Has anyone got solar panels on their roof?

[oldrider]

When it comes right down to it none of the so called "Green" political aspirants are interested in backing you in this country!

Every connection is capable of two way energy flow and the thought of every customer doing what you are doing scares the generation companies shitless!

No need for any new infrastructure, most of it is already installed, just add PV capacity and the hydro stations back off until the sun goes down!

Too fucking easy but they would rather build new power stations and continue feeding to the customer one way and demand higher prices!

Good on you but don't hold your breath for cooperation or realisation of payback.

[steve_t]

Our PV set-up had its 1st birthday in late February. The year's generation was 7,650kWh
The problem is that Meridian have now announced that as of April 8th they will be knee-capping all of their 'Distributed Generation' customers by reducing their buy-back rate for exported excess generation by effectively 2/3. Now looking at power storage systems including Plug-in Hybrid Electric Vehicles, as the Commodore is due for replacement in any case.

Wow! That's some good generating!! Meridian have been way better than everyone else anyway but how shit is it to disincentivise self generation by reducing the buy-back rate?!! Grrr... Dicks. Batteries are expensive. The Holden Volt is expensive!!

[SPman]

Our PV set-up had its 1st birthday in late February. The year's generation was 7,650kWh
The problem is that Meridian have now announced that as of April 8th they will be knee-capping all of their 'Distributed Generation' customers by reducing their buy-back rate for exported excess generation by effectively 2/3. Now looking at power storage systems including Plug-in Hybrid Electric Vehicles, as the Commodore is due for replacement in any case.

That's about right for a 5Kw setup - our 1.5kW setup is generating about 2550 kWh a year, and we have slightly better sun hours than over there. Luckily we're still getting 42c kWh for our excess.
Power companies hate home PV - and so does the current Government - after all - how are you going to flog off power companies,if demand is falling........

[Winston001]

Every connection is capable of two way energy flow and the thought of every customer doing what you are doing scares the generation companies shitless!

Power companies hate home PV - and so does the current Government - after all - how are you going to flog off power companies, if demand is falling........

With all due respect I doubt the electricity generating companies even notice domestic generators. They sure as heck are not scared. They will make a profit whether you backload 5MW or 100MW. In fact the more you generate the happier they will be.

Its far cheaper for energy companies to not spend anything on new generation, instead they could rely on domestic generation. The problem is they can't actually rely on it being there. And at the moment the contribution is infintessimal.

Plus you are naive to expect anyone to buy back their own core product at their own sale price. Naturally they will pay a little less. After all, you could sell your excess kw to someone else.

[Winston001]

Don't get me wrong - I've been interested in solar energy for 20 years and want to see it standard in all homes. The thing is, it just is not cost effective yet. Solar panels, wiring, inverter, batteries - all expensive stuff and not particularly efficient...but hopefully not too far away.

The best option at the moment is solar water heating and even then you've got to figure the complex plumbing involved, abandon a high pressure water system, and add in electric heating (or reverse circulation) for frost protection. I keep hoping these problems will be solved but to date there isn't one easy solution.

[paturoa]

Don't get me wrong - I've been interested in solar energy for 20 years and want to see it standard in all homes. The thing is, it just is not cost effective yet. Solar panels, wiring, inverter, batteries - all expensive stuff and not particularly efficient...but hopefully not too far away.

The best option at the moment is solar water heating and even then you've got to figure the complex plumbing involved, abandon a high pressure water system, and add in electric heating (or reverse circulation) for frost protection. I keep hoping these problems will be solved but to date there isn't one easy solution.

See post #20. I was looking some time back and the merkins and canucks are wiring direct from the panels, one switch into 12v and 24v immersion heaters in cylinders. For those people on grid, that strikes me as the least capital, fastest payback method if you're up for a new cylinder.

Edit: would need to have a good boil / high pressure solution.
Edit 2: And some were using dual wind and solar panels.

[RoscoP]

Not correct, we installed solar hot water heating about 18 months ago. Cost $2700 for the 20 tube collector plus about $1200 for plumbing / installation. Was connected to a rheems 180 litre mains pressure HW cylinder. I recently replaced the 180 cylinder (it was 15 years old) with a stainless 330 litre solar cylinder ($2,450). We haven't had the element turned on since November last year and last year didn't turn it on until early May. We now have enough stored (very) hot water to see us through 2 to 3 days of no sun. In the winter we are $220 plus for power per month, with the solar running in the summer about $130.00 per month. A couple of other benefits are that you can have long hot showers whenever you want and hot rather than cold clothes washing. I am thinking of adding another collector to boost winter performance. On a really hot summer day the temperature on the collecter can get to 88 c and 78 c at the bottom of the cylinder.
If we are saving $700 plus per year (which we are) the ROI will be 9 years. The is based on current power prices, as prices increase to ROI time becomes less. I like to think of it this way. $6000.00 (the cost of the system) invested at 3.5% per annum would return me $245.00 per year less tax of say 28% = $177.00 per year in the hand. Makes $700 savings on the power per year for the investment I have made look good, as well as offering a degree of futureproofing and the feel good factor of sustainability

[Akzle]

See post #20. I was looking some time back and the merkins and canucks are wiring direct from the panels, one switch into 12v and 24v immersion heaters in cylinders. For those people on grid, that strikes me as the least capital, fastest payback method if you're up for a new cylinder.

Edit: would need to have a good boil / high pressure solution.
Edit 2: And some were using dual wind and solar panels.

solar and wind require two different controllers (or some clever electrical cuntery.) - solar goes OC when batteries are full, wind requires resistive load to brake the turbine.

wind is a better option for heating water tanks, as the element provides more resistance when hotter, so brakes the turbine, plus heats your water. if you still ahve nergy spare.. well shit, buy a fucking prius.

Not correct, we installed solar hot water heating about 18 months ago. Cost $2700 f...

blahblahblah and GFY. (really).

that's passive water heating, ie, the water gets heated by the sun, it's a fucking good system and idea, and everyone should do it. tubes are available on TM cheap as shit, you can line your roof and walls with them, all you need is a gas torch (30$ at bunnings) and some copper brazing wire-flux and spare pipe.
(though i'd tell you to reduce your water use)

i'm not quite sure how we got here, as i believe we were talking about PV (ie sun-> electricity) systems. which are LESS efficient for water heating (ie a 3kW element needs more panel surface area than equivalent BTU from vacuum tubes)
there are HEAPS of good passive energy ideas, the best being thermal mass and efficient building design.
fact remains that in modern day society, the geyser/HWC is one of the largest energy consumers in the home, followed by hairdryers, microwaves, dishwashers, ovens (who the fuck uses an oven anymore?) etc...

of course, a bucke painted black and left in the sun will do the same job for 98c.
(or a coil of LDPE, for about 120$ (seriously, go and get one, tie it to your roof and plug the ends into your hot water system, see how much you save))

it's a fucking wonder that wandering black folk with fuckall had this shit down to a T, but modern "civilization" struggles to "incorporate green ideas into development"

[paturoa]

solar and wind require two different controllers (or some clever electrical cuntery.) - solar goes OC when batteries are full, wind requires resistive load to brake the turbine.

wind is a better option for heating water tanks, as the element provides more resistance when hotter, so brakes the turbine, plus heats your water. if you still ahve nergy spare.

The solutions don't have controllers as there is no battery. Panel, cable, switch, heater emement. Probably doesn't even need a fuse.

They are just wired full time directly into the resistive load of the heating element. There was also some stuff where there were combo solar PV, and wind genny systems. Thinking about that some more, it would require some grunty diodes to stop reverse current into either the PV or genny.

[Akzle]

The solutions don't have controllers as there is no battery. Panel, cable, switch, heater emement. Probably doesn't even need a fuse.

They are just wired full time directly into the resistive load of the heating element. There was also some stuff where there were combo solar PV, and wind genny systems. Thinking about that some more, it would require some grunty diodes to stop reverse current into either the PV or genny.

"the solutions"?
PV panels output DC at a fluctuating voltage and current
turbines output AC voltage at fluctuating current. (need to confirm this one)

PV regulators stabilise DC output to ~13, 27, 38, 51V and fluctuate current
tubine rectifier-regulators convert to DC and stabilise to system voltage

at over-current/ batteries full, PV panels go OC, at under-current (shaded panel) a (normally schotty) diode bypass clicks in, bypassing that panel, preventing damage to it from current running though it from other panels etc.

at high wind speeds, turbines fuck off. they are permanent magnet generators, unless they have a resistive load ("dump load" or, say, a water heating element) they will over-spin, and, as point one, fuck off.
the resistive load limits the current flowing out of the coil, thus providing electro-magnetic resistance to the magnets, thus braking the turbine.

never EVER connect a PV panel or turbine to anything without a charge/load controller, and fuses are highly fucking recommended.

[paturoa]

"the solutions"?
PV panels output DC at a fluctuating voltage and current
turbines output AC voltage at fluctuating current. (need to confirm this one)[/quote]

Yeah, PVs have an optimum power output depending on the resistive load. As the light and load side voltage varies so does the optimum resistance value. So recent controllers such as mppt are varying the resistance continously to max the power. By sticking an appropriate immersion heater element (ie wattage and resistance) as the load on a PV with no controller, you may loose a few watts. Controllers are most useful for battery systems. This solution doesn't have any batteries.

Sure, gennies output ac and you will need a rectifier solution. There are heaps of gennies for sale that have inbuilt rectifiers. I agree there would be issues with wind gennies. Too low a resistance and it will overspeed, too high and it wouldn't turn in low wind. I'd guess that overspeed on an immersion load would drive too large a voltage into the element which would be "bad".

PV regulators stabilise DC output to ~13, 27, 38, 51V and fluctuate current
tubine rectifier-regulators convert to DC and stabilise to system voltage

Sort of, several generalisations there.

at over-current/ batteries full, PV panels go OC, at under-current (shaded panel) a (normally schotty) diode bypass clicks in, bypassing that panel, preventing damage to it from current running though it from other panels etc.

at high wind speeds, turbines fuck off. they are permanent magnet generators, unless they have a resistive load ("dump load" or, say, a water heating element) they will over-spin, and, as point one, fuck off.
the resistive load limits the current flowing out of the coil, thus providing electro-magnetic resistance to the magnets, thus braking the turbine.

never EVER connect a PV panel or turbine to anything without a charge/load controller, and fuses are highly fucking recommended.

Not sure you read my post fully as it was about connecting an immersion heater directly to the output without batteries (low up front cost).

Fuses are for pussies!

[SPman]

Don't get me wrong - I've been interested in solar energy for 20 years and want to see it standard in all homes. The thing is, it just is not cost effective yet. Solar panels, wiring, inverter, batteries - all expensive stuff and not particularly efficient...but hopefully not too far away.

The best option at the moment is solar water heating and even then you've got to figure the complex plumbing involved, abandon a high pressure water system, and add in electric heating (or reverse circulation) for frost protection. I keep hoping these problems will be solved but to date there isn't one easy solution.

........all expensive stuff and not particularly efficient
Efficiencies improving - a big push on, internationally.
http://www.energymatters.com.au/inde...aign=EM130312L

They are also putting in massive research now on home storage systems, to bring the price and size of them down - Li-on batteries etc

.......standard in all homes...http://www.energymatters.com.au/inde...aign=EM130312L

.......t just is not cost effective yet. Not cost effective? Our (subsidized) system cost $1,950 on the roof. Un-subsidized - would have been about $4,200 at the time - cheaper now. With feed in tariffs, it's pumping $950/yr worth of power back into the grid. Without feed in tariffs, it would save us $900/yr in power bills due to maximum generation occurring at peak power price times........as far as we are concerned, it's almost paid for itself already - the next 17 yrs are a plus......
Solar power is a bit like a computer. The longer you put committing, because of this reason or that, the longer you will keep on putting things off. We're just glad the Gov over here put subsidies in place to get started (as are 1,200,000 other Aussie households...), even if the pressure is now on and they keep slashing the subsidies at the behest of their big business mates........

[RoscoP]

Not correct, we installed solar hot water heating about 18 months ago. Cost $2700 for the 20 tube collector plus about $1200 for plumbing / installation. Was connected to a rheems 180 litre mains pressure HW cylinder. I recently replaced the 180 cylinder (it was 15 years old) with a stainless 330 litre solar cylinder ($2,450). We haven't had the element turned on since November last year and last year didn't turn it on until early May. We now have enough stored (very) hot water to see us through 2 to 3 days of no sun. In the winter we are $220 plus for power per month, with the solar running in the summer about $130.00 per month. A couple of other benefits are that you can have long hot showers whenever you want and hot rather than cold clothes washing. I am thinking of adding another collector to boost winter performance. On a really hot summer day the temperature on the collecter can get to 88 c and 78 c at the bottom of the cylinder.
If we are saving $700 plus per year (which we are) the ROI will be 9 years. The is based on current power prices, as prices increase to ROI time becomes less. I like to think of it this way. $6000.00 (the cost of the system) invested at 3.5% per annum would return me $245.00 per year less tax of say 28% = $177.00 per year in the hand. Makes $700 savings on the power per year for the investment I have made look good, as well as offering a degree of futureproofing and the feel good factor of sustainability

Just got our latest power bill $101.69 for the month of Feb / Mar (30 days). That is our cheapest bill for many years (family of 4, home all month). I have invested in LED bulbs and multi boxes with individual switches so we can switch off all the energy vampires when they are not in use. Coupled with the solar hot water heating it has made a big difference. I would be interested to know what other folk out there are paying per month for a family of 4 so I can get a feel for what the average is?

[huff3r]

Just got our latest power bill $101.69 for the month of Feb / Mar (30 days). That is our cheapest bill for many years (family of 4, home all month). I have invested in LED bulbs and multi boxes with individual switches so we can switch off all the energy vampires when they are not in use. Coupled with the solar hot water heating it has made a big difference. I would be interested to know what other folk out there are paying per month for a family of 4 so I can get a feel for what the average is?

$130ish over summer for a flat of four here, we are all early 20s so tv/radio/computers on most of the time. The gas cooking/heating/hot water is certainly helping here though. Hits more like $170 in the depths of winter.