So glad you started this forum. I am wanting to put solar panels on our house that we are building to reduce energy prices. What I have found is that it will be about $10K for one solar panel on a house that uses about 1,400-1,600 KW. I also read that the goverment has solar panels to give away, but I can not find any more info on that. Does anyone else have info to help out?  Jessica 

Dale,

I was wandering around SIPWEB.com today and found this little gem about the government actually rewarding people for efficient homes!

Basically, hidden in the last energy bill was a $2,000 tax credit (that's $2,000 in your pocket) for building a home that's 50% more efficient than normal (as defined by resfen).

Here's some more details from this source:

New Homes
This provision offers homebuilders a tax credit of $2,000 for homes that cut energy use for heating and cooling only (no hot water) by 50% compared to the national model code ? the 2004 IECC Supplement (assuming an SEER-13 air conditioner). Producers of manufactured homes can also choose to qualify for a tax credit of $1,000 for homes that save 30%.

Eligible homes must demonstrate savings using software that has been approved by DOE and builders must demonstrate compliance by the use of third party inspectors certified according to DOE rules. While no interim rules have been promulgated to meet these requirements, similar standards exist in Florida and elsewhere under the auspices of Florida's Building Energy Rating System and under the national standards of the national Residential Energy Services Network (RESNET).

The incentives apply to homes placed in service during 2006-2007, although extenders increasing the eligibility through 2009 are a possibility.

**********************************************
Looks like I chose the right time to build my ICF/SIP monstrosity.

AG Werschky

I have been a building contractor since 1986 and I have built five homes for myself during that time.

I have been studying the European [mostly Austrian and German] methods of building zero energy homes. This is called a passive house.

Photos: Euro window detail and ICF wall.

Some of the utility companies offer substantial rebates.

I believe that SRP in AZ offers $1,000/KW up to 3KW.

Many electric companies offer "green watt" programs. By driving up demand, the cost of solar will continue to decline as more manufacturing comes on line. Currently supply can't keep up with demand.

Energy Star is a certified rating thru the EPA.  One can build to that standard without the certification.

A house-sized solar system which consists of solar panels,  batteries, a battery charger, AC inverter and a special panel probably costs in the range of $20K to $50K.  A system like this would be big enough to run an evaporative cooler, but not an AC system.  A backup generator would be needed to do that.  The generator could be fueled by diesel or propane.  If you go this route you will want to build a generator shed as far from the house as possible to minimize noise. You will need a high quality continuous duty generator. Maybe Onan would be a good brand to look at for diesel and Honda for propane.

The intent of the solar system is to minimize/eliminate generator run time for your ordinary loads. Needless to say, the ordinary loads should be made as small as possible by doing all cooking, refrigeration, and heating with gas. Use energy compact fluorescent lamps.  Run small always on loads like clocks directly from the DC system.

Your home design can also reduce generator run time. Shade all windows with overhangs, use the best insulating quality windows and doors you can find. Consider building something with a high thermal mass like a masonry block, ICF or adobe structure.  Avoid south facing windows. When designing your HVAC system, use a program like HVAC calc and consider all of the energy saving features you are building in. Size the system right and avoid oversizing it like all the HVAC contractors tend to do. This will allow you to keep your generator relatively small.  Trane makes a SEER 19 compressor now. Expensive, but maybe worth it, when electric power will be at a premium.   

The good news if you elect to go this route is that there are some tax credits out there.

Look at arizonasolarcenter.com for the Arizona State $1,000 Tax credit. Also check the SRP and APS websites for the credits they offer.

For loads as big as a house, I would go for the utility line extension if the costs are at all reasonable personally.  I have had good luck with solar in remote environments for small loads such as security cameras, telemetry, sensors, and weather stations.

cc.state.az.us/utility/electric/2

americanpv.com

You may want to consider  an alternative to "normal" a/c. And I'm not referring to our beloved swamp coolers. There is a company in Tempe (?) that makes an alternative system that uses chilled water. Very efficient and can run on solar. Company is Alter-Air. Main issue from my perspective is that you have to install a water filtration system or there is a potential of increased maintenance. Also helps control humidity and air quality.

 Dale,

I'm really interested in doing some of these things on a plan I'm going to submit within the next month or so.

Do you have the code references on replacing the bathroom and laundry exhaust fans (or know where to get them)?  Has anyone out there done this?

I'll be using radiant (no ducting) so how will I size that, and how many points are sufficient for intake/exhaust?

Thanks,

AG

The 2003IRC, chapter 15 (M1506) and 16 discuss ductwork requirements. Kitchens require min 25 cfm continous and toilet rooms (bathrooms) 20cfm. Rules are higher for intermittent fan use.

Lots of names of equipment being thrown around here. ERV. HRV. SEER. etc. 

Let me splain. ERV (Energy recovery ventilator) is a unit that brings fresh air into the house and is used in hot climates. HRV (Heat recover ventilator) is the same thing, but designed for cold climates.  If your home is not energy star compliant, chances are that you will be wasting your money on either one of these.  On existing homes, a "blower door test" should be done first to see how airtight the home truly is.  You (or your HARV contractor) will then be in a better position to decide whether or not an ERV or an HRV is needed.  If you are building a house where the A/C system is located within the conditioned air space, you will most definitely need an ERV or HRV. 

Hope this helps.

David

Dale,

If the thermal mass is effectively isolated from ambient temperature swings via eps foam, would that not render the thermal mass useless?  This is not my area of expertise, but it does not make sense on the face of it.  My understanding is that the thermal mass should average temperatures if there is enough mass. For example, if average daytime temps are 100 and nighttime temps are 50, then theoretically the thermal mass should keep indoor temps somewhere around 75, provided there is enough thermal mass.

What I do agree with is that fact that ICF varies greatly in R-Value from one manufacturer to the other. In Florida, we mostly deal with high humidity and hot temps nearly year round. My house will have R-30 walls and R-38 roof and a very tight envelope. That is an effective R-value, not a static R-value. There is a big difference, because static R-values do not take into account breaks in the thermal barrier, such as studs, furring strips or trapped moisture. My point is that when dealing with insulating values, it is best for the buyer to do their homework, as it is a somewhat complicated area.

Thanks

David Avalos

I can confirm what a Arnold has illustrated - I have real-time telemetry in all of my ICF walls - I get temperature readouts on the web of my interior, exterior, roof, boiler runtimes, boiler water temperatures, and yes, the concrete core of my ICF walls.

This time of year, in Colorado, we are having 60-degree days, 20-degree nights.  At 3 am, the coldest part of last night, my thermal mass temperature was 50.5 degrees, but at noon yesterday, we had an outside temp of almost 70, and my thermal mass temperature was around 54 degrees.  So the mass will move toward the outside temperature, but do so slowly.  So during winter, when I have to heat, at night, when it's 20, I'm heating more like it's 50 out.  And during the summer, while the thermal mass does warm up some, it's reversed; at night, it cools off, and during the day, it warms up, but the mass is so large that it never moves up enough that the HVAC system would notice...  So the mass tempers the temperature swings, reducing the heating and cooling loading, and acting like a flywheel.  In climates like ours (Colorado) with large temperature swings each day, the flywheel effect has the benefit of storing a bit of heat for use later, and likewise with the cooling, in a passive mode.

In another month or so, my heat will quit turning on entirely...  The heat during the day will offset the losses at night... L)

John,

Real time data is great. In fact, your data confirms what I have always heard about ICF. It favors climates with great temp swings. I am curious what your thermal mass temperature would have been 3 hours later. I suspect that if you were to graph it, the data would indicate that thermal mass favors cold climates. In other words, I suspect that ICF does a better job at keeping a house warm than it does keeping a house cool. I contend that ICF is not the best performer in central and south Florida in terms of energy efficiency, as the thermal mass would tend to heat up the interior of the home 8 months out of the year. I would hate to think what my cooling costs would be during a long, hot summer when I only have 2 inches (2" x R-4 per inch = R-8) of EPS between my interior space and my hot thermal mass. I only mention this because an ICF salesperson may not neccesarily explain this before the sale.

On a side note, earlier when I stated a cost of $50 per square foot for SIP's, I was refering to the total cost of a finished home, not just the cost for the envelope. If you can acomplish that with ICF, I would like the names of your contractors.

recieved the following email and .pdf from a contact  in the energy field. think it will be of interest to all.

Hot Water:
"We have purchased three Mr. Sun hot water systems and are delighted with all of them. Besides simple payback, the net operating income on the building is $500 greater per year because of the reduced utility cost. If buildings are worth 10 times the net income, as appraisers say, then the solar improvement increased the value of my building by $5,000. This is more than twice what I actually paid for the solar system installed! In looking at solar as an investment, it outperforms nearly every other investment I own. For every $1,000 I've invested in solar, I'm realizing at least a $250 per year cash return. That's 25%. No where else am I getting that kind of consistent return. I just wish I owned more buildings that I could put solar on. I wouldn't hesitate to do it."
Dr. Gene Davis, Beaverton, OR

  Click here to download attachment...

Hey guys, sorry about the slow response. Was actually trying to find some graphics to illustrate the situation. Nothing that I wanted to post, yet.

Anyway, your mass acts as a heat sink. Heat goes in, then comes out. So if heat is coming only from one direction, sun in the summer and your furnace during the winter you are creating a flywheel. The k-value of the mass controls how fast heat moves through the material. So the outside heat source ends ( sunset) now heat is going to move towards the cold (basics of thermodynamics here) . So if both sides are colder than heat sink, heat will move equally towards both sides.

P= -kA T/x (just ask and I'll send you the 26 page paper explaining this clearly, because differential equations weren't a strong interest of mine in college )

An uninsulated mass will move energy faster than an insulated mass. But both conditions will shed the heat. What you are achieving with an ICF is a greater  time-lag within the flywheel.

To stop the outside influenced flywheel you have to isolate that mass. A design that incorporates a high insulated building envelope (SIP walls and roof) with a heat sink (adobe and concrete) completely separated from the outside environment would be ideal. An ICF does not have enough insulation to isolate nor enough mass to create a good flywheel as individual components, but works well as a composite.

Here is an interesting article that I bumped into today at Discovery.com for Zero Energy Homes buildable for less than $200,000.

The key systems include:

• Utility meter that spins backwards when the house is producing electricity
• Energy Recovery Ventilation System
• Tightly sealed ducts
• 2x6 exterior walls
• Owens Corning polystyrene sheathing
• Blown-in fiberglass insulation
• Compact flourescent lighting throughout
• Visqueen vapor barrier
• Low-E glass
• Ground source heat pump
• Photovoltaic solar cells

I think the best part is that most of these systems are things that don't end-up costing much more up-front!

John, read your comments on SIPs.  I'm Curious how your parents project is going.  I'm planning to start building with SIPs this September in Tucson.  If you have any info about SIPS, and who's good or bad as far as manufacturer I'd like to hear about it.  If there is anyone in Tucson building now with SIPs, I'd like to hear from them also.

Thanks, Keith

Keith...I have used  KC Panels repeatedly. Probably 1-3 houses per  year over the several years. Of "locally available" panels my order of choices would be KC, Winter, Premier. reportedly there is a ureathane panel mfg up in the Seattle or Portland area, but I haven't located them yet. Ureathane panels are IMHO better than EPS panels. And frieght is always an issue from any mfg outside of AZ. I have a guy here in Tucson that built some of the KC Panel houses at Civano who is looking for framing projects. Without knowing more about your design, I would suggest writing into the specs for the panels additional conduit for your electrical needs. If you want more detailed info on panel quirks private message me. Also I have an upcoming project that may be of interest to you. At your service, dale.

Solar does work, but is very expensive.  Without grants, tax credits, etc -- it will take you 20 years to get your payback -- providing your panels last that long (most seem to last at least 25 years.).  In order to have a completely efficient system, no cost on electric (in Ohio) you would spend $25,000 on your panels.  Electric by us costs about $100/month average.  You can do the math.  Throw in the extra cost of financing a house, it adds up even more.  Where there are more sunny days in other states, I'm sure the cost is lower.  I just don't see this as a practical solution for most people.

For a note though, I did attend a conference at The University of Toledo where a professor by the name of Al Compaan built a house, used solar panels and uses enough energy to have zero electric bills and charge his converted electric truck.  Very interesting.  He has a web site, if I run across it, I will post.

Jon

Interesting article on solar rooftop sheeting: popsci.com. Be sure to check out the 'SEE HOW IT WORKS' link. 

Netie,

Timber frame with a straw bale exterior would be an excellent choice in any region, especially earthquake country.  The only real downside would be the lack of thermal mass, but since you're in UT, that might not be an issue.

Best regards,

Frank

Hi Roger,

I will respond to your weather station question first since it is probably the easier of the questions. If you think your site has potential for wind power, you may want to set up an anemometer and a data logger. I believe Oregon Scientific and Davis Instruments make some relatively inexpensive equipment that may fit the bill. If you feel you need something more sophisticated there are a number of companies that make professional weather stations used by the Forest Service, etc. Campbell Scientific would be one example.  When you are doing your wind study you should sample sustained wind speeds for a long period of time like a year.  The sampling should also be done at the proposed height of the hub of the wind turbine, to be meaningful.  Wind turbines typically have a hub height from 30 to 100' above ground level.   You may want to erect an old utility pole  (one source is Bowen Poles) or a steel lattice tower (one source would be a Rohn Antenna Tower Dealer) to get the height you need for a meaningful study. 

If you look at the wind isohedral maps for Arizona, the sites that show the greatest potential for wind energy are near the Mogollon Rim, I doubt that any locations down in the desert near Phoenix or Tucson have enough sustained wind to make erecting any kind of turbine worthwhile.

I am not sure what you want to do with your security system. Keep people off the property?  Monitor a cargo container or outbuilding with building materials and tools in it?  How do you want the security system to react when an alarm condition is detected?  Does your security system need to communicate with somebody when an alarm occurs? All things to consider. Does your site have  land based telephone or cell service, if not does it have a clear view of the Southern Sky?  What is the value of the stuff you want to protect and what kind of investment are you willing to make in security?

Some sources of solar power systems on the net include Affordable Solar and Mr. Solar. You can see the cost of the systems is pretty high in terms of dollars per watt. Power consumption is very much driven by what you to operate with the solar power system and how long the equipment has to be on.  A basic DC solar system normally consists of photovoltaic panels, a charge controller (I like the Morningstar brand) and deep cycle batteries. The battery system is typically designed to sustain the load for five days in the absence of sun. Keep in mind that solar panels are only one way of keeping your batteries charged and that site visits with a little generator or a vehicle can also be used if you find that solar panels are too expensive or have a nasty habit of disappearing.

Now you have to decide what you want to hook-up: motion sensors? vehicle detectors on the access road/driveway, CCTV?, infrared illuminators, LED luminaries?  What do you want to do when the alarm triggers? Activate strobe lights, sound sirens, take snapshots, release the hounds, notify you, notify an alarm monitoring center, etc. ?

My first choice for communication would be land-line telephone or a land-based internet connection like a cable modem or DSL. My second choice for communications would be cellular. If neither option works, and there is a clear view of the southern sky, satellite communications are viable; but again likely too expensive for protecting a residential construction site.  

If you like the idea of CCTV, check out this website

sunsurveillance.com.  I have no experience with the company, but have built some very similar systems from components.