Help Me Design It

[Dail R H]

   Need some design help here. This project may end up soon ,n not sure where I'll end up .Have wanted to do an off grid project for some time ,n this may be my chance.
   I have a 12/2 that I've never started ,( 'nother long story). I try to live pretty normaly, and would have the normal stuff one would find in the average home. Heat either wood, or waste heat from Metro,probably no ac ,althouge may consider some sort of absorbsion system.Tv n sattelite ,refridg ,n small freezer , probably a water pump as well/
   I read n read nthe more I learn ,the less I know . Batteries ,inverters ,110 / 220 , 12 / 24 / 48 volt n more dc aaaaarrrrrrrrrrrrrhhhhhhhhhhh ,my brain is on overload.
   Here's what I know I want
   1. The 12/2 ,maybe a 6/1 as well
   2. Some wind ,probably along the lines of the otherpower style
   3. Some solar if funds permit,yeah ,in my dreams
   4. Must be simple to operate n maintain

   Well there ya go fellas,that ought to be a start at least 

[JohnF]

Have a look at my website www.woodnstuff.ca, that will give you an idea of what I have done.  In short, a couple of engines (mainly 6/1's) running on WVO, a largish battery bank and a pair of inverters.  I found wind to be too intermittent where I am and of course solar is very expensive - I can put in 5 or 6 engines for the cost of one good solar array.  I may change that in future, the Ontario government is promoting solar with some good $ incentives. 

It's not really that hard, I live pretty well on my system, you just have to be aware of load leveling.

[WGB]

I hope you get a ton of info!
I'll be looking too!
I've got my 6/1 Metro with a ST pretty much done.
Just picked up a Changfa clone, and a VOLTmaster head was delivered yesterday.
I have a 10' Otherpower turbine about done. I went to a workshop, well worth the time and money! We have commercial wind farms all around us, wind not a problem.
Will install solar on a ground mounted array as money permits.
I am going to drop a load on inverters, and have a battery distributer I know 15 miles from me.
We also have a flowing well we put in last year, A/C maybe? small hydro maybe?

[mobile_bob]

this is the method i chose to use to determine the design criteria for my off grid plan.

based at the time on circumstances following an ugly divorce where my ex seperated me
from a substantial amount of what i had worked for most of my life, another story obviously.

the point being money was short and likely would be so putting together a nice size solar installation
was out of the question, hydro was non existant, leaving only wind power as a possibility and of course
the engine/genset, one of which is very intermittent and the other can be expensive to run all the time.

so basically i figure the engine driven genset is the center of the power generation scheme, everything else
is to be viewed as a suppliment to that source of power, and as the other sources of power come on line
they to some extent will reduce, limit, or eliminate the need to start and run the genset,

so the genset need be damn dependable and the most efficient i can put together.

once that decision was made, the next step is determining how much power you need over time, and how much power
you need for peak times. basically how much average power capacity and how much peak?

this is where you must sort out all your loads, and realistically figure how and when they need to be supplied with power

you might find that your average consumption is 1 kwatt/hr,, and at times your peak is 5kwatts, so
a 6/1 by itself isn't going to service that scenario, however with a little load scheduling the peak load might be reduced to where
the average is 1.2kwatt, and the peak is 3kwatt, here a 6/1 probably can handle this scenario without issues.

getting control of your loads, determining how and when they will be supplied is probably the single most important thing
that will determine what you system needs will be, and how successful you system will be as well.

certainly you can just go out and buy a 30kwatt genset and cover likely ever possibility you can through at it, and live however
you want with not a care one about power needs, but
running at an average of 1.2kwatt per hour that genset will be horribly inefficient and not have enough load on it to burn clean
and live a long life,, so expect high fuel costs, and lots of maintenance and repairs. that is the upper extreme.

on the lower end of the spectrum is controlling those loads in such a way so that the lister 6/1 can cover the loads and run at
or near peak efficiency.

it might be that you decide to buy the batteries and inverters to couple to the 6/1 so that the engine can run at or near the 3kwatt
max to provide 1.2 for the continuous loads and have 1.8 left over to charge batteries, and then not have to run all day long.
you may find that you can cut your run time in half or more using this scheme and with a decent size battery bank and larger inverter
you might find you are able to get the surge capacity needed to provide those high current startup loads like well pumps or other high current loads that are intermittent and short duration that might have been outside the capability of the 6/1 to start with.

basically the first step is to determine your continuous load requirements and your peak load requirement, armed with this info you can
then set out to design a system to cover those needs and have some expectation of success without haveing to duplicate your efforts
or have other less than satisfactory operation problems later.

bob g

[mobile_bob]

upon another "thunk" i would like to add the following so as not to alienate some other folks here.

my use of the 6/1 in the previous discussion was for illustration purposes only, mainly because it is a
typical engine used by many here, however

certainly it might be appropriate for some to have a 12/2, 25/2, or maybe even a 30/1
depending on several factors, such as

do you live in the deep south where airconditioning is mandatory for survival? and have several heat pumps?

do you live in the far north where heating is a huge factor?

do you just want a backup genset?  in which case a large capacity genset like a 12/2, 25/2 or 12v149 detroit
might be just fine for that application where you just need power and you need it now, and your needs are quite
large in comparison to what they might be under normal circumstances in a more moderate climate?

a lot of things to consider, this topic alone would make the subject of a very lengthy book in my opinion
and perhaps it is time for someone to write one?

bob g

[Jedon]

I'm not an expert but have been working on my system for a year or so now, here is what I gleaned for my situation in northern CA.
48V is good for a battery bank so you get less resistive losses.
A newer inverter like the Xantrex XW 6048 would provide plenty of power for what you mention as well as giving you 110V, 220V and even 3 phase.
Start with one bank of batteries and expand as you find you need more, cheap versions are 6V golf cart batteries from Costco or Sams Club, longer lasting would be Trojan L16's or equivalent. Either way they are 6V batteries so get 8 to start and expand to 16 if needed.
Have at least 2 generators, something like a 6/1 for everyday power and perhaps something larger for when you need more power or need to equalize the batteries.
Even though it gets hot here in the summer ( high 90's ) it cools down at night so I designed the house not to need AC which is a huge energy hog.
I heat with wood.
Stove and Dryer and Tankless water heater are all propane.
I have a huge normal 26cf refrigerator, 62" DLP HDTV, computers, routers etc.
I have 780W of solar cobbled together which keeps the fridge going during the day and run the generator about 5 hours a night ( 12HP 5400W Lister SR2 for now until I get the 6/1 working right ).
Don't underestimate the amount of time and effort it takes to get a 6/1 or 12/2 all set up and generating reliable power.
Diesel generators are way better than gas ones. Find a 300+ gallon diesel tank and have fuel delivered.
Good luck!

[Ronmar]

It can't be emphasized enough.  You need to fully understand your current energy consumption.  The more large demand loads(hot water, stove/oven, dryer) you can move over to gas, the better off you are.  This will move your peak loading requirements nearer your average load requirements.  It will also lower the required average, perhaps more comfortably into the realm of a inverter and battery bank to provide for the majority of your runtimes.  It will also lower the required size of your generator, and allow it to be sized to run, when needed, at it's most efficient.  The battery bank/inverter scheme allows for flexibility, and will also free you from full time generator operations.  There is a lot to be said for a quiet night around the house, and that the lights still come on when you flip the switch. 

As Bob mentioned, you can start with the generator charging the batteries as needed, and add solar and wind to augment the generator as funds and resources allow.  Solar water heating panels can also be added to replace some of the gas usage to heat water.  The generator should also be able to power the loads directly.  If you are building up the generator, you can start this way, and phase in the inverter and battery bank.  This is the nice thing about the belt drive on a large listeroid flywheel.  You can have one engine and two or more generator heads(AC and DC), which are only a belt change away from being driven by the prime mover...  A good plan is flexible, and I believe that is the key to going it "off grid" 

[mobile_bob]

Ron has it just right when he mentions flexibility

i suppose there ought to be something like the 10 commandments of offgrid power
starting with

know your loads, and how to manage  them.

conserve everywhere you can, the obvious are compact floresent instead of incandesant, and as Ron mentions
use gas appliances where you can.

be determined to have as many power sources as possible, main genset, and a backup, perhaps one that runs on
another fuel source, solar when you can afford it, hydro if you have the resource, same for wind, micro nuke (ok
maybe not that one) etc.

be determined to produce as many fuel sources as possible, even if small they will all come in handy, diesel and gas are
obvious, propane or other gaseous fuels, veggie oils, waste oils, pressed oils, methane from a digester, gasifier

i am sure there are others that can add to the list

the following is my personal philosophy and you can adopt some/part/or all if you like.

the engine driven genset should be the core of any system, often times it is gets a support role to solar or hydro
and when done that way almost always suffers in attention to detail it deserves with less than acceptable performance
when needed.

it should be viewed as a sort of reactor, something that is due as much attention to detail as one can invest, both in
time and money, some will have more money than time, while others the reality will be the reverse. in an offgrid installation
it is the engine driven genset that not only will keep the lights on when all else fails but very well might save your bacon in
a real time  of need.

everything possible should be done to improve the units efficiency, to harvest and use the waste heats where appropriate
and to use batteries and inverters (the hybrid approach) to reduce run time, increase efficiency, and reduce emissions.
one does not have to be insanely green to understand the benefits of low emissions, reduced runtimes and increased efficiency.
should the time come that fuel is scarce and/or very expensive, time and effort spent in the design of your unit will pay huge
dividends should there be any sort of fuel shortage situation.  we also should understand that the emissions standards will only
get worse and there will be a day when even having a preban engine will be unlawful to operate or will be legislated or taxed out
of use and into the scrap pile.  The less time you run your engine, the cleaner it is, the less likely it will be found down the road.

once you have your machine perfected to produce power efficiently, you can then seek to add other forms of energy production
to further reduce the units runtime.

push comes to shove later when the sun doesn't shine, or the wind doesn't blow, you are old or too sick to climb towers or make
repairs to other power production you will be able to rest assured your diesel powered genset will be something you can depend on.

bob g

[Dail R H]

   Thanks guys,didn't know where ,or how to start.guess I need to evaluate my real power needs first to see how much I actualy need.Already have the 12/2 n 7.5 k head for the shop stuff,may be enough to add personal household load to.
   Re lights,I'm totaly night blind,so leavelights on somewhere all the time.They may be the way to go ,,n I may end up with them,but Ihate cfls n find leds not practicle. Takes a lot of light for me,anything smalletthan a 100w is a refridgerator buld, n I'm much happier with 150

[Jedon]

Maybe you should look into HPS or LPS lights then. http://en.wikipedia.org/wiki/Sodium-vapor_lamp

[mobile_bob]

lighting can be a huge comsumer of the power you generate
for instance 10 one hundred watt bulbs left on with consume 1 kwatt per hour
thats 24kwatt/hrs per day, and that is insane in my opinion, and it happens that some
folks that are oblivious to what is going on can burn a lot of kwatt/hrs

second on that list is the fridge or freezer, bad door gskts, older inefficient units, dirty coils, kids
that have to open the damn thing and just stand there, what seems like 100 times a day can
lead to an enormous amount of power consumed.

electric heating water with kids that take one hour showers 17 times a day is another killer,

worst case senario?  you might need one of those huge 4 cylinder inline listers just to keep up.

bob g

[oiler]

Fact is, you your actual need is lower than you expect it to be.

My 6/1 can supply us with both heat and power if run 24/7 as is is now.
All bulbs are either LED's or flourecent, and our fridge, freezer, dishwasher and oven are lowenergy models.

All you need is to teach your wife not to run it all at the same time.

[Dail R H]

   Ever tried to "teach" a wife anything?

[XYZER]

  Ever tried to "teach" a wife anything?

Yes I did once....It was by accident! We had a power outage caused by freezing rain for 4 days. After 1-1/2 days that you can't flush the toilet or have more than candles at night while you freeze you a$$ off it became clear to me and her at the minimum all you really need is enough energy to get the water pump going so you can flush toilets, the rest of the time it can run heat, lights or fridges. If you want one big enough so you can live like nothing happened then the sky is the limit. The last power outage she was so grateful for just the water, heat and TV! She now really knows what a necessity is.

[Ronmar]

Yep, when you are having to provide the fuel for ALL that you use, less is definitely more...  My 6/1 provides for lights(CFL's), well pump, pellet stove, reefer, freezer and TV/Computer.  If I shutoff the feed to well pump and freezer, we can run 2 small elements on the electric stove, and small microwave during meal prep times.  I have a 240 to 120 transformer that will spread the microwave load across both legs to make this a little easier.  The waste heat from the engine will maintain the hot water tank at 120F, with about a 100 minute recycle time at a 2KW load.  Once the tank is fully heated(hot water enters tank from the top), the hot water comming off the bottom of the tank goes thru a fan coil unit to dump that excess heat into the house if needed, or outside if not.  I can get about as much heat from the generator cooling system as the pellet stove puts out, which was my reason for building the generator in the first place...  A tank of hot water means a hot shower, a few loads of laundry(HE washer) and clean dishes.  If I can figure how to duct the heat from the pellet stove thru the electric dryer, I will have just about all the comforts I currently enjoy on grid:)