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My solar panel setup at home (and other details)

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  • My solar panel setup at home (and other details)

    Hi, for all those seeking real life details, it's been a while since I've been researching but it's not easy to find enough details except from "[I]these are my batteries and this is my solar panel[/I]" specially when it comes to how much useful the system is. So here are my details on my solar setup.

    - Components
    - How useful this is (hot much I get from the set up) hours of light, energy, etc
    - Why I went solar
    - Off grid?

    [COLOR=#B22222][B]My components:[/B][/COLOR][LIST][*]House (critical importance)[*]120W solar panel (not as critical as you would think)[*]Battery[*]Solar charger[*]Inverter[*]The LED bulbs[*]The Boost converter[*]Wiring[/LIST]
    [COLOR=#008000][B]House[/B][/COLOR]. After a lot of research I believe it's the most critical component in terms of light, temperature and efficiency in the long run. My house is nicely built with good natural illumination, a transparent dome and large windows, this translates into spaces that won't even need lighting during many hours of the day. The walls are painted with an almost white color so when you turn on any light you get more than what you would get on any dark wall homes.

    [COLOR=#008000][B]120W solar panel / 22V[/B][/COLOR]. It's small and considered by many as a hobby solar panel. I got it 50% of the original price, really cheap because the glass was broken. Yes it works. You just have to check the wiring, the diodes, the final output without and WITH load, etc. And sure I had to repair it. In some cases you can replace the glass (when the panel is placed inside a box and no glued to the glass), in other instances you will have to use transparent epoxy that turns into almost glass surface. I used clear polyurethane, actually several layers, the panel is absolutely water proof now.

    [COLOR=#008000][B]The battery[/B][/COLOR]. Surprisingly I'm using a small UPS Lead Acid 12V battery / 7aH. Sure, it's a small but it does the job. You have to understand solar panel setups are not just about the panel, or the inverter, it's a multi factor system. In my case using this battery and the UPS inverter I could watch 1:45 hours of TV before needing to recharge, 1:45 hours from one charge, absolutely disconnected.

    [COLOR=#008000][B]Solar charger[/B][/COLOR]. Got it dirty cheap at some electronics sale, it was the last one. It's general purpose with solar input, load output and battery connector. Shows low energy, charging and high current (just 3 leds). After lots of readings I know it's not the best component of my system but it does the job.

    [COLOR=#008000][B]Inverter[/B][/COLOR]. There is none, absolutely no inverter. I made several tests using diff inverters including those found on UPS, average pure sine wave. I'm not using an inverter because it consumes too much energy. You can find some detailed videos where some people took the time to measure how much the inverter takes out of your system, well it can go around 14W in idle mode. If you want to discuss diff ranges please open a diff thread, it's too small of a topic and not a critical matter in this story. When you use inverters you have to choose 2 approaches, (1) is turning the inverter on and off as you need it, or (2) keeping it on powering your whole home and becoming useful when you actually turn on a light or device. Honestly, it doesn't make any sense so I don't use an inverter. One solution that I'm using is charging the battery inside the UPS so whenever I need 110-120V then I just plug the device to the UPS, the end. Remember, solar panels are not expensive, the whole system depends on trying to be more efficient and this involves changes beyond your setup.

    [COLOR=#008000][B]The LED bulbs[/B][/COLOR]. 12v? very difficult to get in my country, the only solution is to buy online, that's not of my personal liking specially having to wait for the delivery. There are electronic shops selling supposed 12V Led lamps using a 110v-120v driver but after trying several of those I found out they turn on around 14V, 18V, 22V, etc. not 12V. So I just opened several of my 110V-120V LED bulbs and modified them. You can find lots of videos and tutorials about this, good luck if you get any final 12V bulb. In my case I found they were using several 3.3V, 7V and 9V leds, so there was no easy way to convert them to 12V unless using a linear regulator 780X style to drive them but there is always energy loss in the conversion so that's a nono for me. [B]What I did[/B]: I modified the bulbs to work from 17V to 21V. It was just about rewiring the leds. This is where my boost converter comes into play.

    [B][COLOR=#008000]Boost converter[/COLOR][/B]. I have a few of those, so I set them to convert 12V to 20V, the led bulbs work perfectly. Even added some small capacitors to the bulbs to help with any flickering. I planed to use several of those boost converters to balance the load but at the end of several tests I found, surprisingly that in my case, one boost converter was enough for the whole house (yes, I'm quite surprised). Something great about this boost converter is I can modify the output, let's say I need full lights then it's set up to 20V, if I need regular lighting I can go 17V mode lasting way more than needed.

    [COLOR=#008000][B]The Wiring[/B][/COLOR]. There is a main box at home where you can see all the connections, in my case the lighting is absolutely separated from the rest of the energy cables, so it was easy to make the modifications. [COLOR=#0000CD][B]I'm using solar panels and my battery specifically for the lighting[/B][/COLOR]. Everything else: tv, fridge etc stays on 110V-120V. But I do use solar energy to charge my laptop, iPad, tablets, phones and power banks, also to watch some TV at times.

    - - - - - - - - - - -

    [COLOR=#B22222][B]How useful is this?[/B][/COLOR]. My home relies on the solar panel and battery for the entire lighting. I get enough. I can use the lights during the day no problem, and when there is no sunlight I was getting 5 hours for bathrooms, bedrooms, office, kitchen, living room, workshop, etc. As any normal house: not all lights are used at the same time for 5 hours, this reported time is for average daily use. This is still new so it will take a few months to find out about savings. The whole system in my case was dirty cheap because I found the components on sale, very cheap. My original solar plan was different but I took the chance on what I found.

    - - - - - - - - - - -

    [COLOR=#B22222][B]Why I went solar[/B][/COLOR]. It all started with a very small kit. Used the home internal wiring spaces to put 6V lights in key places such as the living room, office and kitchen. It was "[I]for emergency only[/I]" but surprisingly we ended up giving it full use unless we were working on something at the office or cooking. For the rest of average life this was absolutely useful.

    If you find this hard to believe then consider my point stating -the home- is the critical component. Why? the walls, the way the house is built and the time I took on multiple tests trying to find the best spot to place the 6V lamps. So, this small kit experience was enough to buy another small kit, and I used it to charge power banks and build an specific 18650 battery charger station along with a AA and AAA battery charger. We simply not use grid energy to charge our cellphones, tablet, iPad, bluetooth keyboards, small humidifier and some emergency lamps using rechargeable batteries.

    Adding the 120W solar panel was a plus. Besides all the devices at home are not passive, meaning only the fridge is using grid energy, the rest is absolutely turned off. TV? there is a dedicated button to turn on the device before using the remote control. When I was living on my own, single, my electric bill was around US$17. My modifications BEFORE the 120W solar panel helped me to get US$10 of montly electric bill, this was very steady, but during specific months the price changes so it's not a whole 12 months monthly price. This is common in my area.

    As for now it will be kinda tricky to get new numbers and savings because I no longer live alone so there are more devices drawing energy. Right at the time finishing the installation the monthly bill was US$24. The major consumption here is the shower / warm water and the fridge. My wife never underestimated the usefulness of the charging stations for the cellphones, tablets, iPad etc, but she is sure surprised on how effective they are. BTW we have an alternate backup water system working on 12V, no grid system

    [COLOR=#B22222][B]Off grid?[/B][/COLOR] nope. A lot of people expect small panels to allow off grid mode, that's not realistic. Solar is good but not as efficient / cheap yet, in many cases the grid is still way cheap (depending on your region). In our case we get enough this way, we get enough sunlight and the inverter for 110v-120v didn't make much sense, specially if you consider how much is wasted on idle mode. My Boost converter setup works amazingly well, it's a switching system so whenever the lights are off, it consumes almost nothing (it shuts down), this thing is pretty efficient. In the future I will probably be migrating to alternate ways to get warm water (and perhaps to alternate fridge system).

    [B]Extra information on the battery[/B]. The 12V Lead Battery, yes, ONE, was enough for us, but after measuring the capacity on full charge and discharge using the TV, the battery won't last as in the past (it's new). The whole thing with these kind of batteries (regardless of the brand) is they don't like full discharge, even if you have protection circuits for discharge limits, some people build their own and set their own safe limits (this is better). I stopped using the battery for 110V-120V production and now is lasting more and more, slowly recovering. Nope mine is not deep cycle. I just bought a BMS to build a 12V battery pack using 18650 batteries, lithium works better.

    I know the system could work even better adding another panel but this is all for now. So, as for now I'm getting 4 hours of light during the night, this is more than what we consume on a daily basis.

  • #2
    You can make LED lights out of standard LED fixtures. For example, I bought a number of 18W flush mount ceiling lights and have a number of them in my garage and house. The LED actually runs on around 40V and the factory converter board is just removed and replaced with a $2 boost converter module changing the 12V to 35. That makes the lamp a 9W which is plenty bright and the LED is more efficient at a lower current.


    • #3
      Originally posted by PNPmacnab View Post
      You can make LED lights out of standard LED fixtures. For example, I bought a number of 18W flush mount ceiling lights and have a number of them in my garage and house. The LED actually runs on around 40V and the factory converter board is just removed and replaced with a $2 boost converter module changing the 12V to 35. That makes the lamp a 9W which is plenty bright and the LED is more efficient at a lower current.
      Exactly, that's what I did.

      At first played with one 18W exactly, turned out to be 35V without the driver. Using the boost converter I was able to use it in the range of 25 to 35V, quite bright, efficient, very low current. Yet those aren't as cheap as other options considering I needed many of them for the whole house, and they don't have the E40 and I didn't want to modify anything else, you know, easy to put and replace. That one cost me US$18.5 the first time, this 2019 found the same brand at around US$10, still not good enough for me. If it wasn't for the individual price and the needed modification to put the E40 I would have gone that way.

      So I played with the normal bulbs, initially at US$3.8 each, and then found some high quality and easy to rewire at US$2 each. Very cheap.