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82
Wind Power Machines / Re: Interfacing wind turbines to the grid
Last post by MaryB -
efficiency losses of around 15-20% but you COULD grid tie the inverter and use a separate charger to charge batteries that is grid powered. My charger is 90% efficient so whatever the grid tie inverter losses would be added to it.
83
General Discussion / Hi All
Last post by ClockmanFr -
Good to see a reboot of Fieldlines.

I do have a few PDF files i would like to post on this forum.
OzInverter book 1st Edition, a selection of Ozinverter 2nd edition chapters, basic Energy creation docs as PDF,s, AC Coupling PDF's. Etc.

The Modern version for DIY of the PLANTE lead acid 2v cell will also be published here. Sadly all the last info on the old Fieldlines forum is probably lost.

My move from France to Wales was completed end of Sept 2025. But how the heck to find all my stuff amongst 400 packing bpxes and tons of machines has been very hard.  Plus building my new workshops, Chem labs and facilties has been very hard. Plus getting my house 12 rooms presentable is also hard work.

I keep finding bits of my good old very large memory and fast systems PC has also been hard, hopefully in 7 days i will be back operational.

I have been working with the Facecloth IFLA group who have been a  very helpfull group of guys and gals.
87
Wind Power Machines / Re: Interfacing wind turbines to the grid
Last post by SparWeb -
First I have to figure out exactly what I want to do, then out how to do it.
First: What to do:
1) Export energy to the grid?
2) use the AC for other purposes?
3) use the energy for stored heat?

My PV set-up allows me to do both.  When the PV inverter is exporting, it's not going directly to the grid, yet.  It goes to a common bus at the base of my meter, and if the house is using power then the house can be supplied by PV.  This is passive and just the balance of current flows, based on Ohm's law, and it's marvelously simple.  I don't have to distinguish between goals 1 and 2, then.  Goal 3 is much harder, since I put the PV panels on the garage, not the house, meaning storing heat in water or sand doesn't let me heat anything that needs to be heated.

Actually, the excess energy from my wind turbine is being used for heat - just a simple bank of resistors that lose heat to the air in my garage.  Hardly useful but necessary to ensure there's always an electrical load on my wind turbine.
How can the excess energy be better used?
1) feed wind DC to the batteries that back-up the PV inverter?
2) feed the WT's output into a separate grid-tie inverter?
3)

Number (1) is obvious, since my wind turbine is designed charge batteries, and that's exactly how I have it hooked up.  But can the system export to grid the extra wind energy?  No.  The problem with (1) is that inverters simply DON'T export the charge from batteries to the grid - they are designed to do the opposite: store energy from the grid in the batteries. Only when the grid fails do they withdraw energy from the batteries, and then it's only to run the backup circuits.  This mode of operation is familiar to us in uninterruptible power supplies and off-grid power setups.  So as the wind charges the batteries, they get full and the excess wind energy just gets lost as heat.  At least I have a backup power supply that's always ready.

Solution (2) promises to export excess wind energy to the grid, but the options are limited.  Most grid-tie inverters will simply not accept the feed from a wind turbine.  If you tried, you would find that the inverter disconnects the wind turbine's electrical leads from time to time.  A wind turbine running freely will spin its blades very fast - destructively.

To get anywhere with Solution (2) one needs a separate control for the wind turbine.  It has to be independent of any grid-tie inverter to do its safety-related job.  There are such devices on the market and you can get simple ones or fancy ones.  I already have a controller in my WT system, because it's basically an essential safety device, whether the WT is meant to be on-grid or off-grid.  Almost invariably, a diversion load (resistor bank) goes with it.

With that controller in place, does this help choose the grid-tie inverter?  While I mentioned safety, the device that's connected to the grid really should be a UL/CSA/IEEE tested device.  This rules out most of the products you can find, particularly the blue ones on Amazon.  Aurora used to make a fine machine, but sadly they are no longer in business.

There may be options on the market that I haven't noticed yet, though.  If anyone knows of one, please feel welcome to suggest it!
88
Wind Power Machines / Interfacing wind turbines to the grid
Last post by SparWeb -
Custom-building wind turbines... is hard.  Interfacing wind turbines to the grid... is also hard.
But it is lucrative to come up with a way to grid-tie an inverter, sell the excess energy when the batteries are full.

There are products you can buy, but when they fail things can go drastically wrong.  They're all made in China, of course.  While I'm seeing better products from China all the time, the flood of bad ones hasn't disappeared.  This example might be a good one: https://www.engelecenergy.com/On-grid-Inverters-pl3261504.html
But it doesn't charge batteries.  I want to do both: Keep a battery set charged, and export excess energy to the grid.

My solar panel hybrid inverter does that.  Why can't my wind turbine do that?  I've checked, and my SOL-ARK inverter will not manage the operation of a wind turbine.  It will not accept 3-phase inputs nor will it accept inputs that drastically vary from 50-60 Hz.  While I've been looking for a way to interface my wind turbine to the rest of my RE system, so far all it does is charge the batteries.

A wind turbine bought as a commercially-available unit will usually includes a grid-tie interface, unless the WT is designed solely for charging batteries or running pumps, etc.  Examples include Bergey and Proven, where you can choose from either on-grid or off-grid versions.  Again, if you want both, you need to get more equipment.

Also, their GT inverters are designed for the specific wind turbines they build and sell, not "any" WT.  Since I'm custom-building a wind turbine, one of these would require substantial modifications to adapt it.

What am I to do?

Improvise, I suppose...
89
General Discussion / Re: AI
Last post by SparWeb -
Using Win 11 at work there are annoying things that I'm glad I don't have to deal with at home.
For all the computing advances of the past 10 years, I haven't seen many that improve my productivity, ability to express ideas, or analyze a problem. This computer is running just fine with an i5 CPU and Windows 7, plus plenty of security doodads to keep the unwelcome parts of the internet out.  Software stalled out somewhere in the 2010's, and today engineers are using the same programs they were 15 years ago, just adorned with nicer GUI's (with some dreadful exceptions).

I haven't been keen to adopt too much AI in my daily computing, either.  That said, I'm generally impressed by the ability of Copilot to summarize discussions and meetings, and extract useful lists of tasks to follow up when my colleagues decide to do something.  But you have to get used to the idea of a Microsoft AI listening to every word you say and all the graphics up on the screen...

I have seen some struggling coworkers attempt to cover their shortcomings with AI results, but it's usually obvious and scatterbrained.  People mistake AI for "expert systems" which these LLM's aren't.  They actually have no more insight into how the world works than a 2 year old. 

This will change when AI becomes more sophisticated.  Personally, I think that AI's will remain dumb imitators for a while.  Once developers team up the AI's with robotics and give these combined machines more independence, then in time the AI's may gain the spark of experience to truly understand "right" and "wrong".