On May 18, 11:27*am, Andy wrote:
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

Also don't forget that many states that have promised rebates have
defaulted on them. That would be a hell of a shock to my budget if I
had installed a system and counted on that money being there. I ve had
my roof replace twice in 20 years due to storms, First time was a
tornado and recently hail damage. Also over the years that have been
other hail storms that didnt damage the roof but probably would have
damaged the photo cells. I had actually planned on installing a system
at one time so I checked what it did to the value of my home. The
effect was pretty much neutral basically depending on how the buyer
saw it.

Jimmie

Jimmie

On May 19, 2:20*am, harry wrote:
On May 18, 9:00*pm, Andy wrote:





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

There is a number for your area. *In my case it is 830. *This is the
number of Kwh generated per year per kwp installed. You need to find
out what your number is, (prob. around 1000 fir you).
Thers additionally a chart that shows % reduction in output as the
array deviates from due South and from the optimum angle (to the
ground).
My optimum angle is 35 degrees, it will be more like 10 degrees in
Texas I should think.

This is all for fixed arrays. *The cost of rotators is not generally
viable.

The current technology is silocone but they are not all a like. Some
perform better in lower light conditions than others, ie in the
shoulder period. *So while they have the same Kwp, they generate more
Kw because they perform better during the shoulder periods.
Most power is generated between 10.00h and 14.00h.

So you need to look at the graphs of power generated/available light.
The less"peaky" the curve the more power you get in any given day.

A very major issue is shading. *As the panels are series connected,
shade on one panel effects them all.
I cut back trees on my property to overcome this problem, later in the
day in my case.- Hide quoted text -

- Show quoted text -

Having to cut back shading can be a major issue. Several years ago a
test was done in North Fl I think near Jacksonville. Trees were
removed or pruned to allow the sun to get to solar panels mounted on
the roof. Net results were higher energy cost caused by the loss of
shade. Planting trees sounds like it may be more benificial than
installing solar arrays when used in areas where solar arrays would
operate most effectively. This doesnt surprise me since using solar
energy to directly heat something has always proven to be morre
efficent than using it to generate electricity via photovoltaics. Now
the question becomes more complex than just whether or not to install
photo-voltaic but whether to spend my money on super insulating my
home, adding solar water heaters, planting trees or maybe adding
reflective shingles on the south facing side of my house. How do I
figure out what is the best way to go?


Jimmie

On May 20, 8:19*pm, JIMMIE wrote:
On May 19, 2:20*am, harry wrote:





On May 18, 9:00*pm, Andy wrote:

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

There is a number for your area. *In my case it is 830. *This is the
number of Kwh generated per year per kwp installed. You need to find
out what your number is, (prob. around 1000 fir you).
Thers additionally a chart that shows % reduction in output as the
array deviates from due South and from the optimum angle (to the
ground).
My optimum angle is 35 degrees, it will be more like 10 degrees in
Texas I should think.

This is all for fixed arrays. *The cost of rotators is not generally
viable.

The current technology is silocone but they are not all a like. Some
perform better in lower light conditions than others, ie in the
shoulder period. *So while they have the same Kwp, they generate more
Kw because they perform better during the shoulder periods.
Most power is generated between 10.00h and 14.00h.

So you need to look at the graphs of power generated/available light.
The less"peaky" the curve the more power you get in any given day.

A very major issue is shading. *As the panels are series connected,
shade on one panel effects them all.
I cut back trees on my property to overcome this problem, later in the
day in my case.- Hide quoted text -

- Show quoted text -

Having to cut back shading can be a major issue. Several years ago a
test was done in North Fl I think near Jacksonville. Trees were
removed or pruned to allow the sun to get to solar panels mounted on
the roof. Net results were higher energy cost *caused by the loss of
shade. Planting trees sounds like it may be more benificial than
installing solar arrays when used in areas where solar arrays would
operate most effectively. This doesnt surprise me since using solar
energy to directly heat something has always proven to be morre
efficent than using it to generate electricity via photovoltaics. Now
the question *becomes more complex than just whether or not to install
photo-voltaic but whether to spend my money on super insulating my
home, adding solar water heaters, planting trees or maybe adding
reflective shingles on the south *facing side of my house. How do I
figure out what is the best way to go?

Jimmie- Hide quoted text -

- Show quoted text -

You would not use PV electricity for direct home heating, that would
be foolish.
A lot depends on your local climate also the cost of energy.
The first thing you need to look at is draught proofing and insulation
as they require no maintenance. Insulate the roof first.
You need to remember, the steps you are taking now are to save energy
at tomorrows prices not today.
The price of energy is going to increase dramatically, especially
since this Fukushima event. Nuclear power has been set back decades,
this will result in increased demand for fossil fuel.

You need to work out a paybck for your expenditure. Base it on energy
costs going up by 7% every year. In the UK the price of natural gas
is to go up by 15% this Winter.

On May 21, 1:44*am, harry wrote:
On May 20, 8:19*pm, JIMMIE wrote:





On May 19, 2:20*am, harry wrote:

On May 18, 9:00*pm, Andy wrote:

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

There is a number for your area. *In my case it is 830. *This is the
number of Kwh generated per year per kwp installed. You need to find
out what your number is, (prob. around 1000 fir you).
Thers additionally a chart that shows % reduction in output as the
array deviates from due South and from the optimum angle (to the
ground).
My optimum angle is 35 degrees, it will be more like 10 degrees in
Texas I should think.

This is all for fixed arrays. *The cost of rotators is not generally
viable.

The current technology is silocone but they are not all a like. Some
perform better in lower light conditions than others, ie in the
shoulder period. *So while they have the same Kwp, they generate more
Kw because they perform better during the shoulder periods.
Most power is generated between 10.00h and 14.00h.

So you need to look at the graphs of power generated/available light.
The less"peaky" the curve the more power you get in any given day.

A very major issue is shading. *As the panels are series connected,
shade on one panel effects them all.
I cut back trees on my property to overcome this problem, later in the
day in my case.- Hide quoted text -

- Show quoted text -

Having to cut back shading can be a major issue. Several years ago a
test was done in North Fl I think near Jacksonville. Trees were
removed or pruned to allow the sun to get to solar panels mounted on
the roof. Net results were higher energy cost *caused by the loss of
shade. Planting trees sounds like it may be more benificial than
installing solar arrays when used in areas where solar arrays would
operate most effectively. This doesnt surprise me since using solar
energy to directly heat something has always proven to be morre
efficent than using it to generate electricity via photovoltaics. Now
the question *becomes more complex than just whether or not to install
photo-voltaic but whether to spend my money on super insulating my
home, adding solar water heaters, planting trees or maybe adding
reflective shingles on the south *facing side of my house. How do I
figure out what is the best way to go?

Jimmie- Hide quoted text -

- Show quoted text -

You would not use PV electricity for direct home heating, that would
be foolish.
A lot depends on your local climate also the cost of energy.
The first thing you need to look at is draught proofing and insulation
as they require no maintenance. *Insulate the roof first.
You need to remember, the steps you are taking now are to save energy
at tomorrows prices not today.
The price of energy is going to increase dramatically, especially
since this Fukushima event. Nuclear power has been set back decades,
this will result in increased demand for fossil fuel.

You need to work out a paybck for your expenditure. *Base it on energy
costs going up by 7% every year. *In the UK the price of natural gas
is to go up by 15% *this Winter.

GTF OUT OF HERE HARRY, YOUR UK PLAY MONEY ISN'T GOOD HERE.
YOU ENGRISH FOLK ARE ALL LIVING A FANTASY DOLLHOUSE KIND OF LIFE, AND
WE DONT PLAY WITH DOLLS....GET REAL....OR GET NUMISMATIC.
TGITM