New system

northerner

Re: New system

NorthGuy wrote: »

There's no doubt that the system with properly sized battery bank will work better.

However, batteries are very expensive. If you cannot afford or do not want to spend on a big bank, it is quite possible to organize your system to work well with smaller bank. And also it is possible to use part of the money saved on batteries to compensate for a small bank with "cheap" panels.

That's like houses. Big luxurious house is definitely better. However, people who cannot afford or do not want to pay for big ones, live well in smaller houses with less amenities.

I know what you're saying NG. I myself am debating on how much $ to put into a battery bank. I look at the batteries as an expendable part of the system. With solar panels being much cheaper now than ever, it does alter the formula somewhat, in order to achieve the best bang for your buck. This is why I'm eagerly anticipating a better battery than the lead acid. If a battery will last a lifetime, be purchase cost competitive, and operate efficiently, then I would have less of a problem investing into a sizable bank!

BB.

Re: New system

There is also the "oops" factor... Somebody leaves the pump and/or inverter on during winter, etc. and drains the bank dry--Damaging the battery bank. Guests come by for a week in the mountains with hair dryers, and every light/appliance on in the home--And there goes the battery bank.

-Bill

NorthGuy

Re: New system

BB. wrote: »

There is also the "oops" factor... Somebody leaves the pump and/or inverter on during winter, etc. and drains the bank dry--Damaging the battery bank. Guests come by for a week in the mountains with hair dryers, and every light/appliance on in the home--And there goes the battery bank.

And the bigger the bank, the bigger the loss ...

Cariboocoot

Re: New system

People who try to minimize component capacity have more regrets than those who don't.
Battery capacity decreases with time no matter how well-treated they are.
Trying to get by on the calculated smallest possible battery will always be the wrong thing to do.
Likewise buying far more battery than is needed is just throwing money away.
That's this "balanced system" thing we keep talking about.

Edwardo

Re: New system

Whats a good way to heat the home other than wood?By our BC building code our primary heat source can't be wood.

westbranch

Re: New system

Where do you read that? (not being facetious...) Basically any structure not on grid in this area will have a component of wood heat from 100% and down. that's the way mine is.

Edwardo

Re: New system

Inspector hear in town...

westbranch

Re: New system

You want to see that in writing.

Oour new place has been planned and built by a recognized/qualified architect and Timber Frame builder team and the primary heat has always been WOOD. They Never mentioned there was an issue with wood heat from the construction view, Insurance and Local Burning regs may impact but not the building code AFAIK.

Tell him you will be electric heat and wire in a 110v baseboard heater as primary, 1000w will be more than enough. Or a 10,000 btu propane wall mount horizontal vent heater. Either will heat you down to -20*C, believe me I know.

Edwardo

Re: New system

I have been measuring the power consumption of our stuff with my amp meter.The fridge draws 1.25 amps or 150w but I don't know how many hours a day.

BB.

Re: New system

If you can find a Kill-a-Watt type meter--That will do the job for any standard plug-in appliance. They may be available from a larger hardware store or on-line.

Regarding measuring Amps/Watts... You cannot measure AC Watts with just a amp meter. There is a third part of the power equation--The "phase angle" between the voltage and the current or inductive (motor) loads.

Power = Volts * Amps for DC loads

Power = Volts * Amps * Cosine (phase angle between volts and amps) = V*A* Power Factor

Power factor - Wikipedia

For designing an off grid system... More or less, the Inverters and AC Gensets use the V*A (Volt Amps) measurements to size the components (and transformers, wire gauge, etc.).

For designing the battery bank and solar array, it is the Watts (Power=V*A*PF) and Watt*Hours that we use.

Many devices have "poor" power factor (0.67 or even as bad as 0.50 power factor)--Which forces a larger inverter and/or genset to support the loads (worse case, only 50 to 67% of the current actually "does work"). Motors, many older electronic devices, battery chargers can all have "bad" power factor. Newer electronic power supplies may have Power Factor Correction, filament light bulbs, electric heaters and such will have PF in the range of 0.95 to 1.00 power factor.

And then there is the work... Which is Watts*Time (hours in our usage). If the refrigerator runs about 1/3rd the time, your daily usage may look something like this:

1.25 amps * 120 volts * 0.75 PF * 1/3rd duty cycle * 24 hours per day = 1,200 Watt*Hours = 1.2 kWH per day

So, you would size the wiring/fuses/breakers for 1.25 amps. The inverter/backup genset for VA (1.25a*120v=) of 150 VA. As well as the peak starting current (which for electric motors may be 5x running current +/-)--For a typical energy efficient full size refrigerator, around 1,200 to 1,500 Watt (VA) rated inverter minimum.

And the battery bank+solar array for 1,200 WH or 1.2 kWH per day (lots of fudge factors for losses and poor weather, etc.).

-Bill

inetdog

Re: New system

BB. wrote: »

If you can find a Kill-a-Watt type meter--That will do the job for any standard plug-in appliance. They may be available from a larger hardware store or on-line.

And in addition to showing you both Watts and VA, the Kill-a-Watt (TM) will add up the total energy over a period of time, so you do not have to watch the meter or time the refrigerator cycles.

Edwardo

Re: New system

We have started building now and I could use a generator for the skill saw,and later for the system back-up.I'm thinking a Honda 1000 may be too small...although I like the compact size.
I would also like to start ordering stuff for the solar system and could really use more guidance in sizing it and specific reliable components.
I have not been able to find a kill-a-watt meter.

Cariboocoot

Re: New system

A Honde EU1000i will not start a circular saw. The EU2000i will (I have both and have tried them with various tools). You should turn the eco throttle off when running tools. The 2000 will also just start my air compressor for the nailer (providing it's warm).

Finding a Kill-A-Watt is not difficult: http://www.solar-electric.com/kiacpomome.html

You really do need some sort of power requirement numbers to work with for planning a system. And definitely plan it before buying anything; even the location of components can make a difference in what components you get. For example if it's a long distance between the array and the charge controller it may be necessary to run a higher Voltage array and a MidNite Classic 200 controller instead of a 150 or an Outback FM80 et cetera.

BB.

Re: New system

The Honda eu1000i is probably too small for you day to day needs... It is only a 900 watt generator (continuous max power). The eu2000i is 1,600 watts continuous and just about large enough to run up to a skill saw. The eu2000i will run a fridge--I don't think a eu1000i will run a standard fridge reliably (if anyone has more information, please let us know).

However, if you will be using the skill saw a lot (and larger saws)--Get a second cheap 3.5 -5kW genset (aka noise maker) to run the large tools when needed. And keep the smaller Honda to run the rest of the smaller tools/battery chargers/radio/lights/etc.

This will give you both backup power and the ability to run the larger loads when needed.

-Bill

Cariboocoot

Re: New system

Bill;

The 1000 is 800 Watts continuous and will just start my 'frige - providing the lines are short and there's nothing else on it and the eco throttle is off.

The 2000 has trouble starting the water pump all on its own; surge demand against remaining pressure can overload it. With a little fuss it can do it, but you sure can't leave it to go on its own.

One thing the 1000 will do is run the battery charger for the cordless tools. Since this includes a small circular saw it is great for middle-of-nowhere work. But when you're building an entire house you want that full-size circular saw.

If anyone is wondering, it's actually easier to start a saw than a pump; saws start in 'free air' with no load against the motor so the initial surge demand is very low. The current goes up when you apply it to the wood.

Anyone remember where all that tool testing I did landed? It's on the forum somewhere, probably under energy use and conservation.

Cariboocoot

Re: New system

Well I found some of the tests:

For what it's worth, I just ran my 10" Skil tablesaw through my UPM meter. The saw is rated as 13A @ 120 VAC. The start-up was 4.9 Amps (118 Volts here). I pushed a piece of wood through it and loaded it fairly well: 8.6 Amps / 952 Watts.

Small "pancake" compressor used to power air nailers: 12.4 Amps, and basically held peak from start-up (against pressure). 1372 Watts - sucked the line Voltage down from 118 to 112!

6 gallon ShopVac: 6.5 Amps. 744 Watts.

2.5 HP Skil circular saw: 8.3 Amps. 928 Watts (while cutting wood).

Black & Decker reciprocating saw: 6.6 Amps. 750 Watts (while cutting wood).

As you can see the Honda 1000 would not handle some of that.

BB.

Re: New system

A few random link that Marc/Cariboocoot has commented on:

Honda eu2000i generator, question before I buy

Here is an older thread with lots of discussions of what generator and what loads they can run:

Honda generator big enough?
Fedders 5000 BTU A/C test
Choosing a good generator

I could not find the thread that Marc was typing about.

-Bill

Cariboocoot

Re: New system

Typical of my laziness it wasn't in a thread: just some posts about tool power usage in another thread asking about what inverter could power a saw.

Anyway I hope the examples cited will give the OP some idea what the power demands of the tools might be.

Edwardo

Re: New system

our power bill shows daily consumption,i'm going to turn our heat off and try and estimate our consumption that way.No coffee maker either that thing is horrible.

BB.

Re: New system

If you have alternative heating (natural gas, propane, etc.)... A few numbers to look at:

A full off grid very efficient home (including clothes washer, well pump, lighting, laptop computer, etc.)--You can get down towards 3.3 kWH per day or ~100 kWH per month.

My suburban home in summer (no AC, natural gas for cooking/hot water, etc.) I run around 200-300 kWH per month.

"Average North American home" is around 1,000 kWH per month.

-Bill

Blackcherry04

Re: New system

Here is a P3 International Kill-A-Watt for $18, if you can find someone to send it to you.

http://www.walmart.com/ip/14282370?wmlspartner=wlpa&adid=22222222227000000000&wl0=&wl1=g&wl2=&wl3=21486607510&wl4=&wl5=pla&veh=sem

solar_dave

Re: New system

BB. wrote: »

"Average North American home" is around 1,000 kWH per month.

-Bill

And then there is an Arizona home with three 3-ton AC units, a swimming pool and 2 electric cars in July last year using 3200+ kWh! LOL :D:D

Our winter usage is about 1200-1500 kWh depending on how much we drive.

Surfpath

Re: New system

BB. wrote: »

A full off grid very efficient home (including clothes washer, well pump, lighting, laptop computer, etc.)--You can get down towards 3.3 kWH per day or ~100 kWH per month.

-Bill

I went from thinking I would need 7 kwh/d to 6 to to 5, to 4. I then lived without electricity for 7 months. Now I use 3.2 kwh and that seems luxurious.

I know this last number will likely creep up over time but because energy efficiency is now part of my daily routine it's not likely to rise that much.

Trying not to sound too philosophical now, but this 'system balance' spoken about here is a difficult thing to achieve. Sometimes you get lucky. Generators, alternative charging sources (ie. wind, hydro), and good old fashioned watchfulness are also key to striking this equilibrium.

Fortunately, there are lots of excellent guardian angels on this site who help steer us in the right direction if it appears we are off balance.

BB.

Re: New system

I should add--That power usage is a highly personal set of choices... The numbers I gave about are there to give a rough idea of what one can aim for in the "big average" that is our world.

There are folks here that live very happy on 1 kWH per day--But they use propane fridge and and do other things to minimize power usage.

I did not want to "grade" or rank anyone on their power usage.

-Bill

Rybren

Re: New system

Many Public Libraries will lend a Kill-a-watt meter. Here in Ottawa, the loan period is one week.

YehoshuaAgapao

Re: New system

My house reached 3850KW-h for the billing cycle of July 10 - August 10 of 2012. No electric or plug-in hybrid cars. 3.5 ton AC and pool pump and a home theater system that consumes 1000-1200 watts depending on the volume on the stereo.
Running about 1500KW-h now, mainly with the swamp coolers instead of A/C.

solar_dave

Re: New system

YehoshuaAgapao wrote: »

My house reached 3850KW-h for the billing cycle of July 10 - August 10 of 2012. No electric or plug-in hybrid cars. 3.5 ton AC and pool pump and a home theater system that consumes 1000-1200 watts depending on the volume on the stereo.
Running about 1500KW-h now, mainly with the swamp coolers instead of A/C.

Now I don't feel so bad! AZ is a beeech in the summer for electric consumption.

Edwardo

Re: New system

We purchased a Honda EU3000 generator yesterday.A Skil saw sure cuts faster than my old hand saw.

Edwardo

Re: New system

Hi,I have not bought a kill-a-watt meter yet.I have been using the BC Hydro site to watch our daily usage.The place we currently live in has electric hot water tank,base board heaters,effluent pump and electric range.
We use between 5 and 25kwh per day.Lately our heat is off,I have turned off the breaker to the hot water tank and not using the range to try and get an idea what we will be using in our new home.We went away for a couple days with these items off as well as the computer,lights etc and our reading on there web site still shows us using 9kwh in a day.I'm starting to wonder if the reading is false and they are estimating our usage.

westbranch

Re: New system

fyi our house is about 16 kwh per day without things being shut off, that is all year as in summer we pump more water and in winter the clothes dryer gets more use. Gas heat and gas hot H2O. 2 fridges, 2 freezers.