Monday, February 3, 2014

The big solar No-No !!

This short posting is going to be about the big Solar No-no. That is particularly concerning off-grid, but still applicable to the general idea of solar derived electricity.

Yesterday evening I had this discussion with a local woman about the Tiny House and it being solar powered. She made the comment about knowing very little about solar. I knew basically nothing about it when I dived into it to power my home.

One thing she said really struck me. "My co-worker believes that you cannot run electric heaters with solar and that it isn't entirely viable." Or something very close to it.

I am a happy, go with the flow sort of man. However, this struck me. Unbeknownst to me, a man living in a small home with a large solar array, did not realize that my usage of Kettles (1500watts), 42inch tvs, super computers, and even the SIN OF ALL SOLAR SINS, electric resistive heating.


It brings to memory, Elmer Fudd. He is chasing a raskly rabbit off a cliff and Bugs turns and explains gravity to him, where upon he plummets in a yelp.

Oh, bother!

I tell you, here is how it works for me. I have 2000 watts powering a place that uses 2KWH typically a day. (Kettle, tv, internet, lights, electronics aside from space heating). My battery holds 5kwh. So, I use half its capacity until the next day when the glorious Colorado sun charges them back up again. Mostly before I get up at 10am.  You see, I am only using 20% of my available limit. With 5 peak hours of sunlight in Colorado here. I should be able to harness 10KWH. But. I cannot hold it. Once the system puts in the 2 I used, plus the inefficiencies, That is it. No more juice coming in other than covering what things I have on at the moment.

All winter I have been thinking about what to do with my excess energy. I'n a grid home, you want to conserve. It costs you money. In my off-grid home, if I do not use the available, it is wasted to me. It simply heats up the earth outside. My idea is to build a gazebo with plexiglass windows around it and a hot tub in the center. Divert the excess power to a heating element int he tub when the batteries are charged. I would love to sit in a hot tub on the mountain here while it is blizzarding.

Back to this oil filled-electric radiator style heater I have. It uses 1500 watts. So if you ran it 24 hours a day it would use a whopping 36KwH or about $4.50 a day or $130 a month. So, yuck.

Most of my heating is through passive solar and the fireplace. All lovely things.

On a sunny day, which up here is basically every day, I might as well toss on the space heater to warm up the inside a bit quicker, then allow the sun to hold it. Letting the heat be absorbed inside the home for later in the evening.

I am still able to harvest sunlight till a little past 4pm now. What I will do is wait til the battery is fully charged, then toss on the heater, then set my alarm for 3pm. At 3, I'll shut it all down. The battery is left to float. If there was a disparity between consumption and production, that last hour will take care to have the batteries full by evening time.

From then it is onto Fireplace heating.

What does this mean? My daily usage shoots from 2 to nearly 9! No worries. Im using it nicely.

This week was a lot of clouds and snow. There is a foot worth on the field. I grew tired of brushing off the panels. Even in cloudy conditions they still produce something, but when covered in snow, forget it.

I went through 3 days or Cloudy/snowy weather, collecting maybe 1kwh a day. All with a 5kwh battery. The only thing I changed was to not use the big tv. Just watched Netflix on my mac air instead. When the system was fully charged. It took a little over 3.5 kwh.

Pretty darn good. It is all about having overhead. Done intentionally to keep from needing a generator. Plus having a battery chemistry that doesn't care if you do not have them fully charged on a daily basis.

The lighting I use is all LED. When I was in Michigan, I purchased a Philips bulb for $50. It was the first government L-Prize winner. For highest efficiency. 94 lumen per watt. This thing is bright. 940 lumens. A gorgeous incandescent warm glow. Uses 10 watts. Basically replaces a 75Watter. It states having a 20 year life. Now that is generally laughable. Especially with CFLs. However, this bulb was built in the US, so I think it has a fighting chance!

The next bulb I use is a little less efficient. 800 lumens for 11 watts. 72 lumens per watt. However, it was purchased at Walmart for $7 buck. It is also a warm color. I was surprised at how nice it is. I do not expect it to last that long due to cost and cheap walmart goods. BUT. When it does fail, take it back to Walmart and get a replacement. So, it doesn't matter.

Lastly, I use Christmas LED strings. When I do not want to have a bright light in the house, I leave the string lights running. It creates a nice colored glow inside that provides plenty of light to function once you acclimate to night time light levels. Plus, it only uses 5 watts or so. Great for Off-grid batteries.

Finally quality lighting is cheap enough to replace all your fixtures and compound over time.

- Thanks! Cloud

Heater, Kettle, Cork floor (not glued yet)
Outside conditions
C.C. Happily Keeping Up.
Cell Voltage
Battery bank @ cell connection

Recharging at 75F
Recharging at 10F

Philips - L Prize winner 94Lumen/watt -$50

Walmart LED - $7

LED Christmas Lights - Night Time Ambient


  1. I love reading how your solar power is working. I suppose you need to push the usage so you know where your limitations are.

    1. I imagine it would be if I ran the Kettle AND Space heater at the same time. 3000 combined watts per hour. At the moment, I have both of them on the same power strip so it would trip. If I plugged them both into the outlet directly with the 30 amp breaker... Im sure I could tax something.

      My inverter would be busy pushing the fan to deal. But it is big enough to do it. It is 3600 watts continuous and a bit more for short durations or surge loads such as a fridge kicking on.

      A kettle is only on at most 7 minutes to boil a full liter/liter half which is only 2-300 watts/hours.

  2. We always used LED rope lights on our AZ porch. I love all the light they put out, they're cheap, and they look so neat. You might want to consider them as a replacement for the Christmas lights some day. Or not. Tell Kiki he looks bootiful with that bow in his hair :-D

  3. Your concerns about wasting a resource that is renewable tells a lot about you. I think your no-waste and calculated frugal living should be emulated by everyone. That way, they can live their lives to the fullest using only what they need, without ruining the environment. Thanks for sharing how your power system works! The cat is adorable, by the way.

    Jason @ Sunshine Renewables

    1. Thank you, Jason. It's amazing how with even the inefficiencies of solar panels, there is still usually enough space in a persons property to have an energy hog of a home. IE, toss up enough panels to not even be 'non-wasteful'.

      You can generally keep your life the exact same way with little change to it.

  4. Thank you so much for posting. I have been looking for something like this.Solar Panels for sale