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Solar power 101?

 
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So totally new to solar power but with the craziness in the world of late I figure may be a good time to start looking into solar. What are some good resources to get into in order to learn about solar power?
 
instructor
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Hey James,

I did a 14-part course called Ecological Solar Design for the EAT Network back in 2017. It focuses on the big picture of solar (with the garden being the most advanced form of harnessing solar power) from a Permaculture viewpoint, but goes through all of the basics of solar PV, off-grid, batteries, etc.

The emphasis is on helping you understand how to integrate solar technologies into your Permaculture designs and giving you the basic understanding to work with a good solar designer if you are working on bigger projects.

It looks like EAT has the first class in the series available for free viewing here: https://www.eatcommunity.com/ecological-solar-design

Unfortunately the rest of the series seems to still require their payed membership. I don't know how much they are charging for a membership right now, so maybe you could watch the first class and decide whether it is worth it to you. I really need to go back and update/re-record this class sometime since technology has continued to advance since I first did the course...
 
Rocket Scientist
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Hi James; Welcome to Permies!

This is where I bought quite a bit of my equipment.
They have a lot of good information.

www.backwoodssolar.com

Other wise right here at Permies!   We have some folks here who are very knowledgeable about the newest solar products.
I have been 100% off grid with solar and hydro for over 35 years!
However my system is old and funky and not nearly up to the current levels.
Others on Permies will be able to inform you about improvements since 1983...

Good luck! There has never been a better time to learn about and buy solar products
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Solar panels on roof
Solar panels on roof
 
gardener
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Hi James,

What plans do you have with solar power?  There are all kinds of things applicable to solar power, but it is tempting to think about going completely off grid from the get go.

Solar has its own quirks and limitations and is very capable but within specific contexts (not winter on the Alaska north slope of course!).  My personal suggestion is to start small and cheap and see how it behaves.  I built a little battery box with a 20 watt solar panel for something like around $150ish.  It is a nice way to get acquainted with how powerful solar can be but also recognizing its limitations.

If you want any details from my build I will gladly share them with you as a sort of solar baby step.

Good Luck,

Eric
 
James Taylor
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Alan thank you for the webinar. Looks like it could be a good resource. I know a bit about electrical work but basically nothing about solar so I'm sure it will help alot.

Thomas when it comes to hydro power do you have running water on your property? I am assuming you do because I have never heard of anyone getting hydro power other than damming a up stream.

Yea Eric I figured I would start out small. I live on 14 acres in the southeastern usa and have 4 wells on the property. So I want to start out by powering atleast one pump and going from there and eventually going totally off the grid. I'm not a fan of having to rely on the power grid for water.

Also I appreciate everyone's fast responses
 
thomas rubino
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Hey James;
I have an artesian spring bubbles out of the mountain.  
Using 2200' of 1.5" poly pipe with 300' of vertical drop. I have 125 psi water pressure at the hydrant in my yard.
I use a Harris hydro, permanent magnet alternator with a single nozzle.  I only use 2-4 gal. per minute and I produce  100-140 watts @ 12 vt  24 hrs a day seven days a week.
The waste water goes down to my livestock pens and from there out to a draw in my fields.
 
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Hello James

Very doable.  We need some input from you about what you want to power.  The first thing you need to do is a power audit, to document what it is you want to run.  No sense putting together a 10kW system if you just have some LED lights.  On the other hand, you're don't get to run power tools on a car battery with a 100W panel.  So, first outline WHAT you want to power, and then we can go from there.

I can give you a few generalities that can help you make decisions.  First, people ALWAYS underestimate what their power consumption is, and OVERESTIMATE what their panels can produce.  For whatever number you come up with as consumption, then double that, 2X in terms of system size.  In terms of what you can produce, multiply however many panels you want by 0.8X to get an honest value for production.

I do NOT recommend you buy an all-inclusive kit that includes solar panels.  What I've found is that shipping all that glass is grossly expensive, and you will find far better deals on your local Craigslist, instead of mail-order.  Buy your electronics over the internet.  Buy your batteries and panels locally.

There are generally two large classes for solar right now, 12V and grid-tie.  The 12V panels have a large price premium because they are for the automotive market.  High-voltage grid-tie panels though have lots of production overruns and are being sold dirt-cheap on Craigslist.  For example, you can get a 100W 12V panel for about 80-100$ right now, but you can get a 240W 30V grid-tie panel for 55$.  But, the high-voltage electronics are more expensive.  A 12V only charge controller might cost 40$, whereas the high-voltage controller might cost 130$.  So, the smallest systems favor 12V, whereas the larger systems favor higher voltage.  I'd say the break-even point is around 200-300W.  Once you get over a 300W system size, high voltage is the clear winner in every respect.

More importantly, the really good, sophisticated electronics start at 24V.  What does that mean?  At 12V, you are pretty much limited to inverters have 1-2 standard 120V NEMA sockets on them.  Starting at 24V, you can buy sine-wave inverters that have split-phase 120/240V AC, a built in generator charging pathway, and can be hard-wired directly into your house's main electrical panel.  BTW, you will want to have sine-wave power if you want to run anything with an electrical motor, such as your electric drill/saw, refrigerator, ect.  Square-wave and Modified Sine-Wave is cheaper, but produces low quality power suitable only for things like incandescent lights.

I'm gonna recommend you go with 24V.  At a minimum, here's what I think you need....

4 6V 225Ah golf-cart batteries, 130$ each
4 240W 30V grid-tie panels, 55$ each.  Wire these in two parallel strings producing 8A each at 60V.  That's referred to in solar designations as 2S2P, meaning two parallel strings with two panels in series for each string.
1 12/24V Epever MPPT charge controller 130$
1 24V 1500W Sine-wave inverter, Samlex is 520$
Total = 1390$  Throw in some copper wire and fuses/breakers, an call it 1500$  Add a 5000W gasoline generator costing 500$, so 2000$.

Here's what this system can provide....
Assume you don't want to deplete the batteries more than 50% for prolonged life.  What you can get is 225Ah X 24V X 0.5X capacity = 2700Wh or 2.7kWh.  Assuming you want the batteries to last 2 days, then 1350Wh per day.
The panels could produce about 85% of the power they are rated for times the number of SunHours you get per day.  In winter assume 1000W X 3 SH X 0.85X production = 2550Wh.  In summer it would be 1000W X 5SH X 0.85X production = 4250Wh, or 4.25kWh of power.

This is system that can grow as your needs increase.  In a few years swap out the golf-cart batteries for larger 400Ah L-16 batteries.  Add a third or fourth string of two panels.  Add a second or swap out a larger charge controller.  Swap out a larger more feature rich inverter.

Good luck!
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Solar Panels
Solar Panels
 
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