diy solar

diy solar

Solar power in Haiti

Hinchebyinch

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Joined
Dec 17, 2019
Messages
9
I just wanted to say hi to everyone, I've been watching videos on youtube and it has helped me so much.

Let me tell you a little bit about myself, me and my wife live in a small town in Haiti called Hinche. We have grid power, but its only about 10 hours a day when its going well, sometimes they will have a problem and the system can be down for weeks. When we first arrived almost 2 years ago, we didnt know a lot about batteries and inverters. Our friends took us to buy the stuff and we ended up with 6 x 6v trojan lead acid batteries and a 1500w 12v magnum inverter.

Our system works great for us, most of the time. There are things that we cannot do on batteries, so we wait until we have grid power to use the washing machine, or pump water into the tank on the roof. If we are in a pinch we can hook up to a generator and do what we need while charging the batteries. We aren't super heavy electric users, we have a small, efficient fridge and a chest freezer, a couple of lights that we run and our laptops. It is hard to buy what we need here, so we tend to shop in bulk in the capital for any meat or dairy and store it all in the freezer. Our biggest problem is when there is a storm or riot or something and we lose mains power to charge our batteries.

I would love to integrate some solar into the system. We are on a tight budget because we are doing volunteer work here, but I am hoping to do it modularly. The one thing we are not short of here is sun! I am thinking about adding 400-500w of solar panels into the system to help keep the battery topped up. I would like a charge controller that can work at 12 or 24 or 48v. In a few years when the batteries die, i would like to replace them with a 24v lithium set up. Longer term, I'd like to change out the inverter for something that can handle bigger loads. Super long term dream - run air conditioners in the day to the rooms aren't hot at night, then we dont need air-com once the sun has gone down

One of our biggest challenges is that we dont have much equipment here, we cant just go on amazon and order what we want. Everything has to be made from what we can find locally, bring in a suitcase, or occasionally fit in a barrel a friend is shipping

I'd love to hear any suggestions anyone has for me, and if anyone has experience of trying to set up a solar system in a developing country. Thanks for all your help

Sam
 
Wow, sounds like a challenge. I can't imagine. I don't know if you are able to order from Epever, but they make charge controllers that can handle 12/24/36/48 volts. Possibly you could ship it to someone on the forum close to you and they could ship it on? I don't pretend to know how things work there but I'd be happy to help in that regard if I can. Anyway, welcome to the forum! I'm looking forward to seeing some pictures of your area.
 
If you want to go modular I like microinverters. One $160 microinverter per panel (enphase has a 25 yr warranty and is mounted under the panel, so you don't give up any additional interior space). You get AC out and can add as many as you like. Beats the heck out of paying a lot up front for a big inverter that might die before you expand into it. Downside is no DC if you need it.
 
Thanks for your inputs. Thats interesting about micro-inverters, something new to me there. I will try to read more about them. The great thing about our houses here is they all have flat concrete roofs with stairway access (we actually have two sets of stairs up onto our roof). We have so much roof space. Probably at least 25mx15m of useable roof space with every inch of it in direct sunlight.

I've seen epever on amazon, i'm gonna take a look at them
 
funny how we take it as just getting off the grid, just for the hell of it. most places are lucky to have a bit of power, or none.. Last month the power went out , my son said to me dad, can you not just flic a switch so he could get back to gaming, I have a generator back up, decided not to start it. sit out the outage. see how lost my son was.. sad
 
What about making some wind turbines from car alternators?
 
We are inland and rarely have any breeze. But out of interest, how much power can you generate from a diy wind turbine?
 
To follow up on the microinverters to add-on a panel, as he said they're probably your best bet but you don't directly get DC, however you can "AC couple" to a 'hybrid' inverter which will then charge batteries, this bypasses the need to have charge controllers in addition to your inverter. It also boosts the voltage for the same amount of power so you can use smaller wires which saves money in wiring costs - and copper wire is expensive. It's also more efficient to move high voltage through a wire than low voltage.

During the day with the solar producing AND a full battery you'll get the output from both sets of inverters but at night microinverters will drop off leaving the main hybrid inverter to carry the load. As an added benefit the hybrid inverter will charge your batteries from the grid when it's up and then pick up the load when the grid goes down and you won't even notice the grid power is out.

'AC coupling' is simply the hybrid inverter inputting power into the house wiring and the solar panel microinverters syncing to it. The two sets of inverters are 'coupled' by the AC power they're both putting out. A detailed explanation is outside the scope of a forum post, but you can google it and read up on it. It's not the cheapest way to go about a solar installation but it's the most flexible for adding on mismatched panels.

You can also use Tigo "optimizers" to add on panels but it restricts panel output to equal the lowest panel in the string. Using optimizers might be cheaper but then you have to use a charge controller. It'll take a lot of number crunching on your part to find the least expensive way to meet your goals.
 
We are inland and rarely have any breeze. But out of interest, how much power can you generate from a diy wind turbine?

generally you dont want a breezy location as that is the wrong kind of wind. You want atmospheric wind because its steady so you mount the turbine 40ft+. The higher mount the higher the output.

Alternators generally produce 65-90A with some as high as 200A rated.
 
Also, you can more panels if you add another separate mppt charge controller to your battery, mppt charge controllers are often run in parallel. In this case you are 'DC coupled'.

After thinking about it and considering the costs involved this might actually be your best bet. For the cost of one microinverter you can get a pretty decent epever charge controller that can handle a lot more than what just 1 microinverter can do.

Much later edit: And straight inverter/chargers cost a lot less than hybrid inverters.
 
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> We are on a tight budget because we are doing volunteer work here,
God Bless you!! Have you set up any kind of funding site?

Reading through the original post, I think Maast is right. Use a charge controller.

Step 1) "Add 400-500w of solar panels"
The lowest initial cost way to do this is with a solar charge controller. Just make sure you get one that operates at 12 volt for now and can be switched to 24 volt later. Most of them can do this but finding a good price on one that can also do 48 volt may be a challenge. Also make sure the panels you buy can be configured to a high enough voltage to drive 24 volt systems.
Note 1: Mixing old and new panels in the same array is not generally a good idea, so when/if you add panels later, you will most likely add another charger as well.
Note 2: Have you measured or estimated your current usage? Do you know what your Whr/day is? It would be good to know this for planning purposes, but from your description, I think you will find that 500W of panels will go a long way.

Step 2A) "when the batteries die, i would like to replace them with a 24v lithium set up. "
Good move, but this could end up being a pretty big step. Your first decision will be around the size of the new battery. Do you just replace the capacity of the old batteries or do you grow the capacity and by how much. Do you prepare for doing laundry and pumping water? Do you prepare for AC? Adding new batteries to an existing bank later on can be tricky so this is a difficult choice.

Step 2B) Inverters are generally designed for a single input voltage so you are going to have to make a hard decision:
Option 1: (Lowest initial cost) Stay with 12 volt and keep your existing inverter. If you do this, you may want to buy two batteries that can later be arranged in series to convert to 24 volt. This might be a little more expensive but it keeps the 24volt option on the table for the future.
Note: 24 volt is generally a beeter way to go but staying at 12Volt is always an option.... even for larger systems.
Option 2: (probably highest long term cost) Go to 24 volt and replace your inverter with another one around the size you currently have. This will help keep the price of this step down, but later on you will end up adding another inverter in order to "handle bigger loads" . This will be more expensive, but if you buy an inverter that can be 'stacked' you could later add an identical inverter and end up with 220 volt. This might be useful for your long term dream of having AC
Option 3: (Highest initial cost) bite the bullet and go with 24 volt and a large inverter.

I don't know enough of the specifics of your case so I can't really make an informed recommendation. However, based on what you did say, I would avoid option 2. I would say either 'go all the way' or take the minimal step and save your money till you can get what you really want.

When you start narrowing in on what you want to do, post details here and we will be glad to make recommendations. The more detailed the proposal, the more specific our recommendations can be.
 
One more thing: If you havn't already done so, switch all of your lights to LED. An incandescent light can be 7-10 times more power than an equivalent LED. When you are on batteries, that is a big deal. Not needing the power is a lot cheaper than producing and storing the power.
 
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