DIY idea!

      So I am looking to resolve my solar issues once and for all! After shopping around and finding that no matter what it’s going to cost me a lot of money, I stumbled onto this site here: DIY Solar Kit and the light bulb went on! So I started a new track of research and finally realized that I can save a ton of money and build my own custom panels!

      My large system that I have plans to build is based on a 48VDC side. But some of the problems I was running into were finding solar panels that were configured in 48V. I found one by Solar Canada, but the price is rather steep and further research showed that I can build a more powerful panel that meets my 48VDC requirement (actually it would be 49.5VDC which is optimal!) and generates an estimated 20 Watts more power per panel.

      Better yet since I already planned on building my own array platform this would allow me yet even more control over the final system. So now I am looking to buy this set-up here: More gooder DIY solar panel kit! I just need to shuffle some money around to do it. And since right now I need to increase my solar capacity, this DIY panel kit has the wattage AND amperage I need to make up the difference. Toss in a 10A charge controller and done! I have a bunch of wire at home so this would be easy to set up.

      And I also learned how to make my own combiner box for a couple dollars. So will definitely be doing that soon! Okay, that’s all for now, I have to bolt soon!

Okay... so cloudy days, they suck worse than you think!

      Okay! So cloudy days really suck for amorphous solar panels! The peak amps I saw were about 3.2 and not for very long. The average was just over 1.4A. So the realization that I will need more powerful and efficient panels hit home hard. Not to worry though it's all part of my learning experience. With full winter sunlight at peak I will see 6.1A from the current set-up I have (photos are still coming) and average of 4.6A.

      So I am looking at these systems here as an augment to what I have in place now:

170W System from Lowes - This is most likely the one I will get... when I have the $$$.
260W System from Lowes

      So going back to what I said about matching your capacity to your load... guess I need to take my own advice! LOL!!! Anyhow this brings up another interesting element that needs to be covered eventually... so why not now?

      Solar panels... holy crap! There are hundreds of them to choose from and they are of differing compositions! Which one to get? What wattage to get? It's enough to really drive you bonkers! So I will start  by defining the types of panels available and what the pros and cons are.


      From my research I have found that there are four main types of solar panels that you can currently purchase. They are Monocrystalline, Polycrystalline, String Ribbon, and Amorphous.

Monocrystalline Silicon Panels - Monocrystalline (or single-crystal) silicon solar panels are around 14% to 18% efficient. They are made from a single continuous sheet of silicon that has pieces of metal connected to the edges so as to increase conductivity and to assist with the excitation of electrons.

These panels are the more expensive of the panel types you can buy but they are also more effective, so in the long run these are the best bet for a good ROI.

Polycrystalline Silicon Panels - Polycrystalline (or multi-crystal) silicon solar panels are about 12%-14% efficient. Essentially these are a lot of individual photo voltaic cells grouped together that also use metal conducting materials connected to the sides so as to help with electron excitation as well as connect the individual cells together.

Polycrystalline panels are the most cost effective to produce as well as the most cost effective. An added benefit is that if one of the cells on a polycrystalline panel is damaged then you can replace the individual cell instead of the entire panel. This is one selling point of polycrystalline over monocrystaline panels.

String Ribbon Silicon Panels – String ribbon silicon panels are constructed similarly to the polycrystalline silicon panels and have generally have about the same level of efficiency The fundamental difference between string ribbon and polycrystalline is the photo voltaic cells in a string ribbon panel are constructed of strips of silicon attached to metal bars that connect the strips to form a cell.

By using strips of silicon to form the cell in lieu of using a  solid square of silicon make the production cost of string ribbon panels a bit lower than the production cost of polycrystalline panels.


Amorphous Silicon Panels – Amorphous silicon panels are the least efficient of all types of solar panels. Amorphous silicon solar panels generally run about 5%-6% efficient. This is due to the panels not being manufactured from crystalline silicon. Generally they  are comprised of a semi conductive metal, such as copper, with a thin silicon film over the top that is attached to some metal connecting pieces.

These are the least expensive panels to manufacture and they are great for small short term projects. But their inefficiency does not make them a cost effective long term solution for solar applications.

      So there now you have a bit more insight to various solar panels. Again I have a base system that is using the amorphous technology, and I knew getting into it that it will be a short term set-up. I also knew that it was the least efficient. But by starting small and inexpensive I have been learning a lot about off-grid solar power.

Some of my calculations sheets...

      As I had said in another post, I would start posting my calculation sheets for people to use in their own off grid endeavors!

https://docs.google.com/spreadsheet/ccc?key=0Av2bNlufN8JodEJnMTlyTnBseE95cWd5TkVranlXVXc

      Oh... and to use the sheet any area that is bold and blue is a field you edit. The other fields will update as you make your changes. But this sheet is a critical part of planning your system out. There is more information coming later... I have to go now but check back occasionally and see the changes I make to the calculations sheet. There is a lot more I have to upload.

      Okay, I have updated my worksheet a bit more. Now there is a sheet that allows you to compare batteries for cost versus performance based on configuration. You can tweak the numbers to match the system you plan on designing. As I noted elsewhere most systems are 24 volt, I am working on implementing a 48 volt system due to it's efficiency over 24 volts.

      I have also included a rough battery charge calculator sheet. One thing you have to look at is how long will it take with your system do recharge the batteries? The goal is to have it so your panels will keep you at least up to 95% capacity. Remember once a month or so you will have to equalize your batteries anyhow, so if you can recharge without running the generator then excellent!

My current system, an experiment to learn from...

    So before I invest a lot of money and time into a full blown system, I decided to start small. And I am really glad I did! First it’s going to be a while before the house is finished so there is no real drive to have a full blown system in place. Second I don’t have the money right now for a full blown system. So it’s saving time and with a new kid on the way, the economy borked and my pay raise an insulting joke... well it’s going to be a while before I can afford all the components I will need.

    All I need is power for my TV, DVD and some simple lights. Since we have a propane refrigerator (I really hate that fucking thing!) I don’t need to run my big energy hog of a fridge. Actually my AC fridge is pretty efficient but is still takes a bit of power. As for my deep freeze, I have that over at a neighbors for the time being.

    So I looked at my load requirements and realized I can support the load so long as I am very very careful with use. And it’s been about a month now and so far so good! My TV and DVD (home theater) draw about 280Watts which converts to about 2.333A. The lights I am using draw .5A each (they came with the kits I bought). So knowing this I started to shop around and I found this:

http://www.harborfreight.com/45-watt-solar-panel-kit-90599.html

    After some rough math in my head, I determined that 3 of these kits would suffice. And so far... so good! I have 2 of these set up on the balcony of the cabin with the third kit up at the “barn”. Along with the kits I have 2 12V 105AH batteries in parallel, which gives me 210AH of capacity. We run the generator every 4-6 days so we can pump water from our well into our storage tanks so I will then run a charger to top off, equalize and float my batteries.

    The inverter is an inexpensive 12V inverter which I am estimating to be about 85-88% efficient. I say this as my Trimetric TM-2025RV battery monitor shows a draw of about 7A, and I know it’s not the TV and DVD player and lights. Having measured them independently and then validated their consumption using a Kill-A-Watt the extra draw has to be from the inverter. Either way, the solar array of 6 – 15 watt panels has been keeping my batteries pretty consistently around 95-98% charged. Although we just today had our first cloudy day so I am anxious to see how the panels performed.

    I will post some photos of my basic set up later. First I have to take the pictures of the system... anyhow I will briefly describe why I made the statement “And I am really glad I did!”. See little dumb ass... well, I am not really little but I definitely pulled a dumb ass move! I screwed up when setting the batteries up. See I tried to do it from memory. Mistake #1. While what I was doing technically was not wrong, how I did it was and the accident that happened shouldn’t have.

    I wired the batteries in series, which like I said isn’t wrong, but for my application it was. As when you wire in series you double voltage not AH which is what I wanted. What saved my ass and equipment is the fact that I connected my components to a single battery instead of across the series. What? Each battery has a positive and negative terminal, we know this. When you wire a battery in series you connect the positive terminal of one battery to the negative terminal of another and so forth. So a better way to explain this is lets say you want a 48VDC system, to keep it simple we will use 12V batteries to create it. You will need 4-12V batteries.

    You connect battery 1 positive to battery 2 negative, battery 2 positive to battery 3 negative and battery 3 positive to battery 4 negative. Now this is a series connection. But in order for the 48VDC to be realized you need to connect battery 1 negative and battery 4 positive to your inverter. If you do like I did and connect your inverter to battery 1 positive and negative... well, you just get 12V. And that was a mistake that saved me a bit of money.

    Now I almost blew myself and batteries up because I wasn’t paying attention to detail and I didn’t have any instructions with me and I was working tired. A stupid way to operate and I know this. Why I am admitting this is very simple, I hope you the reader learns from my dumb assery. Anyhow I dropped a connecting cable that essentially created a loop on the batteries... fortunately I was fast and saw (more like smelled) what happened and all that was damaged beside my ego was one of the terminal threads was melted. I checked the batteries and they all test fine with the hydrometer and volt meter.

    So some words of advice...

• Be well rested.
• Don’t rush, take your time and triple check your every move.
• Read the instructions, they are there so you don’t do something stupid.
• If you are unsure of something STOP! READ! ASK! There is no shame in asking for help.
• Use personal protective equipment for just in case an accident does happen.

    Okay, so anyhow onto more gooder information. The system I have set up is pretty neat and as I said it’s a small starter system and I learned a ton from doing it. I can control the inverter from inside the cabin as well as the lights have switches in them now. And I can monitor the entire system from inside the cabin as well. Now this may not seem like a big deal but when you see how it’s set up (and I will describe it in just a minute) it is.

    The current system consists of the following components:

• Sony home theater
• Sony 40” TV
• Three 5W 12V CFL lights (there are actually 6 available but I am only using three in the cabin) all with inline rocker switches installed.
• 800W 12V DC-AC inverter
• 15A battery charger (it’s a multi-stage charger and will perform all the battery maintenance I need)
• Trimetric TM-2025RV battery monitor with a 500-50 shunt
• 3 – 45W solar panel kits from Harbor Freight(these kits come with a charge controller, lights and panels) (2 are used on the cabin and the third on the "barn" which is a small office with a laptop and printer and 2 - 12V 5W lights)
• Extra wire for the lights
• CAT5 for the Trimetric monitor
• 20A circuit breaker
• 8ft of 8GA wire
• Battery interconnect wires
• 1 – 15W trickle charge solar panel
• 2 – 12V 105AH deep cycle batteries

    How it’s all connected is simple. The two batteries are wired in parallel which keeps my voltage at 12V and doubles the AH to 210AH capacity. This is an important design feature I wanted so I could run for a couple of days with minimal charge from the panels. Since I don’t allow my batteries to go below 50% I needed the capacity to allow this. Watching 1 movie for say 2.5hrs and running 1 light for 3-5 hour my consumption is about 18.4AH a day use. This gives me about 5 days with no charge coming in on the batteries (that’s the theory but reality is always different).

    Now don’t assume I allow the batteries to be drained down so far on a regular basis. Actually with the solar panels in place and our usage I am finding the batteries are never getting below 70% and they are generally recharged to 95-98% capacity with just the solar panels I have set up. I verify this with hydrometer reads, voltage read with a volt meter and my Trimetric monitor (which was a damn good investment!) Anyhow I have a metal box on the balcony of the cabin where my batteries and components are all kept. This is so I can keep the off gassing from inside and to also keep the noisy ass inverter outside.

    So I then punched two holes in the back of the box and through the cabin walls so I could run the lights and power for the inverter into the cabin. These were later sealed up once the wires were run through them. We get some real nasty weather up on the mountain where we live and the last thing I want to do in the evening is go outside to turn off lights and inverters after watching a good movie. How the inverter is connected is I cut the hot side of the battery cable and ran it through a 20A circuit breaker (yes I know... it’s not a “proper” switch, but it works AND I have the added protection of a breaker in place!) and the main power button is left on. Then the inverter is left connected to the batteries with its main power switch in the on position. When the circuit breaker is tripped or open, no power to the inverter. When it’s reset or closed, power to the inverter and I can then run my TV and home theater!

    Now the lights that came with the solar panel kit don’t have any kind of switching and rely on you either plugging them into the charge controller or unplugging them. So I used a simple inline rocker switch so I could keep them plugged in yet control their state from inside the cabin. I also had to run some extension wires as the existing leads were insufficient to reach where I wanted to in the cabin.

    So we have power on the property now... not the full system I have designed and in planning but it’s a start and I am learning and have learned a great deal about living off grid. It’s not as easy as many make it out to be and you have to sacrifice some conveniences. But if you are like me, it’s well worth it. Life is a bit more simple in many ways and a bit more complex in others.

    Until next chance I have to write... C U L8R!