The Straw House Blog


Wind Generator Update

We dropped the tower a couple of weeks ago to see if it was alright before we ordered new blades.

Our main concern was that the bearings and bushings might have been damaged by the vibration of the unbalanced turbine. Once the tower was lowered we took as much of the assembly apart as was feasible, checked the moving parts for excess movement and everything seemed to be just fine. We put the tower back up - the safest place for the tower is up in the air, not down on the ground.

J.P. from Generation Solar ordered us new blades and I figure they’ll probably arrive right as the summer doldrums start. Right now it’s sunny and there’s a strong (though gusty) wind blowing outside. Normally at this time of year there’s an abundance of both sun and wind that we never have to run the genset. With the wind generator out of commission we’ve had to run the genset a few times over the last couple of months. I hate that.


Here’s J.P. and a good shot of where one of the blades broke off from the turbine. You can see that the blades snapped off just past where they attach to the turbine. We still have no idea why they broke. We did find the other blade though, it was about 200 metres downhill from the turbine, laying in the grass.



Throwing blades

We went out this morning to play in the snow (more on that later) and we could hear a strange rattling noise. Things are usually pretty quiet around our house and the sound was coming from the north, which is very unusual because there is nothing but fields behind us for quite a distance. It turns out that the strange noise was coming from our wind generator which had thrown two blades sometime early this morning.

I’m not sure how this happened as it wasn’t particularly windy or cold or this morning. When I got up around 6am we were producing around 10A of power from the wind generator so I can only assume that it still had three blades.

Anyway I tripped the brake on the wind genny charge controller which slowed it somewhat then climbed the back hill to trip the main brake which is located in a sealed box at the base of the tower. That brake shorts out the leads and causes the turbine to stop.

Once that was done I set about looking for the thrown blades. I found one quite near the base of the tower but the other is missing. Depending on how fast the turbine was spinning and what direction it was facing the blade could be very far away.

The biggest problem for us is that we make the bulk of our wind power in the spring. In fact we’ve had such a wonderful confluence of wind and sun for the last month and a half that we haven’t run the generator in ages. There’s so much snow in the back fields that it’ll be quite a while before we can get a truck up to the hill to lower the tower. Not to mention that the gin-pole is buried under nearly two feet of snow.


Off-grid System Maintenance

I’m not sure why but some people seem to have it in their minds that living off-grid, generating your own electricity involves lots of work (though if tinkering is what you want it can, as a quick browse through the the archives of Homepower magazine will demonstrate). However for most people, myself included, the system takes care of itself quite well. So for the benefit of the curious I thought I’d detail the maintenance needs of the various parts of my system.

The Solar Panels
The panels themselves are solid state and require no maintenance. In the winter I prefer to brush off the snow, but that’s just because I don’t want to wait for the snow to melt off. If I’m up on the roof I usually do a quick inspection of the panels and racks just to make sure that nothing is loose or damaged in any way, and in the last year nothing has been.
Total Time: one hour every six months (if that)

The Wind Tower
Like the panels whenever I’m at the top of the hill I do a visual inspection of the tower, just to make sure nothing is obviously loose or noisy. Every two years the tower must be lowered to do an inspection of the generator itself, and lubricate/clean/tighten various parts.
Total Time: visual inspections / half day every other year

The Batteries
Once a week we try and make sure that the batteries get a full charge in them, this often means running the generator for a few hours. Once every month to three months (depending on the season) we do an equalize charge, which requires sun, wind, and the generator running all day. Every month I check the fluid levels of each cel, and top them up with distilled water if needed. Before and after an equalize charge I take readings of each cel with a hydrometer to measure the specific gravity of each cel, this is the most accurate method of determining stage-of-charge.
Total Time: half an hour every month

I’m lumping the inverter, solar charge controller and wind charge controller into this group, and aside from monitoring (see below) there is no maintenance for any of this equipment, it’s all solid state.
Total Time: zero

Monitoring the system performance is important for many reasons: first it lets you know how your power generation and power consumption are comparing, which I think we can all agree is pretty vital, second by tracking base line numbers you’ll realize if something does go wrong. My biggest gripe with various aspects of the system is the lack of quality monitoring, especially where the wind generator is concerned. I keep a chart by the inverter and every night before I go to bed I write down how much the solar panels generated that day and cumulatively, the battery voltage, amp/hours away from full charge (which is an approximation), and details about whether the generator was run, if we achieved float, full charge, equalize, and if water levels were checked.
Total Time: two minutes each night

Gas Generator
Unfortunately this is still an important part of the system, and with months like November likely always will be. Aside from adding gas, I check the oil once a month, clean the air filter every other month, and just generally check it over whenever I gas it up.
Total Time: one hour every month

To sum up that comes out to about three hours every month, which is less time than I spend cutting the grass. Every couple of months I might have to spend an extra hour on some aspect of the system, and in fact most of the extras (like equalizing) are highly automated, start the generator at the beginning and stop it when the equalize is done.

For most people using a wind generator or solar panels in a grid inter-tie situation there is even less work to be done, since the vasy majority of my maintanence is the care and feeding of my batteries.

I have a well planned system installed by professionals (I recommend the fine folks at Generation Solar), if you’re a hard-core do-it-yourselfer your milage may vary, and if you go with some fly-by-night installers all bets are off. Remember when you’re talking to any kind of contractor ask lots of questions, if they can’t answer them in a way that you can understand that’s a bad sign. Ask for references, and CHECK THEM! Ask to see some systems they have installed, pay attention to the details, is the wiring neat and well routed? Does the system look like a pro job or some kid’s science fair project? How long have they been in business? How many systems have they installed? You might spend a bit extra but the results will be worth it.



The Wind Generator & High Winds

Some folks have asked how my wind generator deals with high winds. I took some pictures the other day with wind speeds around 35km/h.

Basically there is a angled pivot in the body of the generator. As wind speeds increase the blades are pivoted up at an angle, out of the wind. In the highest possible winds, I imagine, the blades would be parallel to the ground, horizontal rather than vertical.



The big tall new toy

Spent the day working on a job for a client, but still ran into the back room every hour to check on the wind generator, batteries, and charger. For the first part of the day we had both sun and wind, but as of yet we still don’t really know how much power we’re getting off the wind generator at any given time. Dad hooked my multimeter up to the DC outputs on the controller box so we can see how many volts we’re getting, the high was around 57VDC, and the average, seems to be in the 50VDC range. But it’s not just the volts that are important, it’s the watts, and both rise and fall according to the wind speed.

We’ll learn, and we’ve got a new metering system coming very soon.

Took the dogs for a nice long walk around the land tonight, beautiful night, not too many bugs, and everything is green green green. ‘Course I just walked around looking up at the tower, ‘cause it’s the cool new toy.

Oh, and I took the camera.



The Tower Part Two: Turbine

It’s up. J.P. flipped the switch at 5:00pm last evening and we started generating power. There wasn’t really much wind, so we weren’t generating very much power, but it was very gratifying none-the-less. We got a bit more wind later that night and I stood outside for a while, and when it’s really spinning you can just barely hear the turbine down at the house. Unfortunately there is no meter of any sort on the wind generator controller box in the house so I have ordered a separate meter to track the wind power.

The cable that runs from the tower to the house has three 2 guage aluminum wires: a positive, negative, and neutral line, each consisting of five strands. The entire cable is about 1” in diameter. Dad and Simon set the spool (of 650’) up on blocks so that it could unwind as they pulled. Then the dragged the cable through the bush behind the house, across the little valley, and up the steepest part of the back hill. I helped for the last little bit, then helped pull an extra twenty feet through from the house. Seriously hard work. We had exactly enough wire, barely a foot to spare. When Eric comes to put in the septic bed (next week) he’s going to bury the cable.

While Dad and Simon ran the cable, J.P., Jason, and I made some adjustments to the tower. Two of our anchors weren’t lined up properly and we needed to add an adjustable turnbuckle to allow us to drop the tower, when the lines are tensioned. By the time we had that done Simon and Dad were back and we all started working on attaching the generator, running the wire up the tower, and attaching the junction box at the bottom of the tower.

While we raised the tower, Dad and Simon went back down to the house and started working on the inside wiring. And then the yell came from below: “Turn off the brake!”



The Tower Part One: Erection

We could not have asked for a better day to raise the tower. 22 degrees, nice breeze, warm sun and clear blue skies. The breeze helped keep the black flies and deer flies away, mostly.

Simon and J.P. from Generation Solar were here to provide the know-how, my father, and myself to help. It took us four trips up the hill with the truck to carry all the pipe and tools. We had seven lengths of schedule 40 pipe (from Turkey, oddly enough), two at 22 feet, five at 18 feet. Five of the pieces were for the tower proper, and two were for the Gin pole. It turned out we had to clear a bunch of brush to make way for the guy wires. You try to be green and you still end up cutting down trees!

It took us from 10am to 5pm to assemble, raise and tension the tower properly.  Next week we’ll lower the tower and attach the wind generator. Then the real fun begins.

Rather than try and explain the whole process I have annotated the pictures. Enjoy.



Half a Fine Day

We had Mike and Dave for only half the day today so we started at 8am. It was warmer than it has been for a while and we set them to work on trimming the back beam and setting up the boxes for the back windows. Meanwhile Rene finished up the fascia board and put up blocks for the ceiling drywall. I helped Dad, helped Mike and Dave, and shovelled the last of the snow off of the roof.

Jo and my Mom stayed behind in Omemee and put another coat of stain on our doors. When they arrived at the land Jo and I took off for Peterborough and bought our chimney and flashing. We’re going to install the chimney now, so that the roofers can flash the whole thing in properly. We don’t really know for sure when we’re going to put in a fireplace or wood stove.

When we got back Eric had arrived and was in the process of installing our wind tower anchors at the top of the hill. He carried two anchors at a time in the bucket of his backhoe. So we’re ready to get the wind tower installed. As an added bonus Eric’s coming back tomorrow to install our septic tank and cut the trench from the well to the house. Things really seem to be rolling along! It’s very exciting.

All of the pictures are of Eric installing the anchors.



Poured the Floor

We poured the floor today. Rick Russo and his crew did a fine job, of pouring and smoothing 34 cubic metres of concrete. We had the concrete tinted a brown/tan colour and the results look fantastic.

We also filled our anchor forms (built by my father) that will be carried up to the top of the back hill and used to anchor the wind tower guy wires.

Tomorrow Jerry and his crew will be starting on the post and beam, so we are on track for our straw bale deadline. Things are looking pretty darn OK.



Ready to Pour

Scratch another alternative career from the list. Foundation work, especially in 30 degree heat is NOT fun. I don’t need to do that again. We worked all day Friday, and Saturday. Joanne, my dad, and I went back today to finish up, we worked until 10am just finishing up a few things that were missed and tying the rebar in the wooden forms. But the forms are done and we’re ready for the concrete to get poured either Monday or Tuesday.

After we finished that up we took the truck and drove it to the top of the back hill. If you’ve never been out to the land this is a big hill, about 90 metres tall, and quite steep. The wind tower is going to be located at the top of the hill on an 25m tower, and we needed to see make sure that we could get all of our equipment to the site. It was a heck of a lot of fun as well!