Solar Water Heating benefits

Michael,

YES YES YES!!!! Solar water heating is the best (worst?) kept secret. Frankly it should be a building code specification. All new construction should have one. It's absolutely ridiculous to waste so much NG (or worse, Coal fired electricity) to heat water. It's really a no-brainer. We'll be adding one to our next house for sure.

What region of the country are you in? Just curious.

 

Cool. Here in Denver I think that we'd do rather well too. There are some folks who've brought this up before and who have solar thermal in Seattle and say that it does well there too. That one did surprise me.

 

We need a major shift in building codes. Solar water heating should be required, but first:

1. The entire building should be energy efficient and climate appropriate. No more trying to constantly heat and cool the outside. The Energy Efficiency Index for the residence, business, school or church should be less than 10 and as close to 1 as possible. EEI is the ratio of Joules to interior surface area to climatic demand for energy (heating- and cooling-degree days) for a specific location. EEI is objectively comparable between sites, regardless of elevation, latitude, building type and purpose and climate.

2. Incoming water should first go to one or more well-insulated slave tank(s) that allows water to warm up (great than soil temperature) first.

3. Heated water can then go through a gas or electric (or solar assisted) "on-demand" tap. This provides unlimited hot water at the point of use and minimizes the need for a tank with a pilot light or glow plug that is always operating. Hot water is there only when needed, not constantly being produced when not needed.

4. All pipes, valves and tanks must be well insulated to prevent heat loss.

5. To the extent possible, pipes should be clustered in a utilidor to minimize how far water must travel to the point of use and to facilitate maintenance. Water-using rooms (bathroom, kitchen, laundry) should be clusters to minimize pipes.

6. Solar hot water is sustainable, renewable, silent and minimizes the potential for toxics, It increases the comfort and peace-of-mind factors while keeping long-term cost to a minimum.

7. Optimum solar relies on local resources and is independent of fossil fuels (natural gas, propane, fuel oil) and therefor not subject to the whims of corporations, distant countries or domestic special interests.

 

LEED is movement in the right direction. I attended a LEED educational workshop six months ago. The presenters absolutely refused to acknowledge the efforts of the Rocky Mountain Institute and advantages of efficiency. They had no knowledge of the Energy Efficiency Index (EEI). The presenters were intent on teaching the "party line" - that funded and forwarded by utilities around the country.

 

I have had solar water heating on my current house for 10 years and my previous house for 11 years. It absolutely makes sense - especially here in Dallas. I toured my boss through my house and we now have solar water heating at our new office complex.

See the Westbrook House for more energy saving info including my new wind turbine.

See the New TI Green Fab to see efficiency scaled WAY up.

I'm a LEED Accredited Professional.

 

<div class='quotetop'>QUOTE(largomike1 @ Nov 6 2006, 02:10 PM) [snapback]344705[/snapback]</div>

I absolutely aplaud this, and am currently looking into solar hot water here. I'd be remiss if I didn't mention that this whole "payback" thing is not equal for everybody, however.

For example. my $10k PV system paid me back the MOMENT that I turned it on. Not a year from installation. Not ten years. The MOMENT I turned it on. My monthly payments on the loan that I took out to install the system are lower than my average monthly power bill. Presto. Instant payback. When the loan is paid off in just two more years, I'm making money. My PV system provides all the electricity for my house AND the fuel for our main vehicle.

And for solar heat... my average monthly NG bill for heating water at my house is $10. In the summer, it is $2. More in the winter, obviously. I dare say that my "payback" on a solar water system will be way the hell longer than my PV system was! But that isn't even making me hesitate. It is the right thing to do, and I'm going to do it as soon as I find the right unit for my needs. My point here is that way too much emphasis is put on the "payback" time of these things, and I think they can get by on their own merits.

Thanks for your site. I'm gonna go check it out more thoroughly now.

What brand/model did you end up with?

 

I've got a natural gas water heater at present. When it goes I want an on demand tank.

Question for you all.

Would it be better to go Solar with the current gas water heater instead of going to an on demand gas heater.

Or does it make sense to do both Solar tied to an on demand system? Is that overkill?

It's not like I use a lot of hot water. Like eveyrone when I need hot water I want it and I want it now and I don't want to run out. Even though I live alone I can't wash my hair and do laundry at the same time.

That said....I don't want the gas pilot going constantly to heat water I'm not using. Having the water hot while I'm at work for 8 hours or sleeping for 8 hours seems just plain stupid.

 

When it comes time to replace my hot water heater I will consider a solar system. We average about $33 / month for our hot water. To break even - if electric rates are constant - after installing a solar system it would be some 80 some-odd months. Since I don't have $2.8K readily available for this investment, it makes no sense for us to do this at this time. However, if the cost of the system were significantly reduced (it cant be that much to manufacture these components - why does it cost so much for basically a radiator system?) then I would reconsider the investment. But that's just me. Don't get me wrong - I'm all for alternative energy (we do own a Prius after all) but the economics of replacing this perfectly good hot water system just doesn't make sense right now for us.

Here's the site that got me to thinking this way: http://www.backwoodssolar.com/interests/ElecBill.htm

 

<div class='quotetop'>QUOTE(Florida Prius @ Nov 6 2006, 11:17 PM) [snapback]344861[/snapback]</div>

Did you figure in the 30% Fed Tax credit? The cost is in the installation (the complexity of) and it really seems to depend on how easy/difficult it is to retrofit. The size of the system, of course, also plays a part. You may not need to fork over $2.8K.

Of course electricity rates won't remain constant but just how much they'll go up is anyones guess. Is your system NG or electric? NG prices are really volitile and there's a fair amount of upward pressure on the price though it looks like supplies are good this year.

 

Question -

Has anyone installed the solar panels on the ground away from the house. If so - how far away from the house did you place them? And- finally, what type of pipe did you use (copper, pex, etc.)

 

<div class='quotetop'>QUOTE(TonyPSchaefer @ Nov 7 2006, 01:14 PM) [snapback]345098[/snapback]</div>

My first thought is the visual appearance of the panels on the roof. I know that PV systems are becoming more integrated into the roofing membranes, and will eventually become virtually invisible and not in competition with the architecture. But currently, hot water systems require more substantial equipment which can detract visually.

Heat transfer from remote panels might be a problem depending upon what type of heating application you are servicing. I've retrofitted my house with radiant heat which requires only 110 to 120 degrees of heating. I would think the heat loss would not be as great of an issue, provided an adequate volume of heat storage is provided.

Your heat loss concern also brings to mind the option of a geothermal ground loop which relies upon the constant temperature of the earth for both heating and cooling. While more expensive to drill wells or massive excavations for horizontal loop systems, this solution appeals to me since there is no dependence upon providing excess storage for periods of cloudy days. The ability to cool is also attractive too.

 

<div class='quotetop'>QUOTE(largomike1 @ Nov 7 2006, 09:29 AM) [snapback]344923[/snapback]</div>

I think you could probably just use a home equity loan or line of credit, these are nice in that the interest is tax deductble. You could also do a refi on your residence if you are looking for a lower interest rate and take some extra cash out for the PV system, it depends on your circumstances (current rate on your mortgage, amount of equity in your home, etc.)

Dennis