Grid tie in with Solar Panels and Off Grid with Solar Panels and Diesel gen.

[Tango Zulu]

I would have thought this is a common question with multiple answers on the forum or the web but I haven't really found much on the topic. Only set ups with battery storage. A "generator support" set up in addition to a solar panels always appear to include batteries. Is it possible to have a grid tied systems that will not require batteries?

Would it be possible to have the following configuration:

1. Grid tied solar panel array.
2. No batteries.
3. Diesel generator that works in tandem with the solar panel array in case of loss of power from the grid.

Are there inverts / controllers that are able to handle that?

[ButchDeal]

It is possible to HAVE the configuration but it will not work off grid.

The grid tie inverter will work with the grid.
The generator will work without the grid.


It is very possible to have a bimodal grid tie that HAS batteries and a generator
But a Grid tie inverter will not work with a generator.

[jflorey2]

Is it possible to have a grid tied systems that will not require batteries?

Sure. The SMA "secure power" system (provides backup power without the grid) is available today. The Enphase system, based on the IQ8+ inverter, will be available next year sometime. So definitely possible.

Would it be possible to have the following configuration:

1. Grid tied solar panel array.
2. No batteries.
3. Diesel generator that works in tandem with the solar panel array in case of loss of power from the grid.

Are there inverts / controllers that are able to handle that?

No. To do that you would need very tight coupling between the inverter and the generator so you don't overspeed or overcurrent the generator. That sort of coupling does not exist today.

[ButchDeal]

Sure. The SMA "secure power" system (provides backup power without the grid) is available today. The Enphase system, based on the IQ8+ inverter, will be available next year sometime. So definitely possible.

The SMA secure power is NOT a backup power system by any means. It is at best an occasional provides power without the grid system on dedicated circuits that are not wired into the house and unlikely to have power when you either want or need it. (night time, storm time, etc.).

The IQ8 system is not released and again not a backup system. It appears to be able to operate some circuits that are wired into your home when solar is of sufficient capacity for those loads which is better than the SMA secure power system but still in no way will it be a backup system that will have power any time you need it.

[Sunking]

Sure but why would you waste all that money that gains you nothing?

Best Set Up there is is Grid Tied Solar, with a whole house generator for outages. Least expensive, most effective, with highest reliability.

[Tango Zulu]

Thanks for the responses.

Let me back up a bit and ask this: Would it be possible to have an offgrid system that runs on a diesel engine and solar panels alone? Without a battery bank?

Sure but why would you waste all that money that gains you nothing?

Best Set Up there is is Grid Tied Solar, with a whole house generator for outages. Least expensive, most effective, with highest reliability.

It'a actually the opposite of wasting of money. At least in my situation. I already have an MEP831A diesel generator. It is rated at only 3kw however. Not enough to power the whole house. I love the damn thing (yanmar diesel in a quite enclosure) and have no intention of changing it for a larger more expensive diesel unit or a larger cheap gas unit. That's why I was hoping I could power the whole house by increasing the installed power output through solar panels but not having to buy batteries. If its not doable then that's that - I am not going to spend the money to buy a larger generator only for convenience.

Just seems a little counter productive to have to shut down the solar panels during a power outage and run on the diesel alone unless I have a battery bank.

[organic farmer]

Thanks for the responses.

Let me back up a bit and ask this: Would it be possible to have an offgrid system that runs on a diesel engine and solar panels alone? Without a battery bank?

Yes, that is possible.

I have a neighbor who runs a windmill, solar panels, and a generator. He is a welder by trade, any time that he starts welding he runs his generator. [he also makes a lot of iron art work].

... It'a actually the opposite of wasting of money. At least in my situation. I already have an MEP831A diesel generator. It is rated at only 3kw however. Not enough to power the whole house. I love the damn thing (yanmar diesel in a quite enclosure) and have no intention of changing it for a larger more expensive diesel unit or a larger cheap gas unit. That's why I was hoping I could power the whole house by increasing the installed power output through solar panels but not having to buy batteries. If its not doable then that's that - I am not going to spend the money to buy a larger generator only for convenience. Just seems a little counter productive to have to shut down the solar panels during a power outage and run on the diesel alone.

In our town, it is very common for homes to have two generators. Since the grid power is normally down for a week every month anyway, the 'on-grid' homes all have generators. But running two generators is a lot cheaper for them.

These homes have one large genny that can power the entire home, and a small genny just for lighting and PCs.

The idea is that the small genny runs 24/7 [whenever the grid is down], so the family can have lights, and do stuff on-line.

Then once a day, they fire-up the big genny. Once that is running, they flush toilets, start laundry, do showers and turn on the circuits for refrigerators and freezers. After 3 or 4 hours of running the big genny, everyone has
used the toilet, had a shower, all the household laundry has been done, and the freezers are kept cold. Then they shut down the big genny and go back to the small genny.

I am kind of surprised that so many people in our culture seem to have gotten accustomed to grid power ll the time. Here on the East Coast the public utility grid has never been very reliable.

Someone will always say that grid power is the cheapest, and I guess that is correct, for whatever day of the week the public utility decides to provide grid power to your town. But by year-end you have to look at how many days were you without grid power, looking back at any 365-day period just how many of those days was the grid even going?

Should we all sing "Kum ba yah" how cheap grid power is, we should all just stay on grid, in the dark with no power? Or seek an alternative power source, so we can do the dishes, laundry and flush the toilets?

[SunEagle]

Thanks for the responses.

Let me back up a bit and ask this: Would it be possible to have an offgrid system that runs on a diesel engine and solar panels alone? Without a battery bank?



It'a actually the opposite of wasting of money. At least in my situation. I already have an MEP831A diesel generator. It is rated at only 3kw however. Not enough to power the whole house. I love the damn thing (yanmar diesel in a quite enclosure) and have no intention of changing it for a larger more expensive diesel unit or a larger cheap gas unit. That's why I was hoping I could power the whole house by increasing the installed power output through solar panels but not having to buy batteries. If its not doable then that's that - I am not going to spend the money to buy a larger generator only for convenience.

Just seems a little counter productive to have to shut down the solar panels during a power outage and run on the diesel alone unless I have a battery bank.

You still need the batteries to stabilize your voltage source. A PV panel is a current source and will not power an inverter or any AC loads. You can run small DC motors (pumps & fans) directly from PV panels but they will run at different speeds depending on the amount of sunlight hitting the panels.

Yes it may seem counter productive to have to shut down solar panels when the grid goes down (actually that should happen automatically) but with batteries you can continue to charge them and use them. Right now the current solar pv inverter hardware does not allow it to work unless there is a grid or if there is special hardware like the Secure Power made by SMA.

People like Organic farmer have found ways to live off grid but their lifestyle is much different then most that are accustomed to soft grid tie life. Some people can change their life style but most can't or won't. It is a choice but not an easy one.

[Sunking]

TZ and Organic Farmer has a lot to learn and should not be giving anyone any advice. The batteries will cost m ore than the a generator, and batteries need replaced every few years. Good luck with that logic. Please do not vote.

[J.P.M.]

People like Organic farmer have found ways to live off grid but their lifestyle is much different then most that are accustomed to soft grid tie life. Some people can change their life style but most can't or won't. It is a choice but not an easy one.

Not necessarily speaking for O.F., but I've found Dolphins and retired Dolphins to be a different breed, more self reliant than most and more able make do with the situation as they find it, or at least to be able to tolerate it better than most, but sometimes that makes them a bit myopic and perhaps intolerant of us mere mortals and our shortcomings.

Respectfully,

[bcroe]

Should we all sing "Kum ba yah" how cheap grid power is, we should all just stay on grid, in the dark with no
power? Or seek an alternative power source, so we can do the dishes, laundry and flush the toilets?

Most people in these parts have no idea how good they have it, or what it takes to provide the services
they take for granted. But I have not forgotten the hand pump in my aunts kitchen (in central MN), or the
kerosene lights so recently retired, with the out house in back. Laundry and dishes can be done by hand.

Here in N central IL, recognized by few, there are remnants of the days that a town built its own power
generator. One huge diesel set I saw running right after the war (61068), is still alive doing standby duty.
Bruce Roe

[J.P.M.]

Thanks for the responses.

Let me back up a bit and ask this: Would it be possible to have an offgrid system that runs on a diesel engine and solar panels alone? Without a battery bank?



It'a actually the opposite of wasting of money. At least in my situation. I already have an MEP831A diesel generator. It is rated at only 3kw however. Not enough to power the whole house. I love the damn thing (yanmar diesel in a quite enclosure) and have no intention of changing it for a larger more expensive diesel unit or a larger cheap gas unit. That's why I was hoping I could power the whole house by increasing the installed power output through solar panels but not having to buy batteries. If its not doable then that's that - I am not going to spend the money to buy a larger generator only for convenience.

Just seems a little counter productive to have to shut down the solar panels during a power outage and run on the diesel alone unless I have a battery bank.

Most anything is doable. Practical, cost effective and/or convenient are separate questions.

[organic farmer]

Not necessarily speaking for O.F., but I've found Dolphins and retired Dolphins to be a different breed, more self reliant than most and more able make do with the situation as they find it, or at least to be able to tolerate it better than most, but sometimes that makes them a bit myopic and perhaps intolerant of us mere mortals and our shortcomings.

Respectfully,

I rarely run into any other 'dolphins'. Yesterday I was in the city and I saw a guy wearing a USS Philadelphia (SSN-690) ball cap. As it turns out he served one enlistment and got out, he is now in his third year of getting his E.E. He has no idea what he wants to do when he finishes his EE. I told him that when I finished mine in 1987, I re-enlisted to get the 20-year pension, it gave him something to think about.

I enjoy bumping into other submariners.

[organic farmer]

Most people in these parts have no idea how good they have it, or what it takes to provide the services
they take for granted. But I have not forgotten the hand pump in my aunts kitchen (in central MN), or the
kerosene lights so recently retired, with the out house in back. Laundry and dishes can be done by hand.

Here in N central IL, recognized by few, there are remnants of the days that a town built its own power
generator. One huge diesel set I saw running right after the war (61068), is still alive doing standby duty.
Bruce Roe

I find it very surprising to see how many people build outhouses today, and the state licenses them without hesitation.

My wife wants to limit petroleum coming onto our property, so no kerosene lanterns. We heat with wood and solar-thermal.

The last city we lived in was in Connecticut, the city has it's own power grid isolated from the state power grid, and the city owns it's own NG power plant. We were living there in 2003 when there was a big blackout for the Northeast. We saw no interruption in power for our home.

[organic farmer]

... The batteries will cost m ore than the a generator, and batteries need replaced every few years. Good luck with that logic. Please do not vote.

I think that would indicate an extremely cheap generator.

Lets say that your batteries were to last 10-years, just for a cost comparison.

Now running this generator for one week a month, two weeks some months, is going to consume some bit of fuel. Do that for 10 years and I suspect the fuel cost alone will be far more than the price of batteries. Oh before we forget, the cost of the generator. A good genny costs a lot.

One of my neighbors is a gunsmith. His insurance company required a minimum standard in generator that he had to install for his shop and home. It is a nice one, I can get you the specs if anyone cares. It cost him $5k installed. He normally consumes $100 to $150 in fuel each month to satisfy his genny.

Good generators are not cheap, but the real cost to running a genny is not the genny itself, but the fuel that it consumes.

Budget $1,000/year and $10k in 10 years, as compared to I spent $2300 on my batteries.

In my mind, [and there alone] $10k every 10 years is a mite more than $2300 every 10 years.

As sunking says I have a lot to learn, and maybe my math is off. It has happened before.

Is 10k [plus the price of a genny] more than 2300?