Grid-tied solar

   / Grid-tied solar #111  
Photovoltaics in the northeast is a feel good hobby at best, if you already have public powerlines to your place. I don't care how many people put up forcasted projections. The great technological breakthrough the makers were hoping for back in the 80's never happened. The efficiency still sucks <20%. Then you have all your losse converting storing DC to AC . PR press can't wait up for tech breakthroughs, so everyone in the business has been/ still is still talking it up, even though it can't compete cost wise or convience. If you are in a dry area somewhat close to the equator,solar becomes feasable, but in down-east Maine... sorry. You have to cook the books to make it look cheaper than the grid. Never mind no power during a snow storm, don't forget to go out and clean them off afterwards. Efficiency loss over time? Yup you bet. Look at your cars paint job, or the headlght covers. Look in your rain gutters. Personally, just the thought of mothering a flock of batteries at my house would be a deal breaker by itself. Dealing with a room full of batteries sucks.What's wrong with this one- oh- bad cell, Hey what's that smell, ohh- over charging- just venting.
If you don't have grid power available, then that's a different story.

I've dealt with batteries and solar panels for 30 years and have not had a battery fail early. The panels are vertical for the winter so snow accumulation is not a problem but darkness is. What's your experience? I haven't had to deal with power company for 30 years. Its obvious that the payback will be quicker in an area with more unobstructed sun or areas with high electricity costs.

A true comparison to other energy sources would be a very complex challenge that would include all internal and external present and future costs.

Looks like nearly all states and the Fed offer incentives. It must not be so obvious to them.
http://www.solar-estimate.org/index...solar-incentives&subpage=&external_estimator=

Loren
 
   / Grid-tied solar #112  
As the thread title states, we are talking about "Grid Tied Systems." Batteries should not be part of the discussion. As a PV system owner where electricity costs on average $0.18Kwh (and rising) I believe it makes sense! I can invest my $'s many places elsewhere with less return. I expect my system will still be producing nicely 25+ years from now. What do think a Kwh will cost then?
 
   / Grid-tied solar #113  
As the thread title states, we are talking about "Grid Tied Systems." Batteries should not be part of the discussion. As a PV system owner where electricity costs on average $0.18Kwh (and rising) I believe it makes sense! I can invest my $'s many places elsewhere with less return. I expect my system will still be producing nicely 25+ years from now. What do think a Kwh will cost then?

if typical yearly increase of the rate is 3% 0.18 25 years later will be 0.38.
 
   / Grid-tied solar #114  
I just got a quote for a hardware DIY for a system that would produce about 55000 kWh/ year. $96000 pre-incentive.
180 ea 250W mono panels.
20 kW inverter or add $10000 for 180 micro inverters.
Support structure
disconnect etc.
If their calculation are correct (I doubt they are wrong) the pay back period, assuming constant rate 0.11c/kWh, would be about 11 years.
I think I buy 45 panels and see how it will go.
 
   / Grid-tied solar
  • Thread Starter
#115  
I just got a quote for a hardware DIY for a system that would produce about 55000 kWh/ year. $96000 pre-incentive.
180 ea 250W mono panels.
20 kW inverter or add $10000 for 180 micro inverters.
Support structure
disconnect etc.
If their calculation are correct (I doubt they are wrong) the pay back period, assuming constant rate 0.11c/kWh, would be about 11 years.
I think I buy 45 panels and see how it will go.

Wow. You don't mess around :laughing: Look forward to hearing about your project if you go ahead with it.
You would need to adjust their payback calculation by the fact your are paying less for your heating/cooling usage, whatever percentage that is of your total use.

I looked at micro-inverters. I guess the pros are that they isolate any panel in a sub-array or string from affecting the other panels in that section. The cons seem to be more potential points of failure and cost. FWIW, the people at Revision Energy didn't think they are worth the risks, although they do install some.
 
   / Grid-tied solar #116  
We have 100% electric house. So heating cost is already factored in. Microinverters increase the cost by about 10% but I think they are way to go. Especially for DIY projects.
They provide redundancy, optimize each panel especially if some shading is involved and marginally increase performance of the system. There are few more advantages:
The software that comes with it monitors every single panel/inverter so troubleshooting is relatively easy.
Adding panels is straightforward by just plugging them in.
When you work with panels you deal only with small voltages from single panel. You can turn off the output but not the panel when illuminated. When you work with interconnected panels you work with large life threatening voltages. You have to cover them before working on connections.
 
   / Grid-tied solar #117  
I am reluctant to state this but photovoltaic panels degrade rather quickly over time producung less and less power. To those that want to get off the grid...more power to you. I pay around .06/kW for electricity in my location. I wish they made coal fired home generators.
 
   / Grid-tied solar
  • Thread Starter
#118  
Ladia,

The left image shows our consumption at 11 c/kWh rate and the geo consumption at 4.2 cents

You lost me on the 100% electric home. From your post with the graphs of geo and non-geo use, you aren't paying the same rate for all of your power. I look at that as meaning you need to account for that in calculating payback time as they will differ at 11 cents versus 4.2 cents. If you net-meter only the non-geo 11 cent rate consumption with solar pv, replacing your most expensive electricity, then I see your point.

Will your local utility give you the geo heating 4.2 cent rate and net-metering combined?
 
   / Grid-tied solar #119  
Source of that data? When we were looking, degradation even after 20 years appeared to be minor. Of course, this was sales stuff from multiple companies.

I am reluctant to state this but photovoltaic panels degrade rather quickly over time producung less and less power. To those that want to get off the grid...more power to you. I pay around .06/kW for electricity in my location. I wish they made coal fired home generators.
 
   / Grid-tied solar #120  
Ladia,

The left image shows our consumption at 11 c/kWh rate and the geo consumption at 4.2 cents

You lost me on the 100% electric home. From your post with the graphs of geo and non-geo use, you aren't paying the same rate for all of your power. I look at that as meaning you need to account for that in calculating payback time as they will differ at 11 cents versus 4.2 cents. If you net-meter only the non-geo 11 cent rate consumption with solar pv, replacing your most expensive electricity, then I see your point.

Will your local utility give you the geo heating 4.2 cent rate and net-metering combined?

My electric installation has three meters. One is total power. One is for geo in the house and one for heat pump in the shop building. The power consumed by geo and the heat pump is subtracted from the total and charged at lower rate during the heating season. If I understand interconnection agreement correctly the coop will install another meter measuring power delivered to the grid. The meters are read once a month. If there is excess compared to total power delivered from the grid it is applied as credit for next month etc. If there is still excess at the end of a year it will be converted to cash at rate 3.5 cent or whatever the wholesale rate is at that time. In other words the solar system should be sized to just cover the consumption for the best ROI.
 
 
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