Cob: Solar Power

[David & Sheila Knapp]

Assuming you are building a reasonable sized Cob home (one that you can finish in THIS lifetime), your prospective PV system for your current home would be a magnitude bigger than what would be needed for your future COB home (wasted money).  PV prices are slowly & steadily coming down and you could save a lot of money by waiting until you have fully designed you new Cob home and did a site survey and load analysis to buy the "right" sized PV system.

I second everything that Shannon says.

You do not need a solar PV system to learn how to live lightly on the planet.  PV electricity is very expensive and it is not very cost effective if you already have grid power.  A lot of grid power may only cost you $50 - $150 per month, but a whole lot of PV power will only generate the equivalent $5 - $15 per month.

It is almost impossible for you to cost effectively change to a PV system where you now live because 90% of your appliances are going to be the wrong type.  Electric water heaters, water bed heaters, electric stove, base board heaters, etc. are automatically out of the question.  Your refrigerator, any chest freezer, air conditioner, or dehumidifier is also going to have to be replaced or removed.  Efficient refrigerators that work well on solar PV power will cost you $1500 - $2500.  Why?  The extremely efficient refrigerator will use 1 - 2 solar PV modules worth of power vs. your conventional refrigerator which will use 15 - 25 solar PV modules all by itself (at $400 - $600 per PV module). They do make propane powered refrigerators (not the RV type!), but I do not care to use any more propane than I have to.

Also, your electronic appliances like your TV, VCR, microwave, clock radio, doorbell transformer, garage door opener, Sony Playstation, GFCI outlets & breakers, etc. will steal a huge unacceptable load from your PV system that you never even knew about on grid power.  These phantom Ghost loads come from the clocks and other circuitry that is standing by waiting for you to use the remote control or to read the time or to instantly activate their functions.  You would need a whole PV system just for these wasted loads if you did not know about them and know how to deal with them.  We have our TV & VCR on a wall switch outlet and turn the switch on when we want to use them.  TV's take a lot of power (like running a 100 watt light-bulb for many hours for most families).  We dumped our clock radio and use solar powered clocks from Jademountain.com.  We use outlet strips and unplug or shut them off when the appliances are being used.  Our microwave oven has a mechanical timer rather than a power wasting clock.  Our gas cook stove is the electronic ignition type.  Most gas cook stoves are the glow bar type and gobble down tons of electricity just to bake a dozen cookies with gas power.

You don't need a huge PV system to learn to live like you will in your future COB home.  We lowered our grid power bill from ~$125 a month in 1991 to about $25 per month over time by 1996.  We got rid of phantom Ghost loads one at a time as we discovered them.  I brought home one compact fluorescent light per month until we got rid of all of our heavy energy consuming incandescent lamps (except for the coat closet).  We still have a Sears refrigerator and a Sears chest freezer and an old hand me down Sears electric dryer (we use a close line 90% of the time).  If we could afford to replace these appliances now, we would.  We would also lower our utility bill down to about $5 per month plus meter charge.  We would do this, but it is not cost effective for us to do it right now.  Instead we are working on paying off our mortgage while our son is finishing graduating from high school in three years and then we will build our new off-grid solar home on our new land in CO (with no utility access) with new highly efficient appliances.  We do have a small PV system now.  It would cost about $2,500 if purchased new now (I am an engineer and love to scrounge).  We use it as training wheels to power our washing machine, utility lights, recharge electric lawn mower & weed eater, & as backup power for utility outages (kind of handy).  When we move into our new solar home we will know how to use power wisely not because we have a PV system, but because we know how to lower our monthly utility bill as low as possible without sacrificing much comfort.

Please follow all of the links given to you, but do not feel afraid if any look too technical or overwhelming.  I sent my dear wife to a solar weekend workshop and it was great that she could now follow my conversations about PV!  I was so impressed that I sent Sheila and our 14 year old son to a local college class and afterwards they passed their Technician Ham Radio license tests with flying colors (now we don't need cell phones to stay in touch via our solar recharged ham radios).

To learn more about living on PV and more importantly how to lower your power usage, please read this great article written by a good friend of mine: Going Solar? Why Not Go All the Way? at: http://www.chelseagreen.com/Chiras/GoingGreen.htm  and Fine Tuning for Solar Electric Living. What you need to know to design a successful solar electric system. http://www.chelseagreen.com/Chiras/FineTuning.htm

After you read these articles, will be set to built the most efficient powered Cob house you can ever dream of!  (or at least know what questions to ask!).

Take care,

Dave
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David & Sheila Knapp 
Winnebago, Illinois
http://www.esolarliving.com/
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----- Original Message ----- 
From: "Shannon C. Dealy" <dealy at deatech.com>
To: "Kimberly Hoyer" <knh78 at yahoo.com>
Cc: <coblist at deatech.com>
Sent: Wednesday, April 25, 2001 6:03 PM
Subject: Re: Cob: Solar Power


> On Wed, 25 Apr 2001, Kimberly Hoyer wrote:
> 
> > This may or may not be appropriate for this discussion
> > list but I'll ask anyhow. I am looking to convert to
> > solar power. I currently own a 3-bedroom, stick-built
> > house from roughly 1930. In the future, I plan to buy
> > some land and build a cob home. I would like to find a
> > system that is compatible with my current home but can
> > take with me when I build the cob home. I have almost
> > zero knowledge of good solar systems and the companies
> > attached. I also know nothing about electrical
> [snip]
> 
> While this is kind of off topic, most people are going to want power in
> their cob house, so . . .
>