Solar Living Mindset

[RainbowKraut]

So as I’m learning exactly how much I don’t know about solar, a question has crossed my mind. Do I need to change my “philosophy” about power usage in my home?

I’ve been concerned about the relatively low levels of “pass through” power in most of the hybrid grid-tie inverters (with the exception of SolArk). This concerns me because I have a large house with a 400 amp service (two 200 amp panels). Currently (no pun intended) I can, without reservation, turn on anything in my house at any time without regard to what else might be on and/or running, including 25.9kW in emergency strip heat should my heat pump fail. Granted, the likelihood of my needing 400 amps of power all at once is very small, but it is there should I need it.

I’m working on trying to understand the amount of power I truly need on a daily basis, and with the help of others on this forum, I’m zeroing in on a number, possibly in the 17,000 watt array size. But I’m still uncertain about the amount of pass through power I should have. And perhaps I need to educate myself on exactly how much power is truly being used at any one time. If that number is in the range of the pass through capacity of the inverters (30-50 amps for most), then I could stop “worrying” about having 400 amps available. Can I get by without 400 amps of pass through power?

That is where my philosophy question comes in. Have you (anyone who reads this) had to adjust your power use habits in order to live on solar? In my RV, I do that, based on what size service is available (30A versus 50A). Just have to remember what can be turned on at the same time, and when to use devices/appliances. Is that the normal condition of operation in a solar powered home?



Thanks for your input.

 

[OffGridInTheCity]

I'm off-grid with grid-assist. Originally, I was interested in powering my (larger) home 100%. I'm up to 48 panels (13.7kw) PV. This gives me enough power to maintain comfortable living 8 months of the year if I had to. THE ISSUE for me is dead winter.

In Dec/Jan I only get 25% of what I get in summer due to seasonal clouds and short solar days. This 25% is just not enough for heat - even to maintain a cool 50F in the house. I would need at least 2x or 3x bigger array = 28kw to 40kw PV array to cover these months.

In conclusion - 8 months of the year I can maintain the home and solar is totally a good solution. However, the winter 4 months and the 2 core months in particular are not good - one needs either a *huge* array or alternate power choices for heat.

Winter is the cold (ha ha) reality that's been hard for me to accept. I've chosen kerosene and propane as my backups for winter (heat) but this means I cannot be off-grid long term without renewing these carbon fuels. I also bought 40 used panels that I store under the house for emergency back yard deployment in a catastrophic long term grid outage but while it will help it's still not enough to have normal comfort in Dec/Jan.

 

[Rednecktek]

Do I need to change my “philosophy” about power usage in my home?

YES!!!

That is where my philosophy question comes in. Have you (anyone who reads this) had to adjust your power use habits in order to live on solar? In my RV, I do that, based on what size service is available (30A versus 50A). Just have to remember what can be turned on at the same time, and when to use devices/appliances. Is that the normal condition of operation in a solar powered home?

I have to do the same thing at my camp even now that I have the larger generator. When I first bought the place and started restoring it I had a small inverter generator that topped out at 13.3a from the outlet. I had to spend a couple days doing as detailed a power audit as I could so I could figure out the exact size AirCon unit I could power without tripping the breaker. I got it to 13.26a load. However, I had to be VERY careful what order I turned things on to not overload the generator.

Once you go to solar you're going to have to do 1 of 2 things, either learn how to account for usage and always be calculating in the back of your head how much power you're using and if you have enough overhead for motor surges and the like...

Or spend $$StupidMoneys on a system so large that you'll never be able to overload it like you do now.

So, unless your name is Musk or Bezos then option 2 isn't so likely.

So yeah, learning about the limitations of your system and surge loads and weather patterns and the like will start to become second nature, and it'll happen quickly the more times you have to go to your utility room to reset something because you didn't take it into account.

Much like any other environment change, it's just a matter of learning what you can and can't do. I wouldn't have nearly as large of a banana hammock collection if I moved to Saskatchewan from Fiji.

 

[Mattb4]

Some folks want to be able to power any and all house loads without need to think about like they get from the grid. Others may be happy going for an absolute minimum of electric power for very basic needs. It depends on what you and your finances are willing to live with.

Also now that off grid AIO's exist that allow you to have both grid when needed or PV/battery, when available, have changed the approach. For instance I am setup with PV to power part of my house loads but have grid as fallback and also there for heavy intermittent loads. Using transfer switches I can select and choose. But I have an advantage a person with spouse and family does not have. It is just me.

 

[12VoltInstalls]

Have you (anyone who reads this) had to adjust your power use habits in order to live on solar?

That’s probably the first logical step.

From your description, the second logical step and one that is likely to be SIGNIFICANTLY less costly and primarily more practical is to establish a form of backup heating that is not electric resistance heating. Like propane, natural gas, or heating oil. Stored propane lasts forever and is also useful to power a backup generator to mitigate a true disaster’s ability to freeze your pipes and destroy the house.

 

[jtvt]

IIRC, a 200a service isn't really a 200a service. Google says it's 160 continuous amps. So take that into consideration.

But yeah, if you want to live off grid the first thing you do is conserve. If you have no idea on the amount of power you are using, you won't be able to properly design a system. In terms of living, off grid people look for sunny days to do laundry or vacuum. They are always monitoring usage and production in order to see if something is not working right. They are always shopping for non phantom load devices and low energy usage appliances. They wire their houses so that TVs, toasters, etc have switched power. They make sure the dish washer, washing machine, dryer, and vacuum are not all on at the same time.

 

[v_green57]

Size your life to your solar.

Not the other way around.

Other benefits (living small and simple) will follow.

 

[Nobodybusiness]

So as I’m learning exactly how much I don’t know about solar, a question has crossed my mind. Do I need to change my “philosophy” about power usage in my home?

I’ve been concerned about the relatively low levels of “pass through” power in most of the hybrid grid-tie inverters (with the exception of SolArk). This concerns me because I have a large house with a 400 amp service (two 200 amp panels). Currently (no pun intended) I can, without reservation, turn on anything in my house at any time without regard to what else might be on and/or running, including 25.9kW in emergency strip heat should my heat pump fail. Granted, the likelihood of my needing 400 amps of power all at once is very small, but it is there should I need it.

I’m working on trying to understand the amount of power I truly need on a daily basis, and with the help of others on this forum, I’m zeroing in on a number, possibly in the 17,000 watt array size. But I’m still uncertain about the amount of pass through power I should have. And perhaps I need to educate myself on exactly how much power is truly being used at any one time. If that number is in the range of the pass through capacity of the inverters (30-50 amps for most), then I could stop “worrying” about having 400 amps available. Can I get by without 400 amps of pass through power?

That is where my philosophy question comes in. Have you (anyone who reads this) had to adjust your power use habits in order to live on solar? In my RV, I do that, based on what size service is available (30A versus 50A). Just have to remember what can be turned on at the same time, and when to use devices/appliances. Is that the normal condition of operation in a solar powered home?



Thanks for your input.

If you get something like the Emporia Monitor you can get an idea of your peak usage and total usage broken all the way down to individual circuits if you want.

That will give you a baseline to determine size.

You can build your system to support as big as you want. It only cost money right? ?

Most try to conserve as much prior so they don’t end up over sizing their system.

Having said that you also have to account for winter time.
My system is designed for winter time and way over produces in the summer.

First thing Inwould do is figure out what you use.
Peak draw in amps, how much you plan to run of your house.

Then you can start looking around at what fills the bill.

Also have to consider if you want this system Permitted or not.

 

[rpdom]

I've made small changes. I only have a small system (3 kWp). Things like getting lower power electric kettles (1kW and 2kW instead of 3kW), so my inverter can supply the whole load even when running on battery rather than topping up from the grid.

Have electric showers during the day instead of early morning/late evening. Much still comes from grid, but the inverter supplies a fair chunk of it.

Put clothes on to wash during the day when its very sunny, or overnight on cheap rate on cloudy days.

Use small electric heaters to assist the gas heating on cold sunny days.

 

[BartHenry]

even before we went solar, I changed all the light bulbs to LED, always shut off lights in rooms as we leave them. was also mindful of using big appliances as little as possible.

 

[Steve_S]

You really do need to look at your ACTUAL Power Usage and depending on your Grid Power provider, you should be able to look at your billing history and work out how much per day in kilowatt hours you are using. Key months to look at are December, January & February and July, August & September because those are generally the highest usage months.

Next, grab a notepad and check your appliances and devices and note the older items and those which you know that are not efficient, are they replaceable or upgradeable ? Also look at your Well Pump and other devices like Air Conditioning and see if they can be retrofitted to use Soft-Start modules to reduce the Demand Surges that hit a solar system (also a nasty waste of energy in a spike).

The FIRST Simple Rule is that Conservation is far cheaper than Generation & Storage. That Fridge & Freezer you inherited from Grandma may work well but they are power hogs that should be replaced.

400A X 240VAC = 96,000 Watts ! That would require 8x 12,000W Inverters to reach that maximum capacity.

Note that Resistive Devices are the Absolute Worst for any battery-based system. Electric Water Tanks, Baseboard heating and such are extremely inefficient and must be looked at. There are many alternatives and more coming (almost daily it seems) that are far more efficient and quite solar friendly.

BTW: I am 100% Offgrid with powerlines more than 1km & $75K away. I'm in the deep North, near Algonquin Park, Ontario Canada.

 

[Quattrohead]

Yes grab yourself one or two emporia systems and install them, they are absolutely fantastic for tracking your power use short and long-term. What area of I assume the USA are you in and do you really need those heat strips, as you already have a heat pump. Maybe you have an old fashioned water tank that can be replaced with a hybrid unit that will consume around 70% less electricity for example. Also look at your insulation and gaps around doors and windows. Yes there is absolutely a lot you can do to reduce your power consumption if you are a little mindful but you don't want to piss off the family haha.

 

[Johneb]

I second Quattroheads recommendation. Conservation first solar second. I put a micro aire easy start on our heat pump, leds throughout the house. LEDs for garage is coming. New doors for house as ours are in need of serious help. I am looking at on demand a whole house on demand hot water heater with point of use water heaters for those sinks that are farther away from the water heater. Then once I have all that in I can work on solar.I am probably going to max out the roof of our manufactured home with solar anyway so as to block the south facing roof from solar heating our home. Sell back what’s not used, and enjoy zero power bills. Do a whole house audit and see where you can cut down on power with higher efficiency items. Then consider running your house cooler at night and daytime. Dress for going outdoors and you can use less heat in your home.

 

[mib]

I use sonoff pow, this is an electricity meter controlled from the phone, there is also tuya, these are the ones that I know, but they are 220 volts, maybe there is something like that under 110 volts

this will allow you to make an energy audit of all devices

we still have very cheap electricity $ 0.042 per kilowatt, but I constantly analyze my consumption

I think you with a higher price it would be even more useful

 

[Brett V]

You'll have to do some things differently but it soon becomes second nature. For some it's easy, and some it's a struggle. Using my home as an example, I grew up very poor and my dad constantly enforced things like not letting the hot water run needlessly and not standing there with the refrigerator door open. My wife on the other hand, grew up in a parsonage so she never even realized utilities were something you have to pay for. I'll admit only limited success over the past 30 years at retraining her, but have made some progress recently with only a 6k Growatt. After a few times overloading the thing and putting the house in to the dark, she finally started to remember she can't turn on the microwave if I have both heat pump mini splits going. Or turn off the window unit AC in the bedroom while she's using the hairdryer. Small victories.

 

[RainbowKraut]

Thanks everyone for the suggestions.

I have made some upgrades, LED's in most all lights. New freezer. Need to get rid of that old fridge in the garage that came from Gramma. The strip heat almost never comes on. Only on rare occasions when it gets cold (<20F) and the heat pump goes into defrost. Or about a year ago the condenser fan failed. That is the only time the strip heat activates. But, I have a wood stove, with a return air grille right above it, that can keep the house warm most of the winter, just using the fan in the air handler to circulate. I also pre-heat my hot water through the wood stove and store that in a tank that feeds the regular electric hot water heater - which I could look at replacing with a more efficient heat pump model water heater.

I don't plan on being able to fully replace the 400 amps with solar. I know there will be times that I'll need the grid, or my generator. I have 4 years worth of monthly usage from my utility, and I'm trying to design a system that will cover that demand. That part is easy. The challenge is finding a grid tie solution where I can sell power back to the utility, have the solar still function when the grid is down, and be able to use the generator to help the solar when the grid is down or to be the only source of power at night when the grid is down. I don't want a huge bank of batteries.

Again, Thanks for the encouragement. This whole process is a bit daunting.

 

[12VoltInstalls]

solution where I can sell power back to the utility, have the solar still function when the grid is down, and be able to use the generator to help the solar when the grid is down or to be the only source of power at night when the grid is down. I don't want a huge bank of batteries.

That almost certainly means top-shelf brands. The battery bank for at least 18 hours of demand just makes sense from a usability perspective, though.