Wind is Obsolete Technology?

This past week-end I have read news reports of what is described as a ‘failed’ experiment using obsolete technology. The comment concerned a political decision to scrap plans to build offshore wind turbine farms.

This is the first time I have heard wind power described as being obsolete technology.

Reading the article  in depth  I find the originator of the movement to  squash  wind turbines saying wind turbines is obsolete  and inefficient  power generation methods.

I am not sure  how  they managed to  calculate free wind  = electrical output  as being inefficient.. As compared to what?   Solar panels are said to be  at 21% - 23% efficient.

Engine driven generators are said to be 37% efficient. Digging into the subject I find   there is something called BETZ limit that says wind turbines have a theoretical maximum coefficient of 0.59 or 59% efficiency. 

Okay so it is not 100% but then again what is 100% efficient? 

Further ruminations got me thinking that in some locations wind power would come at too great a cost in relation to the return. 

Where I live we are sheltered by a deep valley carved by a river that shelters us from most prevailing winds. No amount of wind turbine capacity would serve to power my home because of the long periods of zero wind in between when a light breeze blows.

We also happen to live far enough north that at noon in the winter the sun is barely 30 degrees above the horizon.  That doesn’t produce any great amount of power.. Given the low sun angle those 23% efficient PV panels suddenly look very expensive per watt generated.

Micro hydro does not look feasible because there is no drop in the creek.

However; a number of other options are still possible. 

If it wasn’t for the fisheries & wildlife department, a water turbine that sits submerged in the creek would be workable for generating power.  The objection is that dam’s etc impeded fish migration. However an undershot water wheel that barely submerges more than 5” into the flowing water where the depth of water is a couple of feet would not impeded fish migration. Except;  the bureaucrats are not willing to even look at it.

We live in an area where logging was the mainstay industry. Sadly  the pine beetle has  killed off  thousands of acres  of  forest and  pretty much killed the industry as well..     

The devastation is so wide spread  logging companies  cannot  cut  down  these trees fast enough  to prevent  huge  amounts from rotting on the stump. Many local residents heat  with wood  because  dead pine trees are so abundantly  available for the cost of cutting  them down and hauling them away.

Something called a Stirling engine runs on heat from an external source. It is at present used to generate power either by focusing sunlight on the active heat collector or by burning petro-fuels to heat the heat collector. A European company builds  a home heat  system  that burns wood pellets  and heats the house while generating electricity  as well.

Unfortunately this company has no immediate plans to export such a stove to North America. An American  company  located  in the east  makes  Stirling engines but has no plans  to offer a small engine to the home power market. They say their focus is on military and space  satellite applications.

Although methane digesters  have been used for  many decades  including in Government  Department of Energy  pilot projects this technology  is largely unheard of  in the North American  domestic market.  Else where it is used extensively. When you go to any of the large engine manufacturers  you will find generator  sets  listed  for Biogas fuel and methane which is the fuel developed by methane digesters  These  generators are  sold  all over the world thus proving this is not a rare form of experimental form of energy creation.

Wood gasification is  yet another form of energy creation that is  widely known  and  has been demonstrated to power  anything from a food cooking stove to powering vehicles.

Although  ethanol  creation from corn has been denounced as a waste of fuel, the same  basic process  using suitable enzymes  to break down the feed stock  has been  demonstrated as being able to produce  ethanol for fuel  from  various biomass  that is normally dumped  into landfill sites as garbage.

The list of  previously invented and  developed  energy generating  devices  is  very long.

Yet most of these are not being used because the present generation of engineers rejects them for one reason or another. 

One oft heard reason being  “it’s not efficient”. 

.This one I have  problems with  because I have  difficulty  figuring out how something that runs on free fuel or  continuously running  water  can be calculated  as being  inefficient.

 Sounds more like someone inventing reasons to reject it by any excuse.

I grant you  there is  a capital cost  involved  in building the machine, but this is true  for any  method. Consider it takes a multi million dollar factory to produce solar cells. Even the manufacturers  declare in their  own specifications that their  solar panels  deliver efficiencies around the 21 – 23% range.

The much maligned  internal combustion engine is  said to be  37% efficient when powering a generator  at optimum load.  So why is solar considered better?  The answer being no exhaust pollution.  Well what about  wind turbines or Water  wheels?

My point in this blog  is merely to show there are many more options  available  when considering  power  sources  for a home  away from utility grid power..

~~  END  ~~

.

Oil is not Expensive Enough

In my search for alternative power sources, I have found innumerable projects that actually worked as demonstrated by various pioneers.  Yet people have adopted none of them. I have come to the conclusion the reason being all of these projects required more effort than opening the wallet and extracting some paper money or writing a check. It would appear people are basically lazy and despite complaining of high oil prices they do nothing to build a workable alternative.

Evidently oil is not expensive enough to encourage people to seek alternatives.

Among my findings is an inventor scientist called Jean Pain. Look here:

http://www.daenvis.org/technology/Jeanpan.htm

http://www.permacultureactivist.net/PeterBane/Jean_Pain.html

http://journeytoforever.org/biofuel_library/methane_pain.html

The concept is not overly complicated and to some extent scalable.  In cold northern climates there will be a lower size limit below which extremely cold temperatures over whelm the system.

Although the original system used mostly wood chips, any decomposable biomass will work in a similar manner.  In many parts of the world growing plants poses a nuisance that requires extensive weeding and effort to get rid of.   In this area at least landfill sites have learned to separate out biomass for composting. Why not take the concept one step further?  Jean Pain demonstrated how he could even generate methane for fuel using his process.  This  concept  will work best in a farm  ranch or  agricultural  plantation where  continual  weeding and  plant pruning  is a necessary part of the  operation.   Instead of simply piling the waste biomass in a corner put it to work.

We already know there is not going to be a silver bullet that can replace every possible instance of oil consumption. So why continue looking with a single-minded intensity.

Instead we should spend some time implementing those ideas and concepts that have already shown to be effective.  Some ideas will only work is specific geographic locales. .    That is okay.  At least in those locales independence from oil consumption is that much closer to reality.

Renter in Dead End Job Wants to go Off Grid

This is what you often see or hear, when browsing the forum discussions.

Sounds like being between a rock and a hard place. It's not fun and options sound to be very limited. Realistically what can a person or young couple does if they fit that description?

I do not have any good quick solutions. Reducing   your energy consumption is a start, so is reducing purchases of consumer goods and service.

F you are not already interested and involved in outdoor activity consider starting now.

If you are reading this presumably you have access to a computer and the internet.

Look up bush craft and outdoor skills. Not everything has to be made from high tech expensive material.  There are a lot of things you can make for yourself that are quite suitable despite being homemade.

At one time I belonged to a pioneer re-enactment group and we made everything ourselves. I had a rifle I had assembled from parts. I taught myself to make lanterns and knives. Other people made storage chests or clothing.  It was a point of pride that we did not even allow plastic buttons or zippers on clothing. Tents were canvas not nylon.

Coolers were allowed to keep food from spoiling, but these had to be hidden inside wooden chests for appearance sakes. Nobody used plastic carriers for water. Instead we used wooden casks.

The point being such ‘primitive ‘camps were every bit as comfortable as any modern campsite.

Entertainment consisted of friendly competitions in target shooting, knife and tomahawks throwing and going ‘shopping’ looking to see who had what on their trade blankets.

Evenings were spent round a camp fire spinning yarns or telling tall stores, also the occasional sing-along or whatever, when people brought their instruments. .

Hand crafts included sewing of clothes and fancy work like beading lace etc. gun smithing, engraving and knife making.  There were opportunity to trade for raw materials to make things skins for making buckskins and antlers for making buttons and utensil handles. Cow horns were a popular item for everything from drinking cups to spoons to powder horns.

Perhaps it sounds corny to a city dweller but once you get involved you start to visit pioneer museums and looking with more interest at books about the early pioneering days.

If you learn to fix things look at flea markets, garage sales, and good will stores for things you can restore to use by making your own repairs. The repair does not have to look like factory new. As long as it works it can still be useful.

I have literally found enough material in the dump swap sheds to completely outfit myself for camping.

Going camping in summer is also off-grid. There are documented stories of people starting out by camping while building their first log cabin.

Here is the first big hurdle. Low cost or free land.  Its hard to find.    Sometimes arrangements can be made to get permission to camp out or make other rental arrangement. If you do not have any money, sweat equity may be an option. 

If you can stand it, working in a drudge job that does make some money (and savings) may be endurable if you know you are working towards a definite eventual goal and building a nest egg. The nest egg can give you the fresh start you need.

If you have prepared by avoiding the worst of the consumer society traps and been able to live more simply, so much the better.

Entertainment is geared to separate you from your hard earned money. If you can find low cost alternatives especially the kinds that produces a salable product or service that is even better.  We do not have cable or satellite TV. The wife knits socks and gloves to keep her arthritic fingers limber. To her surprise people are willing to buy these items and she get the wool for free by scrounging. I tinker, make leather craft; fix old things and so on. A friend collects movies then stores them on an external drive so we can watch them on our computer screen. As it happens many of the movies we like are no longer copyright protected. We love old movies. And then there are those old fashioned things called hard copy books. Many places give them away for free. 

Some of these books deal with how to build log cabins make camping stuff, and tools.

Others tell you how to use tools.

Going off grid is as much a state of mind as it is a physical action.  You will not like being off grid if you feel it deprives you of something.  You have to want to be living in the kind of life style being off grid requires.  Mostly it means being away from large urban centers and always being entertained at high expense.

We moved to an area where the biggest population group is 300 people.  We participate in the plays put on at the community center, and go to fall fairs.  If you join a church other activities are also available. Granted it’s not life in the big city but that is what we wanted to get away from.  

~~  END  ~~

Small Packages for Off Grid

A number of people have expressed a desire  for  a minimal  solar power system  intended only for a laptop and maybe one or two LED lights.

The  standard question is  how much power do I need for_____?

That is like asking how long is a piece of string.  Same answer applies. It depends!

Its hard to give an accurate answer  especially one that  can be used by several people.

Put the question another way  will give you something that can be applied  to a variety of situations.

Automotive stores sell several products containing a sealed battery some kind of charge indicator and short booster cables with clamp on grips at one end.

Most of these products  use a battery of 20-amp hour capacity and the larger models use a 40 Amp hour capacity.

20 amps multiplied by 12V give 240 watts and the battery is typically rates at the 10-amp rate meaning it can deliver approximately 2400-watt hours at most. In real life lets call it a conservat8ive 2000-watt hours.

If your laptop uses 25 watts it will consume 25-watt hours each hour. In theory this should allow you to run the laptop for 80 hours maximum. 

I say in theory and at maximum because I am hedging due to certain physical laws we cannot violate.

When the battery is fully charged it will read 12.6V and when it is fully depleted it will read 10.5V Caution depleting a battery to 10.5 v will quickly damage the battery beyond recovery and further use.

Batteries are rated by using an arbitrary test method using standard numbers for equivalency of comparison.

Inverters typically have a 10% conversion loss.  So a 25% load would on average use 10% more or 26.5 watts to drive a 25W laptop.

At 12.6V the load current for the laptop would be 2.1 amps.  When the battery drops to 11.0V   the load current rises to 2.4 amps.

Using close to average numbers we would take 2.25 amps and divide that into 20 amps hours to get slightly more than 8 hours run time before the battery needs a recharge.

Using the charge rule of 25% also expressed as C/4 we should recharge at no more than 5 amps so it will take more than 4 hours to recharge.

Fortunately AGM batteries are fairly robust and can accept a faster charge but at the sacrifice of shorter lifetime. AGM batteries can last 5 years of regular cycling but this decreases to just over a year if you use the maximum charge rate and deplete the battery to its fullest every cycle.  A realistic average is two years life when depleting to 80% depth of discharge and using a 30% recharge rate.

To deliver a 6 amp  charge rate would  require at least a 120watt panel used in  latitudes north of 45 degrees and the location averaging   20% cloud cover average. 

~~  END  ~~

Efficiencies and Energy Conservation

Much has been written about efficiencies of wind solar and micro hydro.

One of the subjects that rarely get any mention is the energy efficiency of the home that an alternative energy system gets installed into.

Proper design of the home can greatly reduce the amount of energy required.  For example a forced air system needs lots of energy to drive the fan that circulates the air in the duct. Improving the insulation and weather sealing will reduce the energy used to circulate the warm air. Better methods of heating a house are available. Some of them hardly use any energy at all if you have a wood stove in a central location natural convection may distribute warm air to all rooms.  My previous house was like that. As long as we kept doors open every room was heated. In fact despite closing the damper our biggest problem was too much heat and we spent most of the winter when indoors in summer wear.  Shorts and a tee shirt were ample.

Hydronic or geothermal heated homes   circulate hot water and the circulation pumps are typically 150 watts or so and run continuously.

Thermosyphon systems with roof mounted solar heat collector panels are another option. With careful design these will not require any electrical power.

Interior lights for rooms and spaces without windows can be illuminated in daytime with something called a light tube. They are much smaller than a skylight yet deliver adequate light without electrical power in daytime. 

The above are things that can be retro fitted to existing housing.  If you are fortunate enough to be building from scratch many more options are open to you.  In most cases you have the freedom to orient the house to take maximum advantage of sunlight and for placing solar heat or PV panels.

The property can be landscaped to provide shelter from prevailing winds. Windbreaks can be planted using fast growing trees. 

Rooflines can be oriented to deflect winds either for shelter in winter or to give cooling breezes in summer.  This could reduce any requirements for energy gobbling air conditioning.

If you are building, plan to include a root cellar. This will give you plenty of food storage that requires no electricity.  Adding a root cellar to an existing house is obviously also possible but usually involves more than closing off a corner of the new house basement.

Why Doesn't My Solar Panel Deliver Rated Output?

This is an oft heard complaint coming from solar panel owners.  The answer is not that simple but the most obvious one is due to geographic location and is rarely mentioned by solar panel vendors.

Scientists have determined that a square meter of   the earth’s surface is illuminated by 1000 watts of sunlight.  However this is only true when the sun is directly overhead such as close to the equator. Due to the axial tilt of the planet   the sun may be directly overhead even 23 degrees north or south of the equator depending on time of year.

In North America the industry decided to establish common standards so the consumers can better compare products. The test labs for doing these comparisons are located in Southern California in the desert away from urban pollution and atmospheric contamination that would skew the results.

Unfortunately not everyone lives as far south as this test lab facility.  As a result the slant range of sunlight reaching the installed solar panel has to pass through more atmosphere than sunlight coming from directly overhead\

This atmosphere often  contains  dust particles and thin cloud layers  which  attenuates   the  strength of the sunlight  and thus  the  maximum possible  output  of the    solar panel.

In California the common bench mark for a 1000 watt panel is a total of 1900 kilowatt hour output per year.  This same panel will only produce half as much total power at latitude 53.North.  You can find and download something called insolation charts.  These charts show how many hours of effective useful sunlight for given geographic locations. Some locations are more prone to cloudy weather than other locations.

A common misconception about these charts being that maximum output is still whatever the rating of the panel is.  These charts simply provide you with the number of hours during which the panel put out the maximum possible watts AT THAT LATITUDE  AND  GEOGRAPHIC LOCATION.   An assumption is made that when the data, is collected  and averaged the numbers will be consistent from year to year. 

Climatologists have  noted that flight paths  which concentrate  the  tracks of aircraft  leaving contrails  in the  sky have a measurable  reduction of sunlight reaching   the  ground . This  should also be taken into consideration. 

The  rough rule  of thumb  for sizing  panels  should  be to derate  in proportion to  how far  from the equator you are.  At latitude 49 expect roughly half  as much output.

Below is a graphic illustration to show how it works

In the diagram the sunrays are shown hitting a meter square panel at right angle. The 45 degree angle represents the angular strike. The red line is the same meter wide panel but only 70% of the same band of sunrays hit the active surface.   At latitude 60 the portion of the same bundle of sunrays hitting the active portion of the PV panel is down to 50%.

 This diagram is representative and does not make correct allowance for curvature of the planet nor atmospheric attenuation. This is going to increase losses.

~END~

How About Solar?

Everybody talks and thinks solar power these days. That works as long as you live in an area with enough sunshine hours. 

Our media is flooded with advertising directed at the lucrative California market.  What is sometimes included is cost figures for state and federal rebates local incentives and Feed-In tariffs for selling back surplus energy to the utility.

But what happens if you are located in an area where there are no incentives or the financing is dependent on you being able to amortize a bank loan over 20 or 30 years.

This ability to repay a bank loan is dependent on having a regular job in a stable economy.  Many people looking to go off grid are either retired on a low pension or just plain out of work.  They seek off grid living as a way to reduce living costs because living in the city simply is not affordable. Think a bank is going to give them a $30,000 loan that will outlast their lifetime and possibly exceed their ability to repay it on a low pension.  If you live in an area that does not have provision for a Feed-In tariff or if that tariff is only a couple of pennies per Kilowatt how long will it take to recoup any of the capital expenditures.

I just received  data from someone in Belgium who quoted statistics  indicating a typical California installation produces 1900 kW H per annum  for each kilowatt installed.

He lives in northern latitude so his annual solar collection is cut to about 870 kilowatt hour or just under half the California statistics.

Other things being equal it supports my own estimate that up her in the north we can only expect half as much power from a given PV panel install as the specifications would indicate.

An additional factor has to do with panel mounting.  At the equator   the sun rises almost due east and sets due west of the observer. The further north you go the more skewed this becomes. I live at latitude 53.5 north. In summer the sun rises in the North east and sets to the North West.  For a period of time the sun is BEHIND a panel aimed directly south which is the recommended fixed position.

In other words for many hours   the sunlight will not reach the PV panel and therefore not produce any power at all.   During the period of time when sunlight does reach the front (and active) surface the output is not always full. It is only when the sunlight strikes at right angles you get maximum power production.  Even so maximum power is not going to be as much as what you would see at the industry test lab in southern California in the desert.   Bottom line being it will be more expensive to get the same output power when located in northern latitudes compared to the theoretical rating achievable in a sunny southern Californian desert.  

This does not even begin to talk about PV panel efficiencies.  Scientists have calculated that the sunlight reaching the earth’s equator is equal to one kilowatt per square meter.

The best available panels on the market delivers just over 200 watt per square meter.

From other industry sources we are told PV panels are 20 – 24 % efficient and that agrees with the other way to express efficiency.

When buying in large quantity the best price currently being quoted is $3.50 per watt.

As a comparison go and price out the smaller panels sold in local stores. I did and found prices as high as $12.00 per watt.  One popular panel is 5watts measures a square foot and cost $60.00 - $80.00.    This much for only 5 watts?

In order to get the $3.50 price, you need to buy at least 1000 watts worth of panels. Add to that the price of controllers, batteries and inverters plus installation and you are looking at a $10 - $20 K price tag.

This is still only going to give you a system where strict energy conservation is called for.  If you want or need more than the minimal energy it rapidly becomes much more expensive.

Surely there is a better way to do the job? And there is.

Wind, micro hydro, methane and wood gas production are options. Not all are equally good and not all of them are suited to your particular location.   These are subjects for other blogs.

~~  END  ~~