How can I maintain 60 Hz output from a generator with variable RPM?

[dlgoff]

So I wonder what happens when enough locals are feeding power back into the grid and there is a power failure such that a section of the neighborhood becomes an island. Do the individual co-generation units know the difference?

Except for wanting to sell power being the main objective, probably wouldn't ever happen. If you can make enough energy to take care of your own needs, you probably wouldn't be connected to the grid. Just sayin'

 

[anorlunda]

So I wonder what happens when enough locals are feeding power back into the grid and there is a power failure such that a section of the neighborhood becomes an island. Do the individual co-generation units know the difference?

That's an interesting speculation. The answer would depend on the technical details of how each unit detects grid presence. I don't know.

Except for wanting to sell power being the main objective, probably wouldn't ever happen. If you can make enough energy to take care of your own needs, you probably wouldn't be connected to the grid. Just sayin'

Even if the neighborhood (or individual homeowner) makes all its own energy, it would be hard for them to provide their own backup and repair service for less money than a grid connection. It has to do with the very high availability numbers we have become accustomed to for electricity. I think any such neighborhood (or individual) would demand backups and 24x7 repair service.

Remember that with wind and solar, a long period with no wind no sun means relying on the backup. Batteries can not get you through a week long snow storm. To be really self sufficient, you need wind power and/or solar plus batteries plus a backup that can run a week or so. The grid connection alternative has to compete economically with that.

 

[dlgoff]

... it would be hard for them to provide their own backup and repair service for less money than a grid connection.

No. I'd bet that most people having these kinds of set-ups are very knowledgeably of them and would prefer to maintain them. But maybe that's just me ... No.

 

[anorlunda]

No. I'd bet that most people having these kinds of set-ups are very knowledgeably of them and would prefer to maintain them. But maybe that's just me ... No.

I agree, but only if we distinguish most people (early adopters) from most people (general population). Much miscommunication has occurred because posters use both of those definitions interchangeably in the same conversation. Averagesupernova seemed to talking about the general population (i.e. a neighborhood of Aunt Millys) while you seem to project people like yourself.

 

[jim hardy]

It's required and would be part of the system.

Good.

I comment here only to encourage other readers of this thread -
jury-rigged generators will backfeed the transformer on your utility pole, energizing its high voltage side. and you don't know how far that goes. In Florida we lost a couple linemen during every hurricane restoration from jury rigged household generators.

If you're not a pretty good electrician - hire one, or stay the **** out of your house wiring and use extension cords

old jim

 

[anorlunda]

If you need more encouragement than Jim Hardys post, be advised that you could be charged with criminally negligent homicide.

 

[Averagesupernova]

I agree, but only if we distinguish most people (early adopters) from most people (general population). Much miscommunication has occurred because posters use both of those definitions interchangeably in the same conversation. Averagesupernova seemed to talking about the general population (i.e. a neighborhood of Aunt Millys) while you seem to project people like yourself.

Well in the average neighborhood that I was referring to it doesn't really matter what type of people live in the houses that are all part of a co-generation island. The simple fact is that the systems that are in place today work without human intervention so it is irrelevant whether or not the owner can watch it all happen and explain everything that is occurring and why.

 

[anorlunda]

Lots of luck with no human intervention. Cut your neighborhood micro grid off from the grid and see how long it lasts.

 

[Averagesupernova]

Lots of luck with no human intervention. Cut your neighborhood micro grid off from the grid and see how long it lasts.

No, no, no, no, no, no, no, no, no, no, no, no, no, no, no, no.
-
That's not what I said. If I were to install a wind generator and get set up to co-generate for my power company a failure of commercial power is supposed to disconnect me from the grid yet continue to provide me with power WITH NO HUMAN INTERVENTION. What happens when you cut a neighborhood micro grid off from the main grid is what remains to be seen. I never said the micro grid would continue to work fine with no human intervention. That was the point of my post. What will happen?

 

[Windadct]

So... do we now see the complexities in residential / distributed generation? There are so many factors in this it is not even funny. First - the basic question is yes - you can generate with a PM ( BLDC) motor - and rectify to DC - then connect to an inverter. ( I have worked with some Wave power companies - it has it's own significant hurdles that I will not get into...)

If you want to have a full time connection to the Utility - allowing power to and from the utility, you will need an inverter made for this, probably a new electric meter, and permission from the utility. For example the inverter needs the safety functions referenced here - but doing this is no different than a typical residential solar case. So for that you do want a professional to deal with the regulations, installation, inspections and utility issues.

If you want to use the power to charge batteries and then operate on your own power, isolated from the utility most of the time, and ATS is a good way to go. They are quite common in the USA for standby generators. So it is possible to have it connected with the Line side being your battery bank / inverter, and the generator side the utility, when your batteries can not support the load the ATS will switch over to the utility. This will still require inspection and approval, but it is much simpler.

There are significant incentives for renewable generation in the USA - but just going this project alone will be difficult to make sure you are meeting the requirements and regulations to qualify - may be difficult.

 

[votingmachine]

I've looked at solar and the automatic transfer switch suggested here is wrong. The solar is turned off if there is a power failure from the utility supply. I asked about a transfer switch. You can have a home generator that feeds into your house, if you have a transfer switch to isolate the power lines from that. As pointed out, when the electric lines are being repaired, they need to keep home solar arrays from electrocuting the linemen.

The ordinary solar system that uses net metering will be shut down when the power company has a power outage. There is no transfer switch to allow internal and isolated electricity.

 

[Windadct]

There are solar inverters set up GRID tie with Islanding Function - this by definition means they will continue to supply the load ( house) when the utility is down (and must provide the necessary isolation for safety). It does make a much more complicated inverter. ( The function you mention is called anti-islanding - where if the utility is down the inverter shuts off)

Looking at a no-cost out of pocket solar deal - you have to pay for standby Battery as additional - for our house it comes to a $4000 adder for batteries and upgraded inverter. ( which is less than a standalone back up generator would be with the ATS - installed)

With an ATS in this case - the Renewable Supply & the Utility would always be isolated, it has a primary (preferred ) source and the secondary. Normal Grid Tied Solar does not use ATS. However you can use an Islanded ( isolated ) Solar - very low cost inverter, typical DIY things, and an ATS - or just a manual switch keeping the utility as standby - very common in areas where the utility is very expensive. You just live with a lot of power interruptions.