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JONATHAN20

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My boss is getting so much work. Check out this new job that we got comin up soon. Some rich dude want's install a whole bunch of solar panals. Now I didnt really understand what they all were talkin about inverter this inverter that. The only thing I know is we gotta upgrade him to a 200 amp panal. What ever happend to 3ways and 4ways???? lol But i guess its actually a good thing because solar energy is the thing of the future and if EC'S want to stay in business that something they gotta learn. Now would that be the utility company that installs that or EC's? From what I understood from all the technical talk is that its involved......anyone here have any experiance with solar panals?
 
In my area, solar panels are installed by companies specializing in solar panel installs. They usually employ at least one licensed electrician for permitting and supervision. It is definitly a growing field that I plan to investigate further.
 
ItsHot said:
Rich dudes are always thinking of ways to save money!:D
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How do you think they got rich to begin with?

Probably not by buying a bunch of "toys". More than likely by consistently spending less each month than they made, making smart decisions and not buying a bunch of "toys" on credit, especially toys that depreciate rapidly.

I know a couple "rich dudes" that drive old pickups, live in modest homes and give no outward appearance of wealth. When they buy expensive things they are capital items that save or make them money in the long run. They aren't concerned with status symbols.

Wish I could be more like them. Especially with regard to my personal balance sheet.
 
Speaking of rich dudes . . .

Speaking of rich dudes . . .

. . . and solar panels. Is anyone here fluent or familiar with them? An architect/GC I have done work with in the past asked me the other day if I had experience with solar. I have not, but sure would like to learn some about them. Does anyone work with solar?
 
In NJ, on larger Commercial & Institutional projects I have estimated these systems can be installed for around $0.75 minimum to $1.50 maximum per DC Kw Therefore a DC 250 Kw system will have a cost between $187,500.00 to $375,000.00. The true cost is usually about $1.10 DC Kw. This will include prevailing wage labor and materials such as solar panels, Inverters, Modules and Battery Banks with reasonable feeder distance included. These costs will most likely be a quite a bit cheaper for residential systems. As stated above there are companies that specialize in these types of systems.

This is a growing industry and not as cut throat as the electrical contracting business yet.
 
080521-0607 EST

DJFNEC2005:

I believe you meant to say $0.75 to $1.50 per DC watt, not kilowatt.

If this is the peak rating in bright sunshine, or even the average or 6 hours, then the cost per watt of continuous power over a day's period is probably at least 4 times these figures.

Since a typical residence use is in the range of 24 KWH per day, this amounts to a large capital investment. This is 24*365 = 8760 KWH/year. At our electric rates this is 0.11*8760 = $963.60 electric cost per year.

For an average of 24 KWH per day and my factor of 4 above we need a solar array capable of 96 KW. At $1 per W this is a capaital investment of $96,000. Or about 100 years for payback. There are a lot of approximations in my calculation, but it is not a 10 year payback.

My own home consumption is more in the range of 45 KWH/day.

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080521-0750 EST

Roger:

No. Interruptions.

But we will compare time clocks. One forum I frequent is off about 1 hour and 10 minutes from GMT.

Edit clocks look good.

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gar said:
Roger I believe you are on EDT.

Although I am in an EDT zone I always keep all my computer clocks on EST year around.

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You are corect.

Roger
 
gar said:
080521-0607 EST

DJFNEC2005:

I believe you meant to say $0.75 to $1.50 per DC watt, not kilowatt.

If this is the peak rating in bright sunshine, or even the average or 6 hours, then the cost per watt of continuous power over a day's period is probably at least 4 times these figures.

Since a typical residence use is in the range of 24 KWH per day, this amounts to a large capital investment. This is 24*365 = 8760 KWH/year. At our electric rates this is 0.11*8760 = $963.60 electric cost per year.

For an average of 24 KWH per day and my factor of 4 above we need a solar array capable of 96 KW. At $1 per W this is a capaital investment of $96,000. Or about 100 years for payback. There are a lot of approximations in my calculation, but it is not a 10 year payback.

My own home consumption is more in the range of 45 KWH/day.

.
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Not to mention that payback has to be calculated on a discounted cash flow basis. Either you have the cash on hand or you borrow it to construct the unit. If you have the cash then you can invest it and after 100 years its value will be much greater than today. If you borrow the money then you have to pay interest and at the end of the term, the total money would be again greater than the initial cost. Based on the current interest rates, I believe the general figure is that your breakeven investment should be less than 2.5 years.

You need to calculate lifecycle cost for the equipment, adding maintenance cost and of course the payback period should not be calculated beyond the equipment life. Electrical equipment life could be conservatively taken at 25 years.

The payback calculation also gets interesting for two reasons. You have to calculate inflation and also take into consideration if the energy cost is expected to outpace inflation, which it currently does.

Spending money on solar today is an environmental gesture of throwing money away. It is also foolish since you can spend the same money and make contribution to the protection of the environment that is economically sound. An economically sound investment returns a reasonable profit to the investor. With solar, you are actually doing disservice to the environment since the disposable cash for the purpose could have been spent with a much greater environmental gain.
 
gar said:
080521-0607 EST

DJFNEC2005:

I believe you meant to say $0.75 to $1.50 per DC watt, not kilowatt.
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Yes, I would guess this is watts too. The problem
is the actual numbers are closer to $6-7/watt. Maybe
after extremely generous rebates and tax breaks, or
perhaps in the long term future if there's a breakthrough
and the solar market isn't supply constrained, there
might be a number close to $1/watt. This isn't
coming any time soon, and the real installed cost is
much higher than $1/watt of capacity.

gar said:
If this is the peak rating in bright sunshine, or even the average or 6 hours, then the cost per watt of continuous power over a day's period is probably at least 4 times these figures.
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Gar, By this math, each "kilowatt" of peak capacity would be
generating 6 KWH/day, so I think you should actually be
dividing by 6 below, not multiplying by 4.

After you divide, the reality of AC-power generated is much
much worse because system inefficiencies.

gar said:
Since a typical residence use is in the range of 24 KWH per day, this amounts to a large capital investment. This is 24*365 = 8760 KWH/year. At our electric rates this is 0.11*8760 = $963.60 electric cost per year.

For an average of 24 KWH per day and my factor of 4 above we need a solar array capable of 96 KW. At $1 per W this is a capaital investment of $96,000. Or about 100 years for payback. There are a lot of approximations in my calculation, but it is not a 10 year payback.

My own home consumption is more in the range of 45 KWH/day.

.
Click to expand...

Where I live, in California, a well sited, well installed
1KW of peak (STC) capacity can generate about 1,400 KWH of
power/year. If we use somewhere like Detroit, the
numbers would work out to a little more than 1KWH
of power per 1,000 KW of peak capacity), which
makes the math easy, so let's use the Detroit numbers. Generating
8,760 KWH/year would take about a 8-9KW system, at
roughly $7/watt, or about $50-60K+/-. (If you want, I
can dig into my notes and get the derivation of these
numbers, and send you the more detailed math behind
the KWH/Watts numbers, but I usually just use these
numbers which are pretty standard.)
 
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080521-1229 EST

rexowner:

I goofed. Since the average is 1 KWH/hour we need maybe a peak of 4 to 6 or more KW at the AC end. Thus, the results you quoted are more realistic.

Since you can not store much energy for long one has has to assume in our area that there still has to be a lot of power drawn from the grid.

When someone makes a mistake and others correct it I think everyone is helped because it causes more thought on the subject. So I am happy when my mistakes are pointed out.

.
 
Thanks Gar..I stand corrected It should of been per DC watt. It was a late night post and I did not have my notes available to me.

Rexowner is also correct. After review of my previous estimates and notes, The cost with equipment and labor will be about $6 to $7 a DC watt. The $1.10 quoted by me in the previous post will normally cover the installation labor, misc mounting hardware and feeders. Add to this the equipment cost of between $5 to $6 a DC watt.

Sorry for the confusion I might have caused. No more late night posts for me anymore.
 
080521-1642 EST

Another point on return on investement.

If we need, for example 6 KW, average over the daylight hours to supply one day's worth of energy, then that can define the capital cost. If this produces 24 KWH on most good days, then even though the collector design is adequate for average demand for a bright day there are dark days and this increases the payback period.

.
 
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