Reliable Off-Grid Packages

[pv_n00b]

Remember too that off grid will typically entail specialized expensive appliances that often are excluded from the "system" cost.

I'm not aware of this being a requirement. It's true only if the system being installed is underpowered to save money on the system cost. The special high-efficiency refrigerators and related high-efficiency appliances are needed then. If the system is sized for the load then no special accommodation is needed. I've known people with electric stove tops & convection ovens, hot tubs, and large HVAC systems that run off their large off-grid power systems just fine. It's all in how much someone is willing to pay for the system. Systems that give a normal grid-connected experience can be very expensive but still be less expensive than running a power line in.
It's when homeowners get a utility estimate of $150k for the power line and think they can put in an off-grid system for $10k that operation expectations are not met.

 

[ggunn]

There is very little in common between grid-tied PV system design and off-grid design. There is a lot that someone without experience can get wrong and those errors all end up with the homeowner sitting in a dark house with no power and an expensive bill to fix. That said, it is often cheaper to put in an off-grid system than to pay the utility to run the power line, but not always that much more affordable. So I recommend you find an experienced off-grid system contractor to quote the system.
A solid off-grid residential system that provides a "normal" on-grid experience is quite expensive. A hair shirt cabin in the woods system that is used for a weekend here and there can be pretty inexpensive.

I believe we are all saying the same thing: off grid electrical design is not for the neophyte. Even if one is an expert in grid tied systems there are numerous expensive and dangerous potential pitfalls for the inexperienced in designing an off grid system. I have been designing PV systems for 14 years up to 1.4MW in size, but I leave the off grid stuff to the experts.

 

[pv_n00b]

I believe we are all saying the same thing: off grid electrical design is not for the neophyte. Even if one is an expert in grid tied systems there are numerous expensive and dangerous potential pitfalls for the inexperienced in designing an off grid system. I have been designing PV systems for 14 years up to 1.4MW in size, but I leave the off grid stuff to the experts.

Maybe 15 years ago my sister was building an off-grid home and asked me if I could help with the power system design. I had a vague idea how it worked but was basically a grid-tied person so I hooked her up with an off-grid residential contractor. Even then it's amazing how rough the design process was. Her system came in at a little over $100k and was still cheaper than running a power line.
There were still a lot of bumps in the road, like when the generator O&M guy switched the generator to 480V and blew up just about everything that was plugged in. I did not know that lightbulbs could actually explode.

 

[gadfly56]

Maybe 15 years ago my sister was building an off-grid home and asked me if I could help with the power system design. I had a vague idea how it worked but was basically a grid-tied person so I hooked her up with an off-grid residential contractor. Even then it's amazing how rough the design process was. Her system came in at a little over $100k and was still cheaper than running a power line.
There were still a lot of bumps in the road, like when the generator O&M guy switched the generator to 480V and blew up just about everything that was plugged in. I did not know that lightbulbs could actually explode.

OK, "a", how does someone do that by accident and "b", did they recover the costs from the company?

 

[winnie]

OK, "a", how does someone do that by accident and "b", did they recover the costs from the company?

That big red switch with the label 'do not pull'? Sometimes it is simply too tempting.....

 

[jaggedben]

I believe we are all saying the same thing: off grid electrical design is not for the neophyte. Even if one is an expert in grid tied systems there are numerous expensive and dangerous potential pitfalls for the inexperienced in designing an off grid system. I have been designing PV systems for 14 years up to 1.4MW in size, but I leave the off grid stuff to the experts.

I agree with all that.

And, the products available to do it now are better and require less user knowledge and maintenance work than was the case 15 years ago, or even 5.

 

[Ravenvalor]

Thank you all for the excellent replies. After reading all of them I have come to the realization that this particular person needs to be grid tied. She has no interest in educating herself about the complexities of being an off-grid homeowner.

I appreciate the help greatly . . .

 

[ggunn]

Thank you all for the excellent replies. After reading all of them I have come to the realization that this particular person needs to be grid tied. She has no interest in educating herself about the complexities of being an off-grid homeowner.

I appreciate the help greatly . . .

Good call. Living off grid can never be "set it and forget it".

 

[pv_n00b]

OK, "a", how does someone do that by accident and "b", did they recover the costs from the company?

No one really knows what happened to switch the generator to 480V, except maybe the tech knows. It happened while they were servicing the generator and no one else was home. The O&M company accepted the blame and there was compensation for the damage.

 

[pv_n00b]

Thank you all for the excellent replies. After reading all of them I have come to the realization that this particular person needs to be grid tied. She has no interest in educating herself about the complexities of being an off-grid homeowner.

I appreciate the help greatly . . .

It is possible to set up an off-grid system that requires no input from the homeowner and they can live like they are attached to the grid. But we a talking multi-million dollar mansions and the homeowners have regular visits from an O&M company to keep everything going. So it is possible if someone can write enough zeros on a check.

 

[petersonra]

At one time I had a fantasy about living off grid turns out that it's really hard to get off grid around here. You can live out in the rural areas but they have been electrified for many years so there is always power out at the road. The other problem with living off grid is there's no jobs there. The way I see it by the time I don't need a job I don't really want to be living off grid. Way too much work.

However I did do some investigation on what it would take. Back then the basic philosophy was propane everything, small generator, a small amount of battery backup for lights. Didn't have compact fluorescent or LED lights back then.

When you need to charge the battery you turn the generator on. When you need to wash your clothes you turn the generator on.

Solar-powered clothes dryer.

 

[ggunn]

It is possible to set up an off-grid system that requires no input from the homeowner and they can live like they are attached to the grid. But we a talking multi-million dollar mansions and the homeowners have regular visits from an O&M company to keep everything going. So it is possible if someone can write enough zeros on a check.

You can buy a system that will cover 9% of your needs or 90% of them or 99% of them or 99.9% of them... How many nines would you like to purchase?

 

[electrofelon]

.

When you need to charge the battery you turn the generator on. When you need to wash your clothes you turn the generator on.

The first sentence is a very common and wrong philosophy. The second sentence is the way you should do it. What you want to be doing is have "generator support" for you heavy loads. Many people will try to avoid using the generator at all costs until the batteries are dead, and then you have to run it for hours and hours. You should be running it for shorter periods as you go

 

[petersonra]

The first sentence is a very common and wrong philosophy. The second sentence is the way you should do it. What you want to be doing is have "generator support" for you heavy loads. Many people will try to avoid using the generator at all costs until the batteries are dead, and then you have to run it for hours and hours. You should be running it for shorter periods as you go

I suppose it would make sense to charge the batteries up if you are using The generator for something else anyway. Back then there wasn't a whole lot of options as far as electricity goes. You could have 12 volt stuff made for cars but they weren't particularly efficient as far as lights go. But you could go a long way with propane water heaters, propane stoves, propane refrigerators, and a well pump you only ran for short periods of time to fill up a fairly large tank.

Some people that lived off grid back then didn't even have electric lights at all. They used propane or kerosene lamps.

Back then there just were no practical photovoltaic options available.

 

[gadfly56]

You can buy a system that will cover 9% of your needs or 90% of them or 99% of them or 99.9% of them... How many nines would you like to purchase?

Decades ago when I was still in the chemical process industry, for product purity or pollutant reduction, the rule of thumb is that each "9" will cost you 10X the last "9".

 

[winnie]

Just musing here: I wonder if there is value to using 'off grid' tech to make the grid connection cheaper.

For example, assume that this small home has fuel based heating, and an _average_ energy consumption of 1kW. What would the total power system installed costs look like if it had a battery energy storage system that could support peak demand, but limited grid draw to say 10A at 240V. The service conductors get much smaller if they don't need to support peak demand load.

If the same controller that manages solar and battery could take say 650V DC from the grid (voltage doubling rectifier at service point) then the long distance conductors get miniscule.

-Jon

 

[gadfly56]

Just musing here: I wonder if there is value to using 'off grid' tech to make the grid connection cheaper.

For example, assume that this small home has fuel based heating, and an _average_ energy consumption of 1kW. What would the total power system installed costs look like if it had a battery energy storage system that could support peak demand, but limited grid draw to say 10A at 240V. The service conductors get much smaller if they don't need to support peak demand load.

If the same controller that manages solar and battery could take say 650V DC from the grid (voltage doubling rectifier at service point) then the long distance conductors get miniscule.

-Jon

It might be a boon to folks who own the grid, but maybe not the end user.

 

[jaggedben]

I doubt that the size of conductors affects what the utility charges for a long distance run enough to make the difference. Or that DC distribution is ever really worth the hassle.

 

[pv_n00b]

Just musing here: I wonder if there is value to using 'off grid' tech to make the grid connection cheaper.

The problem is that PV+ESS can't be depended on by the utility, the customer does not want to depend on it, and codes and standards do not allow dependence on it. It's purely supplemental power. The utility has to be ready to supply the whole house load at any time for any length of time the same as if the PV+ESS was not there. That costs money to be ready for and it's one of the costs that has been impossible for utilities to recover with the old retail NEM tariff since energy costs and infrastructure costs are bundled.

 

[gadfly56]

The problem is that PV+ESS can't be depended on by the utility, the customer does not want to depend on it, and codes and standards do not allow dependence on it. It's purely supplemental power. The utility has to be ready to supply the whole house load at any time for any length of time the same as if the PV+ESS was not there. That costs money to be ready for and it's one of the costs that has been impossible for utilities to recover with the old retail NEM tariff since energy costs and infrastructure costs are bundled.

I think winnie's point was using batteries to smooth the demand as far as the POCO is concerned, not in conjunction with PV.