Grid-tied solar

[dave1949]

This is a great feature and it would seem that it could be done at a minimal cost.

I think the dedicated outlet at the inverter probably makes it very reasonable cost-wise. It doesn't require any changes to the grid disconnect sensing and circuitry when power is off.

 

[Redneck in training]

I extracted data for two cloudless days to show effect of temperature on PV power. Even though the April 1 was shorter day it produced more energy due to low temperature than July 6. The flat part of the April curve is caused by inverter power limiting.
https://picasaweb.google.com/101162...authkey=Gv1sRgCKDV37eW7qyq4AE&feat=directlink

 

[dave1949]

The August, 2013 results.

This August production was very close to Aug. 2012.

My average monthly consumption since installation and converting to the electric water heater is 444 AC kWh, average monthly output is 418 AC kWh. I'm happy with that. The system is producing a lot more of my power than I anticipated.

Month--NREL Model (AC kWh)-----2012 Actual-----2013 Actual

Jan.----388----------------------NA--------------440
Feb.----412----------------------NA--------------375
Mar.----509----------------------NA--------------462
Apr.----374----------------------NA--------------487
May----353----------------------NA--------------375
Jun.----308----------------------NA--------------379
Jul.-----341----------------------NA--------------377
Aug.----383----------------------461-------------470
Sep.----394----------------------481
Oct.----369----------------------378
Nov.----283----------------------400
Dec.----331----------------------297

 

[Redneck in training]

I did some measurement on few panels and determined that the microinverters are about 95-96% efficient. Losses on cabling add another about 2% (at peak current 82A) loss. Initially I used 86% efficiency in NREL model before I built the system. I think I should up it to 94%.
My system produced 3703.303 kWh in August. Estimated production by NREL model (with upped efficiency to 94%) was 3593 kWh.
I am looking on residential energy monitoring system.
Does anybody have experience with TED or something similar? TED for Residential

 

[cqaigy2]

Very nice. Thats great efficiency!

 

[dave1949]

An article about some utilities and fossil fuel special interests getting nervous about grid-tied solar's potential market penetration.

With Rooftop Solar on Rise, U.S. Utilities Are Striking Back by Marc Gunther: Yale Environment 360

 

[Redneck in training]

Our utility is too small to be regulated. Even though it doesn't generate any power (and in my opinion could benefit from my PV system) it is openly hostile to any alternative energy. It doesn't offer net metering and I just got a letter few days back telling me that since I make my own power they will change my discounted heating rate to full rate. In other words my electric bill will go up by about $500 - $700/year. They get about 15MWh of energy from my system for $0.035kWh they pay for $525 and then sell it back to me and my neighbors for $0.115 kWh (worth $1725). If they would give me net metering they would still make about $900 selling my excess.

 

[dave1949]

Our monthly service connection fee is $9.36. It's the same for all residential customers with or without a home solar unit, and includes the service charge only for the first 0 to 100 kWhs of usage. That is supposed to cover the power distribution costs (poles, wires, transformers, grid infrastructure, repairs, etc.) On top of that are charges from the power generator/supplier which is applied to all kWhs.

I will never get paid for any excess power generated that exceeds my annual usage. The best strategy here is to never generate excess power because you will be giving it away to the utility. All states are different on this. Our state PUC sets up these arrangements with the utilities. I am not aware of any here that do not fall under the state PUC regulations. This past summer, our clown governor vetoed an energy bill that would have maintained the state's one-time $2000 rebate subsidy on solar systems.

Following the Lac Megantic, Quebec Province train disaster, the railway that serves some Maine businesses and transports oil to shipping ports is in bankruptcy. The rail line may not be viable economically without state support via partial or total ownership of the tracks. Maine already owns some rail lines in the northern part of the state for the same reasons. I think the governor would find the money to subsidize the railway if it comes to that, he likes fossil fuels and does not like or understand alternative energy.

It's a shame that greed, ignorance and politics are going to delay moving to a more secure distributed electric grid, less pollution and stronger local economies. But, that's nothing new. It's a shame that Thomas Edison isn't remembered for being the arrogant a** who electrocuted an elephant in front of a live audience to demonstrate the "dangers" of alternating current distribution systems rather than his own direct current grid design.

 

[madmax12]

Our monthly service connection fee is $9.36. It's the same for all residential customers with or without a home solar unit, and includes the service charge only for the first 0 to 100 kWhs of usage. That is supposed to cover the power distribution costs (poles, wires, transformers, grid infrastructure, repairs, etc.) On top of that are charges from the power generator/supplier which is applied to all kWhs.

I will never get paid for any excess power generated that exceeds my annual usage. The best strategy here is to never generate excess power because you will be giving it away to the utility. All states are different on this. Our state PUC sets up these arrangements with the utilities. I am not aware of any here that do not fall under the state PUC regulations. This past summer, our clown governor vetoed an energy bill that would have maintained the state's one-time $2000 rebate subsidy on solar systems.

Following the Lac Megantic, Quebec Province train disaster, the railway that serves some Maine businesses and transports oil to shipping ports is in bankruptcy. The rail line may not be viable economically without state support via partial or total ownership of the tracks. Maine already owns some rail lines in the northern part of the state for the same reasons. I think the governor would find the money to subsidize the railway if it comes to that, he likes fossil fuels and does not like or understand alternative energy.

It's a shame that greed, ignorance and politics are going to delay moving to a more secure distributed electric grid, less pollution and stronger local economies. But, that's nothing new. It's a shame that Thomas Edison isn't remembered for being the arrogant a** who electrocuted an elephant in front of a live audience to demonstrate the "dangers" of alternating current distribution systems rather than his own direct current grid design.

You have a very interesting perspective.

The poor aren't installing solar panels. The rich are. We can't pay legitimate debts. Not subsidizing the rich and the solar modifications to save them, individually, money, allows us to just be less in debt. Maine and the US are broke.

The governor is good at math. The rail line is necessary for commerce for all. Solar panels on your house are good for just you. No one is blocking anyone from buying their own solar panels. So, no interference, no loss of freedom.

Now if I want the state to subsidize my gun purchase, where do you stand on that?

 

[Redneck in training]

The issue I have with the utility is that before I built my system they send me an example of connection agreement describing net metering with "banking". After I build my system they back pedaled but let me keep my heating rate for rest of the last heating season. Now they canceled it for the future.
I would be happy if I could al least offset my own consumption and they could keep the excess. What irks me is that they pay me 3.5 cent/kWh and if a cloud goes over the sun they immediately sell it back to me for 11.5 cent kWh.
They don't like zero electric bill. I understand that but they would get my excess energy that they can sell with good profit.
My next purchase will be an electric plug in car. It will eliminate most of the energy excess and save me about 300/month on fuel charges. Also as the new energy storage devices such "ultra capacitors" became available I might invest in an energy storage system.
Anyway solar is going to stay and they will have to learn to profit from it.
To put my attitude in a perspective:
People buy expensive cars and nobody ask how much money they will make.
My wife spends more money for gardening that we spend on loan financing the PV.
CD in the bank earn interst so meager it is not worth much. Our investment in PV saves at least half of our elctric bill.
We can keep our house ice cold all day without a guilt that we polute air.
It was fun project to build and we enjoy having the PV.
As it financially turned out is somewhat disappointing but in fact I don't have much to complain about.