Living Off the Grid: Generating Your Own Electricity
Electrical and Lighting, Featured, Green Living, Repairs and Installation by Bob Ritzman
Our off the grid house near Anaconda, Montana
Taking the Alternative Energy Plunge
When my wife and I moved to Montana last year, we found a comfortable home on several acres with a view of the mountains. There was only one hitch – the house was off the grid. In fact, everyone in the subdivision generated their own power, including the bed and breakfast nearby.
That doesn’t mean it was primitive. The house had solar panels, a wind turbine, a battery bank and inverter, a generator, and a full range of appliances including washer and dryer, refrigerator, stove, satellite TV, propane furnace, and even a dishwasher. Since I had operated a cogeneration power plant before coming to Montana, I wasn’t too concerned about generating my own electric power, so we bought the house.
Solar panel with tracker
Life Off the Grid
The previous owner showed me the critical facilities and told me how to operate them. When we moved in we put CFLs (compact fluorescent lights) in every light socket, programmed the thermostat to automatically lower the temperature at night, and made sure to turn off the lights when we left a room. We thought we had everything under control.
On our third night in the house, we went to bed as usual to the faint sound of wind outside, a sound we were already beginning to enjoy because it generated most of our power. In the middle of the night, I was awakened by the sound of – nothing. No hum of the refrigerator, no furnace fan, and no wind. The tiny power light on the carbon monoxide detector was out, as was the digital display on the clock radio. We had no power.
Wind turbine
I got up and went outside to check the power equipment. Apparently the wind had died during the night and the small amount of power in use had drained the batteries. I started the gasoline generator and it began providing power to our house and recharging the batteries.
I had just learned the first lesson of wind and solar power: they can’t always be counted on when you need them. No matter where you are, the sun will always set and the wind will stop blowing.
Battery bank
Alternative Energy Cost
Since then, I’ve learned the second lesson of renewable energy: while the energy may be free, it still costs more than electricity from a utility company. This may not be obvious, so let me explain. The following are the approximate prices for the equipment we have now, materials only – installation is extra:
| Solar array | 1 kW | $6,000 | |
| Dual-axis tracker | $6,250 | ||
| Wind generator w/50 ft tower | 1 kW | $3,700 | |
| Inverter/charger | 4 kW | $3,000 | |
| Batteries (1 day reserve) | $8,000 | ||
| Total | $26,950 |
If you assume that we receive eight hours of sun and eight hours of wind per day (a generous assumption), we would produce 487 kW-hours of electric energy per month from renewable sources. This is almost half the 920 kW-hours per month that was used by the average American home in 2006.
Electrical inverter/charger
Assuming the equipment has a 20-year lifespan, it will produce 116,880 kW-hours of energy during that time, and my prorated cost for the equipment will be $0.23 per kW-hour. That’s more than twice the average cost of the same amount of energy from the local utility company.
Backup Generator
On the days when there’s not enough renewable energy, we recharge the batteries using a gasoline generator, which produces approximately 3.5 kW-hours of electric power for each gallon of fuel burned. This translates to an efficiency of approximately 10%, with a fuel cost of about $1.00 per kW-hour given the current price for gasoline in 2008. Compare this to a coal-fired power plant that has an energy efficiency near 40%.
That means that the carbon footprint of my generator is more than three times as large as a coal-fired power plant for the same amount of electric energy produced. If my generator burned propane, its carbon footprint would be slightly smaller because the proportion of carbon in the fuel is smaller. If it burned diesel, the footprint would probably be smaller still, because the efficiency of a diesel generator can approach that of a utility power plant.
Backup generator
Lessons Learned
In summary, this is what I have learned about renewable energy by living off the grid:
- You can’t count on it when you need it. You need a battery bank, and you should have a back up generator available, too.
- It’s expensive. While the energy is free, the equipment is not, making the cost of power higher than utility prices.
- When it fails, the carbon footprint of non-renewable backup generation is larger than that of a utility company.
This doesn’t mean I’m against renewable energy, just that given our current technology, living off the grid is not as simple and cost efficient as many people may think.
Additional Information
- Southwest Windpower, Renewable Energy Made Simple
- Oasis Montana, Inc., Renewable Energy Supply and Design
- Xantrex Technology, Renewable Energy Systems
October 20th, 2008 at 11:49 am
thanks for giving us [OffTheGrid enthusiasts] the benefit of your experiences through your website!
November 1st, 2008 at 2:07 pm
Hi and thanks for the valuable information.
I am planning to put in Solar Power for my home at the beach! But, I will have Edison as a backup at night! I want to go 100% Solar, so I don’t have to be on the Gas Methane Grid at all!
If I install a Powered Generator, it would probable be a Bio Diesel Generator, so I could put used Vegetable Oil in it!
Also, I would have put in a 4KWH System in place of a 2KWH System, and larger backup Battery Storage, if I lived in Montana, like they do, just to make sure, I had enough extra power! Better to be safe, than sorry! I would also have a Wood Burning Fire Place as well to heat the house, as it gets really cold in Montana!
Have fun,
Elliott
November 1st, 2008 at 2:15 pm
P.S.: While I was burning wood in the Fire Place, I would also use the heat generated from the Fire Place, to cogenerate electricity!
Just thought you would like to know.
Good luck in Montana,
Elliott
November 5th, 2008 at 12:25 pm
Would not a larger battery bank allow one to tide over the times when no power was being generated?
Or to put it another way, surely you need sufficient storage capacity to last through the expected null power periods? [which didn't seem to be the case above.]
Presumably, if you had sufficient capacity that your usage couldn’t drain the bank completely until there was some power being generated again, then you wouldn’t have to resort to using a petrol generator with the attendant problems?
Or would adding a third source of power, independent of wind and sun, help?
November 5th, 2008 at 8:22 pm
Thanks for saying what the off-grid evangelists are so careful to gloss over. Every few years, I look at the prices of photovoltaics and associated equipment and compute what it would cost to take my house off-grid. So far, the *interest* on that figure (never mind depreciation) far exceeds what I pay for grid energy. I haven’t even tried to find out what would happen to my homeowner’s insurance premium if I were to install a big storage battery and a gasoline-powered generator in my basement.
November 6th, 2008 at 11:40 am
i’d like to make the point that sustainability is not all about technology. perhaps it should be seen more in the light of moderating our use of power. it sounds like your house is pretty chockablock with appliances. i think to really make a go at sustainability, we need to forgo nonessential appliances. for instance, where’s the sense in having a dryer run off of solar power when you could just put your clothes out to dry?
November 7th, 2008 at 6:28 am
Hi,
Interesting site. Of course, Nanosolar’s printed solar panels will bring the cost of solar panels way down.
So far as joe six-pack goes, there are dozens and dozens of ways to reduce your carbon footprint. Check out http://livinggreenlivingwell.com for projects around the house that are inexpensive that pay off big. So far, my natural gas bill went from $125/mo to $79/mo, and my electric (more modestly) went from $125/mo to $110/mo.
It’s about your choice of appliances, lightbulbs, double-insulating your hot water tank (with Reflectix and a fiberglass blanket), installing a solar-powered gable vent or roof fan, insulating your garage door, sealing around the windows, installing a high-PSI, low-flow showerheads (so you’re heating less water per shower).
Then, with these savings, your can either reduce debt save the money in a high-interest online savings account, so you can affords a solar array or windmill or geothermal. Everyone should do all you can do to reduce your carbon footprint first, then consider generating your own electricity. The rates will drop as demand decreases across the grid as well.
Enjoy the day!
November 8th, 2008 at 6:03 pm
There is a co-generation of heat and power product for homes.
http://www.freewatt.com/Technology/freewattpowergen.asp
November 9th, 2008 at 10:41 am
In response to ELLIOTT’s comments: I would like to have a diesel generator running on biodiesel. However, I don’t know of any biodiesel fuel that will remain liquid when the temperature here in Montana dips to -30F. I have operated conventional diesels in such weather and the fuel heating systems are a real pain.
If you know of anyone who is making something to cogenerate electricity from wasted fireplace heat, please post the website for more information. The intent of my article was to address what it costs for what can be done now. I can’t generate power from dreams.
In response to Syona: You are correct that a larger battery bank is part of the answer to complete sustainability. In today’s economy, I am having trouble with the $8,000 price tag. I am hoping that the technology for plug-in hybrid electric cars will produce better and cheaper batteries.
I would love to have a third source of electric generation. I just don’t know of anything that is currently available to me or most homeowners.
In response to darcy: I agree that sustainability is more than technology, and I admit that I am tied to some of my conveniences. When the temperature is -30F, the snow is past your knees and falling horizontally in the wind, that gas (propane) clothes dryer is one of my wife’s favorite indulgences.
In response to James Livingwell and Rene: Thanks for the links.
In response to everyone, thanks for your interest in a subject we will be seeing a lot more of. If you come across new technology that is actually in production, I am interested.
November 9th, 2008 at 12:43 pm
Hello everyone,
Thi is my first time at this site and it is quite interesting and informative.
I would like to put my two cents in for what it is worth if I may.
I live in Yucca Arizona where there is ample sunshine and wind most times of the year on 40 acres at 3000 ft ASL.
My home is 20 miles from the closest grid connection and I have been living off grid quite comfortably for the past 5 years.
It is quite a learning experience to say the least but after working all of the bugs out it is truly amazing the feelings one gets not being connected and dependanton the grid.
My home is 1600 sq ft and construction is insulated concrete which has amazing insulating qualities not to mention fire resistance and soundproofing.
In being offgrid it is extremely important to do EVERYTHING you can to make the structure energy efficient.
My system consists of 12 170 watt PV panels, one small 400 watt wind turbine and 12 250amp hour batteries.
I am using electric appliances including a large refrigerator and freezer and a 52in LCD TV with Home theater receiver. The hot water, cook stove and clothes dryer are propane
I recently added a transformer to step up from 110 volts to 220 volts and I now pump water from my well with my solar system instead of running my propane generator.
In my experience having done 12 volt appliances and extremely expensive propane refrigerator that heats the home in the summer time I deccided it to be more cost effective to buy additional solar panels instead of 12 volt appliances.
In the early morning prior to the sun coming up my battery bank usualy still has 80 percent left unless of course there are lots of clouds the day before.
Living off grid can be a gratifying experience if one plans ahead and takes certain steps to make everything efficient.
Thanks
Bob in Northern Arizona
December 1st, 2008 at 2:00 pm
The great republican depression, now upon us, will force development of realistically efficient refrigeration - Africa uses a solar refrigerator now! Sweden has a solid state DC powered units. LED, DC power lighting systems with no converters to waste power are possible. Super-insulation and solar orientation, as well as ground heat storage have been suggested. Better storage batteries, with designs for the car market are near. Better, DC microwave cooking methods and appliances are possible. Communication by solar powered cell phone systems are already a reality. Expect advances in Compressed Natural Gas technologies to power emergency generators cheaply. Computers already qualify as modern power efficient devices. Off- gridders will have to change lifestyles with the rest of America, and stop trying to mimic on-line decadent lifestyles, and develop their own! The depression will provide a new, realistic, survival based perspective to off-grid. Communal efforts, where one huge windmill with storage facilities may serve a group of homes will make sense as the depression deepens. Newly designed light weight cars getting 50+ mpg will be mandated! The convulsive paradigm shift America will go through, forced upon them by the depression, will vindicate all attempts at off-grid living. We are at the footsteps of a new world and the great republican depression is pushing us ahead. Becoming self-sufficient in food production will be heralded in with GMO’ed, bug proof and fast growing veggies. Zero running cost, zero upkeep homes are technologically possible! The great depression will make them a reality and a necessity for Americans. Smaller self-sufficient, off-grid “Pods” will replace McMansions in the suburbs. Work schedules will give more time off and better commuting arrangements for labor, who will no longer subsidize companies by investing in cars to get to factories! We are up against Mao’s revenge, an endless army of little yellow women, 5′1″ tall, willing to work 24,7, for a bag of rice and a place to sleep on the factory floor! They have proven they can build cars, televisions, computers, anything we can do, they can do cheaper and better! We must exploit this by going off grid and using science and technology to survive!
December 20th, 2008 at 9:46 am
I am helping a friend who is building on an island with no electricity. I read the article, therefore, with great interest until Uncle B’s political, liberal progressive post.
Sorry you do not have some sort of filter that would enable this kind of responses to be on a different page…, perhaps the “footsteps of a new world” (sic) page.