PREPPER PROJECTS By Steve Maxwell
BULLETPROOF
POWER How to create your own independent, collapse-proof electrical system
E
xcept for food and water, energy is the single most
disasters, decaying infrastructures and the interconnected
important commodity in our civilized world. Electri-
design of the electrical grid always reminds me how deli-
cal energy is especially important because so much
cate our peace and comfort is. Society is just one long-term
either runs on electricity or is controlled by it. Trouble is,
power failure away from total anarchy. Over the last century
our electrical system is more vulnerable than most people
our dependency on electricity has become total.
realize. Much more vulnerable. If a sinister group of people
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ever wanted to create the greatest amount of trouble for
Even the most serious prepper can’t do anything to save
the largest number of people, crippling the electrical grid is
society from a breakdown of the electrical delivery system,
definitely top of the list. The destructive leverage involved is
and you can never completely isolate yourself if something
a terrorist’s dream come true. But besides terrorism, natural
like this does happen around you. What you can do is pre-
PREPPER PROJECTS
pare systems now that aren’t dependent on the wider world. That’s
It would take an entire textbook to cover every last technical detail in-
what this prepper project is all about. It delivers a working overview of
volved in building a system like this, so consider this report your start-
how to design an independent electrical system and to make it real at
ing point.
your place. Make no mistake, though. This isn’t an easy job, nor is it cheap. Collapse-proof electricity requires serious engineering, but the results will probably be very worthwhile some day. By the time you’re
Off the Grid Since 1996
done reading this Prepper Project you’ll understand how to:
ing an independent electrical system based on the real-world
• design and build an independent, multi-source power system to supply all the electricity needed for your house, workshop and outbuildings.
experience of smart pioneers, and that’s why you need to meet Fritz and Anne Kettling. Nine-
• see how a real-world system has been performing for nearly 20 years; • explain to friends and neighbours how electrically vulnerable our way of life is, and what they can do to protect themselves now, while there’s still time.
There’s no substitute for design-
teen years ago they built their own multi-source electrical generation and distribution system to provide power for appliances, for controlling their heating system, for powering electronics, energizing their lighting and running power tools in their modern rural home and shop. They live on a quiet corner of a quiet island that’s miles from the nearest power lines. A grid connection would have cost $360,000 twenty years ago. That’s how far they are from the grid. Naturally they said “no way”.
Understanding the EMP Threat
EMP stands for electromagnetic pulse, and it poses one of the biggest threats to the modern world. EMPs are overloads of energy that can fry electronics and the electrical grid. They travel through the air and through power cables and can occur naturally from the sun, or by people intent on destruction. Either way, the result is the same: widespread collapse of the communications and energy systems the world has become so dependent on. Experts believe that at best it could take years for North America to rebuild after a massive EMP event, if rebuilding is even possible at all.
So, what can you do now? Two things . . . First, by having your own independent electrical system you’ll keep refrigeration, running water, heating controls and shortwave communication going at your prepper headquarters. Even an EMP event somewhere else that causes the grid to collapse and shut down your power won’t necessarily fry your equipment. Even though an EMP event can’t usually hurt large, coarse electrical items such as motors, heating coils and major wiring, it can damage sensitive electronics found in computers and anything with integrated circuits. Encasing sensitive equipment in a metal case that doesn’t touch the device is an effective way to protect it. In the world of electronics, this is called a Faraday box, and even a metal garbage can does the trick. Don’t ground the box. Will an EMP disaster occur? No one knows for sure, but the situation seems ripe for one. If you wait for the need, it’s too late. Page 2
But since the Kettlings were absolutely committed to building on their particular spot, they created an independent power system of their own that’s also pretty much completely immune to grid collapse. I say “pretty much” because part of their system does include a stationary propane generator as a supplemental source of power for charging the bank of system batteries if wind and solar systems can’t keep up. Their generator is larger than it needed to be for recharging, but it’s sized to run the 3-phase industrial machinery Fritz has in his metalworking shop. Having fossil fuel backup in their case is understandable since their mission never was to design for disaster protection. That said, a system free of fossil fuels is also something that any serious prepper can design around. More on this later. So, why not just get a really nice generator and be done with it? Why bother with the complication of solar, wind, batteries and possibly micro hydro? Long-term electrical production, that’s why. Having a back-up generator is a wonderful thing during power outages that last for hours, days or weeks, but generators aren’t much good on their own during a long-term, widespread grid collapse. That’s because gasoline and diesel generators still need the support of the entire petrochemical industry to keep running. What good is your generator when the local gas stations have run dry because shipments of fuel have stopped? Or even if there is fuel in underground tanks, what if your local stations don’t have electricity to run their pumps? This is why a multi-source, independent electrical system that uses a combi-
PREPPER PROJECTS
nation of solar, wind, hydro and bio-fuel generation is so essential for long-term security. If the grid goes down for months or even years, it
Part#1: A Bank of Batteries:
Lead-acid batteries are the
takes a special kind of preparation to keep your power flowing and
central storehouse of energy
your life livable.
for the system you’ll learn about here. Total voltage output of the
Even though the Kettlings aren’t preppers in the true sense of the word,
batteries in our design is 24V.
their system provides an excellent and field-tested pattern to follow
The batteries used by Fritz and
when creating a collapse-proof system. It’s provided up to 10 kW of out-
Anne are the original in their
put of grid-free electricity and it’s done it in all seasons without a break-
system, still running flawless-
down for nearly 20 years. Taking their design into consideration, and
ly after 19 years of continuous
learning from the experience of others, here are the seven main parts of
use. They’ve never needed to be replaced, which is unusual for this
our own Prepper Project collapse-proof electrical power system.
type of set up. Fritz chalks this up to proper battery monitoring and management. He never lets battery charge levels get below 80%, and he checks and tops up cells twice a year using distilled water. You can use different types of batteries, but Fritz’s system makes use of an array of 4-volt cells of the kind used in large ocean-going ships. These batteries store 2,600 amp-hours of electricity or 62.4 kWh. Vessels like these need independent power systems, and the batteries they use are amongst the most durable and reliable anywhere.
Why Do We Have a Grid At All?
On November 16, 1896 electric lights switched on in Buffalo, New York for the first time. It was one of the first examples of the centralized, grid-based electrical system we have today and it was the outcome of a technological fight. Beginning in the late 1880s, the two giants of invention, Thomas Edison and Nikola Tesla, battled for two different philosophies for electrifying the world. Edison favoured a system that used direct current supplied over short distances by local generating stations. Tesla was a firm believer in alternating current (AC) delivered by centralized generating stations over much larger distances. Tesla‘s AC system is the forerunner of the electrical grid we have today, and it’s what the authorities in Buffalo decided to implement along with other jurisdictions working hard to electrify their areas. Although Tesla’s centralized AC approach does have some advantages over a decentralized DC system, one of the drawbacks is the vulnerability of the large electrical grid. An overload or EMP event in one part of the country can cause a ripple effect that shuts down electrical supply thousands of miles away. Ultimately, the entire electrical system of North America is one big organism. Kill one part of it and the rest can die.
Part#2: A Wind Turbine:
Our design includes a 1500 W turbine that feeds power into the 24 volt battery bank through underground cables. The system charges the batteries whenever the wind blows, with the charge rate and levels varied by a controller that you’ll learn about later. Not every location is windy enough for a turbine to make sense, but many are. In areas with decent wind, the cost per watt
output from wind power exceeds what you can get from solar panels. In the 19 years the Kettlings have been using their system, their Bergey BWC 1500 wind turbine has never received nor needed servicing.
Part#3: Photovoltaic Panels:
Often abbreviated PV, these turn sunlight into DC power. The best independent power systems have multiple sources of electrical generation, with PV panels working in partnership with wind power in our featured system. The conversion
efficiency of PV panels for changing sunlight into electricity has been rising constantly for decades, and modern panels also last longer than previous types. You can expect a 20 year lifespan for today’s best PV panels – maybe longer. The Kettling’s PV array offers 1400 watts on sunny days, and the original panels are still working perfectly.
Page 3
PREPPER PROJECTS Part#5: Supplemental Generator
When all else fails to produce enough power, the generator is the thing that recharges system batteries when they’re low. Depending on the amount of power you demand, the output of the renewable generating capacity
Lessons from the Amish
Today’s Amish people intentionally live without many modern conveniences because they understand that technology is never without moral and spiritual consequences. The Amish trace their roots back to 1693, the year when Jakob Amman led some followers away from Mennonite communities that Ammon felt had become too worldly. The Amish have always lived without connection to the electrical grid, so in a sense they’re completely collapse-proof, at least as far as electricity goes. The Amish I know do use gasoline and diesel fuel for pumping water and sawing wood, so they’re not completely safe in the event of big trouble. I’ve made it my business to notice how the Amish do things grid-free, and here’s what I’ve seen: Cooking and heating: Always done with wood stoves that need no electricity to operate. No central heating. Pulling and transportation: Horses only. No fuel-powered vehicles, no rubber tires. Running water: Various methods, including self-starting gas-powered pumps controlled by a pressure switch. Lighting: Naphtha lamps with mantles. While the Amish are not preppers in the usual sense of the word, they’d probably fare better than most if modern systems collapsed.
Part#4: Micro-Hydro Generation
This is a miniature version of the way they generate grid power at a hydro-electric dam, and it makes a lot of sense if you’ve got the right location. The flow of
of wind and sunshine you’re experiencing, a generator may be needed to keep things going or maybe not much at all. It all depends on how much you invest in the solar, wind, hydro part of your system. The whole issue of producing and using ethanol to fuel a supplemental generator is the best way to make your energy system completely collapse proof and free from the fossil fuel system. Small-scale ethanol production is a venture in itself, so for now just realize that fossil-fuel back-up generation is simpler, though not as dependable in extended power failures. If you’re going to rely on fossil fuels to power a supplemental generator, then choose propane. It never goes bad in storage and a large tank could last for years of supplemental use. Propane powering a 10kW generator is what the Kettlings use.
Part#6: DC to AC Inverter
This electronic device converts the DC power stored in the batteries into higher voltage AC power that can be used by conventional electrical devices that normally plug into wall outlets. Need to understand AC and DC better?
Check out Understanding Electrical Basics on page 5 for more.
Part#7: Battery Monitor and Charge Controller
A battery monitor is an essential part of any col-
water is harnessed in some way to make
lapse-proof generation system because it al-
a turbine spin, generating electricity as
lows you to monitor key details such as battery
a result. Micro-hydro generation only
voltage, state of charge, charging amps and
works in situations where reliable moving
charging voltage. Another small but key com-
water is present, and that’s pretty rare.
ponent is the charge controller. Batteries can
That said, micro-hydro is a very power-
only be charged to a point. After that, charging
ful source of collapse-proof electricity if
causes damage. Things also get more compli-
you’ve got access to it. Here’s the formu-
cated when charging current is coming from
la for determining the power potential of a given situation:
overall drop of water in feet x flow rate in gallons per minute] ÷ 10 = watts Page 4
you’ve got, and the current level
multiple sources, such as solar panels, a windmill and a generator. A controller combines incoming charges
PREPPER PROJECTS
comes to designing the output side of things. Will the electricity you generate be low voltage DC current only (more on this later), higher voltage AC current, or a combination of both?
Amperage
Using the water analogy again, amperage (usually called “amps” and abbreviated A) is akin to gallons per
Conservation is Key
The Kettlings have a large and impressive off-grid electrical system as these things go, and it peaks out at 5000W for the house and another 5000W for the workshop. That’ll do the job, but it’s way less than an ordinary grid connection. A standard 200 amp electrical service can deliver more than 40,000 watts if you asked it to – 800% more than the system here. That’s why you’ve got to conserve to live within those limits. So, what does conservation look like in an off-grid situation? One approach is to avoid using electricity to make heat. Technically speaking, heat is just one form of energy, but there’s also something unique about heat that affects the way you design your electrical system. Although grid power is often used to boil water, cook food or heat spaces, using electricity for these purposes is too wasteful in an independent, self-supporting power system. You need to pay attention to efficiency when you’ve got your own power system, and generating and storing energy in a high-quality form like electricity, only to change it to a low quality form like heat is crazy. If you want hot water for showers, collect heat from the sun with a rooftop collector or connect to an outdoor wood boiler. If you want to cook food, burn a fuel like wood or biogas for the heat. Even incandescent lighting is too wasteful for a sustainable, disaster-proof independent power systems. Always use LED lights. They give about 10x more light per unit of energy than incandescents and they last nearly forever.
Understanding Electrical Basics
minute of flow rate. Water can flow in small quantities over time through a pipe or large quantities. Electricity is the same. Higher amperage flow requires larger wires. Amps matter a lot when it comes time to designing your system. More on this later in Designing Your System.
AC and DC Current
In the world of electricity, the letters DC stand for “direct current” and this is the only kind of power that batteries deliver on their own – including the batteries in this Prepper Project system. Polarity remains constant with DC; positive always stays positive and negative always stays nega-
tive. Imagine a whole bunch of electrons piled up against one pole of a battery, desperately trying to get to the other pole. When you hook up a load across both poles, energy flows in one direction, spinning a motor or lighting a bulb in the process. Stored electrical power is always in DC form, but there are reasons we’d like at least some AC power from our own self-sufficient electrical system, too. Maybe all you want is AC. The letters AC stand for “alternating current” and it’s the form of electrical power that the grid delivers. The voltage of standard AC household current in North America rises and falls 60 times per second, and this flip-flop of polarity from positive to negative to positive and back again gives AC an advantage. AC travels very well over long distances
You need basic electrical knowledge to start building your own col-
because its voltage can be stepped up or down efficiently with trans-
lapse-proof power system, and by the time you’re done you’ll be some-
formers. That’s not the case with DC power. The only reason we’re in-
thing of an expert. Start your technical education with the essential
terested in AC as part of our independent power system is because so
electrical concepts here:
many existing electrical items are designed to use it. This means we
Voltage
Page 5
need to create AC from DC, and you always lose power in the process. This conversion is done by an electrical item called an inverter, and Just like water, electricity can have more
good ones aren’t cheap. Conserving your output of AC power is why
or less “pressure” behind it. The higher the
you might consider a dual voltage system with two sets of wires in your
voltage (V), the more electrical pressure a
home and shop: AC power outlets for items that absolutely need it, and
circuit is under. When it comes to creat-
DC power for those things that you can be energize without resorting to
ing your own electrical system, you’ll need
AC. The RV industry is a good source of DC items such as light bulbs
to make decisions about voltage when it
and water pumps.
PREPPER PROJECTS Electrical Power
As you do all this adding up, realize that not all electrical items have Getting a handle on electrical power is similar
wattage ratings stamped on them. Voltage and amperage numbers,
to measuring the power of a gas or diesel en-
however, must be shown by law on electrical items, and that’s a good
gine, except that the words and units are differ-
thing. Simply multiply voltage and amperage specs to get a wattage
ent. Multiply volts x amps and you get watts (W)
consumption figure. Next, you need to realize that some electric items
or 1000 watts – kilowatts (kW) – the universally
draw a lot more power during start up than they do while running,
recognized measure of electrical power. In your
though not all items behave in this way.
work building and maintaining your own independent electrical system, watts and kilowatts are especially important when it comes to
Take a look at “Watt’s What” on page 10 for a sampling of electrical
determining your electrical generating capacity while sizing photovol-
items and their typical wattage demands. Those with what’s called an
taic panels, wind turbines and combustion generators. Watts are also
“inductive” load include motors that draw a substantial spike of start-
essential in determining your electrical consumption. One way or the
up current, then settle down to draw less in a few seconds. Your energy
other, the watts that go out must be matched by the watts that go in.
system needs to be sized to accommodate this extra current spike for
There are no free rides when it comes to the physics of energy.
at least some of the inductive items on your list. Not all will be starting
Electrical Quantity
up at once, of course, so you’ll need to use some judgement as you tally your figures. While it’s easy to under-estimate the capacity you Total amounts of electrical energy are
need, there’s no point in grossly over estimating, either.
measured in kilowatt-hours (kWh). An electrical power output of 1 kilowatt
Want a simple starting point?Most people find a 3500 watt peak power
that’s sustained for one hour is one kilo-
capacity sufficient for bare-bones basic household needs. You’ll find
watt-hour. kWh is a specific “quantity” of
5000 watts ample for a few more things that the basics, as long as
electricity, sort of like the number of gallons of gas or the size of a pile
you don’t have any heat-related loads. Fritz and Anne’s system offers
of firewood. Grid electricity is always sold by the kilowatt-hour.
5000 watts in the house, and a separate 5000 watts of output in the
Designing Your System
There are four main things you must consider as you design your independent power system:
workshop. Household cooking and heating water take a ton of electricity and should always be done using fuel-related energy sources like wood or propane, or directly using solar energy. Don’t use electricity to make heat. It’s easy when the grid is providing the power, but substan-
1. How much total peak power output do you need to
tially more difficult when your system has to provide it.
2. How much stored power do you need to keep power output
How to Build Your Electrical System
3. What’s the geographical potential for wind, photovoltaic or
building something as complex as a total electrical generating system,
4. What proportion of your power needs should be AC versus DC?
you’re selecting components and putting them together. We can’t tight-
sustain your lifestyle?
going when the sun or wind isn’t helping as much as it should?
There’s only so much that the written word can do when it comes to
hydro energy production where you live?
so be prepared to use your own intelligence and technical sense when
All AC? All DC? A dual voltage system?
en every screw or strip every wire for you, but we’ll take you as far as
Finding answers to these questions is the first step towards building a collapse-proof electrical system.
The step-by-step list of the broad-strokes required for building a grid-
Peak power is the maximum flow rate of electrical power you expect to need, and you need to use your imagination to create a list. Watts are the universal yardstick of power in the electrical world, and watts are how your peak power needs are calculated. Add up the wattage of all the things you want to operate at any one time, add an allowance for
we can.
free electrical system are up next. This section will give you what you need to know when you get down to nitty-gritty of choosing products and working with suppliers.
Step#1: Decide on the voltage for the DC side of your system.
This is often 12 volts for small energy systems because so much of the
extra capacity, and that’s the peak power figure you need to design for.
DC world revolves around the voltage made popular by the automo-
Sounds simple enough, but there are complications.
tive industry. This is especially useful if you want to run items like light
Page 6
PREPPER PROJECTS
bulbs and water pumps direct-
and negative-to-negative. The total voltage of the group stays the same
ly using DC current – without
at, say,12 volts, but the amp-hours add up. Combine as many batteries
an inverter – using the kind of
as needed to get the total kilowatt-hour capacity required from step#2.
hardware made for recreational vehicles or the auto industry.
Lead acid batteries give off small amounts of hydrogen gas as they
If you’re only having AC output
charge, and this needs to be vented for safety. It doesn’t take much
from your electrical system,
venting, but your bank storage space needs some way for gases to
other battery voltages might make more sense. Start with the inverter,
get outdoors. Two 4” diameter pipe vents – one high in the storage
then create a battery bank to match the voltage it needs. Connecting
room and one at floor level, works well. Your battery bank should also
batteries in series (positive terminals to negative terminals) causes
have lots of room around it for checking water levels and for battery
voltage outputs to add up. In the case of the Kettling’s system, large 4
replacement.
volt cells are connected together to create the 24 volt output required. 28 volts is another popular DC voltage for home energy systems. High-
The DC side of your electrical system operates on relatively low volt-
er voltage systems allow the use of smaller wires to transmit the same
age, and this means a correspondingly higher amperage of electricity
electrical power and that saves money.
flow and larger wires required for a given power output. Here’s a chart
Step#2: Determine how much energy storage capacity you need.
This is all about your bank of batteries. Aim for about 3 days of storage
of amperage levels and the minimum wire sizes required to carry it. Actual ampacity varies slightly depending on the type of cable and the insulation, but these numbers are for copper conductors and they’ll get you started:
capacity based on the total watt-hours or kilowatt-hours you’ll likely consume during that time. How much is this? That depends entirely on you. You’ll get the best estimates if you learn to read your grid electrical meter, pare back electrical usage to what you expect to need when you’re only using your system, then see how it goes over 3 to 5 days. Expect to be surprised by how much battery capacity you’ll need to keep you going. Quantity of electricity consumed is measured in kilowatt-hours on your meter. Kilowatt-hour capacity of a battery is measured by multiplying the amp-hour capacity of the battery by the voltage of the battery. A 12 volt battery with a 100 amp-hour rating has
20A = #12 30A = #10 40A =
#8
70A =
#4
55A = 85A = 95A =
130A =
#6 #3 #2
#1
150A = 1/0 175A = 2/0
1200 watt-hours of capacity, or 1.2 kWh.
Step#3: Assemble your bank of batteries.
There are different battery chemistries out there, all with pros and cons. In our opin-
200A = 3/0 230A = 4/0
Step#4: Choose and install your wind turbine
The big question here is what size of
ion, the best combination
turbine, and the answer depends on
of performance and value
two things: how much electricity is like-
comes from good, old-fash-
ly to be produced by the wind patterns
ioned lead acid batteries
in your area; and how much power you
connected together in a
expect to consume in your prepper
group. One excellent source
compound. To be completely accurate,
of very heavy duty, very long-lived batteries are those made for the
you need to assess wind patterns where
forklift or golf cart industry. These come in different voltages, and even
you live, then buy accordingly. In prac-
used batteries of these types can work well for years in your own ener-
tice, however, local wind power enthusiasts will have a good sense of
gy system. If you do need to connect more than one battery together
the output of a given size of turbine in your area. A 5 kW turbine, for
to get the required amp-hour capacity, connect them together in “par-
instance, will produce about 8000 kWh of electricity each year in an
allel”. This means cables connecting the terminals positive-to-positive
area with a 12 mph average wind speed. That’s enough to power an
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PREPPER PROJECTS
average home on its own, with no shop. In practice, the addition of photovoltaic panels to your system reduces the need for wind power,
Step#6: Choose and install a DC to AC inverter
This is the device that converts DC
since sunshine will often be available when winds aren’t blowing.
power from the batteries to the AC power that ordinary electrical items
A 5 kW turbine will have blades of about 18 feet in diameter, and it
can use. Due to cost and the com-
should sit on a tower that gets those blades about 30 feet higher than
plicated engineering behind them,
surrounding obstructions. You can expect at
inverters are generally the limiting
least 20 years of life from a small wind tur-
factor in system size. When the
bine. The Kettlings 1500 W turbine has run
Kettlings designed and built their current system in 1996, a 5000W
continuously for 19 years on a 35-foot tower
inverter was the largest available anywhere in the world. That’s why
with no issues. Power cables for their entire
they went with two inverters. One supplies power to the 120 volt AC
system, including the wind turbine connec-
panel in the house and the other inverter energizes the 120 volt AC
tion, run through buried 4” conduit. That
panel in the shop. Of all the components of your independent electrical
sounds big, but it’s essential for pulling big
system, the inverter is most likely to go bad all of a sudden. Although
wires over long distances.
the Kettlings have never had a failure of an inverter, Fritz keeps a spare
Step#5: Choose and install photovoltaics
Watt for watt, photovoltaics are somewhat more expensive than wind power for a given output, and that’s one reason you might not
on hand, just in case.
When you’re shopping for an inverter, there are three main questions to ask: What’s the output?
Inverters can only convert so much power, and the total wattage fig-
want to go with PV alone.
ure on inverters isn’t necessarily how hard they can run all the time.
PV is quiet and mainte-
Choose an inverter 20% larger than needed to meet peak loads and
nance-free, but pricey, too.
it will last longer.
It’s not always sunny out, either. So, what photovoltaic output will you need? This is another situation where you must make an
How clean is the power output?
You want true “sine wave” output from your inverter with less than 4%
educated guess depending on the amount of sunshine you get in your
total harmonic distortion. Any more than this an you’ll get humming and
area and the power consumption you envision for yourself. For PV sys-
unusual performance from electrical items.
tems less than 10kW, cost per watt output of PV panels has dropped from about $10/watt in 2000, to about$5/watt today. So for an array of panels that deliver 1000 watts on a sunny day, you’re looking at $5000.
What’s the idling power consumption?
This is the power consumed by the inverter as it just sits there turned
That’s pretty expensive considering that a basic 1000 watt gas gener-
on, but not doing anything and 50 watts of consumption or less is ide-
ator costs less than $500, or 1/10 the price for the same output. Just
al. Some inverters have the ability to switch themselves off when not
don’t forget something important: photovoltaic panels generate elec-
needed, then kick back from conservation mode at times when elec-
tricity when the rest of society is black and cold. PV is an actual source
tricity is demanded.
of energy, while a generator is typically just a converter of chemical energy into electrical energy.
Step#6: Choose and install a micro-hydro generator – if you can
Does the inverter have a built-in battery charge controller?
Some do and some don’t, and built-in charge control simplifies the design of your system. A charge controller alters the voltage coming into the batteries depending on their state of charge. Batteries will be
Not many places offer running water that’s right for generating electric-
damaged by overcharging or they’ll also be damaged if allowed to
ity, but when you’ve got it, micro hydro makes a lot of sense. A good
discharge too much. A charge controller takes care of this important
flow of water with a total vertical drop of 20 feet or so makes an out-
function.
standing chance to make a perfect system for charging batteries. See Understanding Micro-Hydro on page 11 for more details. Page 8
Naturally, when you’re considering an inverter you must first consider
PREPPER PROJECTS
what you’ll be powering with your system. And of all the electrical loads in a home, a water pump will probably be the most demanding for your inverter. That’s because even a regular household water pump creates a large, inductive load when it starts up. This spike in current draw will probably be the highest demand your system will ever be required to
Regardless of how you power your generator, there are some features of the setup that you should build in: Remote generator switch
Hardwired
remote
meet, and water pumps are always starting and stopping. Expect to
control and generator
pay good money for an inverter that’s capable of handling your water
monitoring makes it
pump load. Household-size water pumps up to 1/2HP are generally
easy to see what the
available as 120 volt or 240 volt models. Choose a 120 volt pump and it
generator is doing and
will make it simpler to design your overall energy system. An electrical
to switch it ON remote-
system with only one AC output of 120 volts is easier and less expen-
ly when you want and
sive to create than the dual 120 volt/240 volt systems typically found in
from wherever. This
most grid-powered homes.
one in the Kettlings house connects to the
Step#7: Choose and install a charge system monitor (and perhaps a charge controller)
generator shed. 12V control wiring
This item sounds simple and it is. But a good battery sys-
The Kettlings laid a
tem monitor is also essential
network of 12 volt
because it lets you see the vi-
circuits between the
tal signs of your setup in real
house and workshop
time. Battery voltage, charge
specifically for gener-
voltage, amps out, amps in.
ator control and mon-
Parameters like these give you insights into the condition of all
itoring. This is the connection block for the system of 12 volt controls
the main parts of your electriA big disconnect
cal supply. You’ll come to think of your system monitor the same way you do the dashboard of your vehicle.
Consider laying a system of separate ca-
Step#8: Choose and connect a generator
bles to deliver power directly to high-amperage
outlets
if
you’ve got big ma-
This provides a backup
chines or welders to
source of electricity for
power, bypassing the
charging batteries when consumption
batteries and inverter.
exceeds
When you’re living free of the grid, feeding power directly to heavy
recharging by sun, wind
tools makes sense. Just choose a generator that’s large enough to
or flowing water, and the
handle the work of recharging your batteries and also powering your
best backup generators
big stuff.
are wired permanently into the system for automatic operation. Will you set up an ethanol production system on your land and convert a gas-
Is a collapse-proof electrical system worth building? You might think
oline generator to run on fuel you produce yourself? It’s possible, but
that depends on whether or not the grid ever collapses. But regard-
it’s also a project on its own. You might want to take it on before or after
less of whether or not disaster happens, building your own electrical
you create the larger electrical system, but not both at the same time.
system will leave you bigger, more capable and better able to handle
Don’t get bogged down with multiple projects. Starting things and not
problems when they do come up. And isn’t that just the personal quali-
finishing them is the classic prepper’s flaw.
ties that make for a good prepper, no matter what happens?
Page 9
PREPPER PROJECTS
Watt’s What?
Adding up the power output of the items you want to run will help determine the size of power system you need. Use peak watt specs for items that draw a surge of start-up current. All of the items listed below typically operate on AC current, which means you’ll need an inverter in your system. Count on only 80% of an
Clean Versus Dirty Power
Power quality isn’t an obvious issue when designing your own electrical system, but it’s important. In fact, it’s absolutely crucial that you understand this concept. The kind of electrical items we all have in our lives is the reason why. Although it’s easy enough to create alternating current (AC) with a generator or cheap inverter, this power can be substantially “dirtier” than what comes out of your household wall socket from the grid. Dirty power can ruin sensitive electrical gear, and to understand why, you need technical information. True AC power involves a rapid and smooth rising and falling of voltage levels at a certain frequency. This is why it’s called “alternating” current. If you were to analyze this power on the screen of an oscilloscope, it would look like a smooth and consistent sine-wave shape. Inverters are the parts of an independent power system that convert DC power from batteries into AC that can power our items that need it. Seen on that oscilloscope screen, the wave pattern of a cheap inverter is square and chunky, not curved, and this chunk pattern may include potentially damaging voltage spikes. All of this is perfectly acceptable for coarse items like large electric motors, water pumps, etc. They operate undamaged with this so-called “dirty” power, though that’s definitely not true when it comes to sensitive electronics like computers, power tool battery chargers and communications gear. These devices need the clean power that only a high-quality inverter can provide
Generator Maintenance
Generators operate for so much longer than other outdoor power products that it’s easy to forget the need to change engine oil. Details vary, but it’s not uncommon to find oil changes required after every 24 hours of continuous operation. It would be a long growing season indeed if you ran a rototiller this much, for instance, but it’s another matter when it comes to a generator. That’s why you need to keep fresh crankcase oil on hand as part of your disaster preparations. Your generator won’t need to run much with the energy system here, but you will need to change oil from time to time. Motor oil keeps indefinitely in the jug, so deterioration isn’t an issue. Page 10
inverter’s rated output being available continuously. More than this and it can overheat. Item
Start-up Peak Watts
VCR
Continuous Operating watts
n/a 50
TV/Computer n/a 350 Furnace fan
1400 700
Microwave oven n/a Sump Pump
750
1400 750
Washing Machine 1500
750
Well Pump (1/2 hp)
1500 750
Refrigerator
1500 800
2-Slice Toaster n/a 1100 Plug-in heater n/a 1500 40 gal. water heater
n/a 3500
7 1/4” circular saw 1500
750
10” chopsaw 1500 750 Drill press
1200 600
Benchtop tablesaw
1500
Fresh Fuel
900
If your energy system relies on a fossil fuel generator in some way, remember that neither gasoline nor diesel fuel stays good forever. This fact matters when it comes to keeping the back-up generator part of your system running smoothly. There are two strategies you need to follow. First, use and replace fuels stored in cans with fresh fuel every new season – four times a year. Here at my place I keep half a dozen 5-gallon gas cans full at all times, then use them to fill up my vehicles when it’s time to refill the cans with fresh fuel. Gasoline, especially, is formulated to be more or less volatile depending on the season. Summer gas won’t burn well in winter, and winter gas doesn’t perform as well in summer. Even with a program of fuel rotation, be sure to add a preservative liquid to your fuel reserves and to the tank of your generator. Allow this treated gas to run through the carburetor before shutting the generator down, to ensure easy starting later on. Natural gas or propane fired generators have no fuel storage issues since these fuels don’t deteriorate with time. Neither does home-brew ethanol.
PREPPER PROJECTS
Connected to the Grid . . . For Now
The electrical grid can be a very useful thing, mostly because it’s capable of providing huge amounts of power when you need it. Electric welding, heavy-duty cutting and operating large machines is one reason you might want to have your prepper compound connectable to both the grid and your own independent system. Fritz Kettling has his own 3-phase generator to power the industrial metalworking machines in his shop, but if you’ve got access to grid power you might consider using it when you can. To make a grid connection safe and legal, you need specialized switching gear wired into the main incoming cables feeding your electrical panel. Typically called a “transfer switch”, this equipment allows either your electrical system to be powering your place, or the grid to be powering it, but never both at the same time. This protects electrical workers who would be endangered by your system power accidentally back-feeding through overhead lines. This system also protects your own system from failure if grid power ever back feeds through unexpectedly.
BONUS SECTION:
Understanding Microhydro
M
icrohydro is a small-scale method for generating electricity
available in his definitive book on the subject. It’s called Microhydro:
from naturally flowing water, and though details vary, most
Clean Power From Water. It’s superb.
installations use some kind of pipe to channel moving water
into a turbine that spins to generate electricity. The amount of power
Davis has won awards for decades of work making microhydro suc-
produced depends on the volume of water flowing and the vertical dis-
ceed around the globe. Many microhydro systems generate 75 to 350
tance it falls through the system. Equipment costs range from several
kilowatt hours (kWh) per month, and this really adds a measure of inde-
thousand dollars for the smallest, to $20,000 for a system large enough
pendence to anyone seeking to collapse-proof their life.
to power several modern homes. There’s no telling how cheaply you can go given enough DIY smarts and hands-on construction. You won’t find many sources of how-to information on microhydro, but that’s okay. Thanks to a guy named Scott Davis, all you really need is Page 11
So, is microhydro for you? That depends entirely on your situation. Right up front you need to know that microhydro only makes sense
PREPPER PROJECTS
when your expectations align with the potential of the site. In its sim-
a 500-foot pipeline or do you need a 1000-footer to get more head?
plest form, the energy potential of flowing water depends on the flow
How will flow volume through the system affect power generated? All
rate (usually measured in gallons per minute), and the pressure behind
these questions are key because they affect power output tremen-
that flow (related to the overall height of water drop, called “head” in
dously. In one case study cited by Davis in his book, variations in pipe
the business).
size, flow rate and static head yielded a 350% output difference across the four options examined on the same spot. Does all this sound com-
Measuring flow rate is essential site assessment #1, but it doesn’t
plicated? It isn’t really. Davis includes more than enough examples
describe the whole energy story. You also need information on the
and tables to get you thinking accurately through the assessments that
pressure behind that flow and this relates directly to the amount of
cover these issues.
vertical drop the water undergoes as it travels through your site. Pressure measurement is assessment #2 and it combines with flow rate to determine the raw energy potential of a location. In turn this then
Finally, the Hardware!
Most people who are attracted to microhydro come to it because it of-
defines the universe of choices for hardware necessary to produce
fers a chance to work with cool stuff while making clean, low-cost elec-
the juice you need at wall sockets, light fixtures and appliances. Flow
tricity in the process. But before you go any farther, there’s something
rate multiplied by pressure equals power. Does this sound familiar?
basic you need to understand. The entire microhydro proposition is
Remember how electrical power is determined by electrical flow rate
really all about applied energy conversion. You take the kinetic energy
(amps) multiplied by electrical pressure (volts)? Flowing liquids act a
of flowing water, convert it to rotational energy on a metal shaft, and
lot like flowing electricity.
then convert it again to electrical energy.
You won’t get very far in the microhydro adventure before you realize
Turbines complete the first part of the energy conversion process, and
something important. There’s more to a good system than just flowing
in many ways they’re the heart of any microhydro system. Many de-
water. You’re also dealing with terrestrial conditions, too, and that’s why
signs are on the market, but most include some kind of fan-like wheel
creating a stream profile is essential site assessment #3.
on a shaft within a metal case that contains and directs water flow over the spinning blades. Turbines are designed for both low and high-head
If you’ve ever studied topographical mapmaking, this is where you can
applications. The electrical side of any microhydro facility includes
finally put your knowledge to use. What you’re aiming for is an ac-
some kind of device to convert the mechanical energy of a spinning
curate representation of the character of the water flow over natural
shaft into electrical energy (either with a generator or alternator).
landforms, and how these features can be used to good advantage in your plans. By using a surveyors transit, a water level or a laser level,
So what does microhydro look like in the real world? On the small side
you need to produce a kind of side view profile of the entire stream
you’ll find places that use a 1 1/4” poly pipe with a turbine that produc-
landscape as water runs from pipeline intake to output port. How does
es a modest 50 kWh per month. On the large end of the microhydro
this information matter? In lots of different ways.
spectrum you’ll find systems base on a 4” diameter pipe turning 350 gallons per minute of water flow into 7200 kWh of power per month,
First of all, a stream profile helps you determine the best location for the
with a continuous output of 10,000 watts. That’s massive.
intake side of the pipe. This is where most of your regular maintenance will happen (cleaning out brush and stream debris, for instance), so
Microhydro can only happen in specific locations, but it’s one of those
you need easy access to that spot. Also, if the flow rate of your stream
rare opportunities where geography can play a huge part in protecting
is more than a few gallons per minute, you may find several possible
you against the failure of key systems in society. It’s a great opportunity
locations for the turbine itself. The stream profile often makes it easier
for those smart enough to look ahead and make the most of the oppor-
to identify optimal turbine siting.
tunity. What could be more reliable than the constant tendency of water to want to flow downhill on its way back to the sea?
Most microhydro installations include a pipeline that travels down from an area of high elevation over land, connecting to an enclosed water wheel (that’s the turbine) at some lower level. And this situation raises key questions. Will a 2-inch diameter pipe give you the best energy potential given the cost of the material and it’s flow rate? How does this compare with a 4-inch pipe? Will your energy expectations be met with Page 12
Steve Maxwell lives on a 90 acre rural island homestead and studied alternative technology in college. He grazes cattle, builds things in his workshop and teaches people how to live self reliantly. Visit Steve online at SteveMaxwell.ca
PREPPER PROJECTS
Windmill
Photovoltaic Panels
Wall Outlet
Inverter
Battery Monitor
Generator Batteries
Charge Controller Page 13