Post by Glen WalpertPost by Don YPost by Glen Walpert18kWh 0.2$/kWh 365days/year 20years = $26,280
Based on below average solar insolation, cost of electricity and system
life expectancy. Solar is the cheapest electricity you can buy in a
lot of places. Why pay more?
What do you factor in for roof maintenance (do you get 20 years out of a
roof?) and the licensed installers who have to disconnect your kit
before you can make those repairs and then reinstall -- and have it
inspected -- before you can resume its use (costs that would be
unnecessary with a "clean" roof)?
Good point, the roof needs to be considered in your economic analysis, and
unless you have a roof which can be expected to last more than 20 years -
brand new fiberglass shingle, or metal, membrane, tile in good condition -
then it will be most economical to replace the roof at the same time solar
is installed.
Most installers, here, will inspect the roof prior to installation.
As *they* usually aren't in the "new roof" business (though that isn't
any guarantee that they aren't in cahoots with someone who *is*!),
you assume they will give an honest appraisal.
Post by Glen WalpertUnfortunately the low first cost fiberglass roofing is more
popular than the durable low life cycle cost alternatives with a good
chance of outliving a 30 year solar installation.
There are many different types of roofs in use, here:
tile (clay and concrete), asphalt shingles, built-up (rolled felt),
metal (tin or copper), membrane, etc.
But, none seem to be truly durable. All of our neighbors have had at
least one "new" roof installed (ours is 30 years old but is maintained,
actively, by me -- on an annual basis).
I suspect part of the problem is related to construction techniques.
I.e., with no snow load to worry about, roof joists are often on 24in
centers, 1/2 plywood deck. Building on slabs means the houses
"shift" with changes in the ground structure (e.g., subsidence from
ground water pumping); almost every home shows signs of cracking in
the exterior (usually stucco over block -- though even stucco over
wood frame has problems!).
A common problem is gaps forming at roof penetrations as things "move"
(hence my annual maintenance activity).
The constant heat and solar exposure also dries out most materials.
It will be interesting to see if the shading afforded by panels
lessens this problem... or, just makes it more noticeable in
unshaded portions of the roof!
We note that "commercial"/public installations aren't *on*
roofs but, rather, are canopies made from the panels -- no
decking under them (which likely improves thermal performance
as it allows for better air circulation). The roof requirement
for homeowners probably is an acknowledgement that most
homeowners have no other structures that can support panels!
Post by Glen WalpertPost by Don YNote that even if you reduce your demand to fit entirely within your
cogeneration capabilities, you will have to pay the utility if grid
connected -- even if just a fixed, monthly "service charge". And, what
they charge can be varied, over time ("We need the solar folks to
subsidize the RENTERS who can't have their own solar power..." etc.)
The utility, here, is working HARD to make solar as expensive as
possible using every legal lever they can manipulate (and, they have far
more clout than individual users/cogenerators)
[I believe I am located in the BEST place (desert southwest) for solar
-- in terms of conceptual payback -- yet it's a struggle to beat the
hurdles that are placed before your adoption!]
A common problem in the US, utilities which do not want competition are
making the "contributions" which insure that legislation written by their
lobbyists is enacted.
Of course! "Momma dint raise no dummies!"
But, this just delays the reckoning. Eventually, the technology will
be such that homes will be 100% "alternative power" with *no* reliance
on the utility. And, the utility will be stuck having to maintain
all of that "cogeneration" that they bet their business on!
[E.g., the phone company has miles of copper that they have to
maintain -- to some degree -- yet doesn't generate any revenue for
them. Losing subscribers (due to poor quality or bad pricing policies)
is just a slow sink into irrelevance: "No thanks, I'll get my
phone service from X, Y or Z -- and my internet/TV from A, B or C"]
Post by Glen WalpertIn Florida a regulation requiring all solar systems
meeting more than a small amount of customer demand be utility owned and
operated - they rent your roof and give you a bit of a raw deal discount
on electricity - was soundly defeated in a voter referendum despite heavy
deceptive utility advertising, and then enacted by executive order by Ron
DeSantis, recipient of big utility "contributions". Not much Solar in
Florida.
All of the "reasons" *seem* to make sense, superficially
(e.g., my suggestion that solar customers will be required to
pay a subsidy to underwrite part of the energy costs of
folks who *can't* have solar -- renters -- in much the
same way that rural telecom is subsidized by other consumers)
But, in sum, all of these nickels and dimes conspire to make
it hard for folks to adopt what would otherwise be a no-brainer
(certainly for younger people!)
Post by Glen WalpertTexas by contrast has little regulation and loads of solar.
Here in PA we have decent regulations but only moderate insolation,
payback time is longer but still worthwhile for those with a good
location.
I think the only *practical* way for me to exploit solar is to
NOT rely on the utility for "storage" -- so they (and the regulations
they have pushed) don't have a say in my installation.
E.g., if I used solar power to run an electric heater to heat
water for a swimming pool, never selling any excess power
to the grid, why should they have a say in my installation?
Similarly, if I was totally "off grid", what say -- other than
building codes?
At least, that's the approach I've planned on. Install your own
panels and payback is probably a couple of years instead of
decades!
~6.5 peak solar hours/day (avg)
~5KW array
~32KWHr/day (avg)
~13c/KWHr *delivered*
~$4/day (avg) or $1500/yr
~$7K equipment cost
~4-5 yr payback