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K8MHZ,

Your point about conservation is not to be overlooked.:cool:

A while ago I thought about doing solar on my own home, I have an exposure that would work well.

But once I really stated looking into it it became apparent that I would be better off spending money on more efficient electrical appliances.

I actually found a place in Vermont that caters to the 'off grid' crowd and they would happily sell me PV equipment but they were honest and said try conserving first before tossing money at PV.

$12.50 for a PC ........... I will have to think about that, I have two that stay on 24/7. :eek:
 
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K8MHZ said:
Zog,

Here is something you need to consider in order to put your investment in the proper perspective.

In class, we were encouraged to use Kill-a-watt meters to see where our energy was going. There were two in class we could check out. I just bought one.

I found that by keeping my desktop computer on 24/7, that added $12.02 cents to my bill.

I also found that by keeping the florescent light over the stove on as a night light was adding 4 bucks to my bill.

I now turn the computer off when I am not using it. I also got some LED night lights that draw so little power that it won't even register on the Kill-a-watt. I put some in the bathroom, too, so it isn't even necessary to turn the light on for a quick visit at night.

I also found a few other areas of waste. I won't know until my next bill, but I am pretty sure I scrubbed off 14 bucks of energy costs off my monthly bill just by changing light types and turning off stuff that isn't being used.

Total investment, about 40 bucks and that includes the meter and the LED's.

An off the cuff estimate of a solar installation that would provide 14 bucks a month is in the 5,000 range. Less, of course, if you do your own installation.

The Kill-a-watt taught me the importance of targeting continuous loads. My next check will be the outside lighting. I have a 175 watt MV or halide that is on all night. I also have a 300 watt set of floods that come on with a sensor. Not a continuous load, but the 300 watts is worth looking into. I am thinking there is another 10 bucks a month there I can scrub off.
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Reducing our usage is the best answer, but not the style of most Americans, ever look at the average kWH used per person by country?

K8MHZ said:
Iwire has mentioned on more that one occasion that PV is not, at this time, 'viable'. I am not so sure he is 100 percent correct, but his real world experiences need to be considered.

I think that there are some areas right now that it would be viable to install solar systems on their own merit. I also think that viability takes some effort on the designer's part. Energy costs, types of loads and times of loading, array orientation and material costs all affect the viability of a PV system.
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I think they are viable now in certian areas where elctric rates are high (Like Hawaii) or remote locations, but for mant areas it just does not make sense now. I have seen some absurd claims out there by installers of PV systems, which got me started on this.

K8MHZ said:
That's the good news. The bad news is that another factor of viability is energy costs. As they rise, they make PV systems more viable. That's bad news for people that have shady locations.

I know someday I will see people cutting down trees that shade their homes in order to run their air conditioners. Stupid, I know, but that is what will happen when the sheeple all 'go solar'.

I won't be there to cut down the trees, or even watch. I like trees. But I will be available to design the systems.
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Are you the Lorax? :)
 
K8MHZ said:
De-icing would be very costly, using up more energy than you would be producing. That rear window de-icer is probably the biggest electrical energy hog in your vehicle. When I was working for Chrysler, alternators were designed around de-icers. If the vehicle had a de-icer, the alternator had to be larger, like 100 amps vs. 60.
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So about 50% of the power produced by a PT cruiser engine??? :)
 
So one of my buildings has a nice flat roof of about 900,000 sq-ft. I could put what up there, about a 450kW system? Any idea what that would cost?
 
zog said:
So one of my buildings has a nice flat roof of about 900,000 sq-ft. I could put what up there, about a 450kW system?
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But depending on the strength of the building you may not be able to put any on your roof, you would need engineering data.

For instance if your building is a typical corrugated metal building many are not designed to hold the additional weight of panels.

As far as cost we used to use $9.00 - $10.00 per watt installed but that must be down a lot now.
 
iwire said:
But depending on the strength of the building you may not be able to put any on your roof, you would need engineering data.

For instance if your building is a typical corrugated metal building many are not designed to hold the additional weight of panels.

As far as cost we used to use $9.00 - $10.00 per watt installed but that must be down a lot now.
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Residential is about 6 or 7 right now and dropping.

Of course that's without extenuating circumstances.

Even at 6, most people go into shock when the see how much it will cost to get 60 bucks a month out of a system. (Roughly, $60,000).

60k on the roof for $60, or 60k in the bank at 5%, unamortized, for $250?

That is what kills a PV salesperson. In order to make PV competitive with a 5 percent savings account, the cost per kWh will have to be around 50 cents per KWh.

I pay 12.4. Factories in my area pay 7. The wind farm will produce for 25 years at 8.

That's a long way to go, and I really can't afford to get there from here....
 
K8MHZ said:
We must realize that the POCOs are being forced to allow and / or provide renewable energy. It certainly isn't in the best financial interest of the POCOs to promote any reduction in the amount of energy they sell.
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That's not entirely true. Austin Energy, the city owned utility here, is a staunch supporter of distributed renewable energy, aka rooftop solar. Their projections show that the addition of solar to their grid will work toward putting off the necessity of building more power plants, so they support it with their own rebate system.
 
zog said:
So one of my buildings has a nice flat roof of about 900,000 sq-ft. I could put what up there, about a 450kW system? Any idea what that would cost?
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I bet, even if you couldn't set up an entire system because of roof loading, you could put several strategically placed arrays to benefit the customer somewhat.
 
Chamuit said:
I bet, even if you couldn't set up an entire system because of roof loading, you could put several strategically placed arrays to benefit the customer somewhat.
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It is a pretty heavy duty building, and it belongs to my company so I would be the customer. I like the idea iwire posted with the live feeds showing production at the site, that would look great on my website.
 
zog said:
It is a pretty heavy duty building, and it belongs to my company so I would be the customer. I like the idea iwire posted with the live feeds showing production at the site, that would look great on my website.
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The electrical design would be pretty straightforward, but for a project of this magnitude you'll need to enlist the aid of a structural engineer with a PE license to calculate and sign off on the roof and wind loading. Which module mounting system you pick can make a big difference. Penetrating systems are generally lighter weight, but if you have a membrane roof such a system will almost without a doubt void your warranty; you'll probably want to look at a ballasted system such as Sunlink. Solyndra modules have the advantage of nearly zero wind loading and are very lightweight, and their proprietary monitoring is pretty snazzy, but they are more expensive per watt than flat panels.

The other thing I would advise you to do is to not take this project on yourself. Get someone to do the job who has experience in putting up systems similar in size and configuration to design and install it.
 
zog said:
It is a pretty heavy duty building, and it belongs to my company so I would be the customer. I like the idea iwire posted with the live feeds showing production at the site, that would look great on my website.
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Would you be using a ballasted system or other? I think that would be a factor.
 
Thanks for the info, I have no intentions of doing this myself, just started think about it with all the PV talk in this thread, don't want to get this thread off track talking about my building, I find this PV stuff very interesting and this thread has had some very good discussion points.

What I am really interested in is the economics of PV systems.
 
Some states are considering helping finance PV systems.

First, a survey is done on the property for viability.

If viable, the state will examine electric bills and determine a monthly average. That monthly average will be the payment on a loan from the state to install a PV system. After the loan is paid off, the citizen owns the PV system free and clear and had to pay no money up front.

That sounds like a great idea, but there will be some problems.

Let's take my place as an example. I have too much shade, so PV is not likely. That will be the same for many. BUT, let's ignore that and just look at the financial aspects.

I live alone, so not only do I use very little energy, I also control it. No bickering in order to get devices not in use turned off. I pay about 65 bucks a month for electricity. I use about 530 kWh per month. By contrast, I know someone in LA with a great job. He lives in a rancher that would be worth about $200,000 here. His electric bill last month was $580. Even worse, he has a solar array that probably lowered the bill by nearly 100 bucks. He used over 3,600 kWh last month. No kidding! He has a pool, a wife and four daughters.

To pay off an interest free $50,000 loan with a 65 dollar a month payment would take 64 years. A smaller system would result in an increase in the electric bill an the idea is for the citizen not to have an electric bill to pay.

PV systems are about 4 times more expensive than they need to be in order to be a big hit with consumers. (Small 'c').
 
zog said:
So one of my buildings has a nice flat roof of about 900,000 sq-ft. I could put what up there, about a 450kW system? Any idea what that would cost?
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I didn't review how you were doing your math, but by my calculations you are off by roughly a factor of ten, on the low side. Probably you just dropped a digit somewhere, but here's how I'd guestimate it...

A typical* 235W panel is 40X65 inches, or 18 sq ft. 900,000 / 18 * 235W = 11,750,000 W = 11.75 MW. Now, you have to divide this number by at least 2 because you'd tilt the arrays at an angle, and then you'd need space in between them so that they don't shade each other. Plus you'll want some walkways and there will no doubt be some areas of the roof where it isn't so feasible to put panels for other reasons. Still, leaving aside roof engineering considerations and assuming you could put up as many panels as fit, it's conceivable you could have a 4.5 MW system instead of a 450kW system.

*Typical panels are 14-15% efficient. If you go with Sunpower, the efficiency is closer to 20%, meaning more power in less surface area. Could be 6 MW instead of 4.5.

The cost for a 4.5 MW system would be somewhere in a large range between about 15 and 40 million dollars, assuming the building could take it as is.
 
jaggedben said:
I didn't review how you were doing your math, but by my calculations you are off by roughly a factor of ten, on the low side. Probably you just dropped a digit somewhere, but here's how I'd guestimate it...

A typical* 235W panel is 40X65 inches, or 18 sq ft. 900,000 / 18 * 235W = 11,750,000 W = 11.75 MW. Now, you have to divide this number by at least 2 because you'd tilt the arrays at an angle, and then you'd need space in between them so that they don't shade each other. Plus you'll want some walkways and there will no doubt be some areas of the roof where it isn't so feasible to put panels for other reasons. Still, leaving aside roof engineering considerations and assuming you could put up as many panels as fit, it's conceivable you could have a 4.5 MW system instead of a 450kW system.

*Typical panels are 14-15% efficient. If you go with Sunpower, the efficiency is closer to 20%, meaning more power in less surface area. Could be 6 MW instead of 4.5.

The cost for a 4.5 MW system would be somewhere in a large range between about 15 and 40 million dollars, assuming the building could take it as is.
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That's a pretty big building. 900,000 square feet is 22.5 acres.
 
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