Anyone working toward Off Grid

[pinballlooking]

I did some research on wind but I am South Carolina and we don’t have good wind.
Luckily, we don’t have snow to cover our solar panels.

Good luck I will sit back and watch this one.

[Robaroni]

Originally Posted by randen

I had been interested in wind for a long time. I was very fortunate to have a close friend that had been in the business of manufacturing these for a short time. These 1-10kw turbines were used in remote areas and were plagued with maintenance issues. It was the day of lead acid batteries and lack of robust designs to keep the costs to a minimum. A proper tower and controls coupled with the cost of installations with proper footings made them quite expensive.

There are so many hurtles with wind. The first one is speed control in strong winds and even more so when the battery is full. To open the charge circuit when the battery is full can allow the turbine to run away with no load and one can expect a catastrophic failure with blades flying in any direction. The furling type is still dependant with having a constant load, however the turbine with pitch adjustable blades does not. Although more complex, for a larger turbine this is highly desirable. If the load is removed from the pitch adjustable turbine, the rpm doesn't increase.

Another factor is the wind is not kind to any dynamic machine. That large spinning propeller being spun this way and that are susceptible to some huge gyroscopic loads. Blades flexing and bearings in weather extremes don't make their expected life spans. The slip rings carrying the current from the alternator down the tower preventing the cable from twisting up, also has a hard life.

I had explored the thought of building an axial wound alternator large enough to power our home but the task is huge. A 5 kw alternator would be a sizeable machine with huge blades to carve and a tall robust tower. $$$$$ A concrete footing with a steel 50' tower, the costs would be prohibitive.

The wind resource is another part of the equation, little wind, no energy-simple enough. Here in southwestern Ontario the winter provides a decent amount of cold dense wind. The solar panels are covered with snow and that coupled with overcast and limited hours of daylight negates the energy equation. So bring on the wind.

The experiment with the 500w turbine is to check power/wind resource and resilience of a mono tower without guy wires. The pole is actually my sons basket ball pole. He won't be using it anytime soon so until then its on turbine duty. When I have some results and firm up plans I will elaborate with the group.

Enjoy Christmas Holidays

Randen

Randen - thanks!
I'm also at the point where I'm ready to install wind. I've been monitoring my Davis station for years now and I have enough good wind on my front acreage. Many years ago I bought a couple of those small South West turbines, about 400 watts each but you need really high winds to get that. I'm thinking if I can get 1/2 that it will be good enough to supplement my heat.
I'll keep an eye out for your findings.
Rob

[randen]

December 21 the day is sunny and no snow to speak of.!! This can change at a days notice. We are off grid and collecting electrons and heat from the solar hot water collectors. The home is heated with in floor heating and by default will take the solar hot water first and then backup with Geo-Thermal which will come into play when the sun is down and use the electrons we had collected from the PV.

However we are subjected to many days with overcast.!!! during winter.

The wind turbine has been working well however my wind resources have been a little shy.
My Mrs. has raised an eyebrow to the turbine as she likes all quiet when sleep is necessary.

The temporary location is quite close to the house but in a windy conditions you hear more noise in the trees and noises the house makes and none from the turbine. Thats a win!!!!

I will be marking a calendar to wind speeds and dates for production made. The turbine is more of a dynamic anemometer.


Anyway the best of the season

Randen

[mrmhf]

We’ve worked hard to get off the grid. We have solar PV and air source heat pump. The ASHP was always the question mark in terms of effectiveness and performance. But we’re approaching the end of winter and the results have been interesting.

[randen]

mrmhf

That is awesome you are off the grid. That's a huge accomplishment !!! Kudos.

I've temporarily installed a wind turbine to monitor the wind resource. I have to say I'm quite disappointed with the wind here in Ontario Canada

The weather has changed so much Feb. is so different now with temps of plus 0 deg.C for a high was unheard of. Today was 8 Deg. Nice because of all the sun which kept us off the grid for the day. But typically it would be snow cold and wind.

The overcast and lack of wind now is another spectical. Winters here typically the wind shook the house. Its been so calm.

We are still testing the boost inverter. 48 VDC to 390 VDC for the lithium pack charging.

Randen

[CrankyDoug]

Gathering wind data over a year or two is good insurance against failure. About 40 years ago someone in our community put up a wind generator based on anecdotal evidence that "wind is always blowing through that valley".

I drove by it every day for two years. Not one day in ten was it spinning. An ice storm finally put it out of it's misery. The owner wasted $10K.

The problem with many turbines from that era was that they wouldn't turn in anything less than 10MPH. Sailboat turbines still have this problem.

[randen]

Its time to make a couple upgrades to the 20KW inverter. 2 items need some improvements:

The small pump motor thats being powered by PWM supervised by a thermistor in the liquid cooled heat sink needs a different method. Lower temperatures cause a PWM signal that makes the little pump motor squeal in a high pitch. Not cool!! at night to hear that squealing noise coming from the garage. I going to change that out for a simple snap switch to simply turn it on and off around 30 Deg C.

also another snap switch for over temp incase for some reason the pump becomes inoperative. 85 Deg.C

The choke coil although it didn't burn off its enamelled wire insulation during high current demands it did get hot. So its now re-wound with heavier gauge copper.

The inverter has been working extremely well !! The electric bill has proven that point. For the time its been off line and we resorted to buying for the grid OUCH.$$$ and its been hot! so the heat pump has been flexing its muscles

Randen

[NiHaoMike]

Originally Posted by randen

The small pump motor thats being powered by PWM supervised by a thermistor in the liquid cooled heat sink needs a different method. Lower temperatures cause a PWM signal that makes the little pump motor squeal in a high pitch.

Try increasing the PWM frequency to above 20kHz.

[randen]

NiHoaMike

The purpose of using PWM was to vary the speed of the pump to the heat load needing to be dissipated while prolonging the life of the little motor. As the thermistors temp was up and down so went the motors RPM.

Im just guessing, but I'm sure the motor was stopped but the low PWM caused a little squealing noise that was extremely irritating during the nite.

The snap switch is a simple device and should last a long time at the required current draw. The pump motor is near silent at the rated voltage and the intermitted duty will extend the life without the noise.!! Win-Win

Randen

[bubbleboba]

off grid is something that I would love to do. However, I dont think I could ever do it, as I have a large family. Maybe I could get my consumption down a bit though