Snow Rake for Solar Panels

by Ben N on December 11, 2017

A few days ago, we got the first snow storm of the year. Not a big deal, but that was the first snow we had since I installed the solar array on my garage. I found that using a broom, even from a ladder, I could only clear the lowest of the three rows of panels.

After reading through a number of web pages, it looked like the most common way that people remove snow from their panels is with a roof rake. So, I found one at reasonable price and ordered it.

Last night, we got another dusting of snow, and as luck would have it, my roof rake showed up as well! It’s a SNOWJOE 21-Foot Twist-n-Lock Telescoping Snow Shovel Roof Rake Model RJ204M. Assembly was easy, just pop the plastic blade onto the end of the telescoping pole and screw on two small aluminum braces.

With that, I headed outside to try the roof rake.

Extending the pole is easy, just loosen by twisting, then extending one section of the pole (it’s four sections total) and then twisting again to lock it down.

IMG_7503At full length, the pole does flex quite a bit. The rake end kind of bounces, but it still feels pretty solid. I had the right amount of reach to get all the way to the top of the second row of panels, and that was WITHOUT a ladder! I could get part of the bottom of the third row of panels, but only if fully extended and with me right next to the building. At that point, I couldn’t actually see up the roof and had to guess at where the rake had landed!

I was hoping that if I could get at least part of the third row of panels that perhaps it would allow the sun to warm the panel and have the snow start to slide down. Although it didn’t get sunny today, it did get a degree or two above freezing for a while. Sure enough, the snow on the top row of panels DID slide down a bit, but not off the roof. Actually, it was almost worse. With the snow covering HALF a panel in the upper row and the middle row, I likely got LESS energy production than if the top row was completely covered and the middle row completely bare!

Using the roof rake is a bit of a workout. Anytime a person is working over their head, it’s always a bit tiring. To me, it felt like a deltoid workout not unlike paddling a kayak. (An like paddling a kayak, NOT something I do every day!) The roof rake itself isnt’ that heavy, (4.8lbs./2.2kg) but with it fully extended, it’s a handful!

Overall, the roof-rake does a pretty good job of clearing the snow from the solar panels. Good, but not perfect. I found that it got caught pretty easily on the mid-clamps that hold down the solar panels. It could also get caught in the gap that separates the rows of panels, although approaching at an angle seemed to help with that issue. A foam or squeegee head might run over the mid-clamps better, but might not bite into the snow as well.

IMG_7506It was also difficult to completely clear the snow. Seemed like there was always a little bit here and a little bit there. Even small amounts of shading on a solar panel can dramatically reduce energy production, so that’s not ideal. On the other hand, if the sun ever DOES come out, those small bits of snow should melt quickly. That’s the one last thing that I’ve been noticing so far with snow and solar panels – of course snow on the solar panels blocks light, but just HOW CLOUDY it’s been seems to have an ever larger impact on the power made.

That is to say that even though the snow is covering the panels, there’s just NOT that much light to convert to energy anyways! In my area, this is an extrememly dreary and gray time of year. Now, if it was SUNNY and the panels were covered in snow, THAT would be a different story!

For now, using a roof rake to clear snow off the panels seems like a simple and practical solution. It’s not perfect, and I certainly wish I could more easily reach that third row of panels, but for now, it’s more than good enough.

Until next time, stay charged up!
-Ben

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Snow-cover on my Solar Panels!

by Ben N on December 9, 2017

I woke up this morning to a gray half-light, and a blanket of snow covering everything…. including my solar panels!

Hmmm. What would this do to my solar power production? To find out, I thought I would clear the snow off as many of the panels as I could and see what the difference would be.

For starters, the bottom edge of the solar panels is about 9 feet high. I reached up with a push broom, but could only clear the very bottom of the lowest row of panels. So, I got out my 8-foot step ladder. On level ground, the ladder is sturdy and solid, and every bit as safe as it would be in summer, as long as I’m careful about my footing. From the ladder, I was able to reach the entire bottom row of solar panels, although I did have to move the ladder quite a bit.

Once I did that, I headed back into the house to check the web interface for my solar panel production. Essentially, the panels with the snow on them were blacked-out, although I was surprised that they DO still make power, just almost nothing compared to the uncovered solar panels.

By around mid-day, there was a little more light, though it was still far from being a sunny day. I’ll have to keep an eye on the panels and see how warm it has to be before the snow can slide off. A few solar friends of mine have extendable snow rake poles which they like. I’m pretty sure I’ll be investing in one in the future.

For now, we’ll see how long that snow stays up there. Based on how much power I create from the one exposed row of panels, I should be able to figure out how much power I “lost” from the others being snow-covered. Heck, I could probably figure out the exact monetary value of what that snow-cover cost me! That snow-rake will probably take some time to pay for itself….

Until next time, stay charged up!

-Ben

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Solar Shading

by Ben N on December 6, 2017

A few weeks ago, I started noticing a shadow creeping up to the solar panels on my garage. Sure enough, in winter the sun would be low enough in the sky for the shadow of a pine tree in my front yard to start blocking solar panels!

What’s a person to do?! Well, other than cutting down trees, (which I also did) the best thing is to PLAN AHEAD!

IMG_7339That started with me originally doing a Site Survey and figuring out how good of a location this would be for solar panels in the first place. Before I even rebuilt the new garage, I was already planning for the solar and used a “Solar Pathfinder” tool to see how much of the garage would be shaded, and at what times in the year. The Solar Pathfinder is essentially a curved plastic dome with a solar chart on a piece of paper below the dome. Looking at the reflection in the dome (sort of like a security mirror) a person can see trees, buildings, and other obstructions that would shade the solar location. Those can then be traced onto the slip of paper, and a little math can be done to figure out what percent of total solar production would be knocked down by the shading.

IMG_7309I knew that one issue with where my garage was is the fact that I have a narrow north-south facing property, and my neighbor has the property line planted with mature Maple trees. Those help keep my house a little cooler on hot summer afternoons, but they also cast a huge late afternoon shadow over my garage. Likewise, in the winter, with the extra-low sun in the sky the shadow of a tree in my front yard may actually be long enough to start blocking out the bottom row of my solar panels. And that’s exactly what I started seeing recently.

IMG_4271So, when I designed the solar array, I planned on using MICRO-INVERTERS. A micro-inverter is a relatively small device which mounts behind a solar panel and converts the DC power of the panel directly to AC power. That AC power is then combined with that created by the other panels, and routed to my breaker panel in the garage. Each panel produces power independent of the others. By contrast, a traditional “Series-String” inverter has many solar panels connected in series, one to the next to the next, and then to the inverter to be converted to AC power. One problem with that design is that a shadow over part of just one panel will reduce the amount of power made by ALL the panels in that string. Imagine the old Christmas lights where when one bulb would go out, they all go out. Only in this case, if one panel isn’t producing power, none of them do. Because of that, even a small amount of shading can have LARGE consequences in terms of photovoltaic energy production.

Another nice feature of using micro-inverters is that the system can provide information about each individual solar panel! Now that’s actually far more information than anybody would want to look at on a daily basis, but it’s very nice to have access to for things like troubleshooting. I’m using Enphase brand micro-inverters and can access all of the data about the panels and micro-inverters through a web page interface. It also allows me to give public access to a streamlined version of that information. If you want to see what my solar panels are doing right now, you can take a look at: https://enlighten.enphaseenergy.com/p…

Looking at the “Enlighten” software graphical interface, it’s very interesting to see how the pine tree shadow sweeps across the bottom row of solar panels. But the best part is that it’s ONLY that one or two panels that takes a hit to power production. Any panel not shaded is completely uneffected.

PineTreeShadingDec2017I also used the software to run an animation of the solar panels late in the day during the summer. Sure enough, it’s very easy to see the shade of my neighbor’s leafed-out Maple trees sweep across the solar array. However, the panels on the east side of the garage just keep producing power, even while the ones on the west side of the garage are shaded. This gives the more easterly panels up to another hour and a half of production time. All that time adds up when it comes to producing energy, and keeping my electric bill low (or NEGATIVE all summer!)

The graphing features in the micro-inverter web display are also interesting. Looking at a week in summer versus a week in winter, I can see how skinny the curves are on winter days. I can also see how the production curve of a typical day is steeper in the PM than the AM. That’s because of that late afternoon shading. However, I’d still much rather have solar panels than not, even if my solar access isn’t perfect!

If you have a location that might be good, but not perfect, for solar production, don’t let it stop you. Tricks like using micro-inverters can help maximize solar resources. That doesn’t mean you don’t do your homework or put panels just anywhere. Careful planning, researching solar, and using tools like a Solar Pathfinder can allow you maximize your resource and start making renewable energy!

Until next time, stay charged up!

PS: In the video, there’s a number of times where I use the terms “Power” and “Energy” almost interchangeably. To be clear, the two are different. Power is how much work is being done right now, whereas Energy is a total amount of power over some unit of time, typically an hour. Power measured in Watts (W) or Kilowatts (kW) and energy usually in Kilowatt-Hours (kWh). Think of it this way, an old fashioned light bulb might use 60 watts of POWER. You will use it for some number of hours over a month, and you will get an electric bill for your ENERGY use in kWh.

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Gen 2 Flux Mopeds DIY Special

by Ben N on December 2, 2017

Recently, I’ve had a fair number of people asking me about electric scooters.

Not only are scooters fun to ride, but you don’t need a motorcycle license, and they are often cheaper to insure and title.

That’s why I was excited to recently hear from Matt at Flux Mopeds. A while back, they had a few of their scooters available for sale, but WITHOUT battery packs. For anyone who could build their own battery pack, it was a great, inexpensive way to get into an all-electric ride without a lot of money. I got one of the scooters and built a pack for it from some Nissan Leaf cell modules I had. Since the scooters were originally designed for a removable pack, they feature a pair of 50A Anderson quick disconnects and DC circuit breakers, making connecting your own pack very simple.

Here’s a playlist of videos from working on one of those scooters:

So now, Flux again has a few of their scooters available, sans battery, as a DIY special. These are now the Second Generation EM1 mopeds. The second gen features a Sabvoton brushless DC sine wave controller.If you can assemble your own pack, you can get a great deal on an electric ride. They are only charging $730 each. These are BRAND-NEW, with a real VIN, all ready for street-legal riding EXCEPT for the battery. Buy two or more and they are only $680 each!
Visit http://www.fluxmopeds.com/innovators for more information. If you are interested contact Matt at mjbrueggeman@fluxmopeds.com

Get them while you can, and tell them Ben sent ya!

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Video of Tour the Mitsubishi iMiev

by Ben N on November 24, 2017

One of our YouTube viewers asked for a video tour of the Mitsubishi iMiEV electric car. So, we pulled out the video camera, filmed it, and gave our honest review of the vehicle. Here’s that video!

We’ve been driving this car for two years now, and have put about 20,000 miles on it. In a car that got 25 MPG, that would have been 800 gallons of gasoline. Fuel prices in my area over that time have averaged very close to $2.40 per gallon. So, that 800 gallons would have cost $1,920 dollars. There’s also been at LEAST four oil changes that have been avoided, but would have been required by a gas car. (I only paid $7,000 for the car in the first place, as the second owner of the vehicle, so it’s already paying for a good chunk of itself.)

I already posted a few blog entries about likes and dislikes of this car. Please take a look at those if you are interested.

Overall, my general feeling about the car is that I like it. It’s a practical vehicle. It’s handy. It has plenty of cargo room and nice hatch access. I really like the upgraded stereo with the features included with it, such as the DVD ripping and the backup camera. The headlights are great, and it doesn’t use a single drop of gasoline.

IMG_7379The battery pack is definitely on the small side. That could be a deal-breaker depending on where you live. If you live way out in the country and expect to hop on the interstate, drive 50 miles, and then another 50 miles back home, it is NOT the vehicle for you! (Although perhaps a Chevy Volt, Bolt, or Tesla Model 3 would be!)

Recharging the car is very simple. Pop the port, plug in the charger cable. Done. Because the car has a smaller battery pack, it DOES recharge quickly. I have two different EVSEs in my garage, so that I can park on either side, reach out into the driveway, or have a friend stop by and charge while I’m charging. Recharging is usually only a few hours (maxing out at no more than 5 hours with a completely empty battery) so there have been plenty of days when I would go for a drive in the morning, put the car on charge when I’m home, and drive again later with a full battery. For a while there when my schedule accommodated it, I was regularly traveling over 100 miles per day, even thought he official range of the car is 62 miles. I also track my mileage for business use. The tax deduction is far more valuable when it’s not just displacing the cost of gasoline!

Free_Fuel_GoSolarI’m also very excited to charge DIRECTLY from SOLAR POWER! I installed my own solar array, specifically to power my house and car. I did the math so that the solar should produce the amount of electricity used by my house and car combined. I’ve only had the solar in for five months so far, but my estimates have been matching up pretty well with my actual production and use. The car has a 3300 watt charger in it and the solar can produce up to 5,000 watts. In the middle of a sunny day, I can charge my car, power my house, and still have a little juice left over to run back to the power company and out to my neighbors (while I get CREDITED for it!)

I’ve also liked having the CHAdeMO high-speed charging port. When I first got the car, there were THREE CHAdeMO stations in my area which were FREE to use! Since then, one of them has broken and never been repaired, one was converted to an overpriced “for pay” plan, and the third is still freely available, but is the most out of the way of the three. Recently, a few more CHAdeMO stations have come online, but they are all part of the same pricing plan, which would cost me almost $1 per hWh. Due to that, I’ve used the CHAdeMO port much less than I had previously, but it’s still a GREAT feature to have available! (Many of those DC Quick Chargers have been funded through companies like Nissan. If you buy a new LEAF, they have a “No Charge to Charge” program, where owners can charge FOR FREE at any of those DC Fast Chargers! Not much help for us used car buyers though!)

The car has great head-room and an excellent view of the road. Those are things that I do NOT like about our 2004 Prius. In that vehicle, I really have to slide and tilt the driver’s seat back to fit me, and even then the roofline, rear-view mirror, and passenger side A-pillar all block my view. Driving the iMiEV is like driving an aquarium by comparison. I’ve always enjoyed driving full size vans and pickup trucks because of the head-room and view I have in them, although I’ve hated the fuel economy! The iMiEV gives me the best of both worlds.

The iMiEV isn’t for everyone, but it’s been a very overlooked and underrated vehicle and I’ve been happy with my choice – affordable and practical. I really believe that there’s a plug-in vehicle out there for everyone! There’s GREAT deals to be had on used EVs, and the newest vehicles have continually increasing ranges and features. Extended range plug-in vehicles (like the Chevy Volt) also can save an incredible amount of fuel and maintenance.

I hope you enjoyed this video tour of the car, and that you get charged up over whichever plug in vehicle floats your boat!

-Ben

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