[chbot] Solar panel, side reflectors

[GRAHAM CHRISTIE]

Those Fresnel lenses can be fun to play with, I had a 1000mm diameter one and it was instant flames on wood, melting tar seal, plastic bins and pity help any skin, actually a bit dangerous.

Regards
Graham

>     On 14/12/2021 22:55 Robin Gilks <gb7ipd at gmail.com> wrote:
> 
> 
>     I was waiting for his shirt to burst into flame as he waved that big lens about :)
> 
>     If he is as stingy with his facts on this one as his last video with the hot water heating vs PV then a good hard look at the overall system costs would be appropriate.
> 
>     PV for hot water:
>         * uses existing cylinder
>         * uses existing heating element
>         * built in backup if no sun
>         * only requires a DC rated contactor with the existing thermostat
>         * cables are easier to run than pipes
>     Thermal for hot water
>         * needs a new cylinder
>         * expensive pipe-work to the roof
>         * steam vents required for when max temperature reached
>         * controller with sensors in the cylinder and on the roof
>         * frost protection or antifreeze and an even more expensive indirect coil cylinder
>         * mains power required for a pump (unless one of those tanks on the roof systems is used - not good in an earthquake zone!)
>     Based on current pricing a 3kw equivalent system has the PV at less than half the price!
>      
> 
>     On Tue, Dec 14, 2021 at 9:53 PM Mark Atherton <markaren1 at xtra.co.nz mailto:markaren1 at xtra.co.nz > wrote:
> 
>         > > https://www.youtube.com/watch?v=FKhszB4E1_M
> > 
> >         Quite an interesting video.
> > 
> >         -Mark
> > 
> >         PS don't forget the Robotics Xmas special coming up on the 20th Dec.
> > 
> > 
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