Year 2 with our solar (PV) system

Very nice,

by my calcs. you are averaging ~18 kwh/day,,, not bad for a 3.8 kw system.

Good luck,

Icarus

 

I find that impossible to believe!
If he has a nominal 3.8kW panel set ( which I have too), then with an efficient set-up he is probably producing no more than 3.2 kW at maximum solar isolation, around mid-day. Even ignoring system efficiencies, 18 kWhr/3.8 = 4.73 hours of power output at maximum daily! Impossible, unless Codyroo has an optimized solar tracking system for both azimuth and elevation. Even then, I find it difficult to believe!
FWIW, I too have a 3.8kW (19 Sharp 200W panels) solar set-up down here in Southern California, with a pretty high level of solar isolation. it is now approaching its 2nd year since originally installed. From April 2008 though April 2009 total solar production amounts to 3,498 kWhrs, or around 8.81 kWhrs per day.

 

You make a good point, That would be in excess of ~ 5 hours at name plate rating 365 days per year. Not very likely. In the real world you would need better than a 6 hour average @ 80% of name plate over 365 days, also not very likely.

Perhaps the OP's numbers are wrong, or my interpretation of them is wrong.

Icarus

 

The first 11.5 months our 2.88 kw PV system produced 3464 kWh's

 

Somewhere around 1/2 of the OP's output,, more realistic.

Icarus

 

4.5 DC makes a bit more sense,

Thanks for the clarification.

Icarus,

PS My real world experience is mostly with off grid Pv systems that have very different efficiency curves.

 

In the off grid world, total efficiencies (losses from, wiring, charge controllers, basic battery charging losses, inverter losses etc) aproach 50% of name plate rating. So a 2 kw system, net/net might put out 1kwh of power for every hour of good sun. We like to use ~4 hour average, so that 2kw system might put out ~ 4-6kwh/day usable out the inverter.

Icarus.

 

Being Grid tied since '04, I find in summer my best day was 44 Kwh generated, in winter, that drops to 20 or so. Here is a shot of todays system stats...



The upper left quadrant is the total plant output. Top right is Inverter #1, the bottom two quadrants are inverters 2 and 3.
The kWh generated today at 3 pm was 31.288 kWh. The day is not over yet, should top out about 34, 35 or so! I bank so much in the summer, the winter in almost free!.
I find the dedicated computer display very helpfull in seeing how the system is performing, and when it needs a cleaning!

You all do clean your systems, don't you?

 

Thanks Codyroo, I feel a little better now!

Interesting that you chose the Sharp 187 panels (ND-187U1?). Mine are the ND-200U1 panels, chosen since they formed the best fit on the South and West facing roofs of my house. My arrangement has 12 facing South and 7 facing West, with a Magnatek 3600W Inverter.

The California Solar Initiative website (CSI EPBB Calculator) enables you to calculate the CSI output used to estimate the state rebate. Mine comes out at 3.18 kW A/C using their formulas and my roof slope of 34 degrees here in Cypress. The optimum slopes are 17 deg south facing and 9 deg for the west facing roof, so I lose some output as a result. However, I have been well pleased with my greatly reduced electricity bills since "going solar".

 

I am very interested in a solar system for my home. How much should I plan on spending. Are there any grants or government money to help with the install?


Any help with info would be helpful.

thanks,

JOANNA

 

sorry computational confunkshun error

see next try.....

 

I Googled "Utah Solar Rebate"

Go here....

[ame=http://www.google.com/search?hl=en&client=firefox-a&rls=org.mozilla%3Aen-US%3Aofficial&hs=jjs&q=utah+solar+rebate&btnG=Search&aq=f&oq=&aqi=]utah solar rebate - Google Search[/ame]

Read, ask questioms after reading, have fun!!!

 

Interesting.
In essence we have done the same, the catalyst being the enormous electricity bill we received after the heat wave of June/July, 2006. Being retired, I took this on as a challenge to my rusty system engineering skills. We replaced the old A/C with a newer, more efficient model, installed CFLs at all those points where lighting was on for extended periods, and replaced old refrigerator/ freezers with energy-star models. As a result our annual grid electricity consumption has gone from around 10,400 kWh in 2004-2006 to 1,604 in 2008! It will be higher this year for a number of reasons, but still way below the mid-decade levels.

 

Joanna,

The is no right answer except to say that your best solar dollar is spent on conservation. For every dollar spent on conservation will save as much as $10 in Pv costs.

Right now, installed grid tie Pv systems run between $6-10 watt. A reasonable sized grid tie system might be in the neighbourhood of 2-4kw. On top of that you can get a 30% tax credit from the feds, as well as some states have other tax incentives. In addition many utilities have rebate plans that can cut the cost considerably.

Having said all of this, the most important thing to do is to do your homework. Read and understand all you can, find folks that have done it, and find installers you can trust. I suggest that you start here:Solar Electric Power Discussion Forum by Northern Arizona Wind & Sun - Powered by vBulletin This is a forum that is populated by some very smart folks who have forgotten more about Pv and Re than most of us will know. It is not geared to try to sell you anything, just to impart information.

Finally, one doesn't do Pv grid tie to save money. The reality is even calculating payoff times it is rarely going to give you "cheaper energy". What it will do is help us all get on the road to being smarter as to how we use and produce electricity. Like I say, do EVERYTHING possible to conserve first. As I am wont to say, it makes little sense to put $20k in a Pv system only to power a thousand incandescent bulbs and a inefficient HVAC system etc.

Icarus

PS With your Utah location you should be able to get fairly easy payback given the amount of sun. Also, solar water and space heat should come first, as it is much cheaper with a MUCH faster payback.

I also suggest you visit:http://rredc.nrel.gov/solar/codes_algs/PVWATTS/version2/ You can plug in your location, roof (or installation location) orientation etc, and it will give you a pretty good idea of how many (net) watts you will yield given any given system size, therefore giving you an idea of how much it will cost.