Do you have solar panels?

[drsmith]

Thanks Smurf for the above contribution. There's some interesting thoughts there to consider and it's something I'll get back to.

As for squirting cool water on hot panels, is that a good idea ?
I'm thinking here in relation to thermal expansion and contraction.

 

[AlterEgo]

Where are you located AlterEgo? Best ours has achieved so far was 24.54kwh on Sunday 6/11. Previous high was just shy of 24 last Feb. As our panels are split between north and east it will never generate the max possible at any one time, but sort of compensates by starting to generate earlier in the morning - I think we only lose about 7% efficiency by not having all the panels facing north. As an experiment, my husband sprayed the panels with water on a hot sunny day last Feb, and they immediately started generating a little more until they heated up again. As I'm in hot & humid Gold Coast I'll be hoping for a mild summer for more than one reason...

I'm in Brisbane. Panels are facing north. They pretty much get full sun all day, except in the late afternoon when they start getting some trees shading them.

 

[AlterEgo]

Spraying the panels with water isn't only useful for cooling them down. Far more important is it to hose down all the dust and grime they collect during long spells of dry weather. We clean ours every couple of weeks if rain hasn't washed them in between. And while we're at it, the HWS gets some too.
Makes a helluva difference for efficiency.

Yeah, earlier in the year when we'd had a dry spell for several weeks, my panel output had dropped to around 18kwh per day. I hosed them off one afternoon and the very next day I got 24.4kwh, which at the time was the highest I'd seen mine produce. So it certainly does appear to make a difference.

 

[Smurf1976]

As our panels are split between north and east it will never generate the max possible at any one time, but sort of compensates by starting to generate earlier in the morning - I think we only lose about 7% efficiency by not having all the panels facing north. As an experiment, my husband sprayed the panels with water on a hot sunny day last Feb, and they immediately started generating a little more until they heated up again. As I'm in hot & humid Gold Coast I'll be hoping for a mild summer for more than one reason...

Panel orientation is critical for a stand alone power system where you want consistent year round power production. But for a grid-connect system it's far less important since it doesn't matter if you end up producing most of your power in a few months each year as long as the annual total is still good. And the practical effect of putting the panels East vs North vs West is that shifts the timing of production but doesn't make a huge difference to total annual output (a few %).

As for spraying the panels with water, there is a direct relationship between panel temperature and output with COLD conditions being preferable to hot. That's why the difference in annual output between Brisbane and Hobart, for example, is far less than you might expect (though output is still somewhat higher in Brisbane).

But I wouldn't personally choose to spray any hot glass with cold water due to thermal expansion / contraction issues. Just like you only use cold water to clear a frozen windscreen in winter because hot water will shatter it, I wouldn't put cold water directly onto a panel that's been sitting in the sun all day in summer. Whether anything bad happens in practice I'm not sure, but the physics of it all does concern me.

 

[Smurf1976]

Yeah, earlier in the year when we'd had a dry spell for several weeks, my panel output had dropped to around 18kwh per day. I hosed them off one afternoon and the very next day I got 24.4kwh, which at the time was the highest I'd seen mine produce. So it certainly does appear to make a difference.

Whether or not you need to clean solar panels is very much location specific. First rule is to have at least a 15 degree tilt no matter where you are located and which way the panels face. The rain does a better job of cleaning them that way.

Whether or not it's worth actively cleaning them varies with location and also considerations as to how easily you can access them for cleaning versus the benefit of doing so.

My panels are on a 22 degree slope in a fairly clean environment so I've never cleaned them (I have checked and they aren't dirty). But that would be very different if I was in an area with industrial fallout, lots of pollution from traffic etc in which case I expect they would need a clean quite regularly.

 

[sptrawler]

Whether or not you need to clean solar panels is very much location specific. First rule is to have at least a 15 degree tilt no matter where you are located and which way the panels face. The rain does a better job of cleaning them that way.

Whether or not it's worth actively cleaning them varies with location and also considerations as to how easily you can access them for cleaning versus the benefit of doing so.

My panels are on a 22 degree slope in a fairly clean environment so I've never cleaned them (I have checked and they aren't dirty). But that would be very different if I was in an area with industrial fallout, lots of pollution from traffic etc in which case I expect they would need a clean quite regularly.

Dust build up on the panels has a major effect.
As this article says the worst countries for dust are the middle east, Australia and India.

http://www.bbc.co.uk/news/science-environment-11057771

I purchased an extendable broom, from Bunnings, that you can connect the hose to. Once or twice during summer I give them a wash.
But as smurph says, this may not be practicle with some installations.

 

[Smurf1976]

Record production today of 9.51 kWh from the 1.36 KW system (limited to peak AC power output of 1.1 KW).

Sunshine not all but almost all day but the real bonus was a consistent reasonably strong breeze from the right direction to keep the panels cool. That plus some decent rain a couple of days ago would have removed any dust too.

 

[todster]

Would it be possible that going down the path of solar panels and the outlay of cash that your use of power would change and also contribute to lower bills.
Human nature type savings.
Everyone i know with panels seem to also be instant power experts.

 

[Smurf1976]

Would it be possible that going down the path of solar panels and the outlay of cash that your use of power would change and also contribute to lower bills.
Human nature type savings.
Everyone i know with panels seem to also be instant power experts.

It stands to reason that there would be a linkage between awareness of energy consumption and installing a solar power system at home. That said, the motivation in many cases would presumably be financial rather than energy or environmental issues.

 

[pixel]

Would it be possible that going down the path of solar panels and the outlay of cash that your use of power would change and also contribute to lower bills.
Human nature type savings.
Everyone i know with panels seem to also be instant power experts.

Would it be possible, todster, that your assertion makes even more sense the other way around? That people, who think about their energy costs and are aware of the need to conserve finite resources, are also more likely to put their money on it?
I can only speak for myself; but in our household, it's been standing practice to fix leaking taps; to plant natives that need less water; to mulch to curb evaporation; and to switch off the lights where/ when they're not needed. Need I mention fluoro tubes and light bulbs? power boards that let us switch off unused appliances: microwaves, radios, TVs, even computers and the modem. But we've done all those things routinely well before solar panels became an option. Therefore, all savings we achieved by installing solar HWS and power generation are the real deal on top of plain common-sense habits.
In fact, even before doubling our solar panels to 2KW capacity, we installed two new airconditioning units, which we use when summer days become uncomfortably hot. But in our climate control, we don't go overboard either; we set the target temperature closer to 28 centigrades in summer, 21 in winter.

 

[todster]

Would it be possible, todster, that your assertion makes even more sense the other way around? That people, who think about their energy costs and are aware of the need to conserve finite resources, are also more likely to put their money on it?
I can only speak for myself; but in our household, it's been standing practice to fix leaking taps; to plant natives that need less water; to mulch to curb evaporation; and to switch off the lights where/ when they're not needed. Need I mention fluoro tubes and light bulbs? power boards that let us switch off unused appliances: microwaves, radios, TVs, even computers and the modem. But we've done all those things routinely well before solar panels became an option. Therefore, all savings we achieved by installing solar HWS and power generation are the real deal on top of plain common-sense habits.
In fact, even before doubling our solar panels to 2KW capacity, we installed two new airconditioning units, which we use when summer days become uncomfortably hot. But in our climate control, we don't go overboard either; we set the target temperature closer to 28 centigrades in summer, 21 in winter.

More power to you pixel or should i say less
Do you see solar panels in Peppy Grove ,Mossie Park around the river or only in the pov areas of Perth?

 

[Smurf1976]

I can only speak for myself; but in our household, it's been standing practice to fix leaking taps; to plant natives that need less water; to mulch to curb evaporation; and to switch off the lights where/ when they're not needed. Need I mention fluoro tubes and light bulbs? power boards that let us switch off unused appliances: microwaves, radios, TVs, even computers and the modem.

It truly amazes me that anyone wouldn't fix a dripping tap or turn off appliances that aren't being used.

 

[pixel]

More power to you pixel or should i say less
Do you see solar panels in Peppy Grove ,Mossie Park around the river or only in the pov areas of Perth?

There will always be areas, where people have more Dollars than Sense. Or where wasting resources is seen as a sign "Look how wealthy I am: I can light my havanna with $100 notes."
However, you will see solar panels in Nedlands, an "inner suburb" around the Uni of WA, for non-Sandgropers. And if I'm not mistaken, the new mansion South of Saunders St in Mosman Park has two rows of solar panels on its roof.
Check it out on Nearmap: http://www.nearmap.com/?ll=-32.014611,115.776513&z=20&t=h&nmd=20110908
Navigate a little further West, and you'll find plenty more.
Or take Subi: http://www.nearmap.com/?ll=-31.941862,115.829622&z=20&t=h&nmd=20110908 which isn't exactly "pov" either.
So whether posh or pov, "thinking people" seem to have taken advantage of the opportunity.

 

[todster]

At the end of the day it is what the Government is going to give back to you.
The rest is bollocks
22 degrees,30degees,north ,south clean panels
Pretenders.

 

[sptrawler]

Would it be possible that going down the path of solar panels and the outlay of cash that your use of power would change and also contribute to lower bills.
Human nature type savings.
Everyone i know with panels seem to also be instant power experts.

Your spot on todster, its a bit nauseas at work, where everyone is going on about mine is bigger than yours and I produced x more KW than you.
Most of the solar installations are in affluent areas, poor areas can't afford them. Which is a shame because they could do with them the most.
Oh well, the rich get richer and the poor get poorer, as usual. It is a strange world we live in.

 

[pixel]

It truly amazes me that anyone wouldn't fix a dripping tap or turn off appliances that aren't being used.

Do you have teenage kids or grandkids?
And have you ever wondered why the Government spends $Millions for TV commercials that urge people to "switch it off at the wall socket"?

 

[noirua]

Would it be possible that going down the path of solar panels and the outlay of cash that your use of power would change and also contribute to lower bills.
Human nature type savings.
Everyone i know with panels seem to also be instant power experts.

Yes, I've noticed people talking about wasting power who happen to have solar panels fitted and only your comment brought this back into my mind. It seems you're allowed to do this if you have joined the solar panel club who have installed at very great cost to save the world.



Have you had time to vote for ASF at the forum poll yet: http://www.thebull.com.au/the_stockies/forums.html

 

[DocK]

Would it be possible that going down the path of solar panels and the outlay of cash that your use of power would change and also contribute to lower bills.
Human nature type savings.
Everyone i know with panels seem to also be instant power experts.

We've always done our best to reduce "wasted power" by turning things off, washing in cold water etc. Since installing the solar panels the only real change is the timing of things like using clothes dryer, dishwasher etc at night in order to maximise the power fed back to the grid. Of course most appliances still get used when normally required, like ovens, aircon etc.

Like Pixel, we were always conscious of wasting natural resources and also have native gardens, 12000 litres of water tanks, we recycle, compost, grow some of our own vegies and generally try to "limit our footprint" where we can - to a point. We do still run airconditioning when hot, have more tvs and computers running than strictly necessary and live a normal life - it's just about balance in my view. If it's cost-effective and relatively simple to be environmentally responsible, I can't see why anyone wouldn't be.

 

[Eager]

Don't know if it has already been asked in this thread or not (I haven't read it in full), but would the installation of solar panels add value to the home?

I would say yes, for the same reason that for a potential buyer, a house with solar hot water would probably sell easier than one with an old off-peak electric clunker. The way I see it, the more that the installation of solar panels becomes 'normal,' the more that people buying houses would demand it, since the initial outlay has already been made.

I've had differing opinions to this question in other places.

 

[drsmith]

Record production today of 9.51 kWh from the 1.36 KW system (limited to peak AC power output of 1.1 KW).

Is that the rated peak AC output of the inverter and, if so, does it go above it.

The reason I ask is that mine is rated max AC output of either 1600W or 1650W, I'm not absolutely sure, but I have seen it go slightly above that (1655 to 1660 on a number of occasions), and on a couple of occasions, up to 1700W but only for about 2 to 3 seconds. This has been in sunny conditions when there is also reflectivity from cloud near the sun. During these conditions, the output can be quiet variable due to cloud movement.

The max putput current is rated as 8A with an AC voltage range (230V norm). 7.2Ax230V=1656W which is around the rates maximum AC output, so, I'm wondering whether the inverter could output 1800W at 250V.

Another consideration is that the PV array short circuit current is 5.5W. What worries me here is that if I add extra panels and that DC current is reached, it will trip the DC circuit breaker and cut all input from the panels. The max DC input current for the inverter is specified at 8A.

I have a replacement 1.5kW inverter on the way to solve the AM radio interference problem (Sungold 1500).

http://www.ginverter.com/products_info.asp?pid=31#

While it is still rated with a max AC power output of 1650W, Max DC input and AC output currents for the replacement are rated 10A and 8A respectively. 8Ax250V=2000W.