Photovoltaic Panels Almost Cost Effective

I have mentioned in the past that I would dearly love to go photovoltaic--it just is not cost effective here until the purchase price gets down to $2 per watt.  I see Wholesale Solar offering Trina 225 watt panels at a price that comes to $2.00 per watt.

A few gotchas:

1. The 225 watt rating is an optimal output.  They admit elsewhere on their website that a more realistic output is 200 watts.  (What a gratifying concept: honesty from alternative energy vendors.)

2. That of course is the price of the panels alone.  You still need inverters and a grid-tie, or a battery backup system.

Still, this is beginning to get attractive--and the tax credits make it more attractive.  There is still a big chunk of capital involved here.  As an example, our last electric bill was for 677 kWh, at about 6.5 cents per kWh.  A pallet quantity of the Trina 225 watt panels would produce about 4 kW, and cost $9000.  I expect that a fixed panel array (not the rotating scheme that I was experimenting with before I found out that there is no real interest in alternative energy systems) would give me at least 32 kWh per day (or 960 kWh per month) for most of the summer, and maybe 12 kWh per day (or about 360 kWh per month) on average in the depths of winter.  That means that for most of spring and fall, we would produce enough power to be self-sufficient, and in summer, we would run the meter backward net--and actually quite impressively backward.  In winter, we would still be consuming power from the grid--and often for many days on end, we would be producing no electricity at all.  I am quite sure that a grid-tie system of this size would probably mean no net electricity bill each year.  Since we spend about $700-$800 a year on electricity, even $12,000 invested in panels, inverters, and grid-tie, would be equivalent to about a 6% return on investment.  (Of course, 30 years from now, those panels are likely to be producing quite a bit less power than they do when new.)

A battery system would be attractive from the standpoint of self-sufficiency--although battery systems are expensive and require frequent maintenance.  If you are expecting the end of civilization (I mean, other than the one scheduled for May 21st that I keep seeing on billboards), this would be worth it.  It would take a lot of batteries, however, to carry over the summer or even fall surplus into winter.

Wholesale Solar does offer a "starter kit" using one Trina panel and an inverter for $729, which they advertise as $556 after rebates and federal tax credit.  This is cheap enough that it might be tempting to give it a try to see how effective it was.  At a minimum, 200 watts continuous at the height of summer would go a long ways towards covering the demands of air conditioning, which is mostly needed, shockingly enough, when solar power is at a maximum.