Micro CoGen.

Lowgear.
FWIW  the wife's uncle  runs a Franklin submerged pump 300 feet down on his off grid homestead.   He upgraded to an Outback 3000 watt inverter hooked to a 48V battery bank consisting of eight L-16 batteries.   It still will not  start the well pump and the uncle can't see  the point  to installing a soft start module from Franklin. We measured  a 7500 watt start surge when driving the pump from a 10kw diesel  generator.
He faces two problems.  Most deep well pumps are  230V  and  most domestic inverters are 120V. Outback's solution is to buy another  inverter wire them back to back to get 230V.  As is he has to start the diesel to run  the deep well pump to fill the cistern where a low power pump them gives him pressure at the tap.
Second problem is the fact  domestically made inverters like Outback and Magnum  use an iron laminated transformer. They cannot deliver more surge than 2X
High frequency switch mode  inverters like the Xantrex Prosine series will deliver  3x surge power provided you use BIG power cables.

In my own designs I use a 230V output  inverter of the switch mode type to drive all big surge motor loads. For 120V utility power I can generally get away with a 4kW step down transformer to feed utility outlets. Most homes use less than 2kW for lights etc exclusiive  of air conditioning and electric heat and of course deep submwerged well pumps.

If you are wondering  where I observed all this. I did at one time work at Xatrex as a marine applications  engineer.
Elnav

I have recently been asked to make a proposal for an off grid  residential project in Mexico. Each residence would probably need  5 kilowatts of  solar panel and a substantial battery bank.  The scale of this project is such it may well be a good candidate  to try this NiFe  approach. 
Unless I can figure a way to convert waste heat into air conditioning it does not look good for a true CHP installation.  I am  looking to see if  the waste heat is sufficient for the desalination system. Otherwise I am looking at a few  hundred  kilowatts of generator power to power desalination RO pumps plus the sewage treatment  system.
Anybody have  good suggestions?

LLoyd the downside to stacking lies in the fact  if one goes down  then your whole system goes down  due to the fault signal  from one shutting down the other as  a safety. 
In my systems I use victron 230V output to drive the heavy loads including air conditioning, then step down th 230V to 115V for light utility circuits. As you know  Victron can be selected for either 50Hz or 60Hz and they can be  paralleled up to 5 units together; provided you can deliver that much DC. 

Hyperion had  about 30 Victrons installed because  the 230V AC power was actually 3 phase. 

Whispergen  was marketed  in Europe  by Victron as an adjunct to their  inverters, chargers, and other  off grid and marine products. This was going back to 2001. Due to an unfortunate  manufacturing problem they suffered an excessive  number of warranty problems and the product was pulled temporarily from the  North American  market  only a month before I was to get factory training as a Whispergen technician. We did have one unit running at the Miami show  and it was fully functional inside the building. Silent and clean burning. Nobody  would believe it was working inside  the building.

Marketing is everything. At the time it was being marketed as a silent generator not as CHP heat source  that also produced electricity.  Naturally that did not sell well to the Miami crowd looking to drive their  power hungry air conditioning  while producing waste heat they could not use.
This past year new dealers in the PNW both near Seattle and Vancouver BC have installed Whispergen in boats cruising our northern water where some heating is required at least six months of the year. but yes it is over priced for the market. Not all of that is due to exchange rates.  If I could get just the  stirling engine   It could be welded to the wood burning boilers a friend sells and then we would really have something.   

Consumer Gas head office in Toronto did the same thing. I worked there back in 1972  as a  calibration  meter service tech. When power went out in nearby areas The Consumer Gas building always drew attention because the whole building was still lit up, and heated or cooled.
Consumer Gas was the biggest natural cas supplier in Ontario but I think they were bought out  in recent years. I wonder how many other such examples  are hidden  away?

6hr to recharge a 440 A-H bank is perhaps  overly optimistic.

The stated  75 amps  is a cold rating if I'm not mistaken. If the  alternator  remains controlled by  the internal single stage  regulator th eoutput current will steadily decrease as the battery  becomes charged.
If the alternator  is controlled by a external 3 stage regulator  it will take  4.5 hours  to reach the transition stage from bulk to absorption. At that point  the battery will still be short 110 amp hours  but the charge current will decay in an exponential manner  at an ever reducing rate.  However  it will take more than  1.5 hours to reacg a state of full charge. Given the usual  efficiencies of  the charging system it will take at leat 110% to fully  recharge  the 440A-H battery bank if fully discharged. The alternator will therefore have to deliver 480 amp hours  not 440.
Prudence  suggest  batteries not be fully discharged.  however  when you recharge  a partially discharged battery  the acceptance rate is lower  and  in turn this  means a lower total current. 
Running any alternator at full maximum current is going to produce heat which in turn causes a reduced output  and thus longer charge times.
For a charging application involving maximum  output for many hours  you should only use a smart regulator that not only monitors  battery temperature but also  alternator temperature. This will prevent  damage to the alternator  stator windings.
Balmar is one such product  that includes monitoring  alt. case temps but also has an Amp Manager.  This feature permits  limiting the maximum output current  as well as invoking  additional  safety features.  This will prevent heat damage.
 

"So, how long does it take to replace valve guides on two heads ?"

REPLY
AS a DIY'er I often ask the same question  but  back when I was a production shop manager  I know ther are constant overhead costs to be covered.  Around Victoria and Vancouver the cost of running a business  means a shop rate of $80 - $100 per hour is needed to cover rent, light and  wages including  insurance mandated by  government etc.   Not to mention which if you are going to do a job and warrant it free of workmanship defects  you have to take care to do  it right the first time. So part of the job is to ensure  nothing goes wrong  ... goes wrong ... goes wrong.
No point in press fitting a new guide if it goes in crooked  because the original install was crooked.  Threading in a new  one  means you have to scrupelously clean the  whole casting to ensure  dirt doesn't get  in there to cause  a problem. 

It all takes time and  likely you will not have time enough left over to switch to the next paying job  before a shop hour is used up.   
Which is why some of us DIY  if we can buy the machine tooling cheap enough  and can afford the  shop space or whole building to house all of it not to mention heat and power for the shop.  But if you  total up the cost of  having your own machine shop then divide it by the number of hours in actual use the cost per hour is often shocking.

Jens  I think you are already  over the max amount of Lye. Back in my younger days when I was rebuilding  hot rod engines  I would use a one pound box of lye for  20 or so gallons of water and I was warned that this strenght would eat away  bearing  inserts and ruin  any aluminum by eating away at close tolerance  machined  surfaces.  After boiling for an hour the cast iron blocks would come out squeaky clean but discoloured.   A session with a soft  brass wheel brush would clean that up.
My boiling pot was a steel drum cut in half  so  capacity was no more than 25 gallons  and less when block was placed into the barrel.

Unless  exact temperatures   are necessary  so as to prevent overlooking the engine  the hand held IR thermometers are usually sufficient.  I have used mine to detect  faulty injectors  by noting which exhaust port ran cooler from a misfiring cylinder.  Reading a manifold  may not be quite exact as reading the actual gas stream but it comes close.
Burning diesel under normal full loading  tend to burn at around 750F   

As explained by the wikipedia file  a thermopile is more pf a Peltier- Seebeck  effect
EMF is also used to denote Electro Motive Force.
The  thermopile used in a furnace  probe or the truck exhaust pipe generator  is direct heat  to electricity conversion  without any movement of wires in a magnetic field like that used in an alternator. 
The thermopile is recovery of waste heat  whereas converting rotary motion into electrical energy is not.
In its native form  the Lister or Changfa  does not include any charging source for an electric start.  That was my point.  The exhaust heat first passes through the thermopile generator then to the heat exchanger to recover more waste heat.   

On the subject of thermo piles.  The question was asked on another forum.  Does a 'thermocouple'  in a furnace produce current or voltage.  I among many others  thought it produced voltage. The correct answer is more current than voltage.  It was pointed out the solenoid valve had few turns of large diameter wire not many turns of thin wire to create enough flux to open the valve.   I didn't quite believe it so I dismantled a gas valve to find out. sure enough  the coil had few turns of relatively thick wire.        

A couple of  years back I read  that one truck company was offering a electrical generator  of 1kW output  that consisted of a exhaust stack  section surrounded by "thermo couples" whic hI now realize should have read "thermopiles".   Hmmm?  Maybe a means to make a non rotating start battery charger if  a belt driven alternator for a slow diesel is not practical?

   

One of the problems with charging  lead acid is the need to taper off the charge  during the latter stages  from 80% to 100%  full charge status. This in itself unloads the charging plant.  On one recent boat system  I coupled a water maker   belt driven to the generator motor  so it could load up the 10HP Kubota  engine during the latter stages of  charging. This resulted in fully loading the engine and doing something useful besides  tapering off the charge . On land this could also be accomplished by pumping  water into a resevoir on an off-grid ranch for example or  use the resevoir as pumped storage  to run a micro hydro turbine.   This is the approach used near Niagara Falls . During low demand from grid, they pump water into a natural resevoir then use  that power  to help buffer  peak demand  periods. 

If you do not trickle charge lead acid batteries right through to the float stage  you end up with some residual sulfation and the  accumulation grows each cycle.  Eventually this will kill the battery prematurely.

One of the things I recently found out about wind and solar  controllers; is the fact the controllers do not usually employ ' smart charging'  techniques. Instead these controllers  simply shut off when the high voltage set point is reached.
Most solar panel controllers simply disconnect the  PV panel from the load and  the better Wind generator controllers divert the output to a diversion load which could be a hot water tank  but is often just a bank of resistors.   Either approach is not optimum.
In recent years AGM has gained  popularity due to the fact lead acid batteries impose shipping restrictions.   
AGM has been exempt  from these restrictions  and can even be carried by air craft. Which is why you now see chinese made lead acid batteries  delivered overseas for domestic sales. The environmentalist have sucesfully closed down most batter fabrication shops  in this continent. 
Lithium Ion batteries  look good on paper  but look at the cost.  They have not been around  long enough for us to have a long history of use.   NiFE made by Edison have been around long enough for us to have some idea of  comparative  performance  relative to lead acid.    Their ability to be deep cycled and  replendished when  the electrolyte is exhausted  makes them attractive despite  the apparent lower efficiencies.   This is something you cannot easily do with lead acid. 
I asked but did not receive  an answer  regarding how Peukerts  Co-efficients  apply to NiFe  instead of Lead acid.
 
I'm showing my age but my electricity lab  had NiFe  batteries to drive the motor generators we used to perform  experiments with . This constituted a substantial load  that was comparable to driving a big inverter like a 3 kW  unit.    Considering we ran those motors for hour long classes  at a time  I have the feeling  NiFe can in fact handle sustained heavy loads as well or better than lead acid.  Why else would they have equipped the school with  them instead of  lead acid?

If NiFe  can in fact stand up as well or better to deep cycling  and sustained high discharge current and frequent recharging it means you can support an off grid home with less amp hour  capacity  relative what it takes  with lead acid batteries.   And charging a deeply discharged NiFe   battery makes for better efficiencies  than  charging a lesser discharged lead acid  battery  if the Sandia test results apply  on a broad  range of brands and types.   

Quote from: Bruce on May 04, 2010, 10:30:44 PM
Last year I started reading about Nickel Iron batteries, and found only China and Europe.

Interesting read on the ZappWorks web site, but are you sure these batteries are actually manufactured here in the US? I would suspect a Chinese import is porbably involve.

REPLY
I contacted Zapp Works and was informed that at the moment they were busy refurbishing some Edison  cells (olld U.S.  mfg.)  in order to do some testing. I had asked for data curves instead of single data point information. The correspondent  indicated they expected to have this testing done in six months   and be able to post  data curves then.  
He clearly indicated  actual manufacturer would be done domestically.  And why not?  a metal shear  to cut iron and nickel sheet stock into plates  plastic  cases  to hold plates and electrolyte.    The formula for mixing electrolyte  from powder and water is readily available.  the case tops will be removable so you can  open up the cells and flus  the plates  prior to replendishing  the electrolyte.

Mike  I think you  are jumping to conclusions regarding  what  system I am envisioning . Ken Gardener  is using thermal masss  to store heat  in between  genset runs.  This is prefectly viable.  During  periods of low electrical  demand it is possible  to run a much smaller  genset for Battery charging.  Minor supplemental heat can be derived from  solar heat collector panels for domestic hot water etc.   
My  uncle in-law  normally runs a 25 kW Lister  to power his resort but when its only him and the wife, he only runs a small 4-5 kW  genset .  His brother who is also off-grid  runs his entire house on a 3 kW Outback inverter and only needs the genset running when charging batteries or  to run the well pump on a 350Ft deep well.  He uses a wood burning boiler for heat because wood is  free except for the fuel for the chainsaw.
I got to thinking about methane digesters because a couple of ranchers I know  has begun raising a few hundred chickens  for eggs so the manure is already there as raw feed stock for making methane  gas which in turn can be used to generate  electrical power.   

Bob wrote:
They also make the claim that in Denmark, CHP accounts for 55% of the electricity generated.  If true, I'm very surprised at that number!

REPLY
Believe it. My uncle ( a steam fitter) worked in that field  for more than  20 years before he shifted over to to work on the nuclear reactor Denmark built on an island .  In Denmark we called it 'distance heat' and was well established  many decades ago. Remember  that Denmark is a very small country. You can put it in your hip pocket of some baggy overalls.