Tuesday, November 15, 2011

We Don't Need Your -Stink'n- Electricity!

Oh, what a dream to be 'off the grid'.  I don't see it happening any time soon because we are living in rental houses and home owners just aren't so accepting of the idea of you installing many thousands of dollars of equipment into their house and cutting into their electrical junction boxes and such.

I would just love to get enough solar panels for a backup though.  I'd be just giddy as can be if I could have a small system all set up where if we lost power I could just carry out the solar panels and set it up, let the batteries charge up and run some critical systems off the inverter while we're out of 'grid power'.

Maybe make the system just large enough to keep the refrigerator going, the microwave and some portable fans for cooling (the air conditioning would just take too much intrusive wiring into the house electrical system).  The microwave, refrigerator and fans though could all be run on extension cords from the invertor without any big issue at all.  It'd be fantastic to know that you won't lose everything in the freezer/fridge if the power goes out for a day or more.  Or to know that you can still cook food and boil water without any electricity.

I've been researching electric and wind power for months now.  Once I got past the 'fear of change' and procrastination and actually started to research it; I was shocked at how simple it really is.  You can go DIY style and buy solar cells on eBay and solder them together yourself and make/buy your own frames for the solar panels; or you can just buy the panels already made up from the factory on eBay as well.

You can make them cheaper of course.. .for like $160.  But that's a homemade frame that might leak when rained on and it's all the work and possible mistakes that comes from DIY work too.   You can buy a brand new 100 watt, 18.5 volt, 5.55 amp

I want to throw up some pictures and the procedure on how to do some of this work yourself.  You'll see just how easy it is to get solar power cranking in your place too.  I'm not going to get into the process of hooking it into your house.  I'm just going to show you how to make a small system that can go with you camping or in your RV or just an emergency system like I mentioned above to get you by until the grid comes back online.

Step 1:

Check out what area of the country you live in and see just how smart it would be to look to solar power vs. other options.  I'd say in Michigan you'd better for sure include a wind power generator into the system because most of the time you can't see that bright burning ball in the sky.

As you can see.. where we live in Arizona we get a crazy amount of sunshine.

Step 2: 

Determine what you want your system to run.  Refrigerator and microwave and some fans?  Do you want to include your coffee machine?  How about your television so you can keep up on the news?  Maybe some extra available power for charging cell phones and laptops and various other things?

There are many different charts you can find within 1 minute of a little Google-ing to help you add up the power usage of most appliances in your home.  Just add up all the items you want to be able to use so you have an idea of then; how big your system needs to be in order to meet your needs.

Appliance Chart

The above was a screen capture off a website.  You can find the original ( here ).
These items won't be used all the time.  Like your microwave.  Wow.. 1500 watts?!  Oh.. but you're only going to use it for 1 hour of the day.  You need your invertor large enough to supply for peak usage, but your battery bank doesn't need to be massive because that 1500 watts isn't going to keep draining your batteries for hours.. just a little at a time and your panels will start recharging the batteries between uses.

When off the grid.. all those tree-hugging earth-worshiping cultist suggestions actually become important.  Unplug that/those items that are not being used.  Save your power.

Just add up the items you want to be able to use.  Keep in mind that some items may peak on startup.  To start a motor or equipment the amps sometimes double until it is up and running.

Also a small hint:  Turn off the warmer plate on your coffee machine just as soon as it's done percolating and making your pot.  The hot warmer plate is a massive drain of power.  Make the coffee, turn off the coffee maker (unplug it even), pour your cups and enjoy.

Step 3:

Design the system size you need.  In my example above we have:
  • Refrigerator: 540 watts: It only runs about 4 hours a day though.
  • Microwave: 1500 watts
  • Table Fan: 25 watts x 4 = 100 watts
  • TV: 25" color: 150 watts (need to get rabbit ears for non-cable reception).
  • Incandescent Lights: Just add up wattage on the bulbs.  Here might be a good place to listen to the earth-cultists again.  Those Compact Fluorescent or LED lights are a fraction of the wattage usage.  I'd say 300 watts for lights. (emergency lighting here.. not having the whole house lit up).
  • Coffee Maker: 800 watts
Like I mentioned above, these wattages are not just added up.  That coffee maker with 800 watts is only used 15 minute of the day.  Instead of an 800 watts for a daily use.. it's far less (375 watts daily usage).  But you have to plan your invertor based on the 800 watts so that it can handle the demand and not blow/trip your fuses.

So.. add up what I have above and use the load evaluation pdf file on the website listed above and get your total load.  Ours would be: 12,486 watt-hours/day.

Holy Cow!  I didn't realize it was going to be that high.  Jeepers.  Looking at the pdf file that you make up off that website when you're entering your appliances, wattage and hours used.. you can really see what takes up your wattage in a huge way.  The refrigerator is like 60% of the power usage.

Maybe it would be a good idea to just get a little mini-fridge and we just shove the emergency items into the mini-fridge and use that instead of having the big 20 cubic foot fridge.  Wow.. what an electric pig!

Step 4:

Take your watt usage peak (add up all items that will run at the same time and double that), that will be the size of the invertor you need.  In our case: about 6,000 peak usage.  It'd be smart not to run the microwave, fans, all the lights, the coffee maker and the fridge at the same time.  It'd be very simple to just make a family rule:  Don't run the coffee maker and the microwave at the same time.  Problem solved.  Just use a 6,000 watt peak invertor.

A 3,000 watt use / 6,000 watt peak invertor I found for sale at eBay for about $225 (including shipping).

Boost Inverter

Step 5:

Now you need to find out how many/what size solar panels you need.

You can pick up a 100 watt solar panel for about $225 each.  A 100 watt solar panel will charge your batteries 100 watts for each hour of sunlight.  The sun though isn't up and useful 24 hours a day.  So you have to plan for only about 6 hours of sunlight (here in Arizona) where the sun is right above and just dishing out the power if you're ready to use it.

So.. 1 panel that puts out 100 watts will give you 600 watts of charging power into your batteries per day.  If our need is 12,486 watt hours per day.  Using online calculators where you put in your data and it tells you how many panels you will need it says I need 8 panels.

But in reading it's calculations it's assuming you will need to charge up for 3 days worth of power.  It's taking into account using solar power in areas of the country that doesn't get as much sun as here in Arziona.

I think it's safe to trim that down to 3 panels instead of 8 if you're living here in Arizona.

Solar Panel

$225 for each panel x 3 panels = $675

Step 6:

Next we need a Charge Controller.  This will control how your batteries are charged from the panels.  It will slow down to a trickle charge when the batteries are almost fully charged, etc.  It also keeps power from coming back into the panels when it's dark and power naturally wants to flow back through the circuits into the panel.

Each panel puts out about 6 amps.  So with 3 panels you are putting 18 amps towards the batteries from the panels.  You need to know this so you can size your charge controller so it can handle the amps you are using.

A 20 amp (just a little larger than your 18 amps) can be bought on eBay for about $93.00

Charge Controller

Step 7:

Last, but not least.  Decide how many batteries you need.  6-volt batteries have many bonuses in these systems.  The main one is that they last longer and function better when they are cycled.  If you drain them down and then recharge them..they hold up better.  A 12-volt batter like is in your car gets real annoyed with you if you keep draining it and recharging it.

So what you do is buy 2 6-volt batteries and link them together with cables.  This makes a large 12 volt battery; but it is made out of 2 s-volt batteries which don't mind your recharging them frequently.

Problem is the 6-volt batteries are larger and then on top of that you need two of them.  So, they take a lot of room.

Checking out battery calculator programs on the internet to figure out how many batteries you would need for our system we would need.  Much of this varies so much because of the type of batteries that you buy.  How many amp/hours the batteries are rated at, etc.

If I choose the highest quality/rating of batter we'd need 3 groups of 2 batteries. Wow.. searching the internet I can get brand new marine batteries (6 volt) for about $230 each.  6 x 230 = $1380.

So.. our grand total:

Inverter: $225
Controller: $93
Panels: $675
Batteries: $1380

We could run our full sized refrigerator, a microwave, a coffee machine, fans and some lights indefinitely (the grid could be completely down).. for about $2375.

Seems like a big pill to swallow doesn't it?  What if you plugged it into your house system with a little different wiring and then you could trim $100 off your monthly bill from the electric company?  About 2 years and it would pay for itself.

You'd have the peace of mind knowing that you're covered if the grid went down and then you'd be making $100 profit every month (reduced electrical cost from the electric company every month)... take that $100 and put it aside for expanding your system.... maybe you can be completely off the grid after a while and then actually have a 'job' where the electric company pays you money every month.


I just love doing the planning and math and calculating; even if it never happens.  I like to know how and that it is possible.

Side Note:  You can buy a $200 kit with 1 panel, a small charge controller, and invertor.  It's a little system that's just set up for 50 watts.  Something like your laptop can be run off it, charge your phone, etc.

Summary:  I hope you enjoyed my little research project and have found that solar isn't all that confusing after all.

1 comment:

obatomy said...

Great article. I have thought about this myself. It would be great to be completely off the grid as far as power and water are concerned. I have even looked up some real estate listings online of some properties near here that have well water and a septic tank, and it wouldn't be that hard to add a solar panel. Just something I am tossing around. It would have its value certainly. Best wishes.