[mythtv-users] [Slightly OT] solar power for all our gadgets

Jeff Walther trag at io.com
Mon Mar 9 14:39:18 UTC 2009


> Date: Sun, 8 Mar 2009 17:48:42 -0700
> From: Marc MERLIN <marc_mtv at merlins.org>
>

> Now we're pretty off topic, but the best investment you can do with your
> money today is solar panels if you have a house: currently in CA with the
> brand new uncapped federal credits, you can get solar for 50% off.
>
> That's what I did and my bill will now be around from now on. It'll take
> about 5Y for me to break even, and around 8-9Y for the system to pay for
> itself. From then, on, I get about 20Y of free electricity.


The idea that solar panels pay for themselves is such a myth (not the
*good* kind of Myth) in most locales.  But it does depend on what you pay
for electricity.

Anyone who decides to install solar panels should do a very careful
examination of the costs and benefits before committing any money.

I recently wanted to install solar panels on my house.  The city (Austin,
TX) will pay half the cost.  Here is what I found out.

An installation with a nominal generating capacity of 3000 watts will cost
about $27,000, installed.   The city will reimburse for half of that so
that my cost is $13,500--but the poor tax payer footed the bill for the
other $13,500.

While you might expect that 3000 watts of capacity would yield
approximately 3KW X 12 hours/day X 30 days/month = 1080 KWH/month, the
reality is that you'll get about 400 KWH/month if you're lucky.  Further
north, e.g. in Ohio, you could expect 300 KWH/month.

Our marginal rate for electricity (the higher rate we pay after some base
usage) is $.12/KWH (Including fuel charge).   So that 400 KW/month will
yield about $50/month if I'm lucky.

Have you ever tried to pay off $13,500 at a rate of $50 per month?   At 5%
interest, the interest would cost more than the rate of return.  And
that's ignoring what you just cost the taxpayer.

Furthermore, the idea that all of that $50/month is available for paying
down the cost assumes no maintenance cost.   Anyone who has been a
homeowner for more than a few years knows that no matter what they tell
you, everything has a maintenance cost.   If nothing else, one must wash
the pollen off panels when things are blooming (yellow oak pollen here)
and dirt after dust storms.

Anyway, this topic kind of chaps me because I frequently hear the media
non-critically hyping how wonderful it is to have solar panels, and the
fact is that anyone who can do simple math (and doesn't live somewhere
with really expensive electricity) can see that they make no economic
sense whatsoever.

Jeff Walther




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