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Do you have solar panels?

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.

Can I be rude and ask how much the solar HWS cost to buy and install? We're running out of roof space for more panels, but have friends with a heat pump HWS that apparently works well for them. I have heard some can be noisy though, so am hoping in a few years the bugs might have been sorted. As our electric system is inside our garage it may last us several years yet and as our total hot water cost is only approx $400 pa, it didn't make sense to me to spend much to replace it - I'll wait until it finally fails. Off peak rate is only 7.92c/kw for us. We mostly shower in the morning, and I wash in cold water - don't know how much difference that makes but we do seem to use far less hot water than the solar HWS sellers quote as the average.
 
Reading were in Spain they shine light' s on Solar panels during the night or cloudy days using diesel generators and collect the subsidy back from the grid.
 
Can I be rude and ask how much the solar HWS cost to buy and install? We're running out of roof space for more panels, but have friends with a heat pump HWS that apparently works well for them. I have heard some can be noisy though, so am hoping in a few years the bugs might have been sorted. As our electric system is inside our garage it may last us several years yet and as our total hot water cost is only approx $400 pa, it didn't make sense to me to spend much to replace it - I'll wait until it finally fails. Off peak rate is only 7.92c/kw for us. We mostly shower in the morning, and I wash in cold water - don't know how much difference that makes but we do seem to use far less hot water than the solar HWS sellers quote as the average.

My two sons actually seem to spend an inordinate amount of time washing themselves - makes me wonder sometimes just what could take so long.....;)
No problem, Doc, and no need to keep it secret: We had the HWS installed by Solargain in May 2009; the company obtained both lots of Government subsidies - I believe it was $1,600 each - on our behalf and only charged us the balance, which amounted to $695 including delivery, installation, GST.
So, even at the lowest saving estimate, it's paid back $750 over 30 months. Now it's printing us money :)
 
Reading were in Spain they shine light' s on Solar panels during the night or cloudy days using diesel generators and collect the subsidy back from the grid.

You would want to be getting your diesel cheap. 20 years ago it used to cost about 30c/ kw to produce electricity with a generator.
 
I think most roof mounted panels range from 20 - 50volts.

They are 12v, you can join them up and have 24v or 48v. it is the inverter that takes the power from 12v and ramps it up to 240v. A lot of people are making money out of this scam.
 
No problem, Doc, and no need to keep it secret: We had the HWS installed by Solargain in May 2009; the company obtained both lots of Government subsidies - I believe it was $1,600 each - on our behalf and only charged us the balance, which amounted to $695 including delivery, installation, GST.
So, even at the lowest saving estimate, it's paid back $750 over 30 months. Now it's printing us money :)

That makes sense - I think we've missed the boat on subsidies now, in Qld at least, so the quotes I've received have been much higher. At my calculation it would take me at least 5 years to be in front, so I'll wait until my present hws packs it in and hope that heat pump systems have had their kinks ironed out by then.
 
They are 12v, you can join them up and have 24v or 48v. it is the inverter that takes the power from 12v and ramps it up to 240v. A lot of people are making money out of this scam.

The dc input for my inverter is 60 - 320v. Currently running at 190vdc from 7 panels approx 27v/ panel
 
How will they know it was exported at night????

As I understand it, although they don't use it for billing purposes, the suppliers record usage in 30 minute blocks for those with smart meters. This apparently will be used in the future to give users a snapshot of their usage throughout the day for planning purposes (particularly business customers). Whether it records usage only or import/export I don't know.

Also, if you are on the smart power tariff, in WA at least, it records import in 4 registers - 7am to 11am, 11am to 5pm, 5pm to 9pm and 9pm to 7am. If when they check your meter, the 9pm to 7am usage is zero or extremely low, it might raise suspicions.

But you might be right in that there is no way of knowing for sure whether exporting takes place at night, but if the activity was to become widespread, they might start looking for anomalies in usage which might cause them to investigate further.
 
That makes sense - I think we've missed the boat on subsidies now, in Qld at least, so the quotes I've received have been much higher. At my calculation it would take me at least 5 years to be in front, so I'll wait until my present hws packs it in and hope that heat pump systems have had their kinks ironed out by then.
Ring Solargain, Edwards, Solaheart, ... whoever is available in your area and ask them for a quote. All you can lose is the cost of a few phone calls.
If I'm assured of cost recovery within 5 years - that's 20% interest p.a. - I'll take it anytime.
 
How will they know it was exported at night????
Over time, the amount fed in relative to nearby installs relative to system size might ring alarm bells, assuming power companies actively monitor such things. In any case, they would need to allow considerable margin for differing usage patterns between households. A single home owner I would imagine would have far more control over his/her electricity usage than a large family.

As far as I'm concerned, the whole thing is a scam. It's illogical in the extreme to offer feed in tariffs that exceed the retail price. It's an obvious target for abuse.

That being said, are there clauses in feed in contracts that limit what can be fed in. If not, then to me, if it's renewable and keeps the inverter going at maximum capacity 24/7, it's fair game.
 
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.
10.6 kWh from a 1.52kW system has so far been my best That was on a cool, sunny day after rain. Two days later with a warmer, sunny day, daily output was 10.2 and I was heading for 9.8/9.9 the next day with a max temp in the low 30's before cloud developed during the afternoon and truncated output to 8.4 for that day.

We have had very few completely sunny days in Perth in spring this year. I suspect the limit might be about 11 on a sunny, but cool day.

Mr Swan Valley Sharp 1.54kW (the one I compare mine to) has maxed out just under 10.6 so far this spring, but got 10.93 on one day in October last year.

http://pvoutput.org/aggregate.jsp?id=202&sid=217&v=0&t=m

My roof slope is a little less than his (22.5 deg vs 26 deg), so I should do a little better than him on a clear day at this time of year, all other things being equal.

While I have a 1.5kW inverter and can't upgrade that without losing a major component of the feed in tariff, I am considering adding two extra panels if it can be done cost effectively. The max DC input/AC output of the inverter is 1.8kW/1.65kW respectively. So far, in clear conditions, the highest AC output I have seen is about 1.4kW, although it can be higher on days when there is some cloud and there is reflectivity from this cloud in addition to full sun, although this is typically brief and intermittent.
 
How will they know it was exported at night????

Smart meter EM1000 channel 60 = KWh generated rate C (off peak) should = 0

There should only be readings on channel 50 = KWh generated rate A (peak)

channel 70 = KWh generated rate B (weekday shoulder)

channel 80 = KWh generated rate D (weekend shoulder)
 
I'm shot for any serious upgrade.

If I upgrade the inverter to a higher capacity one, I lose the feed in tariff.
Depending on what sort of inverter you have, they can be significantly over powered with no harm whatsoever and minimal loss of output.

For example, suppose that you put 2kW of panels on a 1.5kW inverter. You'll just lose any potential output above 1.5kW when the sun is shining brightly at mid day. But how often does that actually happen - in reality the loss will be in the order of 1%.

This all depends very much on the specific inverter in question and how it operates. Some will simply ignore any excess power available and will suffer no harm whilst others will not tolerate it at all.

Stage 1 of my system = 1.02 KW of panels and 1.1 KW inverter. Not large but this was a typical system size at the time. Panels are all installed on the NW roof face.

Stage 2 = increased the panels to 1.36 KW, still on the NW roof face. Losses from over powering the inverter at this level are trivial.

Stage 3 = second string on the NE roof face will take the system total to 2.88 KW, still on the little 1.1 KW inverter. The inverter is going to be working pretty hard that's for sure, but it will still capture 85% of potential energy from the panels according to my calculations. Production will be pretty consistent throughout the day due to the use of two roof faces.

Stage 4 = second inverter which will raise the utilisation of energy from the panels back to about 99% as well as adding a second MPPT (Maximum Power Point Tracker) which will improve efficiency a little.

Stages 1 & 2 have been running for a while and I've decided that Stage 3 will now be a goer. Stage 4 is on hold until it makes sense financially (ie when I can get a good deal on the equipmentand not before I've had Stage 3 running long enough to prove the accuracy of my math).

Note that there's nothing "iffy" about what I'm doing and it's all within manufacturer's specs. But remember no DIY tinkering with 400 VDC unless you really do know your stuff (and are licensed).
 
Aha! At last I get to say "mine's bigger than yours" :D 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.

I've got a 4kw system too, installed earlier this year. It exceeded 25kwh on Monday - the highest reading I've seen on it so far.
 
I've got a 4kw system too, installed earlier this year. It exceeded 25kwh on Monday - the highest reading I've seen on it so far.

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...
 
Curious............
A house in my suburb has got solar panels & two win turbine. How does it work? Feeding power all day & night.
 
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...
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.
 
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