Off grid?

[dave1949]

And there you have the reason, I pay more in rent for the network I use on power
What I need electricity to the light (everything is switched to led), dishwasher, washing machine and other small things. The challenge is welder that needs 220V 16A 3 ~ and the lathe with the same requirements. So I will probably never be 100% off the grid if I do not run a generator. I have a diesel generator on 4500W that can manage welder and lathe, but is impractical. I've Looked but can not find an inverter that supplies 3phase. I'm going to buy a kitchen stove that runs on propane next time so that is no problem

If the 3 phase welder is really necessary, I think you are stuck with the grid. Even if you could find an inverter, the cost of the system needed would be high I think. There are very good industrial quality stand-alone engine-generator-welder units that could probably replace the 3 phase welder. A stand-alone welder would remove that entirely from the load estimate.

You might be able to replace the 3 phase motor on the lathe with a single phase motor. I know 3 phase residential service is fairly common in Germany, but I have no ideas about Norway and what your options are.

If doing those things gets you within a reasonably priced off-grid system, then that works out financially in the long run. If you are making enough money from the welder and lathe to justify the electricity costs, okay. If you use them for home repairs and hobby, then they are just forcing you into expensive solutions that probably cannot be justified. Sometimes you have to give a little to get a little.

I have an off-grid acquaintance that runs his table saw and power hand tools with no problems but his solar system and batteries are sized to do that, and would be expensive to duplicate. He is in the solar system business and it is sort of a religion for him. He installs lots of off-grid systems on islands and places far from the grid. But, it could be less expensive to power those things with a diesel generator.

First things first, you need to know how good your solar and/or wind resources are, then think about the loads.

 

[techman]

Note that 3 phase inverters are common in Europe. The big question is the motor power and the inverter's ability to start the motor. Additionally the motor may draw a significant part of your battery capacity if used for any extent of time.

paul

 

[Beltman60]

you can run 2 110 volt inverters to get your 220
they have to be sized the same
but 3 phase I don't think so
micro inverters would not work
you need to keep your solar panels out put in dc into your dc batteries then inverters to ac to your line

I think you need to keep the generator for the welder & lathe
I run my hay elevator off my batteries just fine but were talking maybe 12 amp at start up

 

[Tor Arne]

Thanks for the good suggestions, I have considered what I need and concluded that it is not appropriate to go off grid (too expensive), but it may I build a small system to test the concept and if I'm happy then it a possibility that I expand little by little

 

[dave1949]

Thanks for the good suggestions, I have considered what I need and concluded that it is not appropriate to go off grid (too expensive), but it may I build a small system to test the concept and if I'm happy then it a possibility that I expand little by little

Do you plan to build a small off-grid, or small grid-tied (on-grid) starter system?

 

[Tor Arne]

Do you plan to build a small off-grid, or small grid-tied (on-grid) starter system?

If I do that it will be an off grid system so I do not have to deal with the power company

 

[dave1949]

If I do that it will be an off grid system so I do not have to deal with the power company

I haven't looked at off-grid designs for a long time now, but I think you begin with choosing the charge controller and inverter hardware with a reasonable total capacity to grow into, then match the batteries and solar panels to each other. You can re-configure the solar panels and batteries as needed if you expand the system.

In the US, I think good start is to aim at a 48 VDC, four 12-volt battery system. That way, you don't start out needing to spend a fortune on batteries. Golf cart or deep cycle marine batteries aren't so expensive, or you could start out with four regular 12 volt automotive batteries for even less up-front spending. Keep in mind that four batteries connected in series can only perform as well as the weakest battery in the string. You want to have four equal batteries.

You might want the charge controller to have the capability of multiple sources like solar and wind. More money up front but something you can expand into over time.

 

[westcliffe01]

Seems the question has been answered, but unless one is in a very good wind zone, the price/watt for solar is much better than for a wind turbine. The wind generators are also far less reliable, and subject to constant maintenance (if you can continue to find parts, that is). No doubt wind and solar are complimentary technologies, but financially you may be better off just doubling the size of the solar array, or taking the wind turbine money and investing in solar water heating, given that heat is a big deal at high latitudes. Just 6 years ago solar was considerably more expensive and wind generators looked like a better deal.

Ideally, one approaches the task by building the most energy efficient house with passive solar design, then buying a solar array and battery/inverter to power the house. If one applies efficient lighting, solar water heating, hot water storage, a backup hot water heater, in slab radiant heat, then many of the large electrical loads will not exist in the first place.

My plan does include a diesel genset that is tied to the hot water system as a co-generation system (recover heat from coolant, oil and exhaust) to power high loads, such as running equipment in the workshop or an electric clothes dryer. The location has no regular utilities and propane is very expensive, so all fossil fueled systems will run on diesel, same as my truck, backhoe and other equipment. I have access to inexpensive softwood, so wood heat will be the primary heat source and diesel only to maintain a minimum safe temp if I am away from home for an extended period during very cold weather.

 

[westcliffe01]

Tor, an inverter to provide 3 phase from a single phase source is not that unusual. If you look at any variable frequency drive (which is used as standard in lots of new equipment today) you will find that they use a diode pack to turn the incoming AC to DC then smooth it with capacitors and chokes and then feed that into the inverter which creates the 3 phase output. Having said that, the kind of load that a welder represents is not a good load for deep cycle batteries. Not if you want them to last, that is... I think if you do go off grid, you will need a better generator, then directly buy one with a 3 phase alternator and it would not be difficult to split battery charging across 3 phases so that they are balanced.

One can implement 3 electric heating elements for water heating (and as a load for the genset) in addition to occasional loads such as welding and running the lathe/mill. If one implements a "load leveling" system in such a scenario, then one could drop out the non sensitive load (water heater) when you used the welder or other "priority" load.

And there you have the reason, I pay more in rent for the network I use on power
What I need electricity to the light (everything is switched to led), dishwasher, washing machine and other small things. The challenge is welder that needs 220V 16A 3 ~ and the lathe with the same requirements. So I will probably never be 100% off the grid if I do not run a generator. I have a diesel generator on 4500W that can manage welder and lathe, but is impractical. I've Looked but can not find an inverter that supplies 3phase. I'm going to buy a kitchen stove that runs on propane next time so that is no problem

 

[Beltman60]

car or truck batteries will not work
they have high cold cranking amps to start the vehicle not sustained amperage for long loads for the night
you can try them but my bet would be they turn to junk in < 2 years