Im a newbie and i need help with planning my system

[Robocheme1]

My monthly bill is 3,000kwh. If I was to divide that by 30 days it would be 100kwh a day needed. Ohio gets 4 hours of sun a day so I divide 100kw by 4hours making 25kw an hour. so my array will be about 25kw. If that's correct math.... I was also told that my panels might have a higher output on certain days so I should get a inverter with about 25% more so I don't burn it out?

Is your usage an average of 3000 kwh/month? Most utilities can tell you how much you use for the whole year. Then go to http://pvwatts.nrel.gov to estimate how big a system you need to provide that amount of KWH in a year?

[shadowaxe356]

I am not sure what the "break point" would be in cost/coverage %. Certainly a larger kw pv system should be less $/watt than a small one but when it gets to a point that the physical size can push the boundry of available roof space. Then the installation costs can go up due to special racking and wiring.

While you may have found some 30kw system for that price range, I believe it would be hard to find a quality system for $1.50/w before rebates. What you are doing is searching for the "cheapest" price for a very large system which may end up getting lower quality panels and inverters and less output then expected.

Something else you need to investigate is if there is any size limit of a pv installation in your area. In some places either the city or POCO limits the array size. Bigger than that limit and it turns into a "Co-Gen" facility which has tougher regulations to meet.

And finally I understand you want to stop "giving" the power company money but in reality installing a solar pv system (even grid tie) can take years to pay for itself which means you "give" you money to someone else all up front, where a reduction in electric use saves you immediately.

Just a thought. I do not know the full situation of you and the other people in the home, but if you are the one paying for the electric bill maybe an incentive needs to be found for the other "users" in the home to contribute to that payment or reduce their usage.

Ok thanks you for that info

[SunEagle]

What would be the cost difference in the system be if I did 80%? The 3000kw a month is December bills. I would really like to go 100% or like 99.9%. I essentially do not want to give any money to the power company's, I mean a few $ in December or when the panels are acting up sure but if I can I want 100%. If the cost diffence in a 20KW system and 30KW is only like 10k then ill take the 100%. I may sound dumb but 100% is my goal. I have been looking on Alibabi.com and found a few grid tie systems with no generator ranging from $12k - $45k for 30kw systems. When looking at panels how do I know they will be worth it? I have seen many "name brands" on sale but a few off brands with better numbers for cheaper, and I cant really trust a salesman in this day and age so I as the people for answers?

I am not sure what the "break point" would be in cost/coverage %. Certainly a larger kw pv system should be less $/watt than a small one but when it gets to a point that the physical size can push the boundry of available roof space. Then the installation costs can go up due to special racking and wiring.

While you may have found some 30kw system for that price range, I believe it would be hard to find a quality system for $1.50/w before rebates. What you are doing is searching for the "cheapest" price for a very large system which may end up getting lower quality panels and inverters and less output then expected.

Something else you need to investigate is if there is any size limit of a pv installation in your area. In some places either the city or POCO limits the array size. Bigger than that limit and it turns into a "Co-Gen" facility which has tougher regulations to meet.

And finally I understand you want to stop "giving" the power company money but in reality installing a solar pv system (even grid tie) can take years to pay for itself which means you "give" you money to someone else all up front, where a reduction in electric use saves you immediately.

Just a thought. I do not know the full situation of you and the other people in the home, but if you are the one paying for the electric bill maybe an incentive needs to be found for the other "users" in the home to contribute to that payment or reduce their usage.

[shadowaxe356]

The way you normally plan for 100% is to plan for sufficient power on Dec 20. For Cleveland, the year round average is 4.0 hours of sun. But in winter, the average is 2.7 hours. So right there, you would be at about 100/2.7 ~= 37kW of PV. And that is the average for all of winter. As Sunking said, you may be on the "light" side at 25kW, so to speak. If your efficiency is 90% (I don't know what is typical), you may need more like 40kW of PV.

And that right there would do it on my space haha.. Well tho the space may become an issue. If I was to continue and wanted to do a generator bit I would only need it for a weeks worth where should I look for something like that?

[Living Large]

What would be the cost difference in the system be if I did 80%? The 3000kw a month is December bills. I would really like to go 100% or like 99.9%. I essentially do not want to give any money to the power company's, I mean a few $ in December or when the panels are acting up sure but if I can I want 100%. If the cost diffence in a 20KW system and 30KW is only like 10k then ill take the 100%. I may sound dumb but 100% is my goal. I have been looking on Alibabi.com and found a few grid tie systems with no generator ranging from $12k - $45k for 30kw systems. When looking at panels how do I know they will be worth it? I have seen many "name brands" on sale but a few off brands with better numbers for cheaper, and I cant really trust a salesman in this day and age so I as the people for answers?

The way you normally plan for 100% is to plan for sufficient power on Dec 20. For Cleveland, the year round average is 4.0 hours of sun. But in winter, the average is 2.7 hours. So right there, you would be at about 100/2.7 ~= 37kW of PV. And that is the average for all of winter. As Sunking said, you may be on the "light" side at 25kW, so to speak. If your efficiency is 90% (I don't know what is typical), you may need more like 40kW of PV.

[shadowaxe356]

Based on panel efficiencies and true sunlight hours a 25kw system may not be enough to meet a 100kWh daily use.

Trying to build a system that covers 100% of your usage tends to get real expensive, especially to get the last 15%. So maybe looking at something that handles 75 to 80% may be more realistic in both size, cost and payback.

What would be the cost difference in the system be if I did 80%? The 3000kw a month is December bills. I would really like to go 100% or like 99.9%. I essentially do not want to give any money to the power company's, I mean a few $ in December or when the panels are acting up sure but if I can I want 100%. If the cost diffence in a 20KW system and 30KW is only like 10k then ill take the 100%. I may sound dumb but 100% is my goal. I have been looking on Alibabi.com and found a few grid tie systems with no generator ranging from $12k - $45k for 30kw systems. When looking at panels how do I know they will be worth it? I have seen many "name brands" on sale but a few off brands with better numbers for cheaper, and I cant really trust a salesman in this day and age so I as the people for answers?

[SunEagle]

My monthly bill is 3,000kwh. If I was to divide that by 30 days it would be 100kwh a day needed. Ohio gets 4 hours of sun a day so I divide 100kw by 4hours making 25kw an hour. so my array will be about 25kw. If that's correct math.... I was also told that my panels might have a higher output on certain days so I should get a inverter with about 25% more so I don't burn it out?

Based on panel efficiencies and true sunlight hours a 25kw system may not be enough to meet a 100kWh daily use.

Trying to build a system that covers 100% of your usage tends to get real expensive, especially to get the last 15%. So maybe looking at something that handles 75 to 80% may be more realistic in both size, cost and payback.

[shadowaxe356]

If I am not mistaken he figured his daily use is about 100kWh, and he was going for 3 or 4 hours of sun, so he figured he would need about 100/4 = 25kW of PV power. I think that is where those numbers came from originally.

yes, sorry for the confusion.

[shadowaxe356]

Huh?

My monthly bill is 3,000kwh. If I was to divide that by 30 days it would be 100kwh a day needed. Ohio gets 4 hours of sun a day so I divide 100kw by 4hours making 25kw an hour. so my array will be about 25kw. If that's correct math.... I was also told that my panels might have a higher output on certain days so I should get a inverter with about 25% more so I don't burn it out?

[shadowaxe356]

Are you talking about these? Every time people start to take you seriously, you post something like this. It is your money, do what you like, but I've found that if I'm not prepared to spend the money necessary to do a job right, it is better not to spend it at all.

People don't have to take me seriously, im asking questions to see what would be better, I know little on this subject. If these panels (or site) is junk then where would be a better place to look? I made this thread so that I would be prepared when I have the money because I do not know much about solar syatems, where to buy or whats the best for me, before 5 posts ago I didn't know I could do a generator system, or what I would need.

[Living Large]

"I would still want to produce 3,000kwh a month/100,000wh a day/ 25,000wh."

Huh?

If I am not mistaken he figured his daily use is about 100kWh, and he was going for 3 or 4 hours of sun, so he figured he would need about 100/4 = 25kW of PV power. I think that is where those numbers came from originally.

[Sunking]

I would still want to produce 3,000kwh a month/100,000wh a day/ 25,000wh.

Huh?

[sensij]

Any sites I should look into for my panels other than the http://sunelec.com/ website? They had 435w panels for 38 cents a watt. making my array cost about 10k without wires or anything else.

Are you talking about these? Every time people start to take you seriously, you post something like this. It is your money, do what you like, but I've found that if I'm not prepared to spend the money necessary to do a job right, it is better not to spend it at all.

[shadowaxe356]

Exactly a grid tied system with Emergency Generator if you demand to have power during outages.

Lets say you use the average 30 Kwh per day. In reality you use a lot more than that. Let's say you live in a decent location with good solar like Kansas City and pay 12-cents per Kwh. Your monthly bill is around $110/month. You say hell with th ePower Company they are screwing me over and you want to go off grid on a battery system. Here is what it will take and estimated cost in equipment only. No Spill containment (expensive and required) labor, material, permits, fees, or yearly inspections by th eFD which is required for more than 500 pound of batteries. Equipment only OK?

Panel Wattage = 15000 watts = $17,000
MPPT Charge Controllers 3 required @ $600 each $1800
48 volt Battery = 3125 AH, 9000 pounds, $33,000 initially and needs replaced about every 5 years.
15 KW Hybrid Inverter with built in Generator support and 100 amp battery charger = $15,000
20 Kw generator = $6000
550 gallon LPG tank = $1500

Total equipment cost = $74,300. You can add another 25 to 30K for all the rest not mentioned. In the first 5 years, not including generator fuel cost the system will deliver you 30 Kw x 1825 days = 54,750 Kwh. Just in equipment cost your first 5 year Kwh cost is $74,300 / 54,750 Kwh = $1.36 per Kwh. Your mean ole greedy power company only charges you 12 cents for all you want all day and night long. Then in 5 years you get to replace the batteries at even higher cost. It will cost you a few thousand in disposal fees and a good $4000 in labor cost on top of another $33,000 for the batteries. You second 5 years drop to 65-cents per Kwh of 5 times more than the greedy ole power company.

Want to sign up for that deal?

Or you could install a Grid tied system and in about 10 years will pay for itself. You initial cost minus the generator is around $3.00 per installed watt. FOR GTI you only need a 9000 watt solar panel system or a $27,000 initial investment that requires no daily work on your part monitoring battery health, weekly watering, and accounting for every light left on in the house. Want power during outages? No problem add a generator of around $10 to $12K installed. Only battery you will replace is the battery for the generator very 5 years for about $100.

So which way do you want to go? A system that provides all the power you want for 1/3 the cost that will pay for itself someday. Or do you want a money pit that cost 3 times more initially, will never pay for itself, bankrupt you, limited power, and comes with a new part time job and yearly visit from the FD and EPA red tape.

If you want the battery route call me. I design the systems and will easily make $15,000 off you. Just send me a good faith check for $50K and I will get the ball rolling. If not me I know Amy will gladly take your biz.

Thank you for the break down, with what a few people have told me I will most likely go with the generator tie in. I would still want to produce 3,000kwh a month/100,000wh a day/ 25,000wh. Any sites I should look into for my panels other than the http://sunelec.com/ website? They had 435w panels for 38 cents a watt. making my array cost about 10k without wires or anything else. For the generator, do you need a tank that big or its just better to buy a bigger tank? When purchasing the inverter would I have to make sure that its generator compatible? Would I need anything additional to add the generator if I already have a inverter that's compatible?

[Sunking]

So if not battery's then a generator? Would i just run off the generators power when the lights go out and use no solar due to it being connected to the grid and the grid being down?

Exactly a grid tied system with Emergency Generator if you demand to have power during outages.

Lets say you use the average 30 Kwh per day. In reality you use a lot more than that. Let's say you live in a decent location with good solar like Kansas City and pay 12-cents per Kwh. Your monthly bill is around $110/month. You say hell with th ePower Company they are screwing me over and you want to go off grid on a battery system. Here is what it will take and estimated cost in equipment only. No Spill containment (expensive and required) labor, material, permits, fees, or yearly inspections by th eFD which is required for more than 500 pound of batteries. Equipment only OK?

Panel Wattage = 15000 watts = $17,000
MPPT Charge Controllers 3 required @ $600 each $1800
48 volt Battery = 3125 AH, 9000 pounds, $33,000 initially and needs replaced about every 5 years.
15 KW Hybrid Inverter with built in Generator support and 100 amp battery charger = $15,000
20 Kw generator = $6000
550 gallon LPG tank = $1500

Total equipment cost = $74,300. You can add another 25 to 30K for all the rest not mentioned. In the first 5 years, not including generator fuel cost the system will deliver you 30 Kw x 1825 days = 54,750 Kwh. Just in equipment cost your first 5 year Kwh cost is $74,300 / 54,750 Kwh = $1.36 per Kwh. Your mean ole greedy power company only charges you 12 cents for all you want all day and night long. Then in 5 years you get to replace the batteries at even higher cost. It will cost you a few thousand in disposal fees and a good $4000 in labor cost on top of another $33,000 for the batteries. You second 5 years drop to 65-cents per Kwh of 5 times more than the greedy ole power company.

Want to sign up for that deal?

Or you could install a Grid tied system and in about 10 years will pay for itself. You initial cost minus the generator is around $3.00 per installed watt. FOR GTI you only need a 9000 watt solar panel system or a $27,000 initial investment that requires no daily work on your part monitoring battery health, weekly watering, and accounting for every light left on in the house. Want power during outages? No problem add a generator of around $10 to $12K installed. Only battery you will replace is the battery for the generator very 5 years for about $100.

So which way do you want to go? A system that provides all the power you want for 1/3 the cost that will pay for itself someday. Or do you want a money pit that cost 3 times more initially, will never pay for itself, bankrupt you, limited power, and comes with a new part time job and yearly visit from the FD and EPA red tape.

If you want the battery route call me. I design the systems and will easily make $15,000 off you. Just send me a good faith check for $50K and I will get the ball rolling. If not me I know Amy will gladly take your biz.