Grid-tied solar

[fordmantpw]

Paying 30 cents a kWh has an impact and changes things compared to someone paying 10 cents... just saying.

Absolutely!

 

[houstonscott]

Selling back never seems to be a worthwhile proposition. For me, I'm on a co-op, and it doesn't buy anything back, no matter how much you are over, so there is no benefit to over-producing. Plus, there is a minimum just for having a meter, so for me, the best place to be is about 80-90% replacement of electricity. Active trackers don't seem to be worth the added expense. When we built our new home, I had my shed built with solar in mind. 5/12 pitch roof (optimal is 6/12, but that's a bit steep for a metal roof, plus the added cost wouldn't be realized in solar payoffs), roof facing due south, etc. Small things now to help optimize solar in the future.

If you are able to change your energy consuming activities to times of excess or overage I wonder just how beneficial that could be over a few years. Examples; make sure you do laundry and dishwasher while your PV is humming. HS

 

[fordmantpw]

If you are able to change your energy consuming activities to times of excess or overage I wonder just how beneficial that could be over a few years. Examples; make sure you do laundry and dishwasher while your PV is humming. HS

Even if you were to do that, your net total usage should be the same (unless you do things like running the dryer at night when less A/C is needed, but that's a completely different discussion). I'm not exactly sure if other places are the same, but the way the net metering agreement works for my co-op is based on a yearly net. If you over produce by x kWH one month, but under produce by x kWH the next month, it equals out. At the end of the year, any extra net that you have gets zeroed out and you start fresh. So overproducing just puts money in the co-op's pocket.

 

[TnAndy]

For anyone considering active trackers, don't do it is my advice. I did the first 3 of my 5 sets of panels on homebuilt trackers when I started in 2007, and panels were $4/watt.

Active trackers are a PITA to keep running....the control units were a perpetual problem (I tried 3 different brands), the linear actuators are good for about 2-3 years and you'll be replacing/rebuilding them, and so on. The parts I built were fine, the poles, the bearing for tilt, etc.....but the support stuff is dadgum nightmare.

Now that panels are a buck/watt and less, there is NO WAY I'd do a tracking system again.....and I didn't. My last 20 panels (5kw) are a fixed, ground mount rack built out of 1 1/2" galvanized pipe with 2" x 3/16's galvanized angle running perpendicular to the pipe for the panel mounting. Not one single issue with it.

SO, save yourself some grief folks....stay away from tracking systems.


My setup (added 10 more panels to the ground mount after this photo). You can see two tracking arrays, the third one is behind one of the others.

View of back on one tracker. Dual axis. Pipe is 8" sch40.

THIS is a WHOLE LOT better way to go:

 

[houstonscott]

For anyone considering active trackers, don't do it is my advice. I did the first 3 of my 5 sets of panels on homebuilt trackers when I started in 2007, and panels were $4/watt. Active trackers are a PITA to keep running....the control units were a perpetual problem (I tried 3 different brands), the linear actuators are good for about 2-3 years and you'll be replacing/rebuilding them, and so on. The parts I built were fine, the poles, the bearing for tilt, etc.....but the support stuff is dadgum nightmare. Now that panels are a buck/watt and less, there is NO WAY I'd do a tracking system again.....and I didn't. My last 20 panels (5kw) are a fixed, ground mount rack built out of 1 1/2" galvanized pipe with 2" x 3/16's galvanized angle running perpendicular to the pipe for the panel mounting. Not one single issue with it. SO, save yourself some grief folks....stay away from tracking systems. My setup (added 10 more panels to the ground mount after this photo). You can see two tracking arrays, the third one is behind one of the others. View of back on one tracker. Dual axis. Pipe is 8" sch40. THIS is a WHOLE LOT better way to go:

Do you have experience with Wattson trackers or allsun trackers. You opinion. HS

 

[MossRoad]

Doubling your money in 8 years means you are getting a return of 9% on your money. There is no SAFE way to do that without risks. What happens when the stock market tanks and you lose 30-40%? Then it looks like a much better investment to go with the known, extremely low risk solar investment.

Its probably a bit lower than 9%. We've been able to double every 7. In 2008 we lost 33% of value of shares in mutual funds. But we didn't sell. We kept buying shares per our plan. It came back to even by 2010 and doubled by 2012. So, it was worth X in 2007 and 2X by 2012 even with the crash of 2008.

Now, had we needed that money to pay bills, then we'd have taken losses. Its probably not a good idea to gamble with they money you need to pay utility bills, mortgages, etc....

 

[fordmantpw]

Its probably a bit lower than 9%. We've been able to double every 7. In 2008 we lost 33% of value of shares in mutual funds. But we didn't sell. We kept buying shares per our plan. It came back to even by 2010 and doubled by 2012. So, it was worth X in 2007 and 2X by 2012 even with the crash of 2008.

Now, had we needed that money to pay bills, then we'd have taken losses. Its probably not a good idea to gamble with they money you need to pay utility bills, mortgages, etc....

Agreed! And investing your money in solar is basically using the money you would need to pay utility bills. That's really where I was going. You can afford to take a bet with retirement money if that is a ways off, but utility bills come every month...

 

[ultrarunner]

We have several solar installs in my neighborhood and one was done 100% by my 80 year old neighbor with a career in the Phone Company.

Every morning it brings a smile to his face seeing how much power generated the day before... guess satisfaction is hard to put a price on.

Also, he did 3 hillside mounted arrays and built the rack so twice a year he can manually adjust the pitch... take no tools and about 10 minutes to do all 3.

He does produce excess power so the gas heater in now electric and the gas dryer is now electric... made the change when the old 20 year stuff needed replacement.

 

[Redneck in training]

What you need to do is shift energy consumption to to electric users. In ex. replace gas water heater with electric, install heat pump to heat/cool your house. Then size the system to provide the required energy.
In example to heat our place would take about estimated 2500-3000 gal of propane/season. At current cost of 1.67/gal the electric heat (geothermal heat pump) beats the propane hands down even without the PV.
Another consideration is direction of the array. It might be beneficial to turn it east or west depending on time of your peak usage. In example your peak consumption or the energy is most expensive afternoon then turning the array west makes sense. You will end up with smaller (cheaper) system while still covering your consumption.

 

[houstonscott]

What you need to do is shift energy consumption to to electric users. In ex. replace gas water heater with electric, install heat pump to heat/cool your house. Then size the system to provide the required energy. In example to heat our place would take about estimated 2500-3000 gal of propane/season. At current cost of 1.67/gal the electric heat (geothermal heat pump) beats the propane hands down even without the PV.

I once read that the cheapest way to supply your electric needs is a single cylinder NG engine generator. Not for everyone but if you are handy and can configure, that it's the cheapest. HS.