7 Cent Solar Power for my House

by Neal Dikeman

The other night I answered an ad on Craigslist.  Not surprising, since  buying and selling things on craigslist is kind of my hobby.  But this one was for solar panels.  180 Wp panels from a wholesaler.  Offering for $190 ea if I bought one, or $180 if I bought 20 or more, and $170 if I bought 100.

Not name brand, but 17% efficient monocrystalline 180 Wp 25 year warranty product.

Holy smokes, residential panels for $1/Wp?  So, add 3.5 kW inverter for $2300 (list price off the web of a name brand inverter), and a bit of steel and mountings and labor, and I can put 3.5 kW of PV on my roof for <$9k UNSUBSIDIZED?  Without getting fancy on the math, that’s an amortized cost of 7 cents a kwh at the warrantied life, cheaper than my 11 cent Texas power now.  Payback’s weak, c 13-15 years, again thanks to my cheap Texas power.  But knock a third off in tax credits, add some back for inverter replacement and contingencies, and damn, this is really, really close. Payback maybe down into the 8-10 year range with a little luck and good design.

Kwh/kW/Yr                  1,500
kW 3.5
Kwh/Yr                  5,250 3.5 KW Panels  $          3,500
3.5 KW inverter  $          2,300
$/Wp Installed Cost Installed Other materials  $          1,000
 $                 2.50  $           8,750  $          6,800
Labor  $          1,950
Avg Degradation Factor over Life
Yrs Life  Total Kwh Life
25             18,125
Amortized Cost / Kwh
 $             0.07

I think I may need to get a couple of bids for my house.

And if you think this is just because I’m looking at wholesale numbers, GreentechMedia did a review of module costing estimates for 2013, WAY down, below 70 cents a Wp, which would certainly support this case.

So let me put it this way:

When it comes to solar photovoltaics, we may not be quite there yet on costs.  But we’re awfully close.  This is real.  Not just for top tier time of use pricing in California.  But for the Texas Gulf Coast.

And it’s here now, not aspirational.  And it really is a gamechanger.

Right now the solar industry is in the throes of overcapacity and price wars, and struggling to make margin.  But those capacity wars are wringing the weak players and the high cost ninnies out of the market.  Making everyone get lean and mean.

By 2015 at latest we’ll likely hit our cost real tipping point for the mainstream end user.  Even with cheap natural gas.  And when we do, manufacturing and install capacity will not be able to keep up.  We’ll have another war on our hands.  The war for the home power bill.


6 replies
  1. Jacob Silver
    Jacob Silver says:

    We have to really try to go solar for all of our electrical power. The full exploitation of the tar sands in Canada, with our forests in the present state of meagerness, and with 45,000 coal fired electrical generating plants still operating will spell doom for our species after 500 or so years. But it solar panels are decreasing in price, and more solar collection places are built, and the grid is adjusted to absorb that power, and we replace all fossil fuels, and we persuade Canada, Russia, and China to follow suit, and we all reforest, then we will have a chance for a future.

  2. Douglas Hvistendahl
    Douglas Hvistendahl says:

    PVT, where the heat is also used, reduces the payback time greatly, provided you have use for the heat. Here in North Dakota, some of us are putting summer heat into the soil under the building. Under my house, after some years of doing this (by blowing summer air through the basement to provide cheap cooling for the house (PS use a dehumidifier)), the soil two inches below the basement only dropped to 52 deg F. Before, the dirt under this old house would be frozen several inches thick in midwinter. No more frozen pipes! And the heat bills are reduced by enough to be noticed. PVT heat could be used also at somewhat larger cost.

  3. @jwrgorman
    @jwrgorman says:

    Very Cool. Do you know that the system you installed is performing up to spec? That's how you will be sure of that ROI. We are developing open-source monitoring software that can chart your solar production and also home consumption, and it's talking to an increasing number of solar grid-connect inverters – here's an SMA 10kW:

    if anyone is interested in contributing to this software project and knows OSGi development – take a look at SolarNetwork here:

    Thanks, John

  4. Alvin Sedano
    Alvin Sedano says:

    When you are serious about your move to solar energy and begin using panels that sink more than 6 watts, invest in a solar controller. These small controls help maximize the efficiency of the charge cycle and prevent any wasted overcharging from occurring. When there is a lot of energy at stake, these are a must have for your solar-home.’

    Have a look at all of the freshest short article at our own internet site


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  1. […] from a wholesaler.  Offering for $ 190 ea if I bought one, or $ 180 if I bought 20 or more, […] Cleantech Blog TAGS:  Cent, House, Power, Solar This entry was posted on Thursday, July 12th, 2012 at […]

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