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Post by walter2 on Mar 25, 2014 6:14:17 GMT -7
This is the list I received from the supplier for our prospective pv system. This is a grid tie-in system. Let me know what you think or if there's anything you see that's missing. Thanks! Attachments:
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Post by marc on Mar 25, 2014 10:56:45 GMT -7
This may the perfect solution for you, but from my perspective:
In theory, that system would give me 6500 watts per hour x 5 hours per day = 32,500 watt hours per day.
32,500 watt hours is 32.5 KWH per day. 32.5 KWH per day x 30 days = 975 KHW per month
Power costs $0.10 per KWH at my house, so:
975 KWH x $0.10 per KWH = $97.50 per month worth of electricity.
For other areas, it will be different - as well as incentives and tax credits.
My biggest concern would be spending the money for a grid tied system that will shut down along with the grid. For me, the beauty of alternate energy sources is being able run without the grid if needed.
With the SMA system, I think that you will need a Sunny Island to standalone? Or has the equipment changed now?
Marc
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Post by tjwilhelm on Mar 25, 2014 10:59:21 GMT -7
I didn't study it, yet, Walter; but, a few thoughts and questions come to mind that would guide my examination of your quotes:
1) WHY do you want this system? What are your energy objectives?
2) Are you aware that you have no back up in a utility-interactive system? When the grid goes down, your inverter output is required to shut off.
3) Are you bound by a local electrical code -- NEC -- and will the system be inspected by the AHJ?
4) Are you planning to do a roof mount of the array? If so, what is the style and condition of the roof? What is the framing beneath the roof deck? What is the orientation of the roof?
5) Have you had a solar site assessment done (SHOULD be the first thing done, BEFORE buying a system)? Did the site assessor bring a Solar Pathfinder or Solmetric SunEye to your site to assure a quality shade analysis and proper array placement?
6) Can you describe your electrical service panel? Brand? Model? Main breaker size? Amp rating of the bus bars (there are specific code requirements about connecting your system to your panel)?
7) Does your local utility offer net-metering? If so, have you contacted them for details (this is another must-do before buying the system)?
8) Where will the system be installed (I don't need a precise address -- just County and State will be plenty)?
If you'll post answers to these questions, it will guide me to giving your system a good look-see to assure it will meet your needs, be safe and code compliant, and will not be a rip-off. I have some free time on Thursday I can give to this...it would be fun!
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Post by tjwilhelm on Mar 25, 2014 11:02:17 GMT -7
Looks like Marc and I were typing a the same time! Good input, Marc!
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Post by thywar on Mar 25, 2014 12:52:00 GMT -7
I love this forum, the great people on here who freely share their knowledge and skill sets. This is great stuff and theoretically can save thousands of dollars while teaching the rest of us great information. Good stuff
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Post by angelhelp on Mar 25, 2014 16:54:49 GMT -7
This is the 2nd time I've seen Marc post his electricity costs. Such a deal! Ours is just under 18.486 cents per kwh.
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Post by marc on Mar 25, 2014 17:39:36 GMT -7
This is the 2nd time I've seen Marc post his electricity costs. Such a deal! Ours is just under 18.486 cents per kwh. You caused me to go and check: $0.0977 per KWH for power consumption. Adding in taxes and service charges, it's $0.1097 - so call it 11 cents. Ten cents is fine for my local calculations, because that's what I can save with conservation measures. The service charge for being connected to the grid won't change, and taxes will change with consumption. So, if I went totally off grid, it's more like 11 cents per KWH. - If I spend $5,000 for a solar system that saves me $100 per month, it would take 50 months to break even - not counting any value of your invested capital. - If I spent $12K with the same $100/month savings, that would provide a simple return on investment of 120 months (10 years) on the same basis. OK, I know that I'm oversimplifying, but I hear people scream about how bad a 5-10 year simple ROI is. Then I ask tell me where your money is earning more than 10% to 20% per year. And THAT is based on power costs remaining the same...... |
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Post by thywar on Mar 25, 2014 17:49:47 GMT -7
That's a good point Marc. I think a lot of those people who voice that complaint don't stay in their houses 5-7 years. Very mobile society. I'd venture most people on this forum stay longer term than that
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Post by walter2 on Mar 26, 2014 12:34:03 GMT -7
i am looking at the sunny island now... would have before just didn't know it existed.
solar panels are to be mounted to barn roof and i was told it is perfect orientation. Barn roof is in great shape. I will look into the other points that have been made concerning
local codes. Thank you for all the great info!
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