The Straw House Blog

Renewable Energy Archives


New Panels

Last month we installed two more 175W solar panels to our array. For those keeping track we now have eight 85W BP solar panels, four 165W Sharp panels, and two 175W Sharp panels for a grand total of 1360W.

Unfortunately one of the realities of building an array piecemeal is that the sizes of the panels change from model-to-model and year-to-year. We really didn’t want to buy new racks so we decided to modify the existing racks that hold the BP Solar panels. We added two new mounting rails and moved the two existing rails to the sides. The new panels squeeze quite nicely in the middle.

This required that new holes be drilled to mate the horizontal rails to the rack uprights. If you look closely you can see a piece of wood we were using a blocker to prevent us from accidently drilling into the back of a panel. With Dad, J.P. and I it took most of the day to get the racks modified, panels mounted and wired.

Most of the time that we worked Declan played outside in the sand pile (side note: a pleasant side effect of straw bale construction is that you usually end up with enough leftover sand for a good play area.) He’s a remarkably self-sufficient kid.

We’ve been really lucky, so far this fall and we’ve had lots of sun. We call this time of year the “100 days of grey” because we typically go from late October to early January with little or no sun. In the last four weeks we’ve had many sunny days and have really seen the benefit of our new panels. Here’s a picture of the readout form our Outback MX-60 charge controller. You can see that the panels are bringing in 31.4A but the MX-60 is upping that to 38.3A. Typically we have to run the generator weekly through the 100 days of grey to keep the batteries charged but in the last four weeks we’ve only run it twice. In addition to saving money on gas, we really appreciate the peace and quiet.



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.


October Update

It’s been a pretty busy fall around here, we had the OSBBC house tour right at the beginning of the month, I’ve been very busy with various work projects and Joanne’s maternity leave has come to an end and she has returned to work.

Aside from my regular work (which has been going very well, thanks for asking) I just recently built a custom 6’ long version of my dining room light for Eurolite. I was somewhat apprehensive at first, I didn’t think it was going to come out very well, I was worried that the proportions would all be off, plus it would have to be hung from four wires rather than two. In the end though I was very pleased with the results, if I had enough plastic I would probably build another one for myself. There are some images of the custom fixture on the lights page.

The Tour

Given the weather (it poured rain most of the day) the tour went quite well. We had fewer people than we expected but still had around 75 people over the course of the day. Mom was on the door, Dad helped with tours, Simon and J.P. from Generation Solar, Peter Mack from Camel’s Back Construction, and Paul Dowsett from Scott Morris Architects were all answering questions, showing people around and handing out business cards by the fist-full. Surprising (to me anyway) was that the majority of people who came through the house had read the blog, many of them from the very beginning.

Afterwards we had a nice BBQ, Tina, Steven & Laurie & Malaika, and Regis (from the Paudash Lake house I worked on) all came by, a pleasant visit was had by all.

Final Grading

We have finally completed the final grading around the house, Eric was here last week and the week before dumping topsoil around the house and leveling it back out. The ICF"s are covered and the west and north sides are backfilled with topsoil. The east side of the house has been built up with gravel/sand from our pit - since we are building a deck on that side we didn’t see any point in buying topsoil.

The Floor

Dan Peel was here again working on the radiant floor system and it looks like we have finally got all of the kinks out of the system. We had been having a series of problems where the various aquastats on the hot water tank couldn’t read the temperature of the water inside the tank accurately and as a result the floor would rob all of the heat from the tank. This always seemed to happen right as we were about to shower and you wouldn’t find out there was no hot water until 5 minutes into the shower - and only then would the boiler come on. Over the course of last winter we also had two broken pumps and a malfunction in the boiler that kept it running for one month non-stop (before we clued in), these problems masked the underlying aquastat issues until spring of last year. But by then the sun was out more frequently so we decided to spend the summer thinking about the problem and Dan suggested drilling a hole through the side of the tank cover, through the insulation and placing a temperature prob right up against the stainless tank insert. That seems to have done the trick. We’ve had almost no solar gain for over a week now and the house has been quite comfortable. Thanks Dan!

Site Update

I recently purchased a Kill-A-Watt, which is a meter that shows how much power in Watts and Amps a device uses over time. It can also display Volt Amps (VA), Power Factor (PF), Kilowatt/Hours (KWH) and time (how long it has been plugged in). It has no data logging built in, while it is plugged it works, unplug it and it loses all data.

So I’ve been wandering around the house plugging all of my various tools and gadgets into the Kill-A-Watt and compiling a list. The list is ongoing but I have added in the values of the various lights around the house and posted it in the house section: Load Chart. As I measure more devices I will add them to the chart, right now it’s mostly just the power tools, and computers.


July - August 2004 Solar Stats

It’s been a pretty crappy summer, and I’m saying that as a guy who doesn’t even really like summer. It’s been rainy, cloudy and cold. We openned the top windows once and within three days had the ladder back out to close them again. Whereas last year we were sleeping with the sliding doors and side windows open this summer we’ve mostly kept them closed. A friend was saying that we’re going to have a really cold and snowy winter but this summer has been so weird I can’t help but wonder if there isn’t a reasonable chance that it’s going to be 30C in December.

June Solar Stats
Monthly Total: 1225.3 AH
Daily Average: 40.84 AH
Best Day: 54.7 AH
Worst Day: 19.3 AH
Days Below 5 AH: 0

July Solar Stats
Monthly Total: 989 AH
Daily Average: 31.9 AH
Best Day: 57.6 AH
Worst Day: 0 AH
Days Below 5 AH: 0

I haven’t been very disciplined about my record keeping this summer so there is some margin for error in those stats. They look about inline with last year though; June was better with 1225.3 AH versus 1174.8 AH (based on daily average for June 2003. July is a bit down with 989 AH versus 1066.8 AH for 2003.


March to May 2004 Solar Stats

This May was our one year anniversary in the house. I can barely articulate how much we have learned in the past 12 months. It has been a fantastic experience, and, notwithstanding the birth of Gil, probably the best year of my life.

We’re quickly coming to appreciate that the spring is a great time to be living off grid; we’re getting appreciable amounts of both sun and wind.

March Stats
Monthly Total: 718.3 AH
Daily Average: 23.17 AH
Best Day: 58.5 AH
Worst Day: 0 AH
Days Below 5 AH: 4

April Stats
Monthly Total: 1011.4 AH
Daily Average: 33.71 AH
Best Day: 63.7 AH
Worst Day: 0 AH
Days Below 5 AH: 4

May Stats
Monthly Total: 985.2 AH
Daily Average: 31.78 AH
Best Day: 57.1 AH
Worst Day: 7.2 AH
Days Below 5 AH: 0

These stats are for the solar panels only, I still don’t have any method of measuring the output of the wind generator (H80) over time.


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.


Stats - December 2003 - February 2004

Things definitely improved as we progressed through the winter.

December Stats
Monthly Total: 607.1 AH
Daily Average: 19.5 AH
Best Day: 45.5 AH
Worst Day: .2 AH
Days Below 5 AH: 8

January Stats
Monthly Total: 654.1 AH
Daily Average: 21.1 AH
Best Day: 55.1 AH
Worst Day: 0 AH
Days Below 5 AH: 8

February Stats
Monthly Total: 868.8 AH
Daily Average: 31 AH
Best Day: 63.1 AH
Worst Day: 0 AH
Days Below 5 AH: 3

This doesn’t take into account the power from the wind generator. I still don’t have any method of measuring the output of the H80 over time. I can state that we have been generating much more power from the wind generator, we’ve had several days where I am certain that we made more than 100 AH from wind.


Positioning Solar Panels in Northern Climates

This isn’t a post about solar panel azimuth or anything so technical. It’s far more practical advice I’m offering today: if you live in an area that gets a great deal of snow (currently we have between 2 and 3 feet), and you are going to be putting your panels up on your roof, make sure that you have a easy, safe method of clearing snow off of them. Yes the snow will eventually melt off, but I hate losing a full day of sun waiting. Clearing the snow off our panels is a chore that I do not enjoy, climbing the ladder onto the very slippery steel roof and clearing the panels is bad enough, but getting back off the roof and onto the ladder is NOT FUN. The only consolation is that if I fall it will be into four foot deep drifts and onto Gator, who will be trying to catch the falling snow, and will instead get me.

If I were doing it again I would build in a dedicated rest for the top of the ladder that prevented it from sliding sideways. Then I would build a metal catwalk with some angle irons and metal mesh - neither of which is an expensive material. For the sake of a couple of hundred bucks I’d be able to walk around the panels in confidence.

Better yet, if your site allows it, mount the panels on the ground.



The House in Pictures

I’ve put together an overview in pictures of the house from the day we broke ground (August 2002) to when we moved in (May 2003).