Subject: Re: Solar Powered Forges

From: [email-masked] (Katana ---/-----------)
Date: Tue, 10 Sep 1996 18:12:27 GMT

> 
>I am a designer of high powered solar heliostats. My prototype 
>is not designed for high temperature but it can produse high  
>temperatures and high poweres when needed. 
> 
>My design is using 180 square foot of mirrors that reflect the 
>suns power onto a receiver at the rate of about 10KWatts  
>including all the losses, if no losses it would be 18KW. 
> 
OK - serious consideration here: 
1. You're talking 80% efficiency here || power out/power in 
    Where are the losses ? - let's figure out how to reduce the losses. 
2. If most of the losses occur in the mirrors, it's possible to use gold
surfaced mirrors with 
   a silicon monoxide overcoat (to protect the fragile gold plated surface)
that have a high  
   degree of reflectivity in the infrared. If you're just talking the
visible light spectrum, there 
   are coatings to give you 98% reflectivity. 
 
>-- 
                                                  Bill Wyant 
   Bladesmith / Art Blacksmith / Past President, Ft. Wayne Astronomical
Society 
                                    Avalon Ironworks, Ft. Wayne, IN 
                                        [email-masked]

---

From: "Duane C. Johnson" <[email-masked]>
Date: Tue, 10 Sep 1996 14:07:19 -0700

Hi all;

> >including all the losses, if no losses it would be 18KW.

There are other considerations besided just the reflection of the mirrors 
in the visoble spectrum. A heliostat also has an average cosine loss caused 
by the mirrors mot being normal, flat, to the sun. Another loss is reradiation
energy loss.

>     Where are the losses ? - let's figure out how to reduce the losses.

I am only saying I have 55% efficiency. 10KW/18KW = 55%
I am also being very conservative with my power estimates. This way I
may be plesently surprized when I get more than I expected.

I have been working a long time on cost reducing my systems. It is posible 
to increase the reflectance of the mirrors but it is expensive. I find that
my glass mirrors, which cost $1.34 per square foot, are much more cost effective
than are the other type which start at around $5.00 per square foot. It is much
cheaper to just put up more mirrors than to increase the reflectivity.

>    are coatings to give you 98% reflectivity.

Again not cost effective. I am using 1/8" conventional rear "silvered" glass
mirrors. The glass is easy to clean a couple of times per year without scratching.

BTW I am fond of saying the big boys are not powered by the sun. They are powered
by government dollars.

My first goal was to generate electricity at a cost less than that produced by the
grid. I think we can do this. I know we can produce heat at far below the cost of
natural gas prices. 

I would like to learn how to produce forge temperatures as a demonstration of how
much power can be atained from solar.

Check out my website for more info on how my systems work. 

-- 
CUL8ER

Duane C. Johnson
WA0VBE
Red Rock Energy
1825 Florence St.
White Bear Lake, MN, USA 55110-3364
[email-masked]
[email-masked]
http://www.geocities.com/SiliconValley/3027/
(612)426-4766 h  635-5065 d