Do you have enough solar to go off grid in winter?

[zƬesla]

@wwu123 The in/out pipes for the SuperStor can be seen to the front left of the unit in the photo.

and I was suggesting using the HP water heater as a pre-heater

cold supply in -- HP WH -- SuperStor water tank -- faucet

So that's the option where the boiler gets removed from potable altogether. My main concern with that is if the HPWH would not be able to keep up in extreme cold. The nice option of the oil fallback is that it uses little electricity if there's an outage allowing us to live-in comfortably for days.

Here's the temp close to basement ceiling for this past week. This is measured close to the boiler:

 

[zƬesla]

@zƬesla heat pump dryers are closed loop; that is the air gets recirculated inside, so I can't imagine why someone thinks a damper on a boiler is an issue. Depending on your laundry needs, one heat pump dryer may be problematic just from the 120-180 minute cycle times. I.e. They work well for one or two loads of laundry a day, and work best with a front loading HE washer on high speed spin to spin out as much water as possible.

The new ones seem to be faster. I do have a HE front-load washer.

 

[DrSmile]

We'd have enough... if we rode electric bikes instead of Teslas. My electric bike is 25x more efficient per mile in the Summer and 40x more efficient in the Winter than the model 3. Cycling in the middle of Winter isn't really plausible, but it does feel great recharging only 150 watt hours after my daily commute.

 

[zƬesla]

Thanks to @BGbreeder @wwu123 et al for suggestions on a heating solution, and sorry all for temporarily hijacking the thread. I would very much like to go off grid in winter but it's just not realistic where I'm at especially if I end up adding to the load with a HWHP. I'm already cringing as we used 90kWh yesterday, probably 85% of which was the mini-splits.

The good news is that I use a lot less oil than I used to and have seen my overall energy expenses go down by over a half.

 

[DrGriz]

Thanks to @BGbreeder @wwu123 et al for suggestions on a heating solution, and sorry all for temporarily hijacking the thread. I would very much like to go off grid in winter but it's just not realistic where I'm at especially if I end up adding to the load with a HWHP. I'm already cringing as we used 90kWh yesterday, probably 85% of which was the mini-splits.

The good news is that I use a lot less oil than I used to and have seen my overall energy expenses go down by over a half.

I feel your pain!

 

[PatrickCH4313]

Not really, I still need some kWh from the grid every month (12.0 kW PV size)!

So I bought 3'442 kWh from the grid in 2021.
I produced 11'000 kWh in 2021 and sold 5'500 kWh to the grid.
So I used 5'500 kWh from my PV System for my needs (electricity, heat Pump / HP Boiler and charging 2 EV).

 

[nwdiver]

Just installed the first array I've done exclusively to maximize winter production. No net-metering here. One interesting 'quirk' is that flat is better for cloudy weather. So the winter array does better when sunny but the summer array does better when it's cloudy even in the winter.

 

[jboy210]

Just installed the first array I've done exclusively to maximize winter production. No net-metering here. One interesting 'quirk' is that flat is better for cloudy weather. So the winter array does better when sunny but the summer array does better when it's cloudy even in the winter.

View attachment 878238

Looks nice. Did the owner considering making it tiltable to get better production in summer?

 

[nwdiver]

Looks nice. Did the owner considering making it tiltable to get better production in summer?

No. They don't really need more production in the summer. Their current array is oriented 270 degrees west so it's great in the summer but terrible in the winter.

 

[Pricedm]

My parents had a passive solar house built 25 years ago, key to the low energy use. By today’s building standards, certainly could have a tighter thermal envelope. No battery storage at this point, but hopefully will change in 2023-24. This would allow taking the house off electrical grid. Plan A is to transition the garage/greenhouse (separate meter) to off grid first. October average generation was daily net positive 4.6kWh. Last week November was daily net positive 1.0 kWh, so definitely see the impact of shorter daylight hours. House is at 6,800 FT elevation in SW Colorado semi-desert region.

 

[aimetti]

26k system i generate around 13kw a day , so ya its not great.

 

[nwdiver]

26k system i generate around 13kw a day , so ya its not great.

What region and what's the orientation of your array?

 

[dhrivnak]

26k system i generate around 13kw a day , so ya its not great.

That sounds crazy low. I have 9.5kW and I am currently averaging 30.3kWh/day. And in NE Tennessee we are not noted for our sun.

 

[ucmndd]

26k system i generate around 13kw a day , so ya its not great.

26 kilowatts or $26,000?

 

[h2ofun]

26k system i generate around 13kw a day , so ya its not great.

I have a 30kw system and am doing about 35kwh per day

 

[aimetti]

Hey guys , don’t wanna thread jack but I have another threat for some specifics if you want to take a look.

26k - low output

 

[zƬesla]

Just installed the first array I've done exclusively to maximize winter production. No net-metering here. One interesting 'quirk' is that flat is better for cloudy weather. So the winter array does better when sunny but the summer array does better when it's cloudy even in the winter.

Interesting. Wonder if I should have one of my 3 poles tilted more horizontal. They're all at 66° now and will be at 70° soon. It's a 17.5kW array with 14.4kW in inverter capacity. Last full sun day was a week ago and generated 44kWh with most of the morning in shade. Plenty of cloudy days around here.

 

[Lloyd]

I live in CA and have been off grid now since October without interruptions. Winter is no problem. I have 14 kw solar and 4 powerwalls. House is 4200 feet, 3 ac units, 2 EV's electric dryer, electric oven and stove. rest is propane. I'm waiting for Tesla to improve the powerwall software before I cut the cord.

The biggest drain is the car charging. The newer Tesla's manage the charging pretty well limiting the charging to a set limit of the powerwalls state of charge. I wish the cars stayed awake when this is activated and polled the powerwalls to start charging when the state of charge is reached to allow charging is achieved. As it is now, you have to wake the car to activate charging. The car should then allow a full sleep once the car is fully charged.

Update: With multiple rainy days and overcast, there is NOT enough to run the house with normal use, let alone the cars.

 

[h2ofun]

Update: With multiple rainy days and overcast, there is NOT enough to run the house with normal use, let alone the cars.

This time of the year, I am not even close to producing vs using. Most folks never see since they have gas heating.
In the summer my usage is just the opposite, I send TONS back to PGE

 

[iPlug]

Here in NorCal this is the beginning of our rainy season so not just reduced solar radiance but often heavy cloud cover like the storms coming through now and recently. Most locations in the world get more of their rain in the summer whereas we rarely get a drop then.

Here is our all electric house/personal transportation data with PV solar (2 BEVs, ducted air-source heat pump, heat pump water heater, induction cooktop, electric oven/clothes dryer, etc). If we still had NG for home air and water heating and ICE vehicles, these demand numbers would be a small fraction or net to grid many days.