Grid-tied solar

[houstonscott]

Anyone have an two axes active tracker. Wife doesn't want PV on roof. I'm looking at Wattson, or Allsun trackers for a 3-4kw system. HS.

 

[Redneck in training]

Anyone have an two axes active tracker. Wife doesn't want PV on roof. I'm looking at Wattson, or Allsun trackers for a 3-4kw system. HS.

HS forget tracker. It is cheaper to add pannels. Putting panels on the roof will save you about 20% of money. Tracker will deliver about 25-30% more energy. Adding four panels will do the same for about less than quarter of the tracker cost.

 

[houstonscott]

HS forget tracker. It is cheaper to add pannels. Putting panels on the roof will save you about 20% of money. Tracker will deliver about 25-30% more energy. Adding four panels will do the same for about less than quarter of the tracker cost.

No, I don't want roof leaks, reading on the subject leads me to think roof mounts are all about chasing roof leaks. I'm going tracker. HS

 

[sseelhoff]

Third quote received today. About $12K net for a 9100 KWh system. German panels, U.S. inverter. Roof mounted.

 

[SirReal63]

Do you have to be on battery to use the DC? WE have to be grid tied to get the utility rebate, which is a big financial incentive.

After doing a little more digging into the DC powered mini-splits I found a hybrid, so no battery required but it looks like the best way is either a standalone DC powered Mini-split or one of the combinations. The price isn't really that bad either.
DC Solar Air Conditioner Heat Pump | Solar Air Conditioning | Solar Heating | Manufacturers

I also have some links to DC powered refrigerators and freezers, in a variety of power configurations, and use about a third of the energy.
Sun Frost Energy Efficient Refrigerators

 

[Jim Nelson]

Until we received our permit to operate today I didn't know the size of our system in KWh,it's 3.337,which is 14 panels. How did you calculate your KWh size? I'm new to this and to the best of my knowledge electricity is about 85% voodoo and the rest plain old black magic.

Third quote received today. About $12K net for a 9100 KWh system. German panels, U.S. inverter. Roof mounted.

 

[dave1949]

Until we received our permit to operate today I didn't know the size of our system in KWh,it's 3.337,which is 14 panels. How did you calculate your KWh size? I'm new to this and to the best of my knowledge electricity is about 85% voodoo and the rest plain old black magic.

The rated size of a system should be the number of panels times the wattage rating of each panel.

Ten 250 watt panels would be rated at 2500 DC (direct current) watts, or 2.5 DC kW. Hours doesn't enter into the rating.

The panel rating is a nominal value based on what the panel would instantaneously (any given moment in time) produce under optimal conditions (temperature, angle of mounting, solar intensity).

A good quality grid-tied system will produce about 90% of the DC kW's as AC kw's.

 

[sseelhoff]

Until we received our permit to operate today I didn't know the size of our system in KWh,it's 3.337,which is 14 panels. How did you calculate your KWh size? I'm new to this and to the best of my knowledge electricity is about 85% voodoo and the rest plain old black magic.

We are not calculating it. We have supplied the contractors with two years worth of electric usage data. We average 9500KWh per year. The 9100KWh system will take care of approximately 92% of our needs based historical usage. We told them we wanted to get as close to net zero usage as possible. Per their projections, Most months we make it. A few months we do not. We are looking at a mini split system and a tankless water heater to make up the difference. New windows would help, but we are taking this in phases.

We turned on our a/c today for the first time this summer. No cold air. Turns out we have a leak in the coils. Also turns out that when they built the house in 2007 they used equipment from 2003. NO warranty. The old system is about to be obsolete on the refrigerant-meaning if we don't replace the coil, next year we can't refill. So we can ride it out one more season(?) or replace our a/c system and stay ahead of the curve. This is turning into an expensive summer.

 

[Jim Nelson]

Thank you both,I get confused with all the figures they throw around. We also gave them our billing history but only one year so we ended up with this company mostly because of recommendations of neighbors.The other company we got an estimate from was $5000 higher for 2 less panels.
We are on propane here so 3 years ago we put in solar water heater because the house was already plumbed for it and we backed it up with a tankless heater.Last year we used 37 gallons of propane and this year we haven't bought any and still have 65% in our tank.Our neighbor put in a tankless and his propane usage dropped by 60% so they are a good deal. I understand what you are saying about the ac situation as our furnace and condenser unit went to heck last year and that's all we replaced but know the compressor is 17 yrs. old and will go soon.Fortunately the climate here is mild enough that we don't need it very much.
Good luck with your upgrades.

 

[madmax12]

We are not calculating it. We have supplied the contractors with two years worth of electric usage data. We average 9500KWh per year. The 9100KWh system will take care of approximately 92% of our needs based historical usage. We told them we wanted to get as close to net zero usage as possible. Per their projections, Most months we make it. A few months we do not. We are looking at a mini split system and a tankless water heater to make up the difference. New windows would help, but we are taking this in phases.

We turned on our a/c today for the first time this summer. No cold air. Turns out we have a leak in the coils. Also turns out that when they built the house in 2007 they used equipment from 2003. NO warranty. The old system is about to be obsolete on the refrigerant-meaning if we don't replace the coil, next year we can't refill. So we can ride it out one more season(?) or replace our a/c system and stay ahead of the curve. This is turning into an expensive summer.

I know old school is ride out the heat with open windows (or find a cave). But I went back to new old school with window units. It's not as attractive, but neither is it all or nothing or as expensive.

 

[sseelhoff]

I know old school is ride out the heat with open windows (or find a cave). But I went back to new old school with window units. It's not as attractive, but neither is it all or nothing or as expensive.

We have a portable cooling unit that we can use if it gets too bad. Except for that 4pm to 7pm time frame in my office (west side of the house), it really has not been that bad this year. We keep the temp set between 82-85. Anything below 82 and we both get too cold.

 

[fordmantpw]

We have a portable cooling unit that we can use if it gets too bad. Except for that 4pm to 7pm time frame in my office (west side of the house), it really has not been that bad this year. We keep the temp set between 82-85. Anything below 82 and we both get too cold.

It's currently 75 in our house, which is about perfect. If I turn the air to 74, we start looking for blankets! The temp does go down to 74 at night for good sleeping.

Before we had our geothermal installed, we kept the air set on 78. Now it's cooler in the house and our bill is less!

 

[sseelhoff]

It's currently 75 in our house, which is about perfect. If I turn the air to 74, we start looking for blankets! The temp does go down to 74 at night for good sleeping.

Before we had our geothermal installed, we kept the air set on 78. Now it's cooler in the house and our bill is less!

The bolded is our goal. How we get there is a work in progress. We're still pushing ahead with the solar for the house. We are researching whether we should replace the air handler and coils, replace the entire system, or go to mini split. Waiting on bids from the HVAC contractors.

 

[fordmantpw]

The bolded is our goal. How we get there is a work in progress. We're still pushing ahead with the solar for the house. We are researching whether we should replace the air handler and coils, replace the entire system, or go to mini split. Waiting on bids from the HVAC contractors.

We are looking to add solar to our new home after the first year. I would like to replace about 90% of our electric with solar, but we are going to shoot for about 50% the first go-around and add more panels as money allows.

 

[Redneck in training]

We are looking to add solar to our new home after the first year. I would like to replace about 90% of our electric with solar, but we are going to shoot for about 50% the first go-around and add more panels as money allows.

If you want to add panels later then go with microinverters. The issue (if you have single inverter) is that the panels compatible with your old panels and inverter might not be available anymore. Since there is single microinverter per panel you can mix and match panels. Microinverters will also give you somewhat better performance (few %) and if you are able to install new power outlet in your house you can install/add microinverters DIY it so easy.
I would also install full system right away:
1.) Interest rates are low and if you add it to your mortgage the interest paid is tax deductible.
2.) The tax rebate for alternative energy will expire.

And very important: Before you make a decision about installing PV make sure that you have contract with the utility about billing etc. Do not assume anything.

 

[fordmantpw]

If you want to add panels later then go with microinverters. The issue (if you have single inverter) is that the panels compatible with your old panels and inverter might not be available anymore. Since there is single microinverter per panel you can mix and match panels. Microinverters will also give you somewhat better performance (few %) and if you are able to install new power outlet in your house you can install/add microinverters DIY it so easy.
I would also install full system right away:
1.) Interest rates are low and if you add it to your mortgage the interest paid is tax deductible.
2.) The tax rebate for alternative energy will expire.

And very important: Before you make a decision about installing PV make sure that you have contract with the utility about billing etc. Do not assume anything.

Thank you very much for the tips! I would love to add it all at the time we build our home, but I don't think it is going to work out. For starters, the panels are going on our detached garage (for several reasons, one being that the roof will face due south), but the garage will not be completed at the time the house is. Also, due to the sale of our current home and a few other factors, we will be right near the 80% on our mortgage and won't be able to fit the panels in without a second mortgage or PMI.

Our plan is to use the tax credit from our geothermal installation plus some other funds and install the panels in the spring of 2015. Then, in the spring of 2016, we will use the tax credit from our initial solar install to add another large chunk. This will also give us a year in our new home to determine actual energy usage to ensure the system is sized properly.

We are planning to go with micro inverters as you mention. I hadn't thought about the compatibility, but that's a great point. I am somewhat mechanically inclined, and am considering doing the second installation myself after the 'big' things are done with the initial installation. Heck, my dad was a carpenter and he had me putting electrical outlets in when I was 8!

10-4 on the utility agreement. I already have the details for that in hand. It is a 'net usage over 12 months' type of agreement. At the end of every 12 months (starting when your installation goes live), they wipe out any excess you have generated. So, if I install in April and generate extra in April, May and June, that will carry over until I use it. However, if I don't have it used by the end of March the following year, I lose any credits...they do not buy any back from me. That's why I definitely don't want to over produce and would like to stay right around 80-90% to just account for the $20 minimum charge just to have a meter.

 

[ultrarunner]

My Utility will not let you install more than 110% of usage...

The solar installers I've contacted all want to hit 90-95% because there is a minimum electric monthly charge if you use no power which fades away when there is a little power used.

Still on the fence for Mom's install... $8300 for the 3kW with Canadian Solar Panels and 215 Microinvertors.

Also one brother thinks it is foolish at her age to spend that kind of money with a payback measured in years...

It would seem using more power shouldn't be a problem... can always plug in a portable electric heater or similar?

 

[Redneck in training]

Thank you very much for the tips! I would love to add it all at the time we build our home, but I don't think it is going to work out. For starters, the panels are going on our detached garage (for several reasons, one being that the roof will face due south), but the garage will not be completed at the time the house is. Also, due to the sale of our current home and a few other factors, we will be right near the 80% on our mortgage and won't be able to fit the panels in without a second mortgage or PMI.

Our plan is to use the tax credit from our geothermal installation plus some other funds and install the panels in the spring of 2015. Then, in the spring of 2016, we will use the tax credit from our initial solar install to add another large chunk. This will also give us a year in our new home to determine actual energy usage to ensure the system is sized properly.

We are planning to go with micro inverters as you mention. I hadn't thought about the compatibility, but that's a great point. I am somewhat mechanically inclined, and am considering doing the second installation myself after the 'big' things are done with the initial installation. Heck, my dad was a carpenter and he had me putting electrical outlets in when I was 8!

10-4 on the utility agreement. I already have the details for that in hand. It is a 'net usage over 12 months' type of agreement. At the end of every 12 months (starting when your installation goes live), they wipe out any excess you have generated. So, if I install in April and generate extra in April, May and June, that will carry over until I use it. However, if I don't have it used by the end of March the following year, I lose any credits...they do not buy any back from me. That's why I definitely don't want to over produce and would like to stay right around 80-90% to just account for the $20 minimum charge just to have a meter.

I have another suggestion. Determine how many panels will fit in the roof and install the racking for full roof. Also buy the Enphase cable for full roof of the panels. This will add only small expense and will make future expansion one afternoon job.

 

[Redneck in training]

My Utility will not let you install more than 110% of usage...

The solar installers I've contacted all want to hit 90-95% because there is a minimum electric monthly charge if you use no power which fades away when there is a little power used.

Still on the fence for Mom's install... $8300 for the 3kW with Canadian Solar Panels and 215 Microinvertors.

Also one brother thinks it is foolish at her age to spend that kind of money with a payback measured in years...

It would seem using more power shouldn't be a problem... can always plug in a portable electric heater or similar?

It depends what is her utility policy. If they give her net metering with banking (common in CA) then the payback is quite short. I also think that the PV increases value of the property.
There are devices that will send excess power to hot water heater or pre-heater. Power Diverter | Powerdiverter Don't know if there US version at this point.

 

[fordmantpw]

I have another suggestion. Determine how many panels will fit in the roof and install the racking for full roof. Also buy the Enphase cable for full roof of the panels. This will add only small expense and will make future expansion one afternoon job.

Those were my thoughts exactly!