Texas Oncor Question- Grid Tie Starting Small

[chrisivc]

So I have been looking at potentially installing a few panels to offset my home office electricity usage and I believe that an enphase microinverter system is ideal for my situation given my situation (I am still a year or two away from pulling the trigger though). 2/3 of my roof exposure is covered by 70+ year old red oak trees, so I have to maximize the use of roof real estate since there is very little. I am starting the planning stages of what I wanted to do but before I even start engineering, it would be good to know if this is even viable given the service provider's rules.

I had a question for those familiar with the Texas Grid in Dallas (ONCOR is responsible for the grid). My proposed grid-tie kit will probably never roll the meter backwards given that I constantly use ~700 watts at all times. Am I required to purchase a Net-metering plan from an retail electric provider(ex. Reliant, Gexa, TXU, etc) for any solar array or only if I want the grid to pay me for excess production? The documentation that I can find is vague on whether you are required to purchase a net-metering plan if you have ANY grid-tie production device, even if said device will not produce enough to roll the meter backwards. If I am required to buy a net-metering plan, the benefits of installing solar suddenly evaporate because most net metering plans are more expensive than the regular "conservation" plans (conservation plans are usually a really low rate for the first 1000KWH of usage, like $0.002/KWH, but then 10c/KWH after that). My home's usage averages 1100KWH/month (6 months are under 1000KWH and 6 months over 1000KWH).

I would love to install it, but it has to make financial sense. I dont want to be required to purchase a more expensive plan for a smaller than normal array. If I am not required to purchase a special plan, I would love to pursue building a kit of about 4 panels on my southern exposure to offset my home office usage (~250KWH/mo). Obviously this is my first obstacle before I go any further, so any help and advice would be appreciated.

Thanks,
Chris

[SunEagle]

Hello chrisivc and welcome to Solar Panel Talk

So if you are looking into a financial smart decision I would say to do the math. If the cost of the solar equipment installed does not generate enough power to pay itself off within say 10 years then IMO that would not be a financial decision that makes sense.

I would expect that your POCO (ONCOR) probably will not allow you to connect to their grid without getting a Net Metering contract. And if you decide to bypass them and connect anyway I would expect you will get a knock at your door from them because they will eventually know what you have done without getting that contract.

Based on everything I know, reducing your electrical usage or using a "Conservation plan" is the best way to lower your costs. That is not saying I wouldn't install a solar grid tie system. I just feel if it didn't pay for itself within say 5 to 7 years I would look into spending my money elsewhere.

[ButchDeal]

you would still need a permit but I believe if you set up and configure the inverter for zero grid feed in then you MIGHT be able to get by without a net metering plan.
To do that you will need a consumption meter and an inverter set up for zero fee in.

NOTE also that you would need a new permit every time you expand the solar array ( you stated "Starting Small" which implies growing solar).

I would suggest that you look into Solaredge inverters instead of the enphase but both can be configured to do zero feed in with the added consumption meter. you will need to confirm the set up with your utility BUT you will get a run around and many will not understand your question. Make sure that you specify that the system is configured for zero feed in NOT that you expect it to never feed in. The difference is that you could install as large of an array as possible with zero feed in and the inverter will only produce what is being consumed but with your plan the inverter WILL produce what it produces and if consumption drops you will be feeding in to the grid (even if just for a few seconds).

[chrisivc]

Hello chrisivc and welcome to Solar Panel Talk

So if you are looking into a financial smart decision I would say to do the math. If the cost of the solar equipment installed does not generate enough power to pay itself off within say 10 years then IMO that would not be a financial decision that makes sense.

I would expect that your POCO (ONCOR) probably will not allow you to connect to their grid without getting a Net Metering contract. And if you decide to bypass them and connect anyway I would expect you will get a knock at your door from them because they will eventually know what you have done without getting that contract.

Based on everything I know, reducing your electrical usage or using a "Conservation plan" is the best way to lower your costs. That is not saying I wouldn't install a solar grid tie system. I just feel if it didn't pay for itself within say 5 to 7 years I would look into spending my money elsewhere.

I understand I would have to pull a permit every time and only plan to do this system legitimately. I was thinking of starting off with 2-3 panels on the south side of the house, with the plan to maybe add 1 panel to the SE exposure and 2 to the SW exposure as a phase II. Those 6 panels would maximize out the real estate that I have without having to trim back trees.

I have a friend who is a Master electrician and he has agreed to help me wire and grid tie the system, so we can essentially do most of the installation labor together. I am hoping that will help reduce the overall installation costs. I will still have a Solar engineer consult and help plan out everything so we can submit the permits. A few of the online sellers have engineers on staff to help with design and permit applications, so I will probably go with them when we get serious.

My master plan is to have a family friend HVAC professional replace my 17 year old HVAC system with a Bosch BOVA series heat pump (and convert my existing gas furnace into a dual fuel setup). The heat pump would be used to heat the house on the milder winter days and then the existing gas furnace will take over during the cold snaps. This should reduce my natural gas usage and having a solar setup to offset SOME of the heat pump usage would be fantastic. Gas is cheap but a heat pump with a pretty high HSPF rating is more efficient, especially on milder winter days. Having a solar setup that could produce 200KWH/mo would help keep my electricity usage around 1100KWH/month and make my utility bills cheap. That is the master plan but I will need to flush this idea out and make sure it is viable and possible to get an ROI of around 5-7 years, otherwise it is not going to happen.

Thanks for the help.
-C

[chrisivc]

you will need to confirm the set up with your utility BUT you will get a run around and many will not understand your question. Make sure that you specify that the system is configured for zero feed in NOT that you expect it to never feed in.

This has been my experience so far. Nobody I have talked to so far knows what the heck I am trying to ask.

I will try to inquire about zero feed. I didnt know this was an option.

[SunEagle]

Depending on the actual amount of useful sun your panels get will determine the amount of kWh they can produce each month.

To get 200kWh you would need a panel array of around 1500 watts (1500 watts * 5 hrs per day of useful sunlight * 30 days * 90% DC to AC conversion factor ~ 202kWh).

So I doubt you could get that much wattage from 4 panels. You will need more wattage along with more sunlight hours on average per day to generate 200kWh per month.

[chrisivc]

Depending on the actual amount of useful sun your panels get will determine the amount of kWh they can produce each month.

To get 200kWh you would need a panel array of around 1500 watts (1500 watts * 5 hrs per day of useful sunlight * 30 days * 90% DC to AC conversion factor ~ 202kWh).

So I doubt you could get that much wattage from 4 panels. You will need more wattage along with more sunlight hours on average per day to generate 200kWh per month.

The spots for Phase I are southern facing and get about 6 hours of direct sunlight in summer and about 4.5 direct in winter (numbers also backed up by a solar calculator for my area). They will be south facing, with no shadows or obstructions most of the days and angled at about 25% due to the 6/12 roof pitch on the house. Phase II panels would have less ideal sunlight as they would be Southeast and Southwest facing as well as only being directly exposed a 3-4 hours a day (I havent watched but I would guess 4 hours of direct sunlight). Phase II may never happen, or if it does, it will be when equipment costs less than Phase I. I fully expect Phase II to have much less production, which is why it is phase II.

In order to maximize the output, I am considering high wattage XL panels (300+ watts/panel with appropriate microinverters), assuming the $/watt isnt significantly higher on the panels. I am also not ready to pull the trigger for a year or two at minimum, so I am assuming the $/watt of panels will continue to go down in a year or two.

All of this won't go forward if I have to purchase a special net metering plan that is 30% more expensive just to have the privilege of having solar panels on my house.

Thanks,
-C

[SunEagle]

The spots for Phase I are southern facing and get about 6 hours of direct sunlight in summer and about 4.5 direct in winter (numbers also backed up by a solar calculator for my area). They will be south facing, with no shadows or obstructions most of the days and angled at about 25% due to the 6/12 roof pitch on the house. Phase II panels would have less ideal sunlight as they would be Southeast and Southwest facing as well as only being directly exposed a 3-4 hours a day (I havent watched but I would guess 4 hours of direct sunlight). Phase II may never happen, or if it does, it will be when equipment costs less than Phase I. I fully expect Phase II to have much less production, which is why it is phase II.

In order to maximize the output, I am considering high wattage XL panels (300+ watts/panel with appropriate microinverters), assuming the $/watt isnt significantly higher on the panels. I am also not ready to pull the trigger for a year or two at minimum, so I am assuming the $/watt of panels will continue to go down in a year or two.

All of this won't go forward if I have to purchase a special net metering plan that is 30% more expensive just to have the privilege of having solar panels on my house.

Thanks,
-C

You may be able to install equipment like ButchDeal stated that will keep you from back feeding into the grid but again you may still be required to get the proper permits and approval to install that equipment.

To keep you from getting in trouble or fined by your POCO I would be real sure about finding out first what you can install and what you can't.

Last bit of info. You are wise not to jump into solar without first understanding what you may be getting into. A 1500 watt system may generate that 200kWh on average per month. But depending on what you actually pay for each kWh it might take you a decade for that solar pv system to pay for itself.

[Sunking]

You are in TX, and TX does not have Net Metering Laws except on the Left Coast Island of Austin. Suprised no one has told you that yet. What that means no provider, (Oncor is not a Provider) will pay you retail for excess generation. You will buy at Retail and sell for Wholesale.

Where I Iived in TX, Dallas metro area, only Green Mountain Energy offered Grid tied services. You buy at roughly 13-cents and sell for 7 cents. Or if you just have regular electric service you can get a 3-year locked contract for 7 to 8-cents per Kwh for the first 2500 Kwh in a month , then it drops to 6 to 7 cents over the first 2500 Kwh. The more you use, the cheaper it gets. So basically the POCO buys from you at 7-cents, and sell it to your neighbor for 8-cents making a profit.

They will say thank you each month when they send you your bill. So if you are looking for a rate increase, solar is the way to go in TX. Only exception is the Left Coast Island of Austin where even your neighbors have to pay 11 to 13 cents. Someone has to pay for free electricity. Austin's only electric service provider is Austin Energy and completely controlled by Austin City goberment a bunch of pot smoking Lefty's.

Lastly if you do this, get a chain saw. FWIW 200 Kwh in TX cost $14, and in Austin $26. That is how we roll in TX. Well they roll something different in Austin.

[ButchDeal]

In order to maximize the output, I am considering high wattage XL panels (300+ watts/panel with appropriate microinverters), assuming the $/watt isnt significantly higher on the panels. I am also not ready to pull the trigger for a year or two at minimum, so I am assuming the $/watt of panels will continue to go down in a year or two.
-C

XL often means 72 cell modules which are usually less efficient. You want high effcient 60 or 96 cell (96 cell modules use small cells 72 cell modules use cells the same size as 60 cell modules but less efficient). The $/W is usually higher on high effciency modules and micros will often limit the output. you would be better off with SolarEdge but thats your choice there.

[bcroe]

Seems like a 72 cell panel putting out 300W is just as efficient with sunlight as a 60 cell panel
putting out 250W. The larger loses less area to the outer framing, but I find 72 cell a lot harder
to manage physically. Bruce Roe

[J.P.M.]

The spots for Phase I are southern facing and get about 6 hours of direct sunlight in summer and about 4.5 direct in winter (numbers also backed up by a solar calculator for my area). They will be south facing, with no shadows or obstructions most of the days and angled at about 25% due to the 6/12 roof pitch on the house. Phase II panels would have less ideal sunlight as they would be Southeast and Southwest facing as well as only being directly exposed a 3-4 hours a day (I havent watched but I would guess 4 hours of direct sunlight). Phase II may never happen, or if it does, it will be when equipment costs less than Phase I. I fully expect Phase II to have much less production, which is why it is phase II.

In order to maximize the output, I am considering high wattage XL panels (300+ watts/panel with appropriate microinverters), assuming the $/watt isnt significantly higher on the panels. I am also not ready to pull the trigger for a year or two at minimum, so I am assuming the $/watt of panels will continue to go down in a year or two.

All of this won't go forward if I have to purchase a special net metering plan that is 30% more expensive just to have the privilege of having solar panels on my house.

Thanks,
-C

Do yourself a favor, invest $ 20 or so and get a copy of "Solar Power Your Home for Dummies". You'll gain a lot of what seems like needed knowledge from it. You'll probably get several orders of magnitude return on the $20 invested from the savings you'll realize from avoided mistakes alone.