Ruffian

Going solar

77 posts in this topic

hey popeye

thnaks for sharing your updates

it really shows that you can help out the environment but also save money via going solar!

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hey popeye

thnaks for sharing your updates

it really shows that you can help out the environment but also save money via going solar!

It surprised me. I had been on a bit of a Power Squeeze, hoping that I will make it through the year without having to pay a power bill.

I'd say that we are well on the way to achieving that aim.

I could be self sufficient in Water as well, but I do still have the toilet flush on Mains, (it irks the b'jesus out of me to be flushing the toilet with rainwater). What a pity I cant have a bi directional water meter to offset the cost of the service charge by pumping my excess water into the mains.:rolleyes:

Edited by Popeye

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Oh, Happy, happy,...

We received our first Power bill yesterday and even though we have only had our bi-directional meter for 70 of the 90 day billing period we averaged a nett credit of $3.37 per day.

It's interesting to note the difference in Power imported from the grid, in the graph below.

aef8bd80.jpg

Very nice! :)

Thanks for posting popeye. What sort of time scale does this entail for ROI? Given power is forecast to rise you have some latitude in your projections. ;)

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I found this helpful.

http://forums.whirlp...1567387&p=4#r79

Depth of discharge determines battery life and it's an exponential thing.

If you go 50% DOD every day expect 5 years life.

15% gives you 10 years life.

5% gives you 20 years.

All the above depends on quality of battery, ambient temperature and humidity and the charging regime that your regulator has.

Lead acid batteries are very organic and are easily upset by what inexperienced people would think were minor problems. Gel cells are even more highly strung.

Gel cells really hate full discharge, which is why you'll regularly find near new gel cells for sale. In mission critical UPS applications three events and they're out the door.

You cannot rely ( in the sense $M rely) on them. Fine for home use but you'll find charging efficiency is woeful and life is very reduced.

Gel cells hate overcharging even more, cos if you start bubbling the electrolyte, well, do I need to draw a picture?

You can see how designing off grid and UPS systems is a bit more interesting than grid connect.

Finding the balance between battery size, battery life and the customer's wallet size is delicate.

My fave batteries are the BP PVStor lead acids. They have about 200mm of acid above the plates, which allows for slack maintenance. They have about 100mm below the plates which allows years of crap to build up before the plates short out.

They are near unkillable – I used to put them on rental properties and even tenants couldn't kill them.

I like the Exide Gel cells. Bloody dear though. The 48V1000Ah set pictured in the usual place cost over $20k.

Second hand Ni-cads can be good. Ni-cads can handle 100% discharge and stupid overcharging. What kills them is using a hydrometer that has been in a lead acid battery. If you do that you can throw the battery away. New Ni-cads are stupid expensive.

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I found this helpful.

http://forums.whirlp...1567387&p=4#r79

Depth of discharge determines battery life and it's an exponential thing.

If you go 50% DOD every day expect 5 years life.

15% gives you 10 years life.

5% gives you 20 years.

All the above depends on quality of battery, ambient temperature and humidity and the charging regime that your regulator has.

Lead acid batteries are very organic and are easily upset by what inexperienced people would think were minor problems. Gel cells are even more highly strung.

Gel cells really hate full discharge, which is why you'll regularly find near new gel cells for sale. In mission critical UPS applications three events and they're out the door.

You cannot rely ( in the sense $M rely) on them. Fine for home use but you'll find charging efficiency is woeful and life is very reduced.

Gel cells hate overcharging even more, cos if you start bubbling the electrolyte, well, do I need to draw a picture?

You can see how designing off grid and UPS systems is a bit more interesting than grid connect.

Finding the balance between battery size, battery life and the customer's wallet size is delicate.

My fave batteries are the BP PVStor lead acids. They have about 200mm of acid above the plates, which allows for slack maintenance. They have about 100mm below the plates which allows years of crap to build up before the plates short out.

They are near unkillable – I used to put them on rental properties and even tenants couldn't kill them.

I like the Exide Gel cells. Bloody dear though. The 48V1000Ah set pictured in the usual place cost over $20k.

Second hand Ni-cads can be good. Ni-cads can handle 100% discharge and stupid overcharging. What kills them is using a hydrometer that has been in a lead acid battery. If you do that you can throw the battery away. New Ni-cads are stupid expensive.

It would be nice to have a cost benefit analysis including the TCO including battery choice. It's difficult to track take up rates and economies of scale in a transitional economy. In the long term I predict we are moving toward a low carbon economy. Invest in such at your own peril. The abbott will be in charge soon. Early adoption is to be applauded. It is the true believers that pay the premium so that we don't have to. It is risky behaviour that benefits the many at the expense of the few early adopters. Morality? Respect.

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It would be nice to have a cost benefit analysis including the TCO including battery choice. It's difficult to track take up rates and economies of scale in a transitional economy. In the long term I predict we are moving toward a low carbon economy. Invest in such at your own peril. The abbott will be in charge soon. Early adoption is to be applauded. It is the true believers that pay the premium so that we don't have to. It is risky behaviour that benefits the many at the expense of the few early adopters. Morality? Respect.

I doubt off grid systems are anywhere near cost effective if grid connect is an option, or just mains power... and may not be for many, many years.

My desire is to get off the system for independence more than monetary reasons. However, even if I had no problem with the capital expenses upfront I'm concerned about the operational expenses for maintenance and lifecycling equipment. It seems like batteries are the biggest issue when considering off grid systems. I get a little freaked out that they may only be good for 5-7 years.

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Todays CM had a 1.5k system ad for $990 installed after rebates.

edit - i was reading the paper while waiting for my coffee so i don't know what the #'s, *'s and %'s were.

Edited by zaph

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Very nice! :)

Thanks for posting popeye. What sort of time scale does this entail for ROI? Given power is forecast to rise you have some latitude in your projections. ;)

At present indications I'd say definitely no longer than 8 years, more likely about 5 - 6 years or less, unless of course power prices rise, in which case it will shorten up in line with the increase I certainly can't see them coming down:D

I paid $9,720, for the system supplied and installed, with some extra work done in the meter box to allow me to plug in my pure sinewave 4KVA genset in times of power outage. My power bill last year was about $1300., so if it only pays my power bill I'm getting a 13%+ return on my investment, although I feel that I'll do better than that averaged over 12 months.... I'm hopeful of a 16% return given the sunshine here in the Mid North of SA.

One of the things i have discovered is that the panels and inverter are much more efficient in cool weather, and that i can get almost exactly the same output on a cool 5/8 overcast day as I can on a hot clear day, What has been bugging me lately is the number of hot humid overcast days.

Edited by Popeye

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At present indications I'd say definitely no longer than 8 years, more likely about 5 - 6 years or less, unless of course power prices rise, in which case it will shorten up in line with the increase I certainly can't see them coming down:D

I paid $9,720, for the system supplied and installed, with some extra work done in the meter box to allow me to plug in my pure sinewave 4KVA genset in times of power outage. My power bill last year was about $1300., so if it only pays my power bill I'm getting a 13%+ return on my investment, although I feel that I'll do better than that averaged over 12 months.... I'm hopeful of a 16% return given the sunshine here in the Mid North of SA.

One of the things i have discovered is that the panels and inverter are much more efficient in cool weather, and that i can get almost exactly the same output on a cool 5/8 overcast day as I can on a hot clear day, What has been bugging me lately is the number of hot humid overcast days.

In the great real time strategy game that is life I will be going for the solar upgrade ASAP. Economies of scale will kick in eventually. I need a house first of course but if I had one... It sounds like the returns are becoming competitive... You know as well as I that the price of energy is heading north regardless of a price on carbon. Necessary infrastructure upgrades will ensure this. For 10 grand I'm assuming you don't store power?

We've had the same kind of summer humidity wise. Interesting observation.

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In the great real time strategy game that is life I will be going for the solar upgrade ASAP. Economies of scale will kick in eventually. I need a house first of course but if I had one... It sounds like the returns are becoming competitive... You know as well as I that the price of energy is heading north regardless of a price on carbon. Necessary infrastructure upgrades will ensure this. For 10 grand I'm assuming you don't store power?

We've had the same kind of summer humidity wise. Interesting observation.

We have a grid tied system. At the moment, storing power is very uneconomical unless of course you have no alternative.

A mate who lives out of town was quoted in excess of $160,000 to get connected to the grid, as it would involve a number of new poles and a transformer being put in place. This cost is added to your quarterly bill and paid back over 20 years or so, but it makes for very expensive power, so he has installed an inverter and a small 24V deep cycle lead acid battery pack for minimal storage with the idea of placingmore batteries in parallel as he can afford them. He has fitted all LED lighting in his house.

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In the great real time strategy game that is life I will be going for the solar upgrade ASAP. Economies of scale will kick in eventually. I need a house first of course but if I had one... It sounds like the returns are becoming competitive... You know as well as I that the price of energy is heading north regardless of a price on carbon. Necessary infrastructure upgrades will ensure this. For 10 grand I'm assuming you don't store power?

We've had the same kind of summer humidity wise. Interesting observation.

I'd go for the solar upgrade myself, also with considerations of the increased price of energy

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Just a quick update on the Solar power status.

We received our AGL Bill a few minutes ago and had a pleasant surprise. Regardless of the crappy weather (sunlight wise), that we've been having during the last 3 months our credit has grown yet again.

The Total is for 5 months as we only received credits for 70 of the 90 days in the first billing period.

2e47cc05.jpg

28dd97aa.jpg

Edited by Popeye

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Maybe I am missing something, but how do you have a 3KWh system, consume 8KWh/day, and receive a credit?

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Maybe I am missing something, but how do you have a 3KWh system, consume 8KWh/day, and receive a credit?

The system is Capable of putting out 3KW per hour which so far has averaged somewhere in the region of 11 KWh per day. Whereas my usage is only 8.3KWh per day.

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The system is Capable of putting out 3KW per hour which so far has averaged somewhere in the region of 11 KWh per day. Whereas my usage is only 8.3KWh per day.

Oh ok, thanks for the clarification.

What type/number of panels do you have?

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Oh ok, thanks for the clarification.

What type/number of panels do you have?

We have 16 x 190W AstroEnergy panels (Sumitomo technology, made in China by Chint).

The panels are not installed at the best possible elevation of 30 degrees, with the supporting frame being placed immediately on top of our skillion roof which only has an angle of 5 degrees, however with a little math it can be determined that the loss will only amount to about 6% at the Winter solstice, so the additional cost ($1500) was not worth it. Also there have been cases reported of wind noise being transmitted from panels on elevated frames through the roof, so we decided against it.

Edited by Popeye

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I'm suffering withdrawal symptoms at the moment.

Since we installed our solar system I have recorded the meter readings every morning and transferred them to a spreadsheet in an effort to gain some insight into the profit or loss being made by our system. In view of the figures on our last power bill, I have come to the decided that it is no longer necessary and that we will certainly more than pay our power bills for the year.

We "older persons" dislike changes in our routine. :wheelchair:

Edited by Popeye

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In view of the figures on our last power bill, I have come to the decided that it is no longer necessary and that we will certainly more than pay our power bills for the year.

Are you able to sell your credits if you have no need to cash them in?

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Are you able to sell your credits if you have no need to cash them in?

I believe that you can, but personally I have made no enquiries about it to my supplier. I will do so at the end of 12 months (in November) when I have a better idea of where I stand.

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