Redneck in training
Elite Member
I am strongly considering installation of large solar array on our farm in south central Iowa.
Here is what I am planning:
1.) Get a loan. That seems to be harder than I thought. Iowa gives interest free loan for 50% of the project provided that the other half is comes from a bank. Since the bank has to do some kind of reporting they are reluctant to commit.
2.) Figure what it would cost. Solar panels are at all time low cost/W. Got a quote for about $435/250 W DC. Have to add cables from the array to the grid, some enclosures, breakers, lightning arrestors etc.
3.) Decide on the set up. Decided to go with Enphase micro inverters that are DIY friendly because of no dangerous voltages and large currents are involved for most part. It will increase the cost of the hardware about 10% though.
4.) Decide on racking. Industrial racking for ground standing support structure is almost as expensive as the panels. Therefore I decided to build supporting structure out of wood bolted together. Saves about 13K.
5.) I got a ballpark quote for turn key installation by local provider $3.90/W. I think I could do it DIY for about 2.15/W or about 53750k.
6.) I used PV Watts to estimate power generation per year. 33500 kWh/year. We pay 10.9 c/kWh so that is $3651/year or about 300/month. Estimated payment on the loan is about 279/month. That doesn't take into account the federal and state tax rebate yet. I think it is no brainer.
Here are few questions to you guys who have done it or have system installed by somebody else:
1.) What precaution you have taken to prevent corrosion of the panels? I am thinking about plastic or stainless spacers between the wooden racking and the panels and use stainless fasteners as necessary.
2.) What voltage drop you or your installer designed the system for? Considering the distance between the solar array and the power meter and/or transformer I think I need to use much larger wires than necessary for the amps because it is recommended to limit total voltage drop to 2% or less. I think I will pull two 4/0 cables instead one 500 MCM. I will have two banks of panels and each will have its own cable for redundancy.
3.) Is there anything else I am naive about? I would like to hear your opinion before I blow the money.
4.) Could I use corugated 3" drainage pipe as a conduit to pull the cables from the array to the building? Or it is a bad idea and I should use PVC.
Here is what I am planning:
1.) Get a loan. That seems to be harder than I thought. Iowa gives interest free loan for 50% of the project provided that the other half is comes from a bank. Since the bank has to do some kind of reporting they are reluctant to commit.
2.) Figure what it would cost. Solar panels are at all time low cost/W. Got a quote for about $435/250 W DC. Have to add cables from the array to the grid, some enclosures, breakers, lightning arrestors etc.
3.) Decide on the set up. Decided to go with Enphase micro inverters that are DIY friendly because of no dangerous voltages and large currents are involved for most part. It will increase the cost of the hardware about 10% though.
4.) Decide on racking. Industrial racking for ground standing support structure is almost as expensive as the panels. Therefore I decided to build supporting structure out of wood bolted together. Saves about 13K.
5.) I got a ballpark quote for turn key installation by local provider $3.90/W. I think I could do it DIY for about 2.15/W or about 53750k.
6.) I used PV Watts to estimate power generation per year. 33500 kWh/year. We pay 10.9 c/kWh so that is $3651/year or about 300/month. Estimated payment on the loan is about 279/month. That doesn't take into account the federal and state tax rebate yet. I think it is no brainer.
Here are few questions to you guys who have done it or have system installed by somebody else:
1.) What precaution you have taken to prevent corrosion of the panels? I am thinking about plastic or stainless spacers between the wooden racking and the panels and use stainless fasteners as necessary.
2.) What voltage drop you or your installer designed the system for? Considering the distance between the solar array and the power meter and/or transformer I think I need to use much larger wires than necessary for the amps because it is recommended to limit total voltage drop to 2% or less. I think I will pull two 4/0 cables instead one 500 MCM. I will have two banks of panels and each will have its own cable for redundancy.
3.) Is there anything else I am naive about? I would like to hear your opinion before I blow the money.
4.) Could I use corugated 3" drainage pipe as a conduit to pull the cables from the array to the building? Or it is a bad idea and I should use PVC.