[XCSSA] Solar and Green events in SA

[xcssa@xcssa.org]

On Tuesday 15 May 2007 14:27, xcssa-admin@xcssa.org wrote:
[...]
> WRT solar water heat, I'd like to talk to more people about that,
> such as that the Green event.   But based on the web research I've
> done, it's not as much a clear win as it seems.  Among them, there's
> a load balancing and "vacation" problem.  If you make the collectors
> too big, it's going to be getting too hot.  Once all the water is at
> maximum temperature, you have excess heat.

Why not just have a simple bi-metal thermostat valve engaged heat exchanger.. 
Just like in the engine of a car.  The water hits like 180.. and the thermo 
valve "pops open", giving a secondary route for passive cooling through a 
convection, radiator/air cooler.  Simple.. passive.. closed loop(s).  It 
could even be designbed to have a secondary higher temp "emergency valve" 
that trips at 210 (well below boiling for pressurized, coolant mixed water).  
And then.. your fail safe is a high temp/pressure blow valve..  Triple 
safety.. no active components.


> It's not to say that better water heating couldn't potentially be a
> very big win.  The average person in the US uses nearly as much
> energy heating water as powering their car.  Look at your electric
> water heater and be amazed by the annual cost estimate.  And kW water
> heating panels are a tiny fraction of the cost of photovoltaic.

I think that's a good two pronged approach..
Use a daylight only PV system (no costly/toxic batteries) feeding juice back 
onto the grid during the daytime, coupled with a hydro-thermal system to 
supplement/replace the hot water.  I bet that would but my eBill by at least 
75% each month. Hmmm...

> But [solar water] manufacturers are few and far
> between, mostly cheap looking, and they heat slowly.

Doing my own sounds like more fun.. :)  Cold also help me beef up on my 
thermodynamics...

BTW.. A really good resource for this kind of DIY, roll you own stuff is the 
Hippie-Granola zine called "Home Power":
	http://www.homepower.com/

It's pretty cool.. and you can pick up a copy at any Borders to the left and 
right of the 'pooter mags (not sure if B&N has it).


> It was thinking about all these problems that made me think, "I'll
> just up my Windtricity.  That's far easier.  Then I'm carbon- and
> pollution- free without all the troublesome and/or expensive
> hardware." 

You're just paying for infrastructure for bankers to make future revenue with 
man.  DIY! 

> I know it's no panacea, which is why I'm still looking 
> into other opportunities.

Sounds like a good comprehensive presentation subject for XCSSA Charles! 
hehe..
And uhh.. computers.. computers.. Ah!  Yes!  A Linux box could function as the 
controller and PV voltage feed monitoring system! hehe.. there we go.  Now we 
have XCSSA justification.. ;)

Tweeks