From: egn@sinix.UUCP (Hr.Naepflein/PHILOS)
Newsgroups: sci.energy
Subject: Re: SOLAR efficiency
Date: 1 Oct 92 11:36:54 GMT
Organization: PHILOSYS Software GmbH, Unterschleissheim, Germany

In article <1992Sep18.170143.5286@pmafire.inel.gov> russ@pmafire.inel.gov (Russ Brown) writes:
>In article <1992Sep16.074932.19998@sinix.UUCP> egn@sinix.UUCP (Hr.Naepflein/PHILOS) writes:
>>
>>Why do we need big collector farms? This sounds like another big
>>technology monster like nuclear power plants (don't flame me). 
>>Why not doing development step by step, by first doing anything
>>possible to conserve energy and then using the areas on roofs
>>for solar energy (collectors and PV). A institute here in germany
>>is currently building a ZERO energy house. This means it doesn't
>>need any energy in addition to what is generated by the house itself.
>>I know, that's to expensive currently, but it shows that its possible.
>
>The ZERO energy house concept has been bruited for Sweden (above the
>Arctic Circle, I recall) in the past.  Some of its "internal" energy
>sources were body and cooking heat.  If it were located underground,
>this might be workable, but that would seem to be a bit of a stretch.
>
>How would such a system be practical if mid-winter weather patterns
>involved a 2-week period of temperatures below 285K, with snowfall
>covering the solar collectors and with occasional wind velocities in 
>the 20 kilometres per hour range . . while the residents were away on 
>vacation?  Such weather is not uncommon in parts of the U. S. Northwest.
>
>Frozen water pipes could be a problem.  Getting the old homestead back up to
>temperatures suitable for bathing the baby could take a couple of weeks
>. . after one thawed the pipes.  Accelerating the pace of such
>recoveries would, of course, have to be included in the energy balance. 
>Would much electrical power be available under such start-up conditions,
>at least in amounts that would reduce the time required to approach
>normal living conditions?
>
>Details, details. 

Sorry, that it took so long, but I had to get some information first.
It's not very detailed, but it gives some impressions about the
techniques used to build the house.

The basic idea was to reduce the energy needed. This has been done
by the architectural concept and by use of extensive isolation. Most of
the south side of the house is glass. This allows to use the whole
house as collector. A further method to get additional solar energy
is to use transparent isolation, this means at day time the solar energy
is transfered to the massive walls behind the isolation. The thermal
energy needs some hours to be transfered from the outside of the
wall to the inside. So the walls are used as thermal storage and
at night when no solar energy is available they give the heat
to the rooms behind the walls. With that concept the house needs very
little energy for heating.
Warm water will be heated by highly efficient solar collectors. 
Electrical energy is generated by a large PV system on the roof
of the house. Excess electrical energy is used to produce hydrogen.
Hydrogen will be stored for use on very cold winter days, when
not enough solar energy is available. The concept of using hydrogen
as seasonal storage was only possible because the overall energy
need of the house will be very low.

I have currently no further information on the size of the house,
the collectors, the PV-System and the method of hydrogen storage.
More information on transparent isolation is available.

Here is a simple plan of the unconventional architecture:



                         North Side

                             ==
                          ==    ==
                         = ****** =
                        = ******** =
======================== ********** =========================
| ***************************  **************************** |
| ***************************  **************************** |
| ******** ##################  ################### ******** |
| ******** ##################  ################### ******** |
 %                                                         %
   %                                                     %
     --                                               --
        ----                                     ----
             %%%%%%%%%                 %%%%%%%%%
                       ---------------


                       South Side


     * Solar Cells         =,| highly isolated walls
     # Solar Collector       % walls with transparent isolation
     - glass

I hope this is enough information to get an impression on the
concept. The house doesn't cool down when the inhabitants are absent,
because the intelligent use of passive solar energy techniques
together with a control system keeps the house warm enough.

Anyway, this concept has been only simulated for the area were
it is now build, so it may fail to work on the South Pole.

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