HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Sep 29, 2012, 10:22 AM
UN Earth peoples true enemy
treehog's Avatar
Euroland
Joined Jan 2004
1,797 Posts
Discussion
Looking at trying to get numbers on electric generators on the market

Special Edit :Update on the larger 160KW generator fuel figures.The original figures of 1/16 liter of hour are wrong as this genertor only needs to make 25 to 30Kw of power and therfore the real number for fuel consumrÁtion will be more more like 0.5 liters per hour per kilowatt. To sort that I have made the new maths in in thread number 24 .The old maths in this OP no 1 post for the 160KW generator will therefore remain wrong

Looking at trying to get numbers on electric generators on the market.

I been looking at the idea of getting of the grid using various solutions from electric generators to solar power and wind power and batteries .

Well my excursion into the local hardware shop and talking to others exposes some interesting facts on how darn right inefficient and fuel thirsty the smaller generators are

To show how this works if we take a large Diesel 160KW generator that I know of used to run a 80 plot camping site and its remarkably efficient but horribly expensive for a individual

Here are the numbers for the large generator size of engine unknown 6 cylinder diesel must be about 300BHP and about 6000 cc engine in a large box with electric generator producing 170KW max and steady state 160KW
Cost to run is €7000 per month and cost of fuel per liter is about ~€1.00 a liter floats between €0.98 and €1.03 a liter
Weight of the assembly minus the ~30 gallon fuel tank fed by external hopper tank must be about 3000 kilos mayby even 5,000 kilos.
Fuel consumption is about €10 a hour and 10 liters per hour .
Power demands in summer time about 100KW
In winter the camp site is full for north Europeans from Sweden and so forth and the power and fuel demands will increase.

One month is ~732 hours based on ~30.5 days

My ball park numbers show that each kilowatt require about ~20 kilos to mayby 32 kg of machine to give 1 kilowatt of power (3000 kg /160 Kw)
Each kilowatt of power requires €0.625 cents each hour and uses 62.5cc of fuel( 1/16th of liter )for each kilowatt of power .(not including maintenance which is steep maybe 50% of the fuel cost ) 1000 cents/160kw 10,000cc /160kw
That compares well with grid power in Spain here about ~€0.20 cents a kilowatt so its coming in about 30% cheaper than grid power ( if my maths are right using 160KWatt as the main divisor )

Now looking the small 750 watt (steady state ) 2 stroke engine weight about ~30kg publicity says ~ 4.2 liter tank runs 6 hours per hour it jumps out that it isn't cheap to run .
The 2 stroke oil is close to ~€9 euros per liter and fuel costs in Spain are ~ €1.50 per liter .
The engine is rated ~1bhp but must be more like 1.25BHP to supply the 750watts
Assuming they are telling the truth on the fuel consumption and 50:1 oil makes a liter of fuel about ~€1.52 (9000 cents / 4200 cc makes about ~22 tanks of 4.2 liters ~€0.2 cents oil per liter )
we can say it uses ~700cc per hour ( 4200 cc/ 6 hours ) so it costs for 750 watts of power each hour € 1 .06 per hour
Based on this we can each kilowatt would cost ( (1.06 /3 )*4) or ~€ 1.40 per kilowatt hour.


Now I know these are two extremes ~€0.0625 cents kilowatt versus ~€1.40 per kilowatt but this means the small machine costs ~20 times as much for each Kilowatt ( 140 cents / 0.625 cents =~22)
Based on fuel use per cc the bigger engine is 62.5cc versus 700cc for smaller engine
This works out at ~11 times as much fuel is needed to make each kilowatt.
(There is the fact that that gasoline has 20% less calorific value than diesel oil which could with fudge number bring that down to more like as ~ times as much similar fuel per kilowatt needed
Power to weight is similar or greater for the smaller engines ~30KG per kilowatt

The problem is as you go up sizes to bigger generators such as 1Kw 2.Kw and 2.5Kw there huge variation in the fuel figures the generator supplier say.
most cheaper generators will quote larger numbers and the more pricy one will quite smaller numbers but non say fuel consumption with load ratio like 80% load ratio
Here is some examples all are same from France genyx four stroke when you exceed 750 watts (made in China )
~2000 watts 12 liters tank 13hours running or costs about ~ €1.50 per hour ~€250 to buy
~2200 watts 15 liter tank 5 hours running or costs about ~€4.5 per hour
(€200) to buy
~2400 watts 15 liter tank 12 hours running or costs about ~€ 1.90 per hour
(€250) to buy

Clearly there is problem the bigger engine 2400 watt is better than the slightly smaller 2200 watt motor
I figure the reality is heavy loads they will be similar costs

All the Genex 2000 watt to 2400 watt motor users I talked to said they stop working after one month with 10 hour day use for things like TV electronics not heavy use and cost about €2.25 an hour to run or more like 10 hours on 15 liter tanks .Thats about ~€250 to buy divided by 300 hours or ~€1 an hour machine cost time on top of the €2.25 hour fuel rate .However under sales guarantee they got new machines and when the second or third broke down they got their money back in all cases I met on the camping sites I talked too

None I met ever paid the big fees like ~€2000 or ~€4000 to get Honda or Yamaha generators so I cant get numbers on how good or bad are the top

Also I was hoping others who had done small diesel generators usualy starting at 5000 watts or 7500 watts might have some real numbers brands

Hopefully with real numbers form other RC groups people those who want to fork out money on electric generators for leisure or business uses will have some info

One number I got from the carpet cleaner who cleaned my apartment carpets using steam machine diesel engine in the van was ~35BHP 3 cylinder that after 3 years he had to get new engine .The motor ran for him about ~3000 hours .
he wasn't happy as he was lead to believe these engines would return ~7500 hours .
Engine costs for him were €10000 new so each hour cost him ~€0.30 cents per hour not costing in maintenance and fuel which he figured was 3 liters an hour or for non road diesel €3.00 a n hour
So I thought I would see if others out there had real experience with different Electric generators that could help us all who have projects like club field with generator or boats or caravans whatever .

I use liters and euros and later will try to convert the numbers used in dollars and USA gallons so expect some editing to go on in the coming few days on this OP and the other stuff on the thread

So if other reply in USA gallons and USA dollars or UK gallons and UK money I will try also to convert those number to metric and euros and so forth

Some numbers to explain why small gasoline engines are bad is that the ideal cylinder for burning gasoline is ~250cc to ~350cc .That is why many small 1000cc gasoline cars are three cylinders of 333cc each
I don't know the ratios for diesel fuel but I suspect that cylinders from 600cc to 1000 are more fuel efficient.

Thermal efficiency from the engine of cars is at best 30%mechanical losses air resistance etc car will seldom exceed ~7 % global efficiency

Thermal efficiency on mega engines like 25,000BHP ship engine with bunker oil and large cylinders can be 50% at the shaft .Losses will bring the ships global efficiency down to less than ~30%

Small model engine of the 4cc type with methanol would be lucky to give back ~5% global and ~15% at shaft .

Electric engines large scale can return shaft efficiency of ~85% steady state less when connected to machines global efficiency returns from electric cars are often less than 12% due to loses from battery resistance factored in

large electric power station 7 stage gas turbine with local water heating peak efficiency record Holland ~1990 is ~87% but global would often be less than ~50% with coal often being ~30% global efficiency to the wall socket in the house

Bigger it seems is better when it comes to burning fuel

I will do separate thread on solar and wind power as right now I need to factor in the back up power from generators costs .



Ralf
treehog is offline Find More Posts by treehog
Last edited by treehog; Oct 14, 2012 at 11:18 AM.
Reply With Quote
Old Sep 29, 2012, 11:04 AM
56S
Certified Balsa Breaker
56S's Avatar
Joined Nov 2006
1,468 Posts
Well Ralf, as soon as I saw diesel I sort of gave up. Read up on the cost of electricity on the Hawaiin islands. About $.40 per kilowatt/hour generation cost. Where I live in Ohio it is about $.06 kw/h.
56S is offline Find More Posts by 56S
Last edited by 56S; Sep 29, 2012 at 05:05 PM.
Reply With Quote
Old Sep 29, 2012, 11:35 AM
Government is a fearful master
electroman7's Avatar
United States, TX, Farwell
Joined Feb 2001
157 Posts
I've been researching producing electrical power on my own also. My findings are that wind and solar power are expensive and unreliable. You can invest in modest systems that will keep a small capacity battery bank charged. This is only good for a few lights and maybe a high effeciency refrigerator.
Using a generator means you have to make the same decisions as when using the other power sources. How much you can operate depends on what you can afford. A generator running full time to power a whole house will be expenxsive to operate. I need a 10,000 watt generator to keep my house fully operational. I use natural gas to power my stove, heater and hot water heater. The AC naturally is electric. I did discover that these smaller generators can be fairly cheaply converted to propane or natural gas fuel. By far the cheapest fuel here is natural gas. I can justify using generator power only by gonverting to gas and using power management for my house. I also need a fairly large battery bank to operate my off grid property. I will need to install a large water tank to store water in so my well only needs to be run for a time then shut down while I use the water in the tank. Also, I will have to cycle my continuously running appliances ( refrigerator, freezer, TV, computer). Only running some of these at any given time. I will have to stop using my central AC and convert to a swamp cooler. I can do this because I live in a dry climate. Wet climates don't offer that option. In winter, I don't have a large problem keeping the house warm as the heater is gas fired. I will only riun the generator as battery power is drained which calculates to about 1/2 the time. Thats better than full time. Using natural gas as a fuel will help increase generator life as will using methods to help keep from running it full time.
Self generation of power will never be cheaper than the grid. You will always be less efficient in generation and you will bear the full brunt of repair costs as well as your time spent maintaining the system. With the grid, you don't have to maintain the system and the power generation on a large scale is cheaper for individuals.
Living off the grid should be all about energy independence, not reduced costs.
electroman7 is offline Find More Posts by electroman7
Reply With Quote
Old Sep 29, 2012, 11:40 AM
56S
Certified Balsa Breaker
56S's Avatar
Joined Nov 2006
1,468 Posts
^^^Excellent post^^^
56S is offline Find More Posts by 56S
Reply With Quote
Old Sep 29, 2012, 12:08 PM
Let slip the dogs of war!
Park_Flyer's Avatar
United States, VA, Virginia Beach
Joined Jun 2005
1,704 Posts
Soooo, the Rossi thing didn't pan out eh?
Park_Flyer is offline Find More Posts by Park_Flyer
Reply With Quote
Old Sep 29, 2012, 12:55 PM
Who, ME?
dll932's Avatar
Euclid Ohio
Joined May 2005
294 Posts
I gave up on the small gens because they don't run very long and ones that make enough KwH to run much are $$$. Nat gas sounds like the way to go.

Now, a guy in S. Carolina I know has a creek behind his lot and plans to set up a water wheel gen. That sounds like something!
dll932 is offline Find More Posts by dll932
Reply With Quote
Old Sep 29, 2012, 01:44 PM
Registered User
UlteriorModem's Avatar
Joined Aug 2011
714 Posts
Nat gas gensets are somewhere around 12-20% less efficent than gas/diesel. However the lower fuel prices may offset that. You just cant get as much energy out of LPG.

Recently did a large generator installation which used BI Fuel technology. It runs for the most part off LPG but when a large block load drops in it starts using diesel. It works but it wasent all it was cracked up to be. Oh btw it was pretty big about 175KW.

The cheapest energey source by far is 'on the grid'. Just a fact of life. Unfortunatly that is about to become more expensive as well.
UlteriorModem is offline Find More Posts by UlteriorModem
Reply With Quote
Old Sep 29, 2012, 02:02 PM
Trons and Fumes
wrightme's Avatar
Fallon, NV
Joined Mar 2007
5,033 Posts
"Economies of scale" are the operative words in power generation. The average homeowner doesn't have that economy. Unless solar generation costs become MUCH cheaper, it is as mentioned above; go off-grid for energy independence, because you won't save money.

It is more cost-effective to spend a lot for the hyper-efficient appliances than it is to go to home gen.
wrightme is offline Find More Posts by wrightme
Reply With Quote
Old Sep 29, 2012, 04:07 PM
Thanks for the Fish!
aerogel's Avatar
Land of cajuns
Joined Dec 2001
1,066 Posts
Quote:
Originally Posted by electroman7 View Post
Living off the grid should be all about energy independence, not reduced costs.
Yea

Redundancy is the key to me.
Iím still tied to the grid and use it every day.
I have two natural gas whole house generators that allow me to switch while one is being worked on.
I have a complete off grid solar system with batteries x2 of what I need.
Maintenance for all is around 2k a year.
The money I spent on all of this I could have paid for on grid power for the next 50 years
Itís more about peace of mind than anything else.
aerogel is offline Find More Posts by aerogel
Reply With Quote
Old Sep 29, 2012, 04:09 PM
Thanks for the Fish!
aerogel's Avatar
Land of cajuns
Joined Dec 2001
1,066 Posts
Quote:
Originally Posted by aerogel View Post
Yea

Redundancy is the key to me.
I’m still tied to the grid and use it every day.
I have two natural gas whole house generators that allow me to switch while one is being worked on.
I have a complete off grid solar system with batteries x2 of what I need.
Maintenance for all is around 2k a year.
The money I spent on all of this I could have paid for on grid power for the next 50 years
It’s more about peace of mind than anything else.
Forgot one thing, I have a steam engine wood/ coal...but that for kick's but I could use it to make power if I wanted to..
aerogel is offline Find More Posts by aerogel
Reply With Quote
Old Sep 29, 2012, 07:32 PM
56S
Certified Balsa Breaker
56S's Avatar
Joined Nov 2006
1,468 Posts
Quote:
Originally Posted by aerogel View Post
Forgot one thing, I have a steam engine wood/ coal...but that for kick's but I could use it to make power if I wanted to..
Didn't I see you on that doomsday preppers show

I have a 1600 watt Yamaha and a 5K briggs powered boat anchor. The 1.6 runs the fridge,freezer,DSL for the wife and a few fans and lights. The 5K will only be used to run the well pump. Usually I'll burn three gallons a day cycling the Yamaha. I heard story of a local guy that ran his whole house on a propane powered generator for a week and the cost was over $1,000.00.
56S is offline Find More Posts by 56S
Reply With Quote
Old Sep 30, 2012, 12:27 AM
foamie re-cycler
daddiozz's Avatar
United States, WV
Joined Nov 2004
2,105 Posts
Quote:
Originally Posted by electroman7 View Post

Living off the grid should be all about energy independence, not reduced costs.
There is no valid reason why it can't be about both.In order to do so however ,requires making radical changes in your lifestyle if you are a heavy energy user.Therein lay the key.

Take a modern motorhome for instance ,utilizing LEDs for most lighting needs ,and ultra efficent appliances its possible to reduce your total energy costs to just a few dollars per day .There are literally thousands of folks that live full time in their RVs and love it.,Without sacrificing much in the way of creature comfort either.There is no reason the same principles cannot be applied to a home .Its all about energy management and reducing your electrical needs.

My RVs power generating system consists of 4 -76 watt solar panels mounted on an adjustable rack on the roof ,related electronics including a Trace 2000 watt inverter/charge controller and a bank of 6 trojan deep cycle marine grade batteries,Fully charged my battery bank can run all my electrical needs ,(laptop/numerous LED lights /microwave oven /fantastic fan/refrigerator) continuosly for appx 36-48 hrs .The refrigerator can run off a standard 20 lb LP tank for up to 3 weeks continuosly instead.The genset is a 4000 watt deisel,it burns fuel at a rate of appx 1/3 gal per hour when charging the batteries for appx 4 hrs as needed or when running the A/C.Heated water /space heating via deisel fuel and cooking is LP...

I very seldom use commercial campgrounds (KOA etc),except when i need to empty /fill holding tanks...when "boondocking" or dry camping ,my total energy needs has never exceeded the equiv of just $60 per month summer months and $100 +- winter time ..
daddiozz is offline Find More Posts by daddiozz
Last edited by daddiozz; Sep 30, 2012 at 08:30 AM.
Reply With Quote
Old Sep 30, 2012, 01:17 AM
Registered User
Beaumont ,peoples republic of Kalifornia
Joined Jan 2004
249 Posts
Surprised I don't hear more about Lister engines used in gensets for this type of life style
Designed to run forever and not real finicky on what.
Then of course there is the wood gas fueled gensets if you have wood ( has to be dry) or feed corn.
debogus is online now Find More Posts by debogus
Reply With Quote
Old Sep 30, 2012, 06:53 AM
UN Earth peoples true enemy
treehog's Avatar
Euroland
Joined Jan 2004
1,797 Posts
Quote:
Originally Posted by daddiozz View Post
....Snip...
The refrigerator can run off a standard 20 lb LP tank for up to 3 weeks continuosly instead.The genset is a 4000 watt deisel,it burns fuel at a rate of appx 1/3 gal per hour when charging the batteries for appx 4 hrs as needed or when running the A/C.Heated water /space heating via deisel fuel and cooking is LP...
....Snip...

..
Thanks those genertor number are useful along with all the other info
1/3 USA gallon is about (4 liters/ 3 =) ~1.3liters .
I asssume your A/C is ~3000 watts type standard for RV i have seen
Off road not taxxed so much deisel cost ~€1.00 euro here per liter so diesel
~4000 watt generator is looking to be fairly economic with running fuel costs of ~€1.30 euros per hour
Thats means assuming its ~3kw power for ~1.3 liters it costs ~0.45 cents per kilowatt which is double the local spain grid rate of ~€0.20 cent per kilowatt ~$0.30cents

In continious mode thats ~€32 euros per day (~$50) or ~€940 euros per month (~$1300)
Thats not counting maintinace and capital replace costs which can be about 1/3rd as much again

In the USA fuel costs are lower from lowwer tax rates so expect the cost per hour are 25% less than europe based on ~$4.00 a USA gallon and that make it about ~€0.75 per liter of fuel there

What make model is that 4000 watt genertor ?
How many hours have you used it and did they supply a expected life time of ~2500 hours or ~5000 hours ?.

Yes I would look at cycling everything from solar to wind to LPG convertions for fridges and cooking and so forth .
For 8 months of the year the requirement for electric generator is seldom mayby two hours a day max based on other solutions LPG solar and wind power.

The other three monthsis different not so much sun shorter days no wind or too much wind and colder times reqiring more power

However there is unusual problem of connecting to grid in spain in the country side can often cost approx €1000 to €5000 euros ($1300 to$8000 )

I prefer the securty of having my own power as the grid locks me in to thier ever rising costs

I rent property on average and for reason of work might need to move every year proably every five years to new locations in spain

Also the rented property with no power is often less than half the price than those with power connected but are real stickville which suits my needs .

Thats connecting to grid cost is a lot of money that might be better spent on staying off grid as the fuel prices rise and the cost of grid electricity rises and worse they get lots of extended breakdowns and brown outs in spain in the country side mostly in winter when you realy need the power .

In spain and most europe the costs of deep cycle batteries are about double or triple the costs than in the USA so storage of power is often not economic

There is the problem that ito get 1000 cycles from these deep cycle baterries you are best never to exceed50% capasity for each cycle
As aresult so you need at least twice as many bateries as the power you demand .Thats not cheap here
80 amp deep cycles are costing often more than €150 euros ($220).
I worked out a figure of something like €3.00 euros a kilowatt for battery power from commercail batteries on 1000 cycle ratio .

The only maybe economic way is to build my own batteries usuing lead and glass walls or try to source second hand the big 2 volt cells the telecoms use for back up power .Those big 2 volt cells last twenty years or more and can be revamped as the lead plates can be removed and cleaned .
Submarines also use these big batteries .
The local metal scrap yard is the place to visit

Solar power in Spain is good for water heating and electric .
However there are times when the clouds are about the solar is down and the wind is no good so the genertor could be in near constant 16 hour use for days weeks or the entire month
Thats why I need to factor in the generator costs first .

LPG defintly works for gasoline engines
A freind of mine has camper home RV with ~4000cc gasolne engine and LPG tanks gets less than 8 miles to the gallon IMP (6 mpg USA gallon ) on gasoline

Basically last year fuel costs ~€1.20 per liter (~250 liters ,~55 gal imp ,~63gal USA )it costs him ~€300 to fill the tank with gasoline to go ~600 kilometers (~400 miles ) (~7mpg imp, ~6mpg USA gallon )
that cost him about ~€0.75 cents per mile or (~$1.00 per mile )
The LPG tank gave him ~600 kilometers and cost €100 so his fuel costs were reduced by ~66%.
I will also look to convert the gasoline genertors to run on LPG and with luck get more than 50% saving on fuel costs .

Also I might look to get waste used frying oil from resterants and convert it into bio diesel to run diesel engines as that would cost 1/3rd the price of normal diesl oil once you do all the cleaning cracking and PH stuff it requires .

But to figure the economics I need real numbers for genertors

Thanks for those Numbers

Ralf
treehog is offline Find More Posts by treehog
Last edited by treehog; Sep 30, 2012 at 07:14 AM.
Reply With Quote
Old Sep 30, 2012, 07:01 AM
UN Earth peoples true enemy
treehog's Avatar
Euroland
Joined Jan 2004
1,797 Posts
Quote:
Originally Posted by debogus View Post
Surprised I don't hear more about Lister engines used in gensets for this type of life style
Designed to run forever and not real finicky on what.
Then of course there is the wood gas fueled gensets if you have wood ( has to be dry) or feed corn.
I agree on that lots of magazines on the subject renovate old motors like Listers.
However my reasearch on the subject showed it would not suit my needs to get up and running quickly and be transportable when I move house as I would be renting annualy so could sometimes move every year
those lister engines are big heavy beasts and not easy to move around.
I rent out my apaprtment in Northern Europe at 10% ratio and that gives me enough money along with working here to live in south Europe and renting a property here .
its not enough to buy property in this time and the rental from spain property is awful less than 5% ratio so it a very bad investment to buy in spain in this time
For the SYN gas too many problems in many parts of spain with sourcing cheap wood .
If I bought a property in spain would defintly look at that .

Do you know of any Lister projects in case I missed something

Ralf
treehog is offline Find More Posts by treehog
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Wimped out on first time trying FPV on my hexacopter, any help to get over the fear jasper7821 FPV Talk 13 Mar 28, 2012 07:15 AM
Alert look at this fat lie from true rc...on ebay trying to con newbies kogibankole Batteries and Chargers 53 Aug 24, 2006 10:48 PM
Question Trying to get opinions on radios to look at, I want a goo expandable system lordbyronxxiv Radios 4 May 14, 2006 12:12 AM