Building a new home around a solar system

[MapleGuy]

Hi...My wife and I sold our house a couple of years ago and have been living in an RV. We are looking to build a 900 sq ft living space over a 900 sq ft garage space in Connecticut and my specific goal is to not have an electric bill and be able to generate all the power that we need from solar. Our RV has a solar setup with battery backup so I am used to the basics and would like to apply what I've learned from this time. However, I'm finding that it's not that easy and little more complicated connecting to the grid like I in the RV and here are my questions for anyone who might be able to answer them.

1. Can I have an off-grid system that only uses power that I generate but still be connected to the grid for times when I can't supply all the power I need? I'd like to try and replicate what we have in the RV but would be nice to take advantage of net metering if we are on the road.
2. How can I find a certified local installer that I can work with and also work with my local utility for all the paperwork that they require? I'd like to try and buy/add components as I can afford them (aka pay cash) without having to re-do everything. From what I've read it needs to be done by a certified installer.

I'm currently making a list of everything in the new house that will use electricity to get an idea of what kind of load I'm looking at. We are also looking at the most energy efficient models for heating/cooling, stoves, washers, dryers, etc. to reduce our needs there. So far I'm looking at about a 100 amp draw on a daily basis (if my numbers are correct). I was planning on starting with 2 100 amp batteries and having a EG4 6000 watt inverter to handle the house power, drawing from the batteries. To charge the batteries I would have 4Kw solar array. Based on what I know with RV life, that should be able to charge the batteries in a few hours so even on the shortest daylight days I'd be able to charge my batteries.

I know I've said a lot here so I'll leave it at that. Am I on the right track with my thinking our should I with the more expensive find a solar installer that does a package deal?

 

[sunshine_eggo]

Hi...My wife and I sold our house a couple of years ago and have been living in an RV. We are looking to build a 900 sq ft living space over a 900 sq ft garage space in Connecticut and my specific goal is to not have an electric bill and be able to generate all the power that we need from solar. Our RV has a solar setup with battery backup so I am used to the basics and would like to apply what I've learned from this time. However, I'm finding that it's not that easy and little more complicated connecting to the grid like I in the RV and here are my questions for anyone who might be able to answer them.

1. Can I have an off-grid system that only uses power that I generate but still be connected to the grid for times when I can't supply all the power I need? I'd like to try and replicate what we have in the RV but would be nice to take advantage of net metering if we are on the road.

Yes. An inverter/charger connected to the grid on its input can fail over to grid to charge batteries and power loads when battery/PV is inadequate.

1. How can I find a certified local installer that I can work with and also work with my local utility for all the paperwork that they require? I'd like to try and buy/add components as I can afford them (aka pay cash) without having to re-do everything. From what I've read it needs to be done by a certified installer.

You need to look at solar permitting for your city/county/state. The requirements are usually pretty straightforward and require some level of compliance with the National Electric ode (NEC). If you can do all the planning and equipment identification, you may not need anything more than a certified electrician to fill in the code compliance blanks.

If you're not looking for grid-tie, there should be little to no utility involvement in the process.

 

[John Frum]

I'd like to try and replicate what we have in the RV but would be nice to take advantage of net metering if we are on the road.

Net metering is not the only option and the red tape may be a PITA.
As @sunshine_eggo mentioned you could just have your inverter/charger fall back to ac bypass when the batteries hit a pre-determined voltage.

How about using the grid as a power source for the first year.
Use something like this

Vue Energy Monitors - Emporia: Revolutionizing Home Energy

Turn insights into savings. Connect an Emporia Vue Energy Monitor directly to your circuits to automate, manage, and control your home’s energy.

www.emporiaenergy.com

to get a really good idea of your consumption
Then design the solar system to meet your needs.

 

[MapleGuy]

Yes. An inverter/charger connected to the grid on its input can fail over to grid to charge batteries and power loads when battery/PV is inadequate.



You need to look at solar permitting for your city/county/state. The requirements are usually pretty straightforward and require some level of compliance with the National Electric ode (NEC). If you can do all the planning and equipment identification, you may not need anything more than a certified electrician to fill in the code compliance blanks.

If you're not looking for grid-tie, there should be little to no utility involvement in the process.

Net metering is not the only option and the red tape may be a PITA.
As @sunshine_eggo mentioned you could just have your inverter/charger fall back to ac bypass when the batteries hit a pre-determined voltage.

How about using the grid as a power source for the first year.
Use something like this

Vue Energy Monitors - Emporia: Revolutionizing Home Energy

Turn insights into savings. Connect an Emporia Vue Energy Monitor directly to your circuits to automate, manage, and control your home’s energy.

www.emporiaenergy.com

to get a really good idea of your consumption
Then design the solar system to meet your needs.

Thanks for the quick replies. I guess I could look at an option where I'm connected to the grid as a backup and not consider net metering to at least reduce some of the red tape/costs with the utility.

In terms of waiting a year to size the system, of course that's an option but we are building from ground up and I don't want to try and retro fit something. I'd rather have the framework in place and add solar panels or batteries if need by. The 6000 watt inverter I mentioned above is about 2x bigger than we need but I like the flexibility.

Our contractor is pretty flexible. I'm going to see if his electrician is certified for solar installs and if they could install the equipment that I'm looking at along with whatever else he needs.

One other question I thought of was in terms of solar panels, do they all have the same connectors or are they different based on manufacturer? I'm wondering if I can buy the components as I have cash but it might mean mixing different models and I don't know if that's OK or a bad thing.

 

[sunshine_eggo]

One other question I thought of was in terms of solar panels, do they all have the same connectors or are they different based on manufacturer? I'm wondering if I can buy the components as I have cash but it might mean mixing different models and I don't know if that's OK or a bad thing.

Vast majority use MC4 connectors. Very useful for connecting panels in strings. it's often easier to cut the last MC4 off when you go to connect to a combiner box and/or MPPT input UNLESS the unit happens to have MC4 input.

 

[Rednecktek]

Since you're in the very rare situation of planning the house around the solar, also noodle out some ideas on where to physically PUT all the panels and batteries and such.

Do you want a ground mount? Are you going to roof mount? What kind of roof? How will you get the snow and dirt off the panels? Can you build a walkway or something to get access to the panels? How will the wires run into the controller space? Will your controller space be climate controlled or will the batteries freeze in winter?

There is a lot of math and planning involved in a solar system, but many times the physics are forgotten about and can end up being kludged together in a sub optimal arrangement.

Just more to think about. Sorry.

 

[MapleGuy]

Since you're in the very rare situation of planning the house around the solar, also noodle out some ideas on where to physically PUT all the panels and batteries and such.

Do you want a ground mount? Are you going to roof mount? What kind of roof? How will you get the snow and dirt off the panels? Can you build a walkway or something to get access to the panels? How will the wires run into the controller space? Will your controller space be climate controlled or will the batteries freeze in winter?

There is a lot of math and planning involved in a solar system, but many times the physics are forgotten about and can end up being kludged together in a sub optimal arrangement.

Just more to think about. Sorry.

Yes, I'm planning on a ground mount system. I plan to put the array on the furthest northern edge of the clearing for the house so it will have the best exposure to the south. We are planning on having a utility closet where the water tank (we'll be on a well) and electric panel will be. That's where I plan on putting the inverter and batteries along with the IT components (modem, router, networking switch, storage). It will be ventilated but I do have to look into how much heat the inverter generates.

I appreciate having other things to consider...I have four months before construction begins!

 

[sunshine_eggo]

YAY GROUND MOUNT!

 

[400bird]

Are you physical building the house? Are you comfortable doing the electrical work?
It depends on your AHJ (city?) as far as requirements to build solar.

I was able to install my inverters, solar panels, battery, new main and sub panels, all on an owner builder permit.

I'd recommend starting with the city and asking about permitting requirements.

You'll run into two issues.
Many of import inverters aren't UL listed and can't be used.
Even fewer of the rack mount batteries are UL listed.
Neither will make it through the permitting process depending on your region.

Also, adding more slowly at a time can be difficult if you need it to pass inspection, as each additional batch of components would require permitting and inspections.
If that is a requirement, you might be best off to follow John Frum's advice, and spend a year both saving up and monitoring energy use to know more about your requirements in the new place.