that the increasing heat will no doubt compensate for longer production times. Ours are half east and half north facing due to roof space available. So far, with a family of four (including 2 teenagers who use far too much power and seem unable to turn anything off) we've had to pay only $140 to Origin since having the panels installed. As we still have electric hot water, off peak, that makes me happy. Our next bill will be the first with 3 spring/summer months and I'm hoping for a credit balance.

 

[pixel]

Aha! At last I get to say "mine's bigger than yours" We've had our 4kw system since mid-Feb this year and am averaging 20-23 kwh daily this week. So far, March, Sept & Oct were all similar at 510, 522 & 515 kwh respectively. I'm located Gold Coast so agree that the increasing heat will no doubt compensate for longer production times. Ours are half east and half north facing due to roof space available. So far, with a family of four (including 2 teenagers who use far too much power and seem unable to turn anything off) we've had to pay only $140 to Origin since having the panels installed. As we still have electric hot water, off peak, that makes me happy. Our next bill will be the first with 3 spring/summer months and I'm hoping for a credit balance.

LOL Doc,
being teenagers, your kids probably don't use all that much hot water.
Still, when we replaced our old electric Rheem by a 300L solar HWS, we noticed straight away a significant drop in our power bill. And since installation 2 1/2 years ago, the booster hasn't been running for longer than 5 hours in total. Yet, after a sunny day, the hot water comes out scalding - hotter than we've ever had it from the Rheem, which would've cost us between $25 and $35 bucks a month.