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Commercial Solar Water Heaters ? - Page 5

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Posted by Christian Kaiser on September 5, 2005, 2:46 pm

I've just been in the Allgäu - a countryside near the alps - and about 10%
of the houses had solar water heating, some of them with additional PV.
I thought of taking pictures, but I drove and we had to get back home as
fast as possible, it was a bit late.


a) As we said, in Germany, people tend to keep houses for a long time (I can
speak for myself in that respect too)

b) In the countryside, people keep houses (farmhouses) in the family for
multiple generations, so they can really think forward a long time.

c) As we get a lot of money for the PV energy, several farmhouses have all
their barn roof covered with PV systems, 10-20 kWp or more. Looks nice. Same
here in Baden-Württemberg, another German state, but due to the better view
up in the hills of the Allgäu, I was able to see much more roofs and more
farm houses than here.

The green party puts "PV systems on every roof" in the bavarian party
program (we have elections in about 2 week's time). I really should have
taken a picture of that poster.


Posted by Christian Kaiser on September 6, 2005, 8:49 am

I just found a picture about "collector area installed in 2003":


Europe:     1,390,000 m^2
USA:             90,000 m^2


Posted by Paul on September 6, 2005, 3:27 pm

  I read somewhere that Europe uses something like 40% of their
installed solar thermal for home heating. It seems like affordable
natural gas in the U.S. has favored using that for home heating.
Perhaps with natural gas being deregulated, solar thermal could
be more popular for businesses and homes.

Posted by Rob Dekker on September 6, 2005, 11:36 pm


Thanks ! Very interesting picture, Christian.
Quite surprising that even a country like Turkey has 5x the installed collector
size of the US.
And the winner : China's 9.5 Million m^2  (100x the US) is a real eye-opener for

Now I have to assume this (collector area) is mainly solar-thermal water
(as opposed to PV).

It's time we catch-up here in the states.

Posted by Morris Dovey on September 1, 2005, 8:00 am
 Rob Dekker (in bPvRe.2071$nB6.1177@newssvr30.news.prodigy.com) said:

|| A commercial high-quality (efficient, long-life, reliable) DHW
|| system including the associated pumps and control subsystem
|| suitable for installation in the upper midwest is likely to cost
|| in excess of $K - which I decided was more than most homeowners
|| would be willing to fork over.
| That's really cool !
| Is that your production cost price ? Or you retail price ?

Sorry, I should have specified. It's the wholesale price that was
estimated (fairly carefully) to cover cost of production plus 20%. If
the product were moderately successful, then the 20% would be eaten up
completely by the costs associated with expansion of the enterprise.
Major success (requiring rapid growth) would unquestionably require
significant price increase.

Not included in the $K: shipping, installation, and costs associated
with any warranties and any costs incurred with meeting any
government-imposed standards (for which your state is famous, even in
remotest Iowa :-).

| Considering that PV systems that people are installing today cost
much more
| than that and probably create less $'s energy savings, there has to
be a pretty
| good market for your system.

Perhaps PV systems are selling well in your neck of the woods. Around
here they aren't because people aren't finding an favorable
cost/benefit trade-off.

| I would guess that in California (more sun-hours/day, virtually no
risk of freezing)
| the collector could be smaller and the system simpler, and thus will
be cheaper,
| so you might have a winner here !

The bad news is that while the cost of materials needed might be
somewhat less, the reduction in total cost would be noticably
smaller - possibly insignificant.

| Also note that the 'million solar roof initiative' is now on our
| Governator's desk :
| http://www.renewableenergyaccess.com/rea/news/story?id#711
| If approved, there would be considerable rebates for buying solar
| That would bring the price of your system down to less than $000.-!

I'm always pleasantly surprised when politicians follow through on
measures from which their constituancies benefit - especially when
they manage to do so without incurring huge deficits or reaching into
their constituant's pockets for still more taxes (or, in California's
case, granting companies like PG&E license to rape and pillage).

| So the market might be ready for a good commercial system.

I think the "early adapters" might be; but the bulk of the market
isn't quite.

|| There's an additional "fly in the ointment" in that once such a
|| system is sold and installed, it's (currently) extremely difficult
|| to find anyone to provide after-sale maintenance/repair service.
| That probably depends on the system that you want to sell
| and the people you want to sell it to.

In my mind, it needs to be as straight-foreward as a conventional
electric water heater. It can't be as inherently simple, but from a
service perspective, a Joe Ordinary service person should be able to
remedy a worst-case service scenario within a half-hour.

| The first real market would probably be the 'self-installers'.
| People that know how to follow installation instructions,
| and know how to hold a crewdriver and would install their own stuff.
| People that buy water heaters at Home Depot, so to say.

I'm not as comfortable with this as you seem to be. Installation
involves carpentry, plumbing, and electrical work - and strict
conformance to building codes. While I'm sure there are people around
who're well-grounded (no pun intended) in all three fields and who
know the applicable codes, I'm acutely aware that this group doesn't
constitute a market by a long shot.

It's been less than a week since I had an e-mail exchange with a
(professional) carpenter who was planning to install solar heating
panels on the north wall of his home - and I happen to know that he's
a reasonably bright guy - his house just didn't face the direction he
thought it did.

| It would require a fool-proof / safe-proof system though....
| Easy to buy, easy to install, and self-correcting (no complicated
| tools, adjustements or test equipment needed).

You lost me at the "fool-proof" part. It's a lot easier to design a
system that can only fail "safe" than it is to design something that a
creative fool can't find a way to screw up or hurt himself with.

| Beyond that, a regular plumber should be able to learn how to
| service a simple solar heater system after in a day of training or
| so....
| Where there is a market, service people will sprout up...

True. My question is: "How many homeowners will have to do without
needed service/repair visits until that sprouting takes place?" The
very first homeowner who can't get the service needed will become an
anti-solar evangelist. The twenty-fifth will be an enterprise ELE
(extinction level event).

Note that none of the problems are solar water heater technical
problems. There are still more hurdles than discussed here - and my
decision (in large part determined by the resources available to me)
were to neither sell nor offer water heating panels.

CAD drawing and CNC program files are safely archived on CDs and if I
can puzzle out some reasonable way to ensure customer satisfaction and
safety, I can put the panels into production. Until then I'll probably
remain as frustrated as you.

Morris Dovey
DeSoto Solar
DeSoto, Iowa USA

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