2010 A.E. Web Log

2009 Log Archive

29 November 2010:

Not a whole lot to report as winter sets in. I ran into a bit of a problem installing my solar hot air collectors, in the years that have past since I last had working collectors up, there are trees that have grown up in front of the Southwest end of the building. I'm going to have to cut some trees down, there's just no two ways about it, so that will be a job for next summer. I'd also like to mount my next array of solar panels on that same side of the building, I'm starting to get late afternoon Fall shade on my panels in the yard, darn trees...

I made a new electronic purchase a couple of weeks ago, I bought a 47" Vizio HD TV and an LG Bluray player. I've been putting that off since I didn't want the extra power usage of a large TV. I went with a Vizio TV rather than a similar LG TV because the power rating on the Vizio was a full 100 Watts less. I discovered something interesting, with the Visio TV set to medium on the ambient room light setting, the TV only uses about 70 Watts and that's with the BluRay player on, with the ambient room light setting turned off, the TV uses nearly 180 Watts. That all has to do with the back light level, if you're in a fairly dark room the back light can be turned down a lot, saving a lot of energy. Needless to say I'm pleased, this new TV is using less power than my old 32" CRT TV which used about 80 Watts. Honestly I think the picture looks much more realistic with the back light lower, when it's at full level it's so bright it looks artificial.

Nothing else new to report, I'll add to my solar array in the Spring again. If I get ambitious I may even buy a back up generator this year to get me a step closer to going off grid for good.

31 August 2010:

Yesterday I started building a set of new hot air collectors, I started a page on the build here.

I added a set of 12 volt lights in my workshop and added 2 new 12 volt circuits out to the shop. At the moment I've got 5) 13 watt bulbs out there and it's enough light to work by at that end of the shop. At some point I'll add more lights, but it's nice now to be able to work out there without using grid power or turning on the inverter. I pulled the wire off the wind generator to run those 2 new circuits, I guess that means I'm not planning on rebuilding or fixing the wind generator...

25 August 2010:

Yesterday I added a new 120 Watt solar panel to my new rack. The plan now is to add a panel every Spring and Fall, I may even add another panel this Fall, but I'll just have to see how things go.

The new 120 Watt panel installed.

The best I've seen out of both racks today is 22 amps or about 280 Watts. 2 more of these 120 Wall panels would pretty much fill this rack and put my solar controller at it's peak of 35 amps. I turned the grid power back off in the house yesterday. Last month I needed more 120 volt circuits than my work shop had, so I had wired the house back into the grid. I think I'll add another 120 volt circuit to the shop, that way I don't need to mess with switching the house power back to grid if the need for more circuits arises again. That will also prep the shop better when I get a backup generator and go completely off grid. This afternoon I'm going to run a new 12 volt circuit to the shop for lighting. I'm going to gradually add 12 volt lighting to the shop. I don't like to have to run the big power inverter when I'm in the shop and just needs lights for a few minutes.

I'm debating getting a wind generator back up for this winter. It sure is nice to have some wind power during those multi day blizzards when you get very little sun. I'm thinking about a Lenz turbine again, it would seem to be an option that is reliable and doesn't mind turbulent lower level winds. I'm not looking for great power in low winds, just something to give me a few amps in the above mentioned conditions.

22 July 2010:

A few days ago I had to tie the house power back on grid. I needed about 44 amps of power to do some rocketry work in my shop, I have been getting by with a single 30 amp grid circuit out there but that just wasn't enough to get this job done. In the past 3 months I've done very well living on just the solar power in my house, well, I did connect my AC to the shop circuit so I'd have some degree of comfort with the heat and humidity summer brings. But other than that I've been living on just the solar power, only once in those 3 months did I have to charge my batteries using grid power, and that was a miserable 8 or 9 day day stretch where the sun nary broke through the entire time. I'm still contemplating what to do for those 3 months or so where air conditioning is pretty much a requirement. I suppose at some point I'll have to use a generator, perhaps propane, and use that for air conditioning when needed.

The wind generator hasn't run for a couple of months. I did manage to lasso the tail strut and get a rope around it. I had hoped I could just turn it into the wind when I needed the extra power, but the geny seems to be frozen now. For what ever reason, those new bearings I installed never took a proper seat, I suppose it's possible they just weren't the right size. A couple of times I almost mustered up the energy to bring it down and replace the bearings with the old ones, but never did get around to it. So I'm thinking now I'll just add more solar this Fall and pull the wind generator down for good.

26 May 2010:

About a week and half ago the wind generator lost its tail. I'm not sure I'm even going to bother fixing it this time, as we move into summer there is much less wind and the solar panels have been pretty much supplying all my domestic electricity. I have used grid power in the house once, during an almost week long rain/cloud event my bedroom floor got wet. So I had to run fans and a dehumidifier to dry the carpet, I ran an extension cord in from the shop to provide utility power. After I dried out the bedroom, I did use the grid power on my TV for 2 days since I went so long without any good sun. I probably could have gotten by without grid power on the TV, my batteries never got below about 12.3 volts, but I do tend to pamper my batteries. I need to get over that and just use my batteries when I need them...

So I haven't had to actually charge my batteries from grid power and I'm getting along pretty well. I can see adding about 2 more of the 60 watt panels would really help me out though. Early this week the temperature hit 95 one day and was in the 90's for three days. I just had to run my air conditioner as the heat and humidity were unbearable. If I ever intend to fully be off grid power, I'll either need a good generator I can run on those really hot humid days or put in enough solar to run a small air conditioner during the day. My small air conditioner only uses about 890 watts and will keep things comfortable. I'd be looking at 1200 or 1300 watts of solar to get some air conditioning, that's seems doable in the long term.

26 April 2010:

It's been 17 days since I switched the house power to all RE and I'm doing fine on just the power I'm making. I haven't had to use any grid power other than some in the work shop. In fact I think there's only been one day where I didn't get the batteries to float voltage. I've had several days where there was little to no sun, but wind usually picks up enough to keep the batteries topped off. Speaking of the wind generator, it seems to have finally loosened up enough to spin up in lower winds, this morning I was putting 7-8 amps into the batteries with only 10-15 mph winds. So it looks like I won't have to pull it down again in the near future. I've been thinking about making a new rotor hub and set of new blades, the one up there now do seem to be a little out of balance. I think I'll make the new hub out of flat plate steel, then use some machined brackets to hold the blades. That will extend my 6' diameter to about 7' and give me full use of the 3' blades. I'll update with some pictures when I get it done and explain it in more detail.

Here's the new solar rack wired up with a junction box.

11 April 2010:

Here's the new rack with my 2 new 60 watt panels installed.

Here's a shot of the back side of the rack.

As you can see in the pictures, the new rack is pretty much done. It's a wood frame supported by a couple of 6" treated wood posts set in concrete. The rack pivots and the lower supports are 1/4" x 1.5" flat steel with holes drilled to adjust for seasonal sun angle. The panels are bolted to 1.5" uni-strut. The uni-strut comes in 10' lengths and was just right for cutting in half since my panels are 30" tall and a pair make 60". I still need to install a junction box and finish the conduit to the box, for now the panels are just wired direct to the wires going into the house. With the new panels on their own wires and the angle a bit more appropriate, I was getting 8 amps into the batteries from just these 2 panels. Which of course I was pleased to see. There's room for 6 more of these panels on the rack plus a bit of fudge room.

I think the wind generator needs to come down again... When it does start up it sounds like the stator is rubbing on the rotor. It takes 15 to 20 mph winds to get it going, when it does start turning it makes good power, but it should be turning in lighter winds and it just doesn't sound right. I'm going to keep adding solar as I go, eventually I'll go with no wind generator at all. It's just too much trouble for what it's worth. Solar just works, every day, day after day with no maintenance.

9 April 2010:

It's been a couple of busy days again for me, yesterday I got the wind generator back up and just on cue the wind came up and gave me some nice wind power. The generator was a little slow starting, but I was expecting that with new bearings, give it a few days of flying in some wind and it'll loosen up. I connected my old analog amp meter out of the rectifier and promptly pegged the meter, it's been pegged most of the day today too with winds in the 20 to 25 mph range. Now it's only a 15 amp meter, but that's still very good power for the size generator it is, and I've got to be losing a lot of power in the lead in wire as it's only 12 gauge wire.

Today I pulled the entire house off grid power and connected the main breaker box to the 2,000 watt inverter. I'm going to leave the grid power on this summer, just in my workshop. For the short term it's cheaper to pay the $12 a month meter charge and use the grid as back up power. I really want to maintain access to my shop tools that run on 240 volts too, at some point down the road I'll set myself up with a good 240 volt generator.

I had a couple of cloudy, rainy days earlier this week. That gave me a good chance to see how low I'd pull the batteries without much daytime charging. After 2 days of virtually no sun, I had the batteries back almost full (13.52 volts) the next sunny day, the day after that the batteries were full by noon. So it looks like I should be in pretty good shape for the summer, especially now since I have some wind to back up the solar.

6 April 2010:

Here's a shot of the electronics room.

I've been busy the past few days. I got the wind generator down and as expected found a broken wire in the downlead. The generator as a whole looks pretty good, there is some signs of heating in the stator but nothing too bad, just a few cracks in the resin around the coils. I decided to pull it apart and inspect everything, once I had it apart I decided it was time to replace the bearings and seal. One odd thing, the tail boom support had a crack in the metal, so I welded it closed, then welded a heavier support piece on side I didn't weld. It's raining and windy today, would have been a nice day to have it back up, but I'll have to wait for calmer winds to get it back on the pole.

As you can see in the picture I've got the Xantrex C-35 installed, I've got a dual breaker box running into it from what will soon be 2 solar array sets. Out of the C-35 I've got a shut for an amp meter with the meter just above in the black box. I did a little re-wiring on the wind generator line coming in. I put a new rectifier on the heat sink (top left) and added a switch to short (shut down) the generator when not needed. I also added 2 more batteries to the bank, that was an adventure too. Iowa has few RE incentives, the only one that applies to me is no sales tax on RE systems. I've had to fight with retailers every time I buy something for my RE system to get the sales tax exemption. Most times if it's not too big of a purchase I just let it go and pay the sales tax. But this time I wasn't going to give in at Sam's club. I hate the idea of having to buy a membership for the privilege of shopping there, so I wasn't going to let them get away with charging me sales tax. I went through a checker, then the head person of the checkout people, then a floor manager, then ended up with the store manager, who was actually an assistant since it was a Saturday and the manager was not working. We argued for several minutes when he finally admitted he didn't know the Iowa tax code, so I mentioned the fact that ignorance of the law is no excuse, he didn't like that... In the end he called the manager at home and I got the tax removed, but what an adventure. I blame not just the store and people there, but the state of Iowa should do a better job educating retail stores about what is taxable and what isn't.

To the left of the batteries is the new Xantrex pure sine wave inverter, and just out of sight to the far left is my 2,000 Watt MSW inverter. Behind the Xanatrex inverter is my homemade diversion load controller. The mess of wires to the lower right is all my DC loads, they run through a pair of DC circuit breakers. That whole mess will soon be in a new breaker box of it's own.

Yesterday I received my second 60 watt solar panel. I started a new rack, got the rack mostly done and one post in the ground before foul weather set in. I'm running the wires into 1" conduit. I really wanted to run some 6 gauge copper, but my budget is suffering so I'm using 6 strands of 12 gauge copper for the time being. When I start getting too much loss in the wiring as I add more solar, I'll replace the 12 gauge with something heavier.

31 March 2010:

The new inverter arrived today, since it's only a 600 Watt inverter I wired it up with 4 gauge copper wire, I'll save my 00 gauge copper for something a little bigger... The inverter works great, I'm using it now, ran the TV earlier and it worked fine too. This inverter has a display that alternates between battery voltage and kWatts being used, a nice feature. I'm not sure how accurate the Watt meter is, it seems a bit low to me, it was only reading between 40 and 60 Watts on the TV and between 80 and 90 Watts on the PC. I suppose this inverter may be a little more efficient than the old one, which would be nice if that was the case.

I almost bid on some solar cells on eBay yesterday, but then I saw the seller I purchased my 60 Watt panel had them on sale again, so I'm waiting to see if I'll get another panel for the same $139 I got it for last time. It's just hard to justify buying cells and making a panel when it's just as cheap in the end to buy an factory panel.

My batteries were full early this morning so I did a load of laundry on the 2000 Watt MSW inverter, nice weather today so for the first time this year the laundry is back on the line to dry. The batteries were full again shortly after noon, so I've been running things on the new sine wave inverter to give it a good test. I like this new inverter, everything runs just like on grid power!

30 March 2010:

I've been considering a lot of options on how to proceed with my RE system. One of the major concerns I have is power regulation, with added solar I had to increase my diversion load, when I add my wind generator I'm going to need to increase the diversion load even more. But that means the regulator I'm using will cycle on and off rapidly on days when just solar power is being generated and the batteries are full. I considered getting a MPPT controller, it maximizes solar output, getting you more charging current out of your solar panels. I also looked at standard PWM controllers. In the end I decided to go with a Xantrex C-35 which is PWM, but it also has a diversion load control option. So I can use it now as a solar controller, and down the road switch it to wind diversion controller. I ordered the C-35 on sale for $88, it should be here Thursday.

The next consideration was for a new inverter. I've been using my cheap 2000 Watt modified sine wave inverter for heavy loads such as vacuuming and clothes washing, and using an old computer UPS for TV and computer power. But even the UPS is modified sine wave, the TV seems to do fine on it, but my computer fans run noisy and I have all too frequent computer crashes on the UPS. I knew I needed a pure sine wave inverter, and it was time to order one. It didn't have to be that big, just enough to run the TV/stereo and my computer. I found a great deal on a Xantrex ProWatt SW600, at $140 it was the best price I'd found on a 600 Watt pure sine wave inverter. The fact that's it's a name brand with a 2 year warranty helped the decision making process as well.

With the new inverter due to arrive tomorrow, I decided to hard wire a couple of circuits dedicated to the pure sine wave inverter. Different power supplies (as in 2 different power inverters) need to be kept separate. You don't want to plug in devices that share a common ground into two different inverters, as in don't plug a computer into one inverter and a printer into a different inverter, been there and done that, once...

Here are a few thoughts:

I still like the idea of running all my lights at 12 volts, in fact I like the idea of running as many appliances off 12 volts as I can. There are down sides, 12 volt CFL's (and appliances) are more expensive and you need heavy wire for 12 volts. But the upsides are no inverter efficiency losses, no loss of use of an item if the inverter fails, no idle power loss from running an inverter 24/7 and I would think an inverter should last longer with less hours of "on time".

Wind is great, but solar is much more reliable in terms of days of production and mechanical dependability. I'm still leaning towards adding more solar as I go. The wind generator is great since during most cloudy/stormy weather you have good wind. I may keep my wind generator shut down most of the time and only use it during extended cloudy periods. I had sold myself that the idea of making your own solar panels wasn't a good idea. While I still believe that, I may just order a set of solar cells and make another panel just for the fun of it. I'd like to order a couple of 100 Watt panels at a time, but with the budget I'm on that just isn't possible. I just love all the people that diss the do it yourselfers that work on a budget. Yeah, It'd be great to drop $4,000 on a nifty inverter and another $10,000 on solar panels, but I'm going to have to go at it slowly, adding when and where I can. That's the nice thing about eBay, at least there you can buy solar panels one off rather than by the pallet, and the prices are still pretty good.

I'd really like at add 2 more batteries to my bank and it's almost now or never. The batteries I have are right at a year old now, it's not a good idea to add new batteries to used batteries, but the set of 4 that I have, have been used very lightly. I don't think I've ever taken more than a 20% charge off the top. So I should probably do that in the couple of weeks.

25 March 2010:

It's been a beautiful sunny Spring day, just what I needed to give the solar panel a good test. My battery bank was full by 11:00 this morning, so I did a load of laundry, by 1:00 PM the batteries were full again so I vacuumed, within an hour the batteries were full again. Peak amps from the solar array hit 10.8 amps at about 140 Watts. I was hoping to get at least 9.5 amps with the addition of the new panel so I was pleased with the performance.

24 March 2010:

Spring is finally here and the snow is receding! It's time to start thinking about adding to my RE system. A few days ago I purchased a new 60 watt solar panel from an eBay seller, the price was right, $139 plus about $21 shipping. I debated ordering a couple more of these panels right from the start, but I wanted a chance to look the panel over before I made a commitment to more of them. The panel arrived today and it looks great. Of course it had to be cloudy today, but I tested the output at 22.1 volts open and 1.8 amps shorted. A little hard to tell what it will do in full sun, but those numbers looked very good to me.

As it sits now, I've got about 6.5 to 7.5 amps @ 12 volts of solar power in full sun. In the winter that's just enough for domestic lighting and a little extra. In the summer that provides lighting, clothes washing and vacuuming; throw in the wind generator and now I've got power for limited TV and shop work. Adding to what I have, once the wind generator is back up... I'm thinking about 15 amps total of solar should just about supply all my residential power, adding another 6 amps this summer should do the trick. My TV running on the inverter uses a total of 89 Watts, my desktop PC about 135 Watts. Whatever I add now just means more hours of TV or computer use.

Menards (building supply center) now sells 12 volt 13 Watt CFL bulbs, it's really handy to be able to pick them up locally, so I've been picking up a bulb or two when I get there and adding more 12 volts lights as I go. My homemade diversion load controller has been running for a year now and still works fine, right now it's controlling everything but at some point I'd like to get a MPPT solar charge controller and run the dump load controller for just the wind generator. I'll need to build a second rack to hold solar panels, still a bit of snow out there and everything is wet, but I'd guess in another week I'll be able to work on the new rack and get at the wind generator.

16 March 2010:

It's time for an update, it's been over 6 months, but what a six months it's been! One of the worst winters on record in terms of both snow and cold, I'm certainly glad it's almost over now and I'll be able to get some work done outside again. The bad news is that the wind generator quit working early last winter, it seems there is a broken wire either in the stator or the downlead wire. I had reinstalled the generator on the utility pole, then some weeks later it just quit. My guess is that it's just the down lead wire, but there's still too much snow to get the wire replaced or lower the machine. Essentially the generator was free wheeling with no load, so I managed to throw a nylon cord through the blades to tangle it up. It was effective and the generator has been shut down all winter.

I've been relying on solar only this winter, and it's been enough for domestic lighting but that's about it. One set of my 45 watt "solar kits" is still mounted in the original ground rack, so it was covered with snow most of the winter. The panels mounted on the large rack were high enough, and had enough wind resistance for the snow to drift around the rack, keeping them pretty open to the sun.

Here's a picture from this winter, you can just see the solar rack behind a snow drift.