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Clarence Martin
11-11-2014, 8:22 PM
Hypothetically, if one were to install solar panels on the roof of an 8' x 8' storage shed, how much electric would that produce, using the whole roof as 2 giant solar panels ???

Jim Matthews
11-11-2014, 9:16 PM
Orientation of the panels, and panel efficiency matter.

More important, how far North do you live?
The amount of sunlight falling on the panel is the primary factor.

http://www.wunderground.com/calculators/solar.html
http://www.solarreviews.com/solar-industry/solar-power-calculator/

Matt Marsh
11-12-2014, 7:34 AM
Too many variables for an accurate diffinitive answer. Location, time of day, season, and orientation of the panels to name only a few. The brighter the sunlight, and the more directly it hits the panels, the more they produce. The panels don't normally lay flat on the roof, and all are usually mounted on brackets facing them due South, at varying inclinations, depending on your latitude. But to give you a rough idea, during optimum conditions, 400 square feet of PV would produce roughly around 5000 Watts. Some of the smaller panels in the 20 square feet range, produce around 240 Watts maximum. The better systems will charge a bank of batteries, and utilize inverters to convert the direct current power into alternating current.

roger wiegand
11-12-2014, 11:23 AM
Our utility company was happy to hook us up with an outfit that came out, did a site survey, and provided several options for panel configurations, financing options, and energy production and payback calculations at no cost. Try giving yours a call.

Our system now makes about 40% of the power we consume and is on track to pay back in ~6 years, about a year sooner than their estimate--maybe sooner, since our local electric company just got approval for a 27% rate increase.

Mark Bolton
11-12-2014, 11:40 AM
Im assuming your talking about a gable roof and using both sides of the roof (covering the entire roof with panels). This wont be worthwhile as depending on orientation of the building one side will make virtually nothing and the other may or may not be facing/sloped adequately either. That said, in about 64 square feet (8x8) one may get about 800-1000 watts of panels in that area. That number is the peak output of the array as well so your total daily/weekly production will vary based on your location.

Its no a big array for the investment.

I have an off grid home with a modest PV system (about 1400 watts of PV). Its not an economically viable option for power unless you have substantial other factors impacting the cost of your power, getting power, or some government subsidies to offset your installation cost.

Rich Enders
11-12-2014, 2:11 PM
A word of caution regarding solar regulations. The rules can change, and that can add years to pay back calculations.

In Arizona APS is one of the big utilities involved with solar. They are now angling for:

-Requiring that solar panels be located facing west. Why you ask? "Because peak energy requirements are in the late afternoon". I wonder who that change would benefit??

-Elimination of Net Energy Metering.

Perhaps this type of irrationality is unique to APS. Any thoughts?

Mark Bolton
11-12-2014, 2:24 PM
I think your going to see more and more utilities start to try to un-do net metering agreements and they will more than likely curtail their future agreements. My state has never, and likely will never, have a lucrative net metering agreement (unless they are forced) due to energy interests here.

Mike Henderson
11-12-2014, 2:36 PM
I think your going to see more and more utilities start to try to un-do net metering agreements and they will more than likely curtail their future agreements. My state has never, and likely will never, have a lucrative net metering agreement (unless they are forced) due to energy interests here.
Net energy metering is being required as a way to encourage people to install solar. But it really isn't fair. Those of us who have solar provide electricity to the power company during the periods of highest usage (middle of the day). But in the evening, we have to draw power from the grid.

I have solar on my home, and I generate enough power that I don't have an electric bill. But I use the grid - I depend on the grid. If it wasn't for the grid, I'd be without electricity for a major part of the day. But I don't pay a penny to support the grid.

As more people go solar, like me, the power company has to increase rates for the people who don't have solar, and that increase in rates encourages more people to install solar.

There has to be a fair charge for people with solar systems for their use of the grid.

Mike

Duane Meadows
11-12-2014, 3:11 PM
Net energy metering is being required as a way to encourage people to install solar. But it really isn't fair. Those of us who have solar provide electricity to the power company during the periods of highest usage (middle of the day). But in the evening, we have to draw power from the grid.

I have solar on my home, and I generate enough power that I don't have an electric bill. But I use the grid - I depend on the grid. If it wasn't for the grid, I'd be without electricity for a major part of the day. But I don't pay a penny to support the grid.

As more people go solar, like me, the power company has to increase rates for the people who don't have solar, and that increase in rates encourages more people to install solar.

There has to be a fair charge for people with solar systems for their use of the grid.

Mike

+1. But many people don't see it that way!

roger wiegand
11-12-2014, 5:00 PM
With increased local generation to meet local peak demand there is need for much less "grid", which utility companies don't like because it decreases their rate base. However it's very good for the rest of us. During the day the power generated on my roof stays in the immediate community, powering a couple houses to each side of me, the POCO investment to distribute it is minimal. The utility company is also able to take advantage of my capital investment in generation capacity for free; its as if I've made them a free loan to build generation capacity. I'm not sobbing any big tears for them; their executives are richly compensated and their share/bondholders aren't doing badly either. As the need for expanding distribution grid and centralized generation declines even the other ratepayers should also see financial benefit. This conversion is, for now, helped substantially by public subsidies but that situation will change with scale and cost efficiencies and we will all be better for having made the investment in conversion-- just as electrification of the country in the early 20th century benefited from large public investment and yielded substantial public benefit, so too will this.

Mark Bolton
11-12-2014, 6:15 PM
Net energy metering is being required as a way to encourage people to install solar. But it really isn't fair. Those of us who have solar provide electricity to the power company during the periods of highest usage (middle of the day). But in the evening, we have to draw power from the grid.

I have solar on my home, and I generate enough power that I don't have an electric bill. But I use the grid - I depend on the grid. If it wasn't for the grid, I'd be without electricity for a major part of the day. But I don't pay a penny to support the grid.

As more people go solar, like me, the power company has to increase rates for the people who don't have solar, and that increase in rates encourages more people to install solar.

There has to be a fair charge for people with solar systems for their use of the grid.

Mike

I couldnt agree more. I think the very early 1:1 net metering agreements by some utilities were very short sighted. There is no way they can pay you the exact KWH for energy delivered back to them as they charge you for energy you deliver over your short lines. You have no transformer and line costs, transmission and regulatory costs, on and on. But the simple fact of the matter is many power companies are wanting to get to a zero return situation (which is where I think this will eventualy go) where you will have panels on your roof and you will still pay a monthly bill and a substantial one at that.

States (mine included) have proposed and opted for a zero return net metering agreement. This is where you feed all you want back to the grid and get little to no return for it. That is to say you can offset your electric bill to zero but it will never go beyond that. Getting to zero is infact possible for a conserving household. It will never happen for the average US consumer but it is possible.

To me it becomes a philosophical issue. I understand full well I shouldnt be credited my KWh rate on my bill but there should be something there. The utilities will most definitely get their way though and you will wind up paying to generate power for them.

Mike Henderson
11-12-2014, 6:18 PM
With increased local generation to meet local peak demand there is need for much less "grid", which utility companies don't like because it decreases their rate base.

The rate base has nothing to do with the grid. The rate base is the number of customers and the amount of electricity they use. More or less grid doesn't affect how many rate paying customers the company has.



During the day the power generated on my roof stays in the immediate community, powering a couple houses to each side of me, the POCO investment to distribute it is minimal.

True, but at night, or during periods of overcast, you need the grid. And your neighbors need the grid. The power company has to have generation and transmission capability to handle the maximum load, or you have to tolerate rolling blackouts. The grid is critical to people who have solar systems, unless they completely disconnect from the grid.


The utility company is also able to take advantage of my capital investment in generation capacity for free; its as if I've made them a free loan to build generation capacity.

There's no way to have a sustainable business if you have to pay the same price for your electricity as you get when you sell it. Your argument would be valid if you sold your electricity to the power company at the price they pay the commercial generators, but not if you're selling it to them at retail prices.

The grid will not - and can not - go away if you want reliable electric service. It provides a critical service to you and it has to be paid for and maintained. If you think it has no value, try doing without it.

Mike

Art Mann
11-12-2014, 6:57 PM
Net energy metering is being required as a way to encourage people to install solar. But it really isn't fair. Those of us who have solar provide electricity to the power company during the periods of highest usage (middle of the day). But in the evening, we have to draw power from the grid.

I have solar on my home, and I generate enough power that I don't have an electric bill. But I use the grid - I depend on the grid. If it wasn't for the grid, I'd be without electricity for a major part of the day. But I don't pay a penny to support the grid.

As more people go solar, like me, the power company has to increase rates for the people who don't have solar, and that increase in rates encourages more people to install solar.

There has to be a fair charge for people with solar systems for their use of the grid.

Mike

I really appreciate that honest and enlightening explanation.

Rick Potter
11-13-2014, 4:12 AM
Mike,
I am a bit confused. My system was installed a few months after yours, I believe. I also have no charge this month for power, used 728 kwh and produced 1064 kwh. At the end of the year I can choose to have any extra refunded to me, but it will be at the rate of 3 cents per kwh, not the going rate. I have chosen to keep the credit to apply to my bill for whenever I may owe them.

About the distribution costs, on page three of the bill I find a fee called delivery charges, which I assume is distribution cost. It is very minor, at 93 cents a month, but it must be paid separately. I just sent them $20 and let them keep track of when I need to pay more. As of this month, I still have a small credit of 12 cents, so next month will be time to send them another $20.

My system has a payoff of 4 1/2 years. It is about 18 months old, and is slightly ahead of schedule. My first full year, I generated a little more than I used, including charging my plug in Ford C-max. I understand the newer systems are even more efficient.

Jim Matthews
11-13-2014, 8:41 AM
[QUOTE=roger wiegand;2333199Our system now makes about 40% of the power we consume and is on track to pay back in ~6 years, about a year sooner than their estimate--maybe sooner, since our local electric company just got approval for a 27% rate increase.[/QUOTE]

6 years?

Even with the rate increase we anticipate,
my ROI was 25 years.

It wasn't compelling enough to put holes in my roof.

Jim Matthews
11-13-2014, 8:52 AM
I have solar on my home, and I generate enough power that I don't have an electric bill. But I use the grid - I depend on the grid. If it wasn't for the grid, I'd be without electricity for a major part of the day. But I don't pay a penny to support the grid.

As more people go solar, like me, the power company has to increase rates for the people who don't have solar, and that increase in rates encourages more people to install solar. There has to be a fair charge for people with solar systems for their use of the grid.

Mike

That's reasonable, but discounts the role taxpayers played in hanging the wire in the first place.
The REA of 1936 paved the way and the Recovery act of 2009 poured $4.5 billion into the infrastructure.

Net metering is a fair, and equitable return for taxpayers.

*******

The killer app for home PVs is the electric car.
If you can afford both, it will pay back real returns.

I came within a gnat's whisker of making dollars and sense
to install PVs with a Nissan Leaf charging in the garage.

I drive just a little too far each day for that to balance
with my basic driving costs.

Combining personal transport (storage capacity) with roof mounted PVs (generating capacity)
is the most immediate mode to return value to the homeowner.

If the purchase price of cars comes down, it's a winning strategy.

Until then, I'll keep burning wood to augment my fuel sources.

http://www.plugincars.com/coming-electric-car-solar-panel-convergence-107405.html

David Weaver
11-13-2014, 8:52 AM
Panels are getting cheaper and cheaper, but I don't know about the rest of the components. We don't have good sun here, and thus no real prospects no matter the price, but I've seen multicrystalline panels for a dollar a watt, which is something i thought we'd not see for a long time.

Our incentives around here are nothing like california's, either, thus any ROI is probably similar to what jim said. My roof is south facing on one side, though, and in the sun all day when there is sun, it's tempting to look at but wouldn't make much sense (we do have net metering) unless I was able to do all of the work getting a system installed. Hail isn't uncommon here, either, which is also a problem.

On the eastern side of the state where the mrs. is from, there are a fair number of south facing arrays (freestanding), but a lot of the folks who own houses out there have old money looking for a purpose and a lot of open space.

Brian Elfert
11-13-2014, 9:40 AM
One thing that is pro for net metering is the fact that more energy is typically consumed on a sunny day, especially with air conditioning. A utility might be paying you the retail rate of say 11 cents a KW, but they may be paying 15 to 20 cents (or more) a KW for peaking power. The spot price for electricity skyrockets on a high demand day. There are power generation companies that exist solely to provide extra power on peak usage days, but they charge a huge premium to do so. It is cheaper in these cases for the utility company to pay you the retail rate for your excess power from your solar panels.

Mike Henderson
11-13-2014, 10:01 AM
Mike,
I am a bit confused. My system was installed a few months after yours, I believe. I also have no charge this month for power, used 728 kwh and produced 1064 kwh. At the end of the year I can choose to have any extra refunded to me, but it will be at the rate of 3 cents per kwh, not the going rate. I have chosen to keep the credit to apply to my bill for whenever I may owe them.

About the distribution costs, on page three of the bill I find a fee called delivery charges, which I assume is distribution cost. It is very minor, at 93 cents a month, but it must be paid separately. I just sent them $20 and let them keep track of when I need to pay more. As of this month, I still have a small credit of 12 cents, so next month will be time to send them another $20.

My system has a payoff of 4 1/2 years. It is about 18 months old, and is slightly ahead of schedule. My first full year, I generated a little more than I used, including charging my plug in Ford C-max. I understand the newer systems are even more efficient.
Yes, I have that also. There's a basic amount, as you and I see, but the bulk of the distribution charge is based on your use of electricity - which was reasonable before solar. Your share of the upkeep of the grid should be based on your usage. Since we net out to zero, we don't pay any more than the base amount.

Around here, the power company does the same thing on payment for excess power: If you generate more kWh than you use (over a year), they will pay you for the excess at the rate that they buy electricity. But be careful. You can zero out in dollars and still not have an excess of kWh because if you're on "time of use" billing, the rate is higher in the daytime (peak rates) than in the evening. So you can use more kWh in the evening and still come out zero in dollars - but be "using" electricity in kWh. Rolling it over, as you do, is the best approach.

in this area, the power company has to approve your installation and one thing they look at is whether you're installing more kWh potential than your usage. They will approve a bigger system if you have a reason, such as plans to buy an electric car, but generally they'll limit you to approximately the potential to generate the amount of power that you use.

Mike

Mike Henderson
11-13-2014, 10:04 AM
One thing that is pro for net metering is the fact that more energy is typically consumed on a sunny day, especially with air conditioning. A utility might be paying you the retail rate of say 11 cents a KW, but they may be paying 15 to 20 cents (or more) a KW for peaking power. The spot price for electricity skyrockets on a high demand day. There are power generation companies that exist solely to provide extra power on peak usage days, but they charge a huge premium to do so. It is cheaper in these cases for the utility company to pay you the retail rate for your excess power from your solar panels.
Absolutely true. I had a power company executive tell me once that he'd buy all the power he could get during a power emergency at "retail" rates. That's the big argument for net billing of solar. But, of course, those events only occur a few times a year.

Mike

[Based on my own system during a power emergency, I'm not supplying any power to the grid - I'm using all of it to run my air conditioner because around here a power emergency occurs when it's very hot. But that's power the company doesn't have to supply me so I'm reducing their overall demand. I could reduce the use of my A/C and achieve the same thing without solar but I have it so I use it.]

Mike Henderson
11-13-2014, 10:12 AM
That's reasonable, but discounts the role taxpayers played in hanging the wire in the first place.
The REA of 1936 paved the way and the Recovery act of 2009 poured $4.5 billion into the infrastructure.

Net metering is a fair, and equitable return for taxpayers.



Even if you take that position, the return is only being made to those who install solar.

But it ignores the reality of what will happen to the system and to those who don't install solar - renters, for example. As more people install solar, they are taken out of the rate base, but the system costs stay the same. Rates then have to rise to pay for the system - we aren't going to allow a power company to fail and shut down. So the people carrying the system financially will generally be those who are not homeowners or simply do not (or can not) install solar. [A neighbor may have large trees shading where the solar could be installed and refuse to cut them down, or trim them.]

No matter who put money into the system in the past, or how much money, you have to face today's reality and search for a fair and equitable solution.

Mike

[The present system also favors people by geographic area. Some places are excellent for solar - southern California for example. But other places may not be as good and as you go farther north the generating potential decreases.]

Jim Falsetti
11-13-2014, 11:02 PM
As is common here we are far off the OP question on would his small system be economic. The answer is probably not, but...I am pretty sure he could use PVWATTS to get an idea.

Net metering may be controversial to some, but in the end the State Public Service Commission decides. Lots of folks think in CA and NY net metering will be here for a long time, as net metering is an important element to achieve the goals of the State.

Regarding costs, I'm not very familiar with residential solar, but have some knowledge about relatively larger PV systems, and would expect the same trends apply. Panels are the most expensive component. The poly panels in bulk are about $0.72 per watt. They are made in China for less than fifty cents, shipped to the USA for about a dime and the rest of the price is the tariff. All the other components are also dropping in price. Installation is becoming more efficient and less expensive. Overall system efficiency is getting better all the time, albeit by small amounts.

Jim

Roger Feeley
11-14-2014, 11:55 PM
We are getting ready to move to what I hope will be our final house. I plan on getting serious about solar then. My idea is to stay connected to the grid and have enough solar to take care of much of our base load (about 3KW). I don't think I could afford the arrays to handle it when I switch on the 17" bandsaw or the Sawstop ICS.

I recognize that I should pay something for the presence and reliability of the grid. At the same time, PV's on my house can reduce the need for peak load generation by the power company.

I spoke once with an electric utility lobbyist and he told me that he liked solar. He cited two reasons:
1. Solar is reliable. If it's a cloudy day, it's easy to compensate because it happens slowly. Wind, can be eccentric which can cause the need for grid power to fluctuate more.
2. Solar is at it's best when the need is greatest.
His feeling was that Solar and the grid could work very well together.

Shawn Pixley
11-15-2014, 1:50 AM
[Based on my own system during a power emergency, I'm not supplying any power to the grid - I'm using all of it to run my air conditioner because around here a power emergency occurs when it's very hot. But that's power the company doesn't have to supply me so I'm reducing their overall demand. I could reduce the use of my A/C and achieve the same thing without solar but I have it so I use it.]

I don't have air conditioning, so on a design day I both shed peak demand and supply power back into the grid. Even in October, I produced 33KWh more than I consumed. So far my excess generation has more than offset the $11 fee per month to be connected to the grid.