Thursday, August 11, 2011

The Other Kind of Solar Power ????


That got my attention.  What other kind of solar power is there?  We have been so inundated with advertising about photo voltaic power little attention has been given to solar thermal. Recently someone brought this application to my attention.


For a very informative article



Europe is much further along in development of solar thermal applications. Imbedded in the above mentioned article are links to a You-Tube video showing how solar concentrators can even melt steel in a few seconds.

On a more mundane scale low heat installations can be used effectively to heat water cook food and heat houses. Cost of installations are lower  than PV and  in terms of energy  it is three time as effective in extracting energy from sunlight compared to PV.



Because I live in high latitudes where we have long dark winters I was extremely skeptical about solar cookers. Then I remembered an old time gadget called the hay box cooker.  You heat up the food in a pot; then when it is up to temp you place the cook pot or Dutch oven in an insulated (hay) box to let the residual heat finish the cooking.  Some limitations apply. This works better for slow simmer dishes. A seared steak on the BBQ is not going to work nor will stir fry. But steamed rice, potatoes, stews would work.

So you use solar heat during the day to generate the heat and let it simmer in an insulated box to finish. To store addition heat you could also heat up ceramic bricks with solar then place them alongside the Dutch oven pot inside the insulated box.



Passive solar homes have been promoted by architects for several decades. Various methods have been promoted to store heat for release overnight. This is another form of solar thermal just by another name. Some of these methods even lend themselves to retrofits on existing buildings not just new purpose built designs.



For some reason we have come to expect one solution fits all. This is not realistic.  But if we can achieve something that displaces an expensive energy source for 50% of the time we have still reduced our annual expense.



The oil industry is even using solar power to recover more oil by heating water to steam and injecting the steam into the almost spent oil pool. More oil can be recovered this way.



Because solar thermal is less known here we have a steeper learning curve head of us.

Low Tech of Yesteryear

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I found a website containing a large number of articles dealing with historical technology going back almost 2000 years.  Yes 2000 years! It’s not a typo.




What is really fascinating is how some technology was eclipsed by other trends and then abandoned.  What is really amazing are the findings of experts that in some cases this technology was more efficient than modern petroleum fuel replacements.

Kind of begs the question as to why did we go with oil?



Hopefully some people will read the articles and will attempt to adopt some of what they read. For off grid in particular I believe   this would be advantageous.

Long before we had steam or electric power   medieval engineers built human powered cranes capable of lifting several tons of loads. Sounds handy for anyone attempting to build their own home from scratch without help from electric or diesel powered cranes.

There is even an article on how not to use alternative energy.

This leads into several articles dealing with pedal powered device.  One of the first lessons it gives is that electrical generation is perhaps the least efficient way to get a job done. The articles illustrate various pedal powered machines including a farm harvesting device   that does a tremendous amount of work just using human muscles.

While some of these may not have a tremendous level of interest in North American the apple harvesting and cider making operation sure caught my eye. I used to live in a region where a lot of apple cider was made. One place I rented had a large number of apple trees so something like that would have been of great interest at the time.

I have in recent times been asked for quotes for solar panels to power wood working shops.  Given they are all one man hobby shops pedal power might make more sense both financially and ecologically.



Even the index is too large to list so go there and see for yourself.



Friday, May 20, 2011

Two Distinct Lifestyles Seperated by a Common Terminology

Living off grid means very different things to different people.

Some people consider living off-grid only as living away from electric utility power.

Other people do not consider it as living off-grid unless all connection with modern conveniences and municipal services are broken. I have even heard someone calling any kind of financial banking as being a grid.  Does this mean you are not truly off grid unless you revert to a barter system and no longer use money?

Propane use is considered as being on-grid, as does having municipal water or sewers or even paved roads.

Ironically, this group does not seem to consider use of solar power as being a form of grid use. This completely ignores the fact  solar panel are very  high tech and relies  on a complex manufacturing process that is  very dependent on many grid services.

The NIMBYS have assuaged their conscience by shifting toxic manufacturing off shore to third world countries where people are more concerned with daily survival than long term environmental protection.

The process of making solar panels involves a lot of technical steps  requiring the use of toxic  chemicals and sophisticated  silicon crystal growing ovens  costing millions of $$$ to fabricate. This is not some little cottage industry with any impact on the environment.



The manufacture of batteries to store the solar energy collected during the day involves use of much toxic material such as lead and sulphuric acid.  Charge controllers and inverters add to the collection of highly sophisticated devices only a very grid dependent manufacturing complex could produce. Clearly the technology that many people rely on to enable them going ‘off-grid’ is anything but off-grid itself. The industry that develops and sustains this technology could not exist if it had to be off grid.



The other common perspective is that you are off-grid as long as you are not connected to any kind of municipal power grid.  The people  in this category  readily accept  the need for and use of other  so called ‘grids’ such as  a road network for transportation, propane for  cooking and petroleum fuel for a back up generator.



The reality is, both groups rely on modern electronics for everything from communications via the internet to LED lighting to some form of fuel to drive their vehicles on public roads. Try finding a non-electric gasoline fuel station that doesn’t have a digital display showing how much fuel is pumped into your vehicle...

Even those who claim to live the simple rustic life where they chop their own firewood do not escape some reliance on electrical power. The steel blade in their saws and axes came from electric furnaces used to produce good quality steel.  If they use a cast iron stove, the cast iron may come from a coke fuelled melting pot but all of the processing after the iron is poured out relies heavily on electricity.

So we have a dichotomy. Living off grid still depends a great deal on grid electricity.

The only escape would be to revert to agriculture based subsistence totally devoid of technology. Even the Amish and old Order Mennonites do not take it so far. They rely on kerosene lanterns, forged farm implements and accessories often made in   factories dependent on grid power.

Even the kerosene is a petroleum distillate derived from what detractors call fossil fuel.  The glass in the preserving jars and the windows is formed in electricity driven factories.  So just how off-grid is that?



The other faction that subscribes  to the  concept that off-grid only refers to not being  connected  to a municipal  power supply  uses all the technology  they can, in order to reduce energy consumption and  in general  try to live as green as possible  by making use of  the latest  technology.

This faction is likely to have satellite TV and internet connectivity. If they have a job, it may even be a telecommuting job so they do not contribute a carbon foot print by commuting in a car.   Because they are plugged in to global communications they are more likely to be aware of developing trends and global social development.



The reality is both factions are dependent on a grid based high tech industrial base.  It is hypocrisy to disdain any forms of municipal structure as grid and therefore to be avoided.

Permaculture is the new buzz word embraced by the promoters of sustainability life style. I am bemused because these principles are exactly the same as what my grandfather was following, except he did not have a buzz word and counterculture gurus to guide him. He just did it because he was using common sense.

I am not saying ‘permaculture’ is bad or old fashioned. I am just surprised it required renaming things as if it was something newly invented by the latest generation...



There is a caution however.  Living in an agricultural mode that is pre industrial is  to  adopt a way of life  where infant  mortality is the norm and if  children survive to adulthood this life is likely to be short because of the brutal living conditions needed to eke out a subsistence living.



The minute you begin to rely on any sort of manufactured products such as knives axes and plow shares you start the movement towards grids.

The old saying beating swords into plowshares speak to more than simply a philosophical   trend.  It is indicative that metal resources were scarce and there was just enough metal around to supply either swords (weapons) or plowshares (peaceful tools) but not necessarily enough for both.

The industrial age led to technical developments that allowed greater production of metal because deeper mines could now produce more metal and engineers invented new machines able to produce new products made from the more abundant metals.



A cast iron axe does not work. It is too brittle and shatters. Steel was difficult and expensive to make until the advent of electric furnaces.  Sheet tin was almost unheard of before the development of rolling mills.  Rolling mills use big electric motors to run. Tin and sheet steel facilitated the production of low cost consumer goods like kerosene lamps.

Without sheet metal it is questionable how many low cost consumer goods would have been produced.   All of this industrialization would not have been as rapid or even possible without reliance on the various grids the PC purists who eschew any and all forms of grids.



In terms of living green; which mode is greener?  There is the back to the lender (err) who hand cuts trees for a primitive log cabin in the woods. Heating and cooking is done with a wood burning fire. Remember a cast iron stove is not allowed by definition of total abstinence of any grid whatsoever.  You could build a fireplace using river stones

Light has to be with home made candles.

Food production will be mostly traditional because anything else relies in some way on grid reliant industrial manufacturing. 

Transportation is by animal or animal drawn wagons or by foot. This places a limitation on mobility and range of social community interaction





The other choice is the high tech off-gridder who only disconnects from the utility power grid. However he uses LED lighting produced in a grid dependent factory and is powered by solar panels produced in another grid dependent factory.  The high tech   off-gridder may have a telecommuting job or commute to work in a modern hybrid vehicle that uses the least a mount of fuel resources.



The high tech off-gridder is fully connected and quite often keeps abreast of new developments that would allow them to enhance their lifestyle.  



They heat their home using one of several options. Wood stoves using catalytic converters or wood gasification to produce zero visible particulates and have non visible emissions that fall within the EPA guidelines.  If they garden to grow some of their own food they conserve water using new drip irrigation technique. They may even water these crops using only captured rain or recycled grey water.  The food will likely be clean organic because their internet connections bringing them news letters explaining these developments and how to implement them at home.



For the majority of people a compromise somewhere in between is most likely to be acceptable.  The point being these politically correct  people who insist on redefining  the term ‘off-grid’ to include all sort of  things  that was never envisioned  by the first electrical engineers who coined the word  should be careful because if you take their  definitions to the ultimate  logical conclusion will find themselves  in a linguistic  corner they cannot get out of..

I subscribe to the meaning ‘off-grid’ only means being not connected to the power grid.



~~ END ~~

Off-Grid or Off-Shore

Many people chose to retire and go live on a boat cruise around.

An even greater number of people buy a large RV or motor home and drive around to see the country. When they camp out in the wild not in a park intended for RV camping its called Boon Docking. 

A common aspect of all this to living off grid is the fact they all need to be self sufficient. The RV owner uses a holding tank and must find a ‘SANI dump’ to empty the holding tank. Boats cruising inland waters or within 3 miles of shore must also find pump out stations.  Building codes requires all homes on or off grid to have a septic disposal system.  In all cases, boats, RV or off-grid homes must provide their own power, lights, and heat in colder areas and cooling in hot climates.

Food storage and cooking is pretty much the same in all cases. 

Off-grid  homes have  several advantages because  they  have  adjacent land on which to place large  PV arrays or wind turbines not to mention storage  sheds  for fire wood and a work shop.  This is not practical for most RV and boat owners.

In practical terms there is little difference in the daily life.  You have to make meals; you spend some time doing maintenance and some time socializing with other people. After sun down is the biggest difference. Unless you have some kind of a battery system you are stuck relying on candles and Coleman style lanterns for light. 

Modern boats now have 24V battery systems while a lot of RV still sticks with 12V but modern off-grid homes rely on 48V battery banks.  The reason has to do with voltage losses in the wiring.  Because RVs often stay in parks catering to campers in 5th wheels and small older trailers and vans 12V is still very common with these people.

Larger boats and not to mention off-grid homes tend to power appliances with 120V AC appliances by using inverters. Once past the inverter it really doesn’t matter what voltage the battery is. Propulsion motors and generators have their own dedicated start battery so this doesn’t really make a difference either.



The bottom line is that these alternative lifestyles all have many things in common.

There is something to learn from each of these that can be applied to the others.

Tuesday, April 26, 2011

COOKING APPLIANCES



I think we can all agree cooking is as much art as it is a science. Cooking appliances are simply tools but it’s pretty hard to be artistic when given the wrong tools.
There will always be a lot of debate when discussing the merits of some specific item. Some people swear by ‘Dutch ovens’ claiming they are the best without really knowing why or how these are best.

For off-grid people the amount of energy that is used is the most important consideration. Cooking is the process of applying heat to food stuff in such a manner as to render the food edible and palatable. A conventional kitchen stove with 3 – 4 burners and an oven is not always the most efficient way to cook food. Counter top appliances are specialized tools intended to do the job in the most efficient way.
Examples of this are slow cookers or Crock Pots. These often only use 100-watt elements to slowly simmer stews and sauces over a longer period of time. This can be very effective when used in conjunction with solar panels that produce a modest amount of power over the span of the day.  The crock pot is often a double layered container with a lid that keeps the heat inside.  In other words very little heat escapes and is wasted.  The better models even have a temp sensor to cut off the power if it gets too warm.
Rice cookers are similar but use more power and are optimized to gently steam rice to perfection.  Compared to a conventional stove with a pot on top this also serves to optimize energy use because it eliminates operator error in guessing how much energy to use. In addition it eliminates the mismatch of pot and burner dimension that allows wasted heat to escape up around the sides of the pot.
The conventional stove with the spiral rings that become glowing red-hot is not particularly efficient in transferring heat into the food using the minimum amount of time and energy to get the job done.
Type of food and style of cooking plays an important part. Consider a wok and a slow cooker. The wok needs very high temperatures to lightly sear the food outer surface while leaving the insides moist and tender. If the wok is held at a much lower temperature   the results are disappointing and sometimes unpalatable. A slow cooker is the opposite. It gently warms a mixture of ingredients and allows the flavor to suffuse the entire mix over many hours. 
Several styles of ‘toaster ovens’ exist; each with its own specific advantages. At its most basic, they are just the same as a toaster laid on its side with some kind of glass door in front like an oven.  They are constructed with a single layer of metal where the outside surface gets almost as hot as the interior. This represents escaping and thus wasted heat. Better models have a double layer construction possibly even some insulation in   between and better fitting doors. There may also be a heat control knob that allows the user to control partial heat settings for less energy consumption.
Some of these ovens use a calrod heater element while others employ a quartz glass tube. Although both glow red when in use the quartz tube emits longer wavelength infra red heat that penetrates deeper. The resistive wire or calrod tends to char or brown the surface of the food like a slice of toast being browned. The quartz tube ovens are better for dishes like pies and deeper dishes because   they heat the entire portion without burning the surface layer as quickly.
Convection ovens heat foods by circulating heated air instead of direct heating by radiant means.  The manufacturers claim this will allow you to bake a cake; something not so easily done in a toaster oven.
Some  convection oven combine a rotisserie  function with the hot air flow for more even cooking  of the  surface of a bird or roast.

Several countertop grilles are now available with the George Forman grill possibly being the best known, thanks to widespread advertising and marketing in big box stores. 
Because these countertop appliances deliver exactly the right amount of heat into the food in the shortest possible time the end result is lower energy use.
These grilles have several advantages. Their design brings heat to both sides of a piece of food simultaneously. When cooking fatty meats the sloped design drains the fats away from the meat. Nutritionists regard this as a preferable method of cooking fatty meats.  This design lends itself to quick food preparation because you can take a frozen meat patty or steak place it on the grill and be done in 4 minutes or less.
The ribbed design leaves air pockets in between the browning strips that give that pleasing striped char texture.  It also makes great grilled cheese sandwiches.
The  small  one  patty size  only uses a 600 watt element  while the  large 4 patty  grill uses a 1100 watt element. The amount of heat wasted is minimal because the grill closes like a clam shell to keep the heat inside. 

Another countertop device is the roaster pan with lid.  Hamilton Beach makes a pan that can accommodate a 20 pound turkey with trimmings.  According to my   cook expert this appliance takes about half the time to cook a bird compared to a conventional kitchen stove.  One reason may well be that the lid fits snugly over the top thus keeping in all the heat.  A normal kitchen oven has a 1” diameter chimney that continuously vents hot air into the kitchen space.
The volume inside the roasting pan is more like an enclosed Dutch oven than the larger volume contained inside a regular kitchen oven.  With a temperature regulating control less energy is required to maintain the heat for cooking inside the smaller volume.
A normal kitchen oven is supplied with 240 Volt to a 3000 watt element whereas the countertop appliance is powered by a 120V fed from a 1500 watt outlet. The rating plate says the pan element is 1100 watts.

From the above it is evident all of these countertop cooking appliances can be powered from a 2500 watt inverter and a suitably sized battery bank. If charging from wind, water, or solar takes place at the same time so much the better.
This is not to suggest  off-grid cooking  can  be done electrically as if  you are still connected to  the grid but it does highlight  that some  careful use  can be made  of  a few  select electric appliances. Unlike  wood stoves or even most  gas fired appliances,  electric appliances can be set to start with a timer  on the  occasions  when everybody has to be away from home  and are not available to  cook  the meal during the  day.
Sometimes this can be a real advantage.  When everyone is away all day, loading a truck with firewood it’s nice to come home to hot chili stew and fresh baked bread. Timers can be used to sequence the bread maker and the crock pot making the stew.


Friday, April 1, 2011

FUELS FOR OFF GRID

A large part of living of grid is finding ways to power equipment and appliances.
At first blush solar looks great due to its apparent simplicity.  However if a hail storm damages a solar panel it is not usually possible to repair by hand in the field.
A wind turbine stands a better chance of being repairable in the field as does a water wheel.
Reliance on fuels and power derived from highly industrialized sources takes away from the independence sought after by people wanting to live off grid,
The recent natural disasters in Japan with earth quakes and Tsunamis illustrate this point clearly. These disasters crippled a highly industrialized nation. Even basic food growing is affected because they need refined fuels for the farm machinery, not to mention a road network to deliver food from farm to city customers.

Because of the massive advertising and general literature many people are not aware of any alternative to buying gasoline at the pump. The ubiquitous internal combustion engine can run on a variety of fuels. Spark ignition engines can run on a variety of gaseous fuel such as propane methane or natural gas which is simply another word for methane. Alcohol is yet another fuel which has been used for decades in both race cars and industrial engine. A hundred years ago naphtha was used as a fuel.
Compression ignition engines  commonly called diesels  can  run on refined diesel fuel but also on vegetable oils  both new and waste sourced and  with  some modification propane and natural gas.
During the war time years ingenious adaptations to use wood gas as fuel was widely adopted in Europe.   Wood gas is something that can be made at home. No one is suggesting these alternative are as  good as  refined diesel or gasoline but  if the fuel is something  you can  create yourself  from local  resources its worth looking into
Waste wood is one of the most common home fuels since time immemorial.  But there are many more methods to use it than simply burning it.
A quick Google search will find enough hits to fill a thick book.

Methane and natural gas are two names for the same chemical substance. The naming is primarily used to designate the source. Gas from deep drilled wells is termed natural gas but the same gas derived from decomposing organic matter is called methane. Both can contain trace contaminants that must be filtered out before use.
Methane is my favorite off-grid fuel because it develops naturally whether you want it or not. That challenge is to collect and store it for later use.
Land fill sites treat methane as a nuisance waste product originating in the garbage heaps. Enterprising land fill operators have for a few decades been collecting this gas and using it for generator fuel so the operation is energy self sufficient.
The irony being land fill sites are designed to minimize methane creation. Think what they could be achieving if they optimized the land fill site to create methane.
All farm and livestock operations generate a huge amount of methane from the animal manure. To them it is a disposal problem. Why not instead make it a resource instead of a problem   A Frenchman called Jean Paine developed a composting system that heated and lighted his farm and gave him fuel for his farm vehicles .Look here:
Another farmer named John Fry experimented with animal manure. Look here:
His book written in 1975 can be downloaded (12 chapters) because it is no longer copyright protected.

Every month I get a different collection of hits when I enter the same search string into Google, clear evidence this is a popular and very active topic.

For those who live in a conducive climate region look up Jatropha and Yellowhorn plants, these are both oil bearing trees and bushes   that can be harvested year after year. The berries are pressed to yield  a vegetable oil suitable for either cooking or direct use for diesel engines,  I have seen figures of 800 gallons per acre per year and  in favorable  regions  perhaps even greater yields. This could be a cash crop in addition to being  a home brew fuel  situation.  Conventional harvesting machinery and techniques  suffice. This is not rocket science requiring  strange new equipment, techniques or knowledge. This is just  ordinary farming  with a different crop.
I have not touched on  the more conventional  subjects of sun wind and water power  because so many other website already cater to these subjects.  My goal is to  highlight  subjects  relevant to being off grid but not covered  in detail in the mainstream literature.

~~  END  ~~

BATTERY CARE AND MAINTENANCE

Everyone already know about checking   the specific gravity of the cells and topping up the electrolyte with distilled water not tap water but there are additional things  related to good care and maintenance.
In addition some people are now using AGM or GEL batteries.   This completely changes battery and maintenance procedures.  With the batteries being sealed it is no longer possible to check specific gravity.

Several reasons justify use of these sealed, spill proof batteries.
Transportation regulations make transport of the traditional acid filled lead batteries more difficult because they are classed as hazardous material.  No such restriction exists for AGM.  This makes it possible to ship them to places carriers like UPS would not otherwise consider.
AGM batteries have less self-discharge and do not sulfate as quickly. This makes them attractive for applications where prolonged periods of inactivity are regularly encountered.   Vacation cabins may have a solar panel on the roof but in the absence of an occupant, who removes snow from the panel in winter times?  The result could mean long periods between full recharge sessions.
Sulfation is most likely to be a problem under circumstances of intermittent use and periods of sitting partially discharged. Lead sulfation is the normal result of converting sulphuric acid and lead into a current flow. 
Although every user manual clearly states to recharge a battery immediately after use how many people actually pays heed to this.
They will partially discharge a battery, and then leave it sitting because they have not discharged it fully. I have to confess I am guilty as the next person. The usual excuse being the battery will be used again real soon and we all know it can be destructive to leave a charger permanently attached and running.  The rationale being the battery goes back on the charger right after we fully discharge it.   Trouble is, that never seems to happen.

Now we have an expensive battery sitting they’re slowly deteriorating and loosing its capacity. 
Apart from constant vigilance and care there are some other things you can do.  Products called desulfators are available.  These are electronic pulsers that soften the accumulated lead sulfate so that it will revert back to sulphuric acid and lead oxide when a charge current is run through it.

As electrons are withdrawn from a battery lead sulfate forms as part of the process.  This sulfate is initially soft but begins to harden over time. A close analogy is thick mud splashed in the vehicle. When it is fresh and wet rain or a regular garden hose can easily rinse it off. As it dries and hardens   it becomes more difficult to remove.  Leave it baking in the sun for a week and you need a pressure washer to remove it.
Sometimes thick encrustations are even difficult to remove with a pressure washer requiring several tries to remove it.
Lead sulfate is similar.  In this case the electrical voltage is the pressure and the volume of water is the current.

Because  PV panels are very expensive  most  solar panel installation  are on the skimpy side when it comes to  charge current  and  weak sunlight  morning and evening also  detracts from the full charge current possible.
The conventional wisdom also contributes.  Most guidelines recommend a three-day reserve in case of cloudy days. This is a sensible approach.
Unfortunately it sometimes results in partial discharges then a couple of days of cloudy weather.   During this period of no sun the lead sulfate tends to harden, making it harder to reverse when finally some charge current once again becomes available.

The available charge current may not be strong enough to completely reverse the entire lead sulfate. This residue will remain and when further discharge occurs this old lead sulfate gets added to with new lead sulfate.   If a large charge current is not used this sulfate build up becomes permanent.  It may only be 1% but over time the accumulation of residual lead sulfate will rob your battery bank of storage capacity.
Attentive and prudent battery owners will have noted instructions in their user manual about  ‘equalization charges done at periodic intervals. The intent of such equalization charges is to flush out lead sulfate.
In essence it is an over charge and will cause the battery to bubble and loose electrolyte; you must top up the battery before starting and after doing the overcharge.
Unfortunately this process is not recommended for sealed AGM or GEL batteries.  The electronic desulfators are the only alternative.
It should also be mentioned that AGM and GEL cells required more care in charging because voltages vary compared to wet lead acid cells. They are less tolerant of over charging and suffer permanent damage if the batteries are charged to the point of out gassing.

Each type of battery has specific recommendations from the manufacturer.  Long service life is dependent on how closely you adhere to these recommendations.
The old garage type charger is no longer sufficient. It is a constant voltage taper current type, which is not suitable for optimum charging of any type battery. 
An added complication has to do with charge current as a percentage of total battery capacity.  Most battery manufacturers will recommend not charging at more than 25%of the amp hour rating. This means a 100 A-H battery should not be charged at more than 25 amps. What they seldom mention is the minimum charge rate should not be less than 10% so you now need at least 10 amps.  Charging a 100 Amp-Hour battery at 2 amps is not doing it justice nor will it reverse accumulated lead sulfate completely.

More recently lithium ion batteries have begun to be advertised as bulk storage suited to marine RV and off-grid homes use.
The technology has proven itself  in small battery sizes but  it is so new   we have not really seen  long term use  in  big  amp hour sizes to know if this is viable. How many people keep the same laptop or cell phone for ten years?
The really high cost also proves to be a detriment.  Not too many people can afford to put themselves on the ‘bleeding edge’ of technology.

END