Solar Systems, Entry level--- More

[Andy]

Andy comments:

On a similar thread , there has been a difference of opinion on whether a solar PV array which powers an entire house is a reasonable thing to do...

Since it seems to have degenerated into some personal attacks, I'd like to propose a new direction for those who are considering this move :

Go and ask a LOCAL realtor, several if possible, what the increase in the value on their house, on the market today, will be if they install a 50K solar PV array . ( This number is from another poster, who posted that an array would cost this, before federal subsidies and state rebates, which could amount to 50% in the US in some areas )

If it is like a swimming pool in Dallas, where a 25K investment would only add a few thousand to the selling price of the property if put on the market, OR, exclude many prospective buyers from consideration, due to the maintenance/operational/repair/replacement costs that many want to avoid........---- they might not want that overhead.....

Like I have published, MY electril bill is about 1500 USD per year for a 3000 sq ft house south of Dallas, and I would be reluctant to shell out

50K USD to have the roof coated, in ONE direction only , with a PV array...

SECONDLY,,,,, check with your homeowner insurance agent.... Since it cost much more to install/re-install a PV array than it does to re- shingle a roof....... will the insurance pay for that additional cost if a windstorm/hailstorm requires replacement... Keep in mind that to re-shingle the roof and fix the leaks (typically 10 yrs, regardless of 15 yr or 30yr shingles, cost MUCH MUCH less than the PV installation), it is typical that the PV installation would have to be removed, the roof stripped and re-shingled, and the PV installation done over again.......Perhaps the homeowner insurance will cover it, but, since it may double or triple the cost, ... you better check... In Texas, this is a most probable thing to happen.... In Europe or the UK or Maine, maybe not so likely... Just consider it for your own situation.

The green wannabee needs to be aware of all the probable costs involved before making the commitment, rather than reading Mother Earth News , and charging off in the abyss without the proper facts......

Finally, be aware that since 50% of US taxpayers pay NO income tax at all, the big federal tax break may not apply, especially if the 'STANDARD DEDUCTION" is more than the "PV cost"......And, they should investigate the rebates and tax abatements of their particular state and town, since they vary all over the map, ... from enthusiastic encouragement to absolute prohibition.... Good luck with all that....The info is available on the internet...

I hope that any additions to this thread will try to keep a civil posture on their replies, so that the novice greenie can make some informed decisions.

Andy in Eureka, Texas , retired electrical engineer

[GROVER]

Thanks for a comprehensive analysis of the questions one should thoroughly understand before plunging into such an installation. A rule of thumb I've used in some similar situations is that if the project acceptance needs government subsidies for justification, it probably has marginal economics.

Another possible hurdle is some state rebate funds have run dry which would delay or negate that portion of the analysis.

Joe G

[DA]

You make some great points but this may not be a concern at all. People that pay no income tax at all have much more to worry about than installing a PV system - raising and educating their children for example, which is what the bulk of tax credits is intended for.

Also, $50K would be one hell of a standard deduction! Is there anyone NOT itemizing at that level? And regardless, it's just a reason not to take a standard deduction for that one year.

I would be much more worried about structural integrity of one's roof. Also, as you pointed out, a conversation with the insurance company seems an important step for me, too.

It would be interesting to learn if insurance companies treat solar shingles any different than your "normal" PV panels on racks. Anyone has experience to share?

------------------------------------- /\_/\ ((@v@)) NIGHT ():::() OWL VV-VV

[JimT]

I think your 50k number is way off.

** This 5060 watt system is $18k. Estimate $5k for install (way high I think) you're looking at $23k. Then subtract the city rebate of $2.5/watt you get $10350

So if you could get a 0 interest 36 month (city sponsored) loan your payment would be $288/month. A bit higher than my electric bill but it would be paid for in 3 years. Roughly.

I could be missing something obvious to you.

Jim

[chaniarts]

> Finally, be aware that since 50% of US taxpayers pay NO income tax

yes. i have a 7.7kw array. i just signed up with a new insurance agent this month. when asked, they said that having a pv install had no difference on the cost of house insurance.

[Kurt Ullman]

That's because currently there are so few of them that it is cheaper to pay the claims than do the extra underwriting. I expect that to change within the next 5 years.

[Andy]

Andy replies

Jim, I am using the 50K number which someone who claims to be knowledgeable about the issue posted yesterday on this newsgroup in a thread with a similar name. I don't know, personally, what an installed system costs. I am also using "his" allegation regarding federal subsidies and state and municipal rebates... If I am incorrect, I'm sure that anyone who is pursuing the matter will want to get his own numbers anyway and not rely on newsgroup advice.....

My purpose is to point out that, regardless of "subsidies" that are borne by the taxpayers, there are many other factors to consider in this endeavor, that most people might only find out AFTER they are too committed to back out......

I find it reasonable for the numbers you quote, assuming that similar rebates apply to the user. They sure don't apply where I live, tho..

And I am curious at to the 5kw system you mention. If that is 5K peak watts from the array, that would only apply in "full sun", which the tables say averages 5.5 hours per day in the Dallas area..... That's about 27 kwh per day, which is probably reasonable for around here. But for those areas that have less than 5.5 full sun hours per day, like maybe Seattle (as a guess), that capacity wouldn't be enough.....

In addition, to achieve the 27.5 kwh/day, the array would have to be tracked so that the sun would be "normal" to the array for the full day. Since I assume the array would be mounted , fixed, onto a roof, the output would be significantly less, and would be a cosine function for the average value, about 64% or so (from memory), and then only if the roof slanted in the proper direction..... So, you see, there is more to this than the factory specs, which will normally assume an optimum mounted system.... However, those are technical factors which one also finds out about only after having the system installed, not realizing the "quoted" potential, and then learning the engineering behind the system....

Anyone who can afford 25K ( or 50K, whatever) for a system has the ability to learn these factors and do the tradeoff for themselves BEFORE making the committment , since "it ain't rocket surgery". My purpose in the posts I have made is to encourage everyone to do so, and not be deterred by anyone who says "it's too complex for you to learn so you should just fork over the money"..... Actually, anyone with a ham operator license above novice class has demonstrated more electrical knowledge than is presented in a "PV installation class", so while such a class might be useful, (or not), ANYONE can learn to do it......

So, as an engineer who has done a lot of this kind of thing, I'll simply say that the knowledge required to hook up a PV system is insignificant compared to getting an engineering degree, and there's lots and lots of engineers.... I'd compare it to changing the oil in your truck, or doing a brake job, which doesn't require a PhD in mechanical engineering to accomplish, tho many many things can go wrong...... Education is the key....

But thanks for your info. It gives interested parties yet another point of view.

Andy in Eureka, Texas

[Andy]

Andy replies:

Harry, I like that idea a lot. In my case, I put the array on my barn since the wife didn't want a mess on the roof, and I was only doing it on a small scale experiment anyway....

I still have the PV arrays, and have moved to a retirement house where I have a garden, and am considering hooking them back up to run a small irrigation pump for the garden... But, just messing.... I have no confidence in the economics of trying to run the house with such a system....

Thanks for your input...

Andy in Eureka, Texas

[Andy]

On May 18, 11:15 am, GROVER wrote: y in Eureka, Texas , retired electrical engineer

Andy comments:

Good info, Joe....... While my comments may not actually have been "comprehensive", I'm sure that by the time this thread ends, posts from yourself, and others, will have pointed out a number of things that weren't covered before..... There's more to this than writing a check and getting free electricity for life.....

Andy in Eureka, Texas

[Andy]

Andy adds: Another think I just though of.... Most likely one has to get a building permit in order to have a system installed. That means that the tax man knows of the addition, and, since it adds to the value of the house, the system will be taxed.... Around here the rule of thumb is that the yearly taxes run about 2% of the value, so that's 2% per year for the life of the system...... and I'll bet they goose the asset value up each year just like they do the house......

Andy in Eureka, Texas

PS to "chainiarts" ---- How much did your 7.7Kw system cost and who is the manufacturer ? Did you get any rebates? Thanks.

[trader4]

If you don't even know what one costs, wouldn't it be better to start there instead of starting another post based on assumptions you have no knowledge about?

Gee, you really think so?

Gee, you mean it's not as easy as hooking up an accessory to a computer?

Most people are never going to learn the engineering behind the system. Good thing they don't have to either, otherwise all the school teachers, lawyers, etc would never get one installed.

I didn't see anyone here making the claim that people should just fork over money. The only outrageous claim regarding complexity was that YOU said installing a residential PV array was as easy as hooking up an accessory to a computer.

Seems like a broad assumpiton, unless you've actually taken the class. And even if one does learn it, in most places in the USA they can't install one for someone else unless they are a licensed electrician. In many places they could probably install it on their own house.

But, if it's really pitfalls that you're worried that people could fall into, why not bring up the obvious issue of warranties. I'd suspect that on a DIY install by the guy who doesn't even take a class, there is a good chance the warranties on the system will be kaput.

I can legally change the oil in my friends truck. I can't legally install a PV array on his house here in NJ because I'm not a licensed electrician.

[trader4]

Andy has that part wrong too. It's a federal tax credit, which has nothing to do with standard or itemized deductions. The credit comes directly off your total tax liability. So, if you install a $50K PV system, you take $15K off your total taxes. Meaning if you pay $15K a year or more in taxes you get the full credit.

[Andy]

Andy replies: The tax credit is against the tax liability, so it comes off the bottom line instead of the top. Still, if the bottom line isn't as great as the tax liability, I'm pretty sure the IRS won't give you credit in excess of the tax you owe. In other words, if you have a 10K tax credit, but only owe 8K in tax, I doubt they send you a check for 2K. But I'll admit I haven't looked into it, tho anyone trying to do it for income tax purposes ought to check it out. Some of the IRS rules are very arbitrary. One place to ask is misc.taxes.moderated which is a newsgroup that is staffed and frequented by tax people.

***** While the panels do add some weight, it would be distributed over a wide area, and I doubt it would bother the structure , especially if there were only one layer of shingles. Personally, I'd be more worried about how the panels are attached to the roof, since it would certainly involve drilling some holes.... a LOT of holes..... which, over time, might cause a problem..... If it did, it would probably be a bear to try to fix and patch...

***** I've never worked with solar shingles. I think I'll go and google it to see how they are hooked together. Google is our friend.... Also, there are a lot of engineers that hang out on sci.electronics.design that may have some first hand experience.....

Andy in Eureka, Texas

Andy in Eureka, Texas

[Andy]

**** Thanks haarry. A back of the napkin calculation says my number is more like 1200 for Dallas (1.0 x 5.5 X 365 X 64% ), but I'd need to look up the specific criteria used in your number to see if I left anything out.

**** I agree. My latitude is about 36 deg N...... and I don't remember the sun path deviation thru the year. ( I should, since celestial nav was once a hobby, but that was a long time ago :>)) )

***** Perhaps some mechanical guy will come up with something eventually. But, in Texas, we need to practically weld the panels to the roof since we are subject to large hail, tornadoes, and , at the very least, high winds.... I don't think you have those environmental variables in the UK..... On the other hand, on my trips to south England, I don't think I've ever seen the sun :>))))))

*** I guess you are using GMT...... Ok, that is consistent with the cosine function I was talking about, with "local noon" being 0 deg. The panels I used were amorphous silicon, by UniSolar. I recently google them again, and they have some interesting new items, including "solar shingles".... They are just lain on top of the normal asphalt shingle and a couple holes bored in the roof to bring two wires thru, and the interconnection done in the attic...... It would be a bitch to replace the roof shingles....

**** Like I mentioned, Dallas is rated at 5.5 hrs of "faverage ull sun" per day. For other readers, that means that the power generated is the same as if the sun were directly overhead at optimun angle for 5.5 hours. It averages out things like clouds but I don't think it averages out the sun movement and seasonal angle , and assumes a tracked array..... I guess I need to check on that.....

**** In my experimental system, I used blocking diodes and paralleled the output to the charge controller. Shading, in that case, applied to individual panels. I understand that some panels are manufactured with "shading diodes" to minimize this, but I don't know if they work well since I've never tried them...

****** I live in a wilderness area with lots and lots of trees, and the south side of my house has some blocking. But in the afternoon, when the sun is in the west, it's pretty clear already. Plus, I have a high , sloped roof, if I were to mount it there.... Actually, that would shade the roof a bit more and cut down on the heat in my attic...... hmmmmm..... ** Thanks for the reply Harry. It's nice to be able to learn from someone who actually has an installation and has the skills to evaluate the performance. So I have a couple questions : 1) What is your system capacity and how much did it cost ? 2) Did it meet the manufacturer's literature, or was the output less due to "other circumstances" ??? 3) What is the cost of electricity per kwh in your area? ( Around here , it is about 10.5 cents per kwh ) 4) Did the cost make your real estate tax go up, and your house insurance premium go up ? (I don't know how it works in the UK, but here in Texas the typical yearly tax is about 2% of the appraised value of the property and about 0.5% of the replacement value for homeowner insurance)

Thanks again , Henry. I'm sure that most of those who post here will have an interet in your first hand experience...

Andy in Eureka, Texas

[trader4]

With regard to #4, under NJ law, your real estate tax appraisal cannot be increased when you add solar. Would not be surprised that similar laws could apply in other areas since the goal is to encourage deployment.

Also, the whole idea of asking a realtor what the increase in property value for a PV system would be is largely pointless. The answer isn't going to be worth much, because so many factors affect a sales price it's very difficult to seperate something like that out. You'd need a study done to try to do true comparable sales analysis and even then it's going to be difficult.

One approach to figuring out what it's worth is to look at how much positive cash flow it produces over it's lifespan and then discounting that back to an equivalent present day cash value. I think that would produce a favorable number, but whether or not you realize that in an actual sale, is anybody's guess.

[Douglas Johnson]

There are refundable tax credits where you can get back more than you owe. The earned income credit is one. But the energy credit is not.

That's because they don't come from the IRS but from Congress by way of the IRS.

-- Doug

[Andy]

Andy replies: In Texas, only state buildings are required to enforce state building codes. Individual municipalites may adopt them, separately, if approved by the local commissions and mayors..... In general, most cities require a licensed electrician to hook to the grid, and many require building permits for such simple things as adding an electrical outlet. The requirements are all over the map. As a licensed electrical engineer, I've wired a lot of stuff, including

200 amp service entrances, to property I own in areas that have NO building codes. The local electrical supplier ( TXU) provided a schematic of their requirements and a list of suggested materials, and when I completed it a lineman came out, saw that it was fine, and hooked it up to the grid. At no time was I asked to demonstrate any qualifications --- either it meets the electric company's requirements, or it didn't. Obviously, that can't be done in Dallas. Like I said, it is up to the local municipality to pass the codes they want. In my present house, which I built 6 years ago, there is no building inspection required unless the owner wants one..... It is up to the owner to select a licensed contractor with a good reputation, and it is up to the contractor to use qualified labor...... In Texas, in these areas, we believe in looking out for ourselves..... Of course, when a house is being sold, a home inspection is usually required and any non-NEC compliant electrical work will be flagged, and the seller will be required to correct it.....

So, you see, things aren't the same in your world....

Andy in Eureka, Texas

[chaniarts]

there were both building permits from the town, and paperwork from the power company to be able to tie into the grid. that part has to be done by an electrician approved by the power company, who came out and inspected twice during my install, and they were also the one to install the secondary meter.

valuation of houses for tax purposes, in my area, go by area of the house, area of the lot, type of nearby houses, outbuildings, pools, and general finish compared to houses built near that time in that area. they don't account for pv installs.

my system 'cost' $44k. federal rebate of 30%. power company rebate of 50%. state rebate of 2.2%. power company buyback is equal to cost (ie if i generate 1kwh, it offsets the cost of 1kwh of grid draw). at the end of the year, if i've generated more than usage, i get a credit for the following year.

i am just completing 1 year of service in 2 weeks.

i have a computerized monitor on it, so have pretty complete data on it.

1.4mwh generated. highest peak is 6.7kw generated. highest daily peak is 54kwh.

my usual power bill is ~$1800/year. last 12 months it was $400, so $1400 saved. power company has filed for rate increases every year for the last 5, and there's one to take affect this summer, so the savings will increase every year.

payback time is about 4.5 years. without rebates, it's not financially feasable.

[chaniarts]

i have a flat foam roof, but panels are installed on stanchions and not directly attached to the roof structure on both flat and non-flat roofs. the stanchions are tied through the roof into the rafters, and then the roof penetrations are resealed.

there's less weight considerations for the modules than there are just walking around on the roof. you do have wind loading to worry about, and of course, hail. you also have to worry about shading from any means, like chimneys, antennas, trees, etc. ideally it should face south, and you should be able to see the horizon both to the east and west.

[Andy]

Andy comments: Wow !! Thanks for that info.....

Andy in Eureka, Texas