Sun Pod One

I’ve launched a new web site for promoting and researching my product, the Wash-A-Ton. Look here:

Wash-A-Ton Solar

On this site, I’ve set up a forum for PV industry discussion and I’m looking for people to contribute data about their washing machines. Please take the time to fill out this survey and help me get my product on the market. I need to know:

- length of cycle
- amount of power used
- brand name of your washing machine

Take the Survey

At the same time, anyone interested in buying individual components for utilizing solar power, feel free to contact me and I can point you in the right direction. Thanks.

I’ve come a long way from just recharging AA batteries and my ipod off of solar power. Today did my fourth load of laundry in two weeks. I’ve finally found an application for solar that is easy to use and doesn’t cost a fortune.

Here is a picture of my balcony from the outside. I live on the 20th floor of my building, so I had to lean out a window and stretch my arm really far to get this picture. It may look crowded from the outside, but when you’re standing on the balcony, there’s enough room to move around and get your laundry done. We don’t use dryer machines here in Taiwan, because we are so close to the equater. Even now, in early February, there’s enough direct sun to make solar applications a reality.

Today was the third day in a row that I did laundry using solar power. My batteries topped out pretty quickly today, although it’s sunny but hazy. I’d say it really is a sunny day, not even a bit cloudy, but I can’t see the usual blue sky for some reason. There’s this whiteness to everything in the sky, almost like transparent fog. Ok, I’m not making sense now. Who knows, maybe it’s just pollution.

I wanted to push the limits of my solar application and see just how far it could go. Actually, when I ran the washing machine at 800 rpms and a 50 minute wash cycle, I didn’t think it would every finish. At the last moment, just before finishing, the batteries were really close to the bottom, so I don’t think I could go much farther with them. Still, it’s pretty cool, because as long as it’s somewhat sunny, even in the winter time, I can run a load of laundry everyday of the week here.

That will make a serious dent in my electric bill next month.

Today I washed a load of socks using only solar power. I went with a light load of socks, and the “quick” wash cycle, which usually runs for about 30 minutes. My main concern was focusing on the end of the wash. The batteries by that time would have drained the most. And it’s during the spin cycle that my washing machine takes the most power. So I hooked up my solar panels and waited until noon, when the sun was in the best position. Right now it is mid-winter here in Taiwan, so using solar to wash clothes in the summer would be even easier.

Today was only a partially sunny day, and I watched with insane anticipation as my battery level dropped whenever the sun went behind a cloud and then rebounded again when the sun came back out. Near the end of the cycle, when things were getting critical, the batteries had already gone from 13.5 volts all the way down to 12.1 volts. This still gave me some room to work with, though. Then, during the last and most aggresive part of the spin cycle, the batteries dipped to 11.7 volts for a split second. Suddenly the sun came out and hit the solar panels with force and beep-beep-beep, the washing machine sang a little song telling me everything was finished! I had done it. Any interruptions in power and I’d be washing those socks by hand.

As my friend Ed pointed out, “You can use the sun to dry them, too!” So I hung them up to dry on the balcony of my condo on the 20th floor of my building.

Solar not only works, but could also be used by people living in tall building with no access to the roof. I estimate that a working setup like mine costs around US$400, retail. That might sound expensive, but just think about how many times you wash clothes during the year. Even if you only wash them twice a week, the batteries in the pack will have plenty of time to recharge during a cloudy week. During a sunny week, a setup like this could be used to power other things around your house, like your computer or TV, on days when you aren’t washing any clothes.

I used this equipment:

2 Brunton flexible solar panels (the black ones): 15 watts of power
1 MIC (Made In China) solar panel (no brand name): 30 watts of power
8 6v4ah rechargeable sealed lead-acid batteries: 12 volts x 16 amps
1 SunForce PWM charge controller: 500 watts 30 amps max.
1 Son Dar modified sign wave power inverter (MIT): 1000 watts max.

Take a look at the picture. It’s not pretty, but it works!

You could go with a much smaller charge controller, but I recommend sticking with a PWM controller. You could also go with a much smaller power inverter, but then I would recommend getting a pure sign wave inverter, although this will cost a little more. I would also lose the 2 flexible solar panels and replace them with another 30 watt panel. This way, with two panels, they could be angled to account for changes in the position of the sun during the day, in a V-shape, because reflections off of one panel would bounce into the other. And 60 watts of power would produce better results than 45. Also, I like the idea of keeping the whole setup portable so it can be easily moved indoors during a storm. Here in Taiwan we have giant typhoons and the balconies are open to the elements.

I’ve been trying to tackle powering some of the mid-sized items around my condo with solar energy. Smaller items, like my ipod and my cell phone, have been been off the grid for months. But things like my TV and my washing machine, those take a little more thought and money to manage.

Take this situation for example. My 42 inch LG flat screen TV can run for an hour off of 6 lantern batteries, once they are charged up to around 13.5 volts and 12 amps. The TV uses around 125 watts of power. But when I tried to run my smaller 32 inch LG flat screen TV off of solar charged batteries, I ran into some interesting problems. Because this TV is older, it actually takes more energy than the newer 42 inch TV. I see it using around 135 watts of power. Not only that, when both TVs are turned off, they continue to use electricty, but the smaller 32 inch TV actually uses more energy than the larger one!

There’s a happy middle in using batteries. With rechargeable sealed lead-acid batteries, they work best between 13.5 volts and 10.5 volts. This means that the alarm on your power inverter can go off for different reasons. Most power inverters have a different sequences of beeps, indicating what the problem is, whether overheating or overloading or simply out of power.

My old power inverter was rated at 150 watts, with a peak of 500 watts. It works really well for things like my laptop computer and recharging my digital camera, which I can’t recharge directly from solar because Kodak doesn’t make a USB type charging cable. So I thought there would be no problem running my 32 inch TV with that power inverter.

Power inverter = 150 watts
TV = 135 watts
Batteries = 145 watts

Sounds nice, doesn’t it? But after about 15 minutes, the power inverter alarm went off. At first, I thought I was overheating my power inverter, because the batteries were pushing the ceiling of what it could handle. 145 watts is pretty close to 150 watts. But when I did the math, I suddenly understood that the voltage level in my batteries was dropping over time, as they were being used. Once they fell below 135 watts, presto, beep-beep-beep goes your little power inverter.

If you have a Kill-A-Watt, plug it in to your TV and let it monitor the power level for about an hour. Then see how much energy is being used. This will give you an idea of how long you have to use your batteries, based on the drop in power over time.

Because my power inverter is too small to handle powering the TV for very long, I needed to upgrade. I went for the big ticket this time, buying a 1000 watt power inverter, with a potential 2000 watt peak surge in power. I stuck with a modified sign wave inverter because they steal less energy than a true sign wave inverter and I haven’t had any problems with them adding noise to the sound of my TV. I picked up a DPI-12100, which has a digital processor in it to monitor power distribution. The model is made by a company here in Taiwan called Son Dar. They are located by the international airport, in Taoyuan, and I have been in contact with the staff there. Really good people. For this unit I paid around US$140, but I probably got a better price than you could outside Taiwan, because they make them right here. It’s pretty heavy duty. I mean, you could probably drive a truck over it and it wouldn’t crush at all.

So, I happily plugged my new power inverter into the 32 inch TV and lined up the batteries. The inverter comes with a 4 AWG cable, much bigger than I needed, because I’m not going anywhere near 1000 watts. I stuck with a 14 AWG cable that is about a meter (or 3 feet) long.

Bi-bi-bi…bi…bi…bi… The alarm began to sing after less than 10 minutes. Wait, I cried! What’s going on here?? (By the way, here in Taiwan, where Chinese is the main language, we say “bi” and not “beep” for the sound the alarm makes. Incidentally, the sound of this new power inverter is much easier to listen to, compared to the grating tone of the older one, something I hope my wife will appreciate!)

Ok, I did the math again.

135 watt TV
1000 watt power inverter
Maybe 140 watts in my batteries

Simply put, the battery level was dropping too fast.

Then an alarm went off in my head. Power OVER time! Why hadn’t I thought of that before? My batteries might have 140 watts in them right now, but over time and use, the level drops! It’s not like when you plug into the wall and you have a constant supply of power.

For the next project, I will try to tackle powering my washing machine. When it’s on and just filling with water, it’s taking about 7 watts of power. As it cycles and moves the water around, the power consumption changes a lot: 32, 60, 90, 20 watts - up and down like that, depending on the amount of energy needed to make things happen - the heavier the load, the more power needed to move your clothes around. This is one of the few items in my house that fluctuates greatly in power consumption over time, making a Kill-A-Watt a very useful tool for measuring power consumption. At the end of the cycle, when the washing machine began to spin the fastest, the power level jumped up to over 200 watts. It might look easy to power a 200 watt (peak) washing machine off of 240 watts of power stored in batteries. But before you know it, your battery level will drop and then your alarm will go off, due to consumption over time, and you won’t see the end of washing your clothes.

In this case, the maximum power consumption happens at the end of the hour, and by then, your battery level has dropped the most, working against you. You will need to start out with much more power in the beginning. My Kill-A-Watt told me at the end of the washing cycle, I had used closed to 400 watts of power. Because my washing machine is on my balcony, near the sun, I think I can plug in my solar panels, and along with my batteries, together make it through a short wash cycle of maybe 30 minutes. My LG washing machine is adjustable and can run a shorter time with a smaller load. However, running for a whole hour, like we usually do, is currently beyond my reach.

I’ve been in contact with the engineers at Son Dar and they explained that any home electronics marked “green” or “reduces CO2″ have been built with solar projects in mind. You see, a modified sign wave inverter will create a fake sign wave by putting together a series of square waves that climb up and down like a staircase. But with each square wave comes a harmonic, also called THD or Total Harmonic Distortion. With a cheaper inverter, THD can be as high as 25%. If you have a signal at 50 hz, then you will have a harmonic at 100 hz, 200 hz, 400 hz, and so on. Older home electronics that were more sensitive, like stereos and TVs, could easily be damaged by this THD. Newer items that have been built with “green” in mind, have been put together to handle THD. Harmonics can be filtered out, making a cleaner signal.

Good luck with your home solar projects!

I’ve been working on a prototype solar panel stand, so I can get the most out of the sun throughout the day. Keep in mind, I live in a condo on the 20th floor of my building. Yet some things are working to my advantage here. Since I live in Taiwan, in the summertime we are directly below the sun, on the Tropic of Cancer. That means, in the winter time, like right now, the sun is 23.5 degrees lower in the sky, to the south of us. Because of the limited change in elevation of the sun on the southern horizon, the tilt of my solar panel is not so critical. Yet even 23.5 degrees can give me .3 amps more each hour, which will add up all day long.

My idea was to take something like a camera tripod and put a solar panel on that. This way I can adjust the angle of the panel and move the solar panel around on the balcony all day long. However, when I went to the store, tripods were mostly expensive and didn’t look like they could hold much weight. Not only that, there was the question, how do you attach a solar panel to a camera tripod?

Instead, I wandered over to the bathroom department, and for around US$8, bought some cheap shower parts. What I came up with looks pretty cool, yet after testing, it has some drawbacks.

First, I can’t adjust the solar panel angle toward the sun, or the tilt, from top to bottom. I’d like 23.5 degrees in the winter and nearly horizontal in the summer. I can turn the panel from left to right, which is helpful, and I can adjust the height, although that’s not too important here. What’s cool about my design is that I can move the panel and hang it anywhere I want on the bacony, as the sun moves across the sky during that day. Not only that, I can take the whole thing down whenever there’s a typhoon nearby, like in typhoon season.

Second, with regards to typhoons, the wind tends to move my solar panel around more than I care. Because the panel is hanging, and not secured tightly, it likes to act like a kite. Not a pretty site, when you see your money floating around like that, about to smash into something and possibly fall 20 floors to the ground below.

So now I will go back to the drawing board and attempt to come up with another design. Any suggestions here would be greatly appreciated!