Going off grid and becoming independent a sustainable. Saving on the same time money and the environment.  Sound good but is less easy that you can imagine. In this article I collected months of research.

Reasons for going off-grid ranged from the practical (remote location) to the environmental/political (renewable energy). In the case of Eliopoli [...]]]>  

Going off grid and becoming independent a sustainable. Saving on the same time money and the environment.  Sound good but is less easy that you can imagine. In this article I collected months of research.

Motivations

Reasons for going off-grid ranged from the practical (remote location) to the environmental/political (renewable energy). In the case of Eliopoli both of them are true. You become a candidate if your sites is sufficiently remote to warrant an off-grid installation based on a straight cost comparison between going off-grid and bringing the utility line to the site.  In the case of Eliopoli we should cover 1.5 Km with utility poles that are expensive and not especially nice to see. From a pure financial point of view, by having already the service, it make less sense. The investment for a good system start with 30.000 Can $. With an electric bill of 3.000 $ / year you have a Return Of Investment after 10+ years only.  On the other side growing energy prices are certain. Starting 2012 Nova Scotia Power, the local monopolist for energy, will increase your bill by 9%.

 How to start

The net is plenty of resources, like http://www.off-grid.net/, but sometime too much information can be overwhelming. This research is an amazing starting point for your consideration. It offers real life stories and practical examples  of people like you and me deciding to go off the grid. Living off-grid is not simply a matter of installing some solar panels. Due to the limits of their energy supply, the people in the research have modified or re-arranged their energy use patterns to adjust to that supply. In some cases, the degree to which homeowners have chosen to reduce their energy consumption would be extremely uncomfortable and untenable for most people accustomed to a typical North American “standard of living”.  For example in houses without refrigerators, the average consumption reduction is around 70%, showing the impact of these appliances on energy requirements. But few westerns will accept to live without a refrigerators.

Jargon you need to learn

A watt is a power quantity which is a measure of energy per time. In the metric system, we have the classical mechanics formula:
1 Watt = 1 Joule per Second.

In terms of electromagnetism,

one watt is the rate at which work is done when one ampere (A) of current flows through an electrical potential difference of one volt (V).

To get Watts from Amps is pretty simple. Wattage ratings are usually listed in equipment manuals or on nameplates. If your equipment is rated in amps, multiply that number times AC utility voltage to estimate watts.

Formula: W=VA

Example: a refrigerator requires 4 amps. So, to get watts 4 amps × 120 volts = 480 watts.

Devices

It is important to buy the most energy efficient appliances you can afford. Keep in mind: reducing the consume is the best way to save money. The first thing to do is to evaluate the daily consume. You can use your utility bill for this:

21 KWh is too much and should be reduced. Let’s examine how.

Water heating

One of the major sources of consume is water heating. But Solar water heating is a good alternative also in not-so-sunny climate like Nova Scotia. Evacuated tubes are affordable and last forever. We decided for an evacuated vacuum tube system produced locally in Nova Scotia.

Refrigerator

As we said before the fridge is another sucker of energy, especially the freezer.

The most energy efficient–and highly usable, easily adaptable systems are walk-in cold rooms, or  “California coolers”, a thermally isolated locker with a cold air vent running up from the crawlspace and a top vent to create a cold air “chimney”. This arrangement brings consistent cool air to food products which need to be kept cool (for example dairy, fragile greens, etc.), with minimal or no energy use.

Sundazer offers efficient refrigerators with 12 and 24 volts. One canadian Dealer is www.enerstore.ca.
Top-load refrigerators and freezers includes

• Sun Frost , very expensive
• Tundra by Dometic
• Norcold
• Polar Power 
• Nova Kool, good compromise between price, energy consumption and size.

We ended with a standard model with acceptable consume but without freezer. In future we intent to buy a separate unit.

Water pump

Depth of your well or water source determine the type of pump.

SHALLOW WELLS, surface spring, creek or storage tank where the water surface is within 10 feet below ground can use the Flowlight Booster or Solar Force pumps as well asShurflo’s AC and DC powered diaphragm pumps located at the surface which can suck the water up to the pump, then push it up to 100 feet higher than the source and great horizontal distances. These pumps can take water from a shallow well or large storage tank and pressurize a tank in your house for better delivery of water to your fixtures. Each pound pressure rating of a pump gives 2.3 feet vertical lift. Surface pumps must be protected from freezing. They can often be a hassle to keep primed.

DEEP WELLS 15 to 200 feet down to the water level cannot have the water sucked from the top of the well. Suction can lift water only about 15-20 feet. For deeper distance to water the pump must reach down to PUSH the water up.

DC POWERED submersible deep well pumps are often the best choice because they do not require large bursts of power or use the inverter at all. DC submersible pumps use only 20% as much energy per gallon of water pumped as an AC centrifugal pump. Most pump very slowly, so do not deplete the water level in a slow recovery well. They can be powered direct by solar modules, without batteries. Or they can be powered by house batteries, like any DC appliance, if the pump is within about 200 feet of the house. The submersible pump will not freeze or lose its prime.

AC POWERED centrifugal pumps are faster and last many years with no repairs. But they use 4 to 8 times the power per gallon pumped than slower DC pumps. AC pumps use much of the full capacity of the inverter, and come on at unpredictable times. Pumping and running a washer at the same time may require a relay to pause the washer, giving the pump priority when it runs. A submersible deep well pump of 1/3 or 1/2 horsepower with 120 volt motor can pump a 300 foot well and be powered by a 2500 watt or larger inverter.  If you use an AC pump, get 110 volt, 1/2 horse maximum, with external starting box. The start box must be relay start control, not solid state control, for non-sine wave inverters. Solid state start works with true sine wave. No surge, or soft-start pumps, like the Grundfos SQ series are best, if depth of water in the well is within their range.

VERY DEEP WELLS with water level down the hole more than 230 feet from the surface need a higher power pump. The Grundfos SQ Flex submersible pumps are AC or DC powered (battery, inverter, or PV direct) and can lift more than 600 feet. Or a 240 volt AC submersible pump might be used  to fill a large  once a week operating on generator power, or a large inverter and transformer, or two large inverters. (more)

The use of an accumulator tank allows for city-style pressurized water that is available on demand. This allows the use of multiple fixtures at the same time while maintaining usable pressure. Accumulator tanks also extend the life of pressure pumps allowing them to run for several minutes at a time to pressurize the tank instead of the rapid on-off that is characteristic of so many water systems that are found in boats and RV’s. more

A solar pump like the  Grundfos 6SQF-3 6 GPM SQFlex Pump can be what you are looking for. We decided for A SHURflo 2088-594-154   Electric Pumps

Light

using 12 volts leds systems for lighting can save lot of energy.

• ORDINARY INCANDESCENTS are cheap, but are only 10% efficient.

• QUARTZ HALOGENS are longer lasting, brighter incandescents; some have reflectors.

• STANDARD FLUORESCENTS give a lot more light for the power used..

• COMPACT FLUORESCENTS give best light quality and efficiency.

• LED (LIGHT EMITTING DIODE) LAMPS are the newest lamp type. They have much longer lifetime, rated 100,000 hours, and ruggedness exceeding all others. Half a watt power use. Light color quality and prices are improving.

COMPACT FLUORESCENT BULBS make far less heat and more light. Using one fourth the power of ordinary bulbs, a 15 watt CF has the brightness of a 60 watt incandescent. It runs 4 times as long on the same power. They give the same soft white light and should last as long as 6 ordinary bulbs.

Lamps used most can save the most energy. Put efficient bulbs in lamps used 20 minutes or more every day. Lights seldom used save only a little energy, so ordinary low cost bulbs are fine for closets and other rarely used fixtures.

For best efficiency, use fluorescents of any type. Install standard fluorescents in workspaces where you can stand the blue-tinged light, hum and flicker. Use compact flourescents in living spaces for a more ‘friendly’ ambiance. Use halogen lighting for outdoor applications where temperature causes problems with fluorescents. Use white LED lighting for applications that normally use dismally-efficient small incandescents…task lights, nightlights, pathway lighting, exit signs, and flashlights. Don’t use incandescent lighting at all if you can afford to avoid it.

Bulb with ballast in the screw-base, all one piece, makes an easy 12 volt compact fluorescent. These just screw into a standard full size light bulb socket of a table lamp, ceiling fixture, or other standard fixture connected to 12 volt DC. Just screw this in to replace 12 volt quartz or 12 volt energy gobbling regular screw-base bulbs. You can use the original switch on the lamp, or connect through a wall switch. (Socket must be wired correctly with + to tip.)  ONE YEAR WARRANTY.

The compact fluorescent bulbs give four times the brightness of a regular bulb of the same wattage. Proven good reliability. At 12V, 7 watt uses about l/2 amp. The 15 watt uses just over 1 amp. The 30 watt uses just over 2.5 amps. 15W is also available in 24V, it uses less than 1 amp.

Choice of  light color between  warm yellow (2700K) or cool white (4100K) fluorescent fuller spectrum in all sizes. Brightness of each equals incandescent bulb of four times the wattage.

Installation and use note: Due to start up surge, only one of these DC compact fluorescent bulbs can be installed per switched circuit with a minimum of 10 gauge copper wire for that circuit. Polarity must be observed with the center tip being (+). And once on, the bulb must stay on for at least 20 minutes for longest life.

A good source of led light is www.buyledbulb.com.

Additionally Lightpipes or suntubes systems can decrease the light consume during the day.

Compoisting toilette

Why a composting toilette matters in our context?

A compoisting toilet like the  SunMarExcelAC can reduce to zero the need of fresh water and the requirement for a pump. This will reduce both your energy and water needs.

Washing machine

Another energy sucker is the washing machine. By using an efficient model, for example the  Staber-HXW-2304-washing-machine, this becomes not a breaker

Devices conclusion

Now create a list of the new devices you intent to use.

Energy Sources

When you know what you consume you can start  considering how to produce the required  energy.

Wind

In reality, wind energy is a converted form of solar energy. The sun’s radiation heats different parts of the earth at different rates-most notably during the day and night, but also when different surfaces (for example, water and land) absorb or reflect at different rates. This in turn causes portions of the atmosphere to warm differently. Hot air rises, reducing the atmospheric pressure at the earth’s surface, and cooler air is drawn in to replace it. The result is wind.

Air has mass, and when it is in motion, it contains the energy of that motion(“kinetic energy”). Some portion of that energy can converted into other forms mechanical force or electricity that we can use to perform work.

A wind turbine power is measured in kW , this means the rate at which it produces renewable energy. If you measure the amount of energy produced by the wind turbine in a given time e.g. in a day, you would do so in kW-h (kW hours). So if the turbine ran at full power (2kW) for 4 hours, then it would produced 2kWx4=8kW-h of energy. Another example is a 100W lightbulb. This uses 0.1kW of power when it is running. If the light was lit for 5hours, then it would use 0.1 x 5hours = 0.5kW-h of energy.

determine how much power you can generate

Determine the average wind speed for your site. In our case we do have an average wind speed of 6.5 ms/sec at 30 meter of altitude. This is  23.5 Km/h (14.6 Mph)

Notice how a set of wind generators will produce more power that a single one.

Kilo-Watt-hours power generated per year

For example, given 6.5 m/sec a 3000 Model will produce 7218 Kilo-Watt-hours per year. 6 wind generators of 500 (in theory same capability) 14088 while 3 of 1000 W will produce 9909 Kilo-Watt-hours per year. This is the theory. the reality is that smaller generators works well with few wind, if you live in a high wind region like Nova Scotia this may be not a viable alternative. We decided to use 3 wind generators from windenergy7.com/

Tower

What kind of tower will you use ?

• Rooftop – a patented windenergy7.com/ technology to attach the generators directly to the roof.
• Guy wire tower – least expensive, difficult to raise and lower, wires may be in the way
• Free standing – more expensive, difficult to raise and lower, no wires in the way
• Hydraulic tower – most expensive, easy to raise & lower, no wires. Note: It is currently only available for turbines up to 10,000 watts

Solar

PV have no moving parts, quiet, minimal maintenance. The downside of PV is the toxic materials used in panels, and their susceptibility to radiation damage (“browning” or “mirroring”). Small-scale residential wind installations are typically high maintenance and site specific.

Wood

Wood was used in all history for produce heat and cocking.  Combine it with a good insulation, like in our Earth Sheltered Dome, to don’t impact to much on the environment.

Propane

Propane can be used for cocking or heating.

Energy Storage

Energy storage is one of the weak point of today alternative energy.

Batteries

This is an example of a system with 48 V. 2 banks of 8 batteries at 6 V.

the most common type of energy storage is a battery.  Batteries are divided in two ways, by application (what they are used for) and construction (how they are built). The major applications are automotive, marine, and deep-cycle. Deep-cycle includes solar electric (PV), backup power, and RV and boat “house” batteries.  Starting batteries are usually rated at “CCA”, or cold cranking amps, or “MCA”, Marine cranking amps – the same as “CA”. Any battery with the capacity shown in CA or MCA may or may not be a true deep-cycle battery.

The major construction types are flooded (wet), gelled, and AGM (Absorbed Glass Mat). AGM batteries are also sometimes called “starved electrolyte” or “dry”, because the fiberglass mat is only 95% saturated with Sulfuric acid and there is no excess liquid.

Never the less most battery will last for seven years only. This is not very good  as Energy Return of Investment EROI. Generic golf car batteries can be expected to last 3 to 5 years, Trojan and similar types around 4 to 6 years, Surrette (depending on type) 8 to 20 years (average life span 12 years), and industrial 15 to 25 years.

A deep cycle battery can be completed drained out. Some suggest using  Interstate U2200 golf cart batteries.

The storage battery bank must have enough storage capacity to meet your power needs between charging cycles. Making sure the battery storage capacity is about double the power that would be used in a normal use day is a good minimum.

Inactivity can be extremely harmful to a battery. It is a VERY poor idea to buy new batteries and “save” them for later. Either buy them when you need them, or keep them on a continual trickle charge. The best thing – if you buy them, use them.

Battery banks

To acchieve the correct voltage and duration you need both to put your batteries in parallel and series

Serial: batteries combine voltages together at a common current while parallel batteries add currents together at a common voltage.

Example: 4ea of 6v batteries Wired in Series becomes 24v

Parallel. The parallel wiring connects all the positive sides of each battery together and all the negative sides of each battery together. This means the voltage is the same for all the batteries but the current is divided between them.

Example: 4ea of 6v batteries Wired in Parallel stays 6v

more on battery.

Inverter

allow you to enjoy the convenience of AC power while using renewable energy power sources. The storage batteries used in alternative energy sytems store DC (direct current) power. Most modern appliances operate on AC (alternating current) power. DC to AC power inverters make this convenience possible. An inverter must be so powerful to be able to power up all the devices that you can use on the same time.

Cables

The  values in our case require a 11 gauge wire. by using it power loss will be no more than 3 percent.

Sizing our system

Some hybrid systems does not work together.  The solar is only a backup for the wind power, with a generator as a third backup.  In a real hybrid  sunny day with no wind or a sunny day that’s windy, solar goes full power either.
If that is the case we would like to go with wind power only with a generator as backup, and get more storage capacity for not windy days.
So we figure we will need 3 wind generators a 1000 kw each, with an 4 kw Inverter and to 16 deep cycle batteries.