Off Grid electricity is NOT free.

Out with the old… The T-105’s are being retired.

I believe I am guilty of promoting free energy on the off grid homestead, and during the summer months it appears that way.  However, during the winter months cloudy skies make solar energy creation improbable, and it’s the battery bank that keeps the home’s electricity going from day to day.  When the fog and inversion continues throughout the week, a 5 gallon jug of fuel is added to the generator. The generator is fired up to produce the home’s power and to fill the battery bank for a few more days.

Winter is the time of the year when an off grid home realizes they are not living “free”.  Perhaps a nice sunny equatorial home would provide the energy the home needs and less reliance on a large battery bank.  But even then, a home close to the equator has a constant 12 hours day and night. In which the daylight begins at 6 and ends at 6 in the evening.  If only we lived on the equator… but I really like the 4 seasons, so that’s out for now.

If you are thinking about going off grid, depending on where you live and what your winter is like as far as darkness and climate, you will want to size your battery bank accordingly.  Our new bank, if we conserve, can get us about 4 days, without direct sunlight.  We have added so many new systems that require more power and we added to our family another person, so power usage has naturally increased.  More lights are on, our fridge runs more often, and the phantom load of the Internet and the propane tankless water heater begin to add up over a few hours.  If I remember, like I just did, I shut them off.

As seen in the video,  I crunched the numbers and our new battery bank (basic electric bill) is estimated at $25.00 a month over a 10 year period.  That’s not bad, but that doesn’t include the generator maintenance or the fuel for it.  A 5 gallon jug is required to charge the battery bank from 50% back up to 100% and to equalize them.  Without equalizing, it’s about 4 gallons of fuel needed.  I am keeping tabs on our generator usage this year with the new bank and tractor generator; it will be nice to be able to prepare a constant monthly budget by spreading the winter expenditures year round.

Off grid electricity is NOT free!

If my wife and I lived on the grid in this area and had solar panels that covered our electrical usage, the power company would still charge us a $25.00 minimum monthly hook up fee.  That doesn’t seem fair, but with many people trying to save money with increasing electrical bills the power companies do not want people wiggling out from their profit margins, plus someone has to pay for all those linemen who repair the down wires after a devastating storm.  Either way off grid or on, you will have to pay someone for your electricity.  As electricity bills increase, so does the price of batteries. The T-105’s I first bought were $155 each in 2011; this year they are $180 a piece.

If you are thinking about supplementing your on grid home or building an off grid power system, now is the time to start because prices are always going up.

When the Battery Bank Dies…

At the end of this past summer, our battery bank of seven years decided to die.  It was an interesting cascade failure event.  One batter cell went dead and could not be revived, then another battery flagged a similar problem.  Pretty soon I was isolating batteries that would no longer hold a 6 Volt change.  The isolation meant I had to drop from a 3 string battery bank to a 2 string system.  I ordered the batteries at the perfect time.  The sun was shining well into September which carried the system long enough until the replacements arrived.  I was happy to receive them, another few weeks and we would have been in real trouble, running a generator to make due for the lack of electrical storage.

The video published was in a file waiting to be edited and published.  I admit blogging and YouTube videos which have grown intertwined has dwindled, and I discussed that briefly on another post.  Currently, I am enjoying Christmas break and I am gearing up for the return to teaching after the New Year’s holiday. I hope this post and the New Year 2019 greets you well.

My wife and I plan to make a list of this year’s highlights this evening and save them to be read next year.  It will be a bonding time between us as we recognize our successes despite the obstacles around us, including replacing a dying battery bank. I plan to include my son in the event as well, and I am curious to hear his own version of events.

May you enjoy this New Year’s Eve, celebrating with family, friends, and have a chance to reflect on the highlights this year.

God Bless,

Electricity: The 411 on the battery bank

(12) T-105 6 volt batteries capable of 675 amps of stored electrical power

(12) T-105 6 volt batteries capable of 675 amps of stored electrical power

The Battery Bank, not a pretty picture, but most battery banks for an off grid home usually are not beautiful, just functional. This is our stored electrical power and how we power the home at night and during cloudy or low solar producing days. What you are seeing is (12) T-105, 6 volt batteries hooked in parallel and series. Each battery has 225 amps of stored power. Each row creates 24 volts x 225 amps = 5400 watts. To understand how much power that is, I could run one 60 watt incandescent light bulb for 90 hours, or I could bake a potato in a conventional electric oven for 1 hour.

The reason we bought the T-105 batteries is because we wanted a battery that would work well for us also we didn’t want to break our other bank of the piggy kind.  We also figured since we never had an off grid house before that to experiment and learn on an expensive battery bank could be costly, especially if we made mistakes in maintenance or neglect.  However, we have had these batteries for 4 years now and they still function as if in mint condition. I would consider replacing these batteries with the T-105 batteries again when the time comes.  If I decide I want more power to last longer in the winter months, I could easily modify the battery box for a 4th string, increasing my overall battery storage to 900 amps or 21,600 watts.

Calculating a fair estimate on how long a battery bank will last due to the home's use.

Calculating a fair estimate on how long a battery bank will last due to the home’s use.

Since 3 rows are here, we have 675 amps of stored power times 24 volts or    (675 x 24) = 16,200 watts of stored power. Amps x Volts = Watts. Now there is an important rule to follow. Never discharge your batteries to 0% of power. It creates a dead battery for one and also limits the life of the battery. Since these are deep cycle cell batteries, the manufacturer recommends not using them below 20% of charge. When discharging or using the energy down to 20%, the batteries life on average is capable of 700 recharges to full before the batteries begin to degrade significantly. So technically, we only have 80% x 16,200 watts = 12,960 watts of usable power.

This is where the game begins, having a home that functions like a conventional home, but uses the least amount of power in all its appliances to stretch the need to recharge through the cloudy days to the next sunny day or partial sunny day for a recharge. Because we designed our home to function efficiently, we do not worry about how much power we are using from February to late October each year, the solar panels keep the batteries powered up during these months. Unfortunately, from November to January, we have to rely on a backup generator for about 5 – 7 charges during these 3 months (Electricity: When the backup generator is called upon…).

Another way to maintain battery life is to create a comfy environment for them. I built the battery box in our utility room. The utility room is part of the main house and the temperature fluctuations aren’t as extreme as if stored outside. Extreme cold can greatly reduce battery efficiency, so to store them outside in an unheated environment isn’t the best option to maintain battery efficiency. I also placed a 2 inch foam board on the bottom of the box to prevent the cold concrete floor from cooling the batteries below room temperature. I placed a fan direct to outside in the box as well that when turned on opens the outside vent and blows out any off gassing hydrogen from the batteries without letting cold air in. Also, the battery box is directly below the inverter and charge controller, so the electricity doesn’t have to travel far. I also equalize them every month. In the winter I use the generator, but in the spring, summer, and fall months the solar panels are scheduled to equalize the batteries through the charge controller. After I equalize the batteries, I always make sure to add more distilled water to them.  I usually end up adding about a quart of distilled water to the battery bank of 12 batteries once a month.

Energy Efficiency Kit possibly at your local library.

Energy Efficiency Kit possibly at your local library.

If you are interested in finding out more about how much power you use on average in your home.  There is a unique program starting at our local library in which a patron can check out an “Energy Efficiency Kit”.  I have a feeling this program is offered in several states, if not nationwide, since I found the same kit on a library website in California.  It includes a meter and pamphlet that explains how to measure your electricity usage.  It’s not necessary to have, but it’s an easy way to see how much power certain appliances use.

Sorry about all the mathematics, but when I asked my high school math teacher when I would ever use math again, I had no clue what I was in for.