diy solar

diy solar

First timer - Thinking about 30,000 kwh ish system!

You live in Arizona, correct? What is their net-metering plan where you live?

If it is a good one, they can be your battery and a STBY generator for emergencies.

Generator for short term power needs is much cheaper than batteries.
 
You live in Arizona, correct? What is their net-metering plan where you live?

If it is a good one, they can be your battery and a STBY generator for emergencies.

Generator for short term power needs is much cheaper than batteries.
Correct, I'm in AZ.

Net-Metering is currently at around 9 cents per kWh.... this is dropping to ~8 cents this month some time (not sure how this works long term.. do we sign agreements with the power companies stating they buy power @ X amount for X years, or can they change it whenever? Today is ~9 cents, 5 years could be 1 cent kind of thing??)

Currently, I can't relay on them as they've gone done too many times in the last year.... and both my wife and I work from home.
 
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If you are talking about a large Generac generator then you are probably talking about a propane or natural gas generator, and those aren't so cheap. Have you price them yet? A 24kW for example is over $6000. Even the 18ks are over $5000. Propane and natural gas are weak fuels for driving engines when compared to gasoline or diesel. Diesel is the best, then gasoline, then propane, then natural gas. If you are a prepper then you also need to know that natural gas in many places depend on diesel and gasoline to be supplied to you. If you go the propane route, then you are going to need a large tank on your property. A 5 gallon propane tank from your grill isn't going to be sufficient. If you go the natural gas route, then you need to do some calculations on how much natural gas its going to take to produce your large electric needs. You will be shocked. Natural gas is strictly a short-term emergency solution and batteries handle that just as well or better in my opinion.

Just get yourself a dual or tri fuel 12k or 13k Duromax generator from Amazon or Home Depot for a fourth the cost. That will handle your computer just fine.
 
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Correct, I'm in AZ.

Net-Metering is currently at around 9 cents per kWh.... this is dropping to ~8 cents this month some time (not sure how this works long term.. do we sign agreements with the power companies stating they buy power @ X amount for X years, or can they change it whenever? Today is ~9 cents, 5 years could be 1 cent kind of thing??)

Currently, I can't relay on them as they've gone done too many times in the last year.... and both my wife and I work from home.
They can do anything they want. They just need to get it approved by state government and that's not difficult. I told you already they have changed my rate from 100% to 40% in the last 5 years. You must not have believed me if you are still asking. They have grandfathered in those who started 6 years ago, but they aren't doing that for anyone else anymore. The power companies are owned and managed now by large corporations not state owned companies. In the west, Pacific Power and Rocky Mountain Power are owned by Berkshire Hathaway Energy - a Warren Buffet company. That's why our rates have gone up so much lately and why they are killing off the residential solar market.

"Rocky Mountain Power, a Warren Buffett-owned utility, is again seeking to kill off residential solar power. Rocky Mountain Power has proposed an almost 80 percent cut to the rate paid to net metered solar electricity, dropping it from the current 9.2¢/kWh to a rough average of about 2.0¢/kWh. Feb 19, 2020"

If you think I don't know what I am talking about read this: https://pv-magazine-usa.com/2020/02...-seeking-to-kill-off-residential-solar-power/

Tyranny of the Minority.
 
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You might have a roofer install standoffs, lag screwed into sheathing or preferably rafters and covered with proper flashing. If you buy a rail system that uses standoffs.
The quickie way is lag screw "L" feet through shingles and caulk. Obviously better to have proper flashing.

First step is design a system that meets permitting requirements. It may have setback requirements for fireman access, etc.
 
There is no way to put 50 400 watt panels on a 2500 sq ft house roof.
I am planning exactly this as soon as my house is done. My roof is 62'x24' on the south side and will fit x54 72 cell panels (18x3) very nicely. House is 2358sq ft. It helps that my roof was purposely built for solar I guess though. I was planning on used Trina 290w panels, but I am leaning towards 400w panels now.
 
I am planning exactly this as soon as my house is done. My roof is 62'x24' on the south side and will fit x54 72 cell panels (18x3) very nicely. House is 2358sq ft. It helps that my roof was purposely built for solar I guess though. I was planning on used Trina 290w panels, but I am leaning towards 400w panels now.
What you are going to do with 130kWh of power everyday?
 
What you are going to do with 130kWh of power everyday?
You think it will produce that much? That would be 6 hours of panels producing full power. Where I live, an installer said an approximation is 4.2 x panel rating.

That PVWatt site shows considerably less.
 
You think it will produce that much? That would be 6 hours of panels producing full power. Where I live, an installer said an approximation is 4.2 x panel rating.

That PVWatt site shows considerably less.
Yes I think it will during some times of the year. I don't know what state he is in but if it is Arizona, they average 7.42 peak sun hours in summer and 6.01 peak sun hours in winter. So peak sun hours are over 6 hours a day all year long. Phoenix, Arizona, sees 3,872 hours of sunshine per year on average. That is 10.6 hours of sunshine per day. Of course you have to take into account rainy days or overcast days, but Arizona has the fewest of these. A good monocrystalline panel can generate a good percentage of their maximum rating even in indirect or reflective sunlight.

Now maybe the PVWatt site is correct, but I don't know what data its using for its calculation. My experience has been full power during peak hours in summers and full power during peak hours in winters. The only factors I have seen are clouds, rain, snow, fog, and the number of hours of peak and nonpeak sunshine a day. The cold of winter is great for efficiency and makes up to some degree the angle. Arizona is ideally suited for fixed panels since the typical angle of roofs is at the midpoint of the angle range for solar panels throughout the year. There are a lot of variables that we don't know about, but people in Arizona have one of the bests chances to maximize power output.

If I'm over estimating, then at 77% what are you going to do with 100kW of power everyday. :)

I would love to have 50 x 400W of panels even if I didn't know what to do with it, so here's my answer: it would fill the largest battery bank I could afford and even on a cloudy day could probably provide what I needed. During the rainy season I could still keep my battery topped off. With a big enough battery and conservative consumption I could run off grid indefinitely. If you have the money and nothing else you need or want then go for it.
 
What you are going to do with 130kWh of power everyday?
The house has two sides (separated by an interior wall), so I basically have two sets of everything (AC, Stove, Microwave, TVs, lights, etc.), plus two garages (1 car + workshop, and 2 car + workshop). I don't have any idea how much power I am going to use, so I am just going to max the south facing roof to start. I still have room on the existing garage for another 7.5kw if I need it.

My ultimate goal is to be able to never lose power. I am ok with losing some things (water heater, stoves), but not heat/cooling or basic items (microwave, lights, outlets). My family was not amused when we had snowmeggedon (Central Texas).

You think it will produce that much? That would be 6 hours of panels producing full power. Where I live, an installer said an approximation is 4.2 x panel rating.

That PVWatt site shows considerably less.
Should get a solid 4-5 hours (Central Texas) most days and my panels are facing just a little west of true south at 27° angle which should give me max production. My original plan was x54 290w (used Trina's) because they are cheap which would give me 50-60kwh on an average day, but I am leaning towards newer 400+ watt panels now which should give me 70-90kwh (80% rating for 4-5 hours). Peak would be 120-130kwh if all the stars (well just one really) align....
 
The higher efficiency panels, 20% or so, can give 50% more power per unit area than some older ones.
I think the SanTan/Trina 250W panels are 15.2% efficient, so 33% more than those.
Not sure about Trina 290W.
 
@SoloCon here is an idea for you that you can implement right now at low cost. Get one or two small grid tie inverters for $70 - $100 and connect a couple of panels to them to produce 800 - 1600 watts of power and just plug them into the outlet that your server is plugged into. That will cover the cost of your server without having to do the big PV install. That should cut most of your power bill.
 
I'm taking this in baby steps and looking at solar panels. I'm working with SanTan Solar who's suggesting 51 of their SolarEver 410W solar panels. They are also doing the plans for the system and getting them approved.

I'm thinking it might be better to go with the SolarEver 455 or better yet, the ZnShine 540W

If I go with the ZnShine, I would only need about 39 of them. Still need to confirm they would fit on the roof.
  • Are the ZnShine as good as SolarEver? The 540w ZNShine are ~1.18 inch thick where as the SolarEver 455w is about 1.38 inches tick


Price wise:
  • They are quoting me $250.00 per panel for used SolarEver 410w. Total of 51 panels which = $12,750.00 for 20,910 watts. That's ~.61 cents per watt.
    • For a used panel, I'm 100% sure I can do better then this with them.
  • The 455w SolarEver off their website is $276.00 bit a brand new panel. If I went this way, I would only need 46 to get me to 20,930 watts. 46 panels * 276 = $12,696 which is .62 cents per watt
  • The ZnShine 540w are selling for $252.89 each, of which I would need about 39. 39 * $252.89 = $9,862.71 which would get me about 21,060 watts, which is ~ .47 cents per watt.

(I plan to buy 2-3 extra panels just to keep on hand)

Thoughts? Any input would be greatly appropriated.
 
When you get up into the higher power panels, you are dealing with bifacial panels. Bifacial panels won't deliver that kind of power on a roof.
This is good to know.

It was my understanding that bifacials would generate the listed power, but increase in production from the extra power generated from the rear (nothing in this case).

Is the listed power at 540w included in the bifacial numbers?
 
This is good to know.

It was my understanding that bifacials would generate the listed power, but increase in production from the extra power generated from the rear (nothing in this case).

Is the listed power at 540w included in the bifacial numbers?
You are correct
 
@SoloCon here is an idea for you that you can implement right now at low cost. Get one or two small grid tie inverters for $70 - $100 and connect a couple of panels to them to produce 800 - 1600 watts of power and just plug them into the outlet that your server is plugged into. That will cover the cost of your server without having to do the big PV install. That should cut most of your power bill.

If the server ever shut off, and the rest of his house loads were low enough, wouldn't that export out onto the grid and get him in trouble?
 
Now I'm confused,

Would it be better to go with the ZnShine Bifacials at 540w or the SolaEver 455 - non Bifacials? (Roof mount)
Bifacials are better for ground mounts, but they'll work fine on a roof. They will be heavy though which may be annoying.
 
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