Why Tankless, Hybrid Electric, and Solar Water Heaters Just Don't Work!

Tankless- expensive, high maintenance, high failure rates, high install costs, limited flow rates, poor winter performance, long payback.

Hybrid Electric- too tall, need surrounding space for heat exchange, poor durability, noisy, may need condensate pump.

Solar- requires southern exposure, cold & cloudy days: poor performance, very long payback, high install costs

What works?

The good old Storage Tank water heater- electric is OK, fast payback for gas or propane fueled(if low fuel price). Easy to maintain. Best to purchase long warranty unit for maximum durability.

How can this be? The best available technology at a reasonable cost will always prevail. And it has to, in a word, JUST WORK! With the exception, sometimes, of federal government mandated technology, (and dehumidifiers)!

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Comment by Bob Blanchette on December 21, 2012 at 2:50pm

Bob Waldrop smarthours is risk free for the 1st summer. You don't have to shut everything off to come out ahead on the program, but every bit helps. If it doesn't save you money over the summer, get off the program and OGE will refund the difference.

Comment by Tom DelConte on December 21, 2012 at 12:06pm

Hello Curt,

Propane is just a fuel, like natural gas. It's not a state-of-mind. It comes from oil refineries, in general. You can get a better price by being nice to your local dealer. The water heater is identical to NG except for the jet is calibrated for propane. It gets you 'off the grid,' sort of. They are very reliable, like NG ones.

Heat pump water heaters are a wonderful, but unproved technology. You left out that their previous format have been installed for 40 years as an add-on heat exchanger to hvac units in Florida. They are expensive, noisy, need lots of space, and like any Cadillac, cost more to service. You lost me when you talked about dehumidifying and heating a garage in Florida. Having just returned from there, not even the 2010 HGTV green home in port st lucie includes the garage in the envelope.

All water heaters want soft water! It's just that some places have very hard water, so be it. If it's too hard, you put in a water softener, that's all. Solar, yeah it works great in Fla., but who's going to pay for the service calls?  Once again, if you are going to put something on your roof, you must beef up the roof structure, and in general, put another layer of shingles on while you still can. More expense!

All of the above means: Storage Tanks Rule! Auto-igniting pilots are better, sure, and high efficiency. Guess what? Fresh air intake doesn't matter, even though the entire energy community, including the big guy, thinks it does! 

Comment by Brian Robinson on December 21, 2012 at 11:09am

Hi Tom,

Not to worry, I'm not a native nor thin skinned.

I suppose it is unusual that our clients like the idea of locking in a worry-free investment that yields 10% annually on each invested dollar, has a value to investment ratio of 1 to 1 or better and frees them somewhat from the vicissitudes of the electric / LP market and relieves guilt over fracking, etc.  Oh, and they don't get taxed on the  "earnings". Ho-hum. (credit to Kilgore Trout of K. Vonnegut novels)

Comment by Curt Kinder on December 21, 2012 at 10:48am

"Propane is a fuel..." Wow! Who knew? I learn something new here every day!

The $3.50+ we pay in the deep south for a gallon of propane isn't going to change by my being polite to my supplier. Propane pricing varies widely by region, with Nebraska the lowest at $1.50 last I checked.

The technology to transfer heat from compressed refrigerant gas to water is not new - its been around for decades. I agree that the 1980s-era desuperheaters were not particularly effective, but they worked well enough.

I don't really advocate solar thermal owing to first cost and complexity, but it starts to make sense in the case of very high daily demand.

Clinging to center flue gas and storage electric water heaters strikes me as similar to pining for 10 mpg carbureted car engines and fiberglass batt insulation. Both work, but time marches on

Comment by Tom DelConte on December 21, 2012 at 9:17am

Hey Brian,

Please don't take it personally. Apology about Maine being special needs, but I've known about this since childhood: Maine . [this article says that maine is doing relatively well now, but is 2nd to alaska in accepting the dole, also again not personal, i just remem. my mom's stories about northern maine] Most Americans think that West Virginia is the worst off! It also follows that maine would have some degree of  fuel poverty, which i covered in a blog last year. The old 'driving around' system comes from mr hewlett of hewlett/packard who used to practice "management by walking around." I think it's great that you have clients that listen to your reccomendations to spend big bucks to just heat water; i don't have any of those, but i am gonna try to get the contract on johnny depp's new estate in nashville, maybe he'll listen! Oh once again, for any of my thoughts on autos, please check my auto blog. Analogies between cars and houses rarely hold water. Thanks, again for your input! ps, this comment has been heavily edited by me in an attempt to not offend a fellow downeaster who makes great comments. t

Comment by Brian Robinson on December 21, 2012 at 8:50am


Interesting how you can determine all this by what you "see, just driving around."  

I agree that the "price" of tanked resistance elec.DHW is lower but would counter that the "cos"t is actually higher.  I encourage my clients to understand at the lifecyle cost of any changes while admitting that no one has 20-20 forward vision.  In this case, an extra say $1,000 for hybrid elec. over pure resistance pays for itself in 3 - 7 years (equiv. to about a 14% to 30% ROI).  For solar, the investment usually looks like a 10% annual ROI - not too shabby in this day & age especially when ROI often is not their primary motivation.

You seem to be advocating or "observing" the equivalent of: "seeing that many folks don't maintain their more expensive cars as they should & therefore need to replace them more often than "necessary" so they eventually just end up buying much cheaper replacement cars.  I guess I don't really observe that happening much.  Do you?

Then again, I'm from a"special needs" state . . .

Comment by Tom DelConte on December 21, 2012 at 8:14am

Hello Brian,

Thank you, and I agree with you on reality vs theory. Also, I totally understand that Maine is a "special needs" state, since my mom was from there(Skowhegan, weston family, 1770, for real). I see now that there's a southern vs northern maine secession controversy. See the Lincoln movie for how he caused the Civil War!

Maybe solar works great there, I couldn't say. What i can say is that in much of the USA, ye old oil heat w' summer water hookup is gone, replaced w/ oil heat w/ electric storage. It's simple. It's relatively cheap. It just works!

Call me the great observer, here's what I see, just driving around. The new owner or the significant other gets tired of the solar system, pun intended, not delivering hot water, or paying for the service calls if it's not serviced by the owner. The roof needs to be replaced. Boom, next thing you know, that solar system is gone, and replaced by the cheapest architectural grade asphalt shingles. No more solar. I expect the same thing to happen to most solar cell photovoltaic systems over time. The owner gets tired of cleaning them, their efficiency degrades yearly, the 'service calls' get to be too much, etc. Feel free to correct me if I'm wrong, everybody else does! t

Comment by Brian Robinson on December 21, 2012 at 6:21am

Hey Tom,

Great discussion you started and wonderful to read the diff. opinions & experiences.  In my experience, I've found the reality trumps theory every time so I always look for verification.

That said, I've found that solar thermal works very well (practical & cost effective) in Maine where we have lots of clear days and are 70% oil dependent for H/HW.  Certainly it works best when the household demand is relatively high.  Personally, my boiler hardly ever runs from April - Nov. and I've tracked savings of at least 20,000,000 btus /year.  I too am relatively unconvinced about the benefits of on-demand LP (no nat. gas here in the hinterlands) though have verified great results with hybrid electric (heat pump) water heaters.  After all, hybrids are at least as efficient as pure resistance electric and potentially up to 2.x times more efficient.  LP currently runs $2.75 - $4/gal here depending on your annual usage with small users paying the premium price.

In a heating only climate (Maine) eliminating the air transported heat loss from capping the vent of a direct fired LP storage tank WH can be significant as well.  

Heat pump water heaters have been used commercially for decades so the tech. while newer to the residential realm is hardly unproven.

Comment by Bob Waldrop on December 21, 2012 at 6:17am

Bob Blanchette, I am signed up for the ogepower site, and check it regularly, I will try an experiment and see what happens.  I haven't signed up for the smart hours pricing plan. I couldn't come to an agreement with my roommates about not using AC during the afternoon hours. We don't have central ac or heating so we don't have any thermostats to replace or set.  Our house is 1548 sq ft, we are well shaded with trees, we have ceiling fans in every room, and three 5K BTU window unit AC, which are rarely all going at the same time. We have 9 inches of cellulose insulation in the walls and 14 inches in the attic, R-20 insulated interior shutters for our windows.  In 2011 we used 14,708 kwh for everything (we don't have natural gas). In 2011 we had 5 residents, 4 adults and one child. We also used a half cord of wood in the woodburning stove. Now we have 3 residents (3 adults and one child who is six going on 16, lol).

Comment by Bob Blanchette on December 20, 2012 at 7:57pm

Bob, have you been monitoring the differences in power use on the myogepower website? This will give you hour by hour breakdown of power use and end the "seems like it saves". It's provided free by OG&E, just sign up. Have you signed up for the smarthours VPP pricing plan? In the summer you could run your water heater during off peak times for 5 cents per KWH then shut it off 2-7 when rates are higher. You can set your AC thermostat to go to a higher temperature from 2-7pm weekdays during the summer and save a LOT of money. If you want a demand response thermostat OG&E will even give you one for FREE including installation just for signing up on smarthours.

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