Re: Power Supplies, Saving Money, and switching vs. Linear?

["Andrew(N)" <andrew.ward@xxxxxxxxx>]

>
> In 99% of the cases I bet the wall transformer is an _unregulated_ power
> supply with the linear regulator being internal to the electronic device it
> powers. Almost anything that uses a wall transformer with a voltage higher
> than +5V is likely to have an internal regulator. In these cases, changing
> the wall transformer to a switch mode supply will do next to nothing to save
> energy as the linear regulator will still waste the excess voltage as heat.
> The "psychological payback" is a delusion. You can get the same "feel good"
> effect by spending the cost of the switchmode supply on a cheap bottle of
> whiskey.

The move of this thread to Solar power is VERY interesting... Because
this is what I am doing.

I now have 28 200+ watt SunPower Solar panels on my roof feeding an
inverter that will take advantage of California's NetMetering regulation
which allows me to put power back into the grid. So, during Peak hours
(M-F Noon - 6 PM) I will be pumping watts back into the grid at the
elevated Rate. No storage batteriies in this system. System is designed
to be a 5 KW system. (Contractor is ReGrid Power, BTW). The panels and
inverter are installed, but these guys haven't gotten back out to make
the connection to my AC mains yet. This should be this week or next. The
panels are wired to give about 400V DC into the inverter and 120 V 2
phase out.

Either way... This is the reason for my huge persuit of power savings...
to cut the usage wherever possible, to get my savings up.

BTW... people are always curious.  Raw system cost is arouns $47K, after
California rebates, my cost is ~34K. I might be eligible for one more
tax credit totaling ~3000.  If I use power at the existing levels, and
if PG&E increases rates consistent with the past 22 years, payback is in
11 years. But, with some conservation, and if PG&E really jacks up
prices, as they are expected to do, then payback could be in as few as 8
years.

My goal is not to be self sufficient, nor to get my bill to 0. That
would be stupid. The real goal is cut off the top two or three tiers
where electricity is as high as $.31 / Kwh.

This is why I am running around with a spreadsheet and two Watt's Up
power meters measuring everything. This linear supply is hard-wired, so
I could only put an amp-clamp on it. I will try to put a cheater cord on
it for a while and re-measure the actual wattage soon.

Thanks everyone for the interesting discussion.

-Andrew