Cheap DIY Solar at $0.09/watt


There are a lot of silly DIY solar scams out there, but here’s the real deal.


  • An average electric dryer run uses about 3.3 kWh of electricty
  • An average home might run 150 dryer loads per year
  • This equates to roughly 500 kWh per year for drying clothes

Let’s say you wanted to “go green” for your laundry drying needs by “going solar.”  How much solar PV would it take to dry this much laundry?  According to the PV Watts website,  a 500W (0.5 kW) PV system would yield about 612 kWh in a year here in Minnesota.  That’s a bit more than the dryer is taking, but panels are commonly 230W these days, so let’s round down to a 460W system, and say it’d net somewhere around 500 kWh in very round numbers.

Hm, or you could just not use your dryer, and hang your clothes outside!  How much might that save vs a solar setup?

Ok, you can’t hang up clothes in a Minnesota winter.  So let’s cut the potential in half – 250kWh/year of clothesdrying in the summer, and this would take about a 230W solar array to compensate.  Let’s say $8/watt for a solar install – really, for a small job like this it’d be more, but again, round numbers – this leads to about $2000 for a panel, inverter,  installation, and hookup.

Or – you could spend about $20 on a couple of retractable clotheslines [amzn], and have the same net effect, plus the zen-like serenity attained by taking a little time out to do a simple task like this outdoors.  $20 for the equivalent utility of 230W of solar … at $0.09 per watt!

(This really is a fine example of why any good solar installer will tell you to do everything you can to conserve first – it’s much, much cheaper!)

8 thoughts on “Cheap DIY Solar at $0.09/watt

  1. As for winter drying here in the Kansas winters, I find that a line by the woodstove works well too. Though I haven’t done the $/watt analysis, I’m sure it’s cheaper than any dryer. Plus, for shirts and such, I find that a couple of rods with several hangers works well, especially if you shake them out before hanging, which prevents most wrinkles and precludes the necessity of ironing, further saving time and money. Smiles!

  2. Nice post. I hang my laundry out to dry for as long as possible in my southwest Ohio city. The cost of my labor to hang out the towels, clothes, sheets, etc is unknown, but it is enjoyable, everything smells better, and the sun and wind are free. And this free energy is the thorn in the sides of big energy. Too bad. Line drying requires no fabric softener or anti-static dryer sheets, nor starch, and so no fake perfume smells, but rather just some bare feet and a little effort. I’d rather expend some of my labor than spend my money on a bunch of toxic-smelling laundry aids.

    You can dry in the winter, but it takes 2 days on the line. I’ve seen Amish clotheslines with towels frozen like boards!

  3. It works when you hang things up indoors too. Usually much better when it’s cold and rainy in the middle of winter.

    We Aussies find it strange that the US has so many Dryers… then again… in the middle of summer I can almost start taking the washing in immediately after hanging it out…

  4. Heya Stewart –

    Well, we have moisture issues in the winter… line drying indoors would probably just rot the house from the inside, unfortunately.

    FWIW it was 95F here yesterday (shattering a 100+ year old record by 7 degrees F…) and yep…. clothes dry quickly. Upside to global warming I guess. ;)

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  7. Certainly, but people need to realise that adding Solar in their home is an asset that should increase the longer term valuation of their house if / when they come to a decision to sell. With the environment the way it is going we simply cannot underestimate any solution that delivers zero cost electricity at no cost to both the shopper and more significantly the earth!

    • Well – no doubt, but it’s important to realize that if we’re going to meet a large portion of our energy needs renewably, we need to tackle it on both ends – consumption and production. I hang laundry in the months when I can, and I have as much solar on my roof as will fit. The combination of conservation & clean production means I make 75% of the electricity our home uses. If the goal is to be easier on the earth, the easiest and simplest way to start is with conservation, IMHO.

      Tacking 4 solar panels on a McMansion in the suburbs is better than nothing, I guess, but it’s a little like lipstick on a pig. We need to look at it holistically…

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