Apparently Enphase now has microinverters and a load balancer that can continue to power the home in a grid power outage without batteries. Obviously not at night, but provides power during the day.
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Do you have enough solar to go off grid in winter?
- Thread starter getakey
- Start date
bkp_duke
Well-Known Member
If you can, charge from solar directly. When you are charging from the powerwalls, you are giving up 10% in losses to the AC/DC/AC roundtrip conversion to/from the powerwalls.
charlesj
Active Member
Seeing your picture, I would think the helicopter transported batteries would have to shed the load over your property, not wait for that truck.
SageBrush
REJECT Fascism
I was just mulling over how much ice is needed to coast through the night.
On a typical day my fridge/freezer consumes about 1 kWh, so about 0.5 kWh of ice is needed for the night
That would be ~ 1700 btu.
It takes 144 btu to thaw one pound of ice, so the answer is about 12 lbs
It sounds like a home with PV power while the grid is down can protect the fridge contents from spoiling.
On a typical day my fridge/freezer consumes about 1 kWh, so about 0.5 kWh of ice is needed for the night
That would be ~ 1700 btu.
It takes 144 btu to thaw one pound of ice, so the answer is about 12 lbs
It sounds like a home with PV power while the grid is down can protect the fridge contents from spoiling.
Congratulations, you have a pretty efficient refrigerator, those numbers are amongst the best energy star rated refrigerators tested by the DOE, for a refrigerator in the 18-24cu.ft. range.
If you look around, there are more efficient refrigerators than the standard brands, but they usually have less room inside due to increased insulation thickness, though I know of one with vacuum insulated panels. The most efficient setup that I have seen was an Australian one that was a chest freezer with a little PID temperature controller to keep the temperature around 35-40F. Daily usage was well around 140 watt hours, IIRC. Similar hack here, admittedly for a tiny fridge, managed 50Wh/day for a 3.5cu.ft/100L fridge.
All the best,
BG
dhrivnak
Active Member
No, at least not in NE Tennessee. Thanks to net metering I typically head into winter with 1400-1700kWh surplus generated mainly in the spring and fall. And I frequently use it all by March.
jgleigh
Member
Are your panels only about 100W each? You'd probably see a bigger benefit with newer 300-400W panels over adding more batteries.
SageBrush
REJECT Fascism
SageBrush
REJECT Fascism
Yep. When I buy an appliance I set energy efficiency as a high priority. This particular Westinghouse was the most efficient available at the time. It is actually EPA rated 304 kWh annually, but I have monitored daily consumption at 0.7 kWh in the winter and up to 1.5 kWh a day in the summer.
Addendum: A Mod removed useful information because it also had a comment about the interval trump years. I wrote that the same model is now rated 350 - 400 kWh a year, I presume a reflection of manufacturer cost cutting and less emphasis on energy efficiency.
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When we installed our PWs I had a freezer next to it (they were the first PWs installed in Idaho). My installer took a picture and sent it to Tesla, with the (true) note that they were installed to preserve my freezer full of precious elk meat. AFAIK, however, Tesla never used it. Alas...
That said, that freezer runs totally on PV/PW.
The load balancer is basically Enphase's gateway for their ESS, can be installed without batteries. A friend is getting solar quotes, particularly with microinverters due to tree shading - the additional quote to support this grid-down scenario was $13K on top of the solar panels/micros, that's without any batteries.
Though it sounds like $25-30K is typical for third-party installers for a gateway and two batteries, so subtract the price of two Powerwalls or other ESS and $13K is typical around here for equipment plus install of a gateway, backup subpanel, and migration of critical loads.
Installing the gateway by itself is just not a wise investment really. Installers don't want to do it and it makes no sense to me and that friend quote was inflated so they don't have to do it. I assume it's that high because Enphase almost always requires you to have a loads panel so pulling all the wiring for that sub-panel is a LOT of work for an installer. Having gone through it myself, if I was the installer (my installer had to pull tons of wiring from the 2nd floor), I'd jack up the price too honestly. Panels/solar can be done in a day, pulling wiring through attics/walls can take multiple days where they aren't using those days to do other easy jobs.
Even without SGIP, 2x batteries after the tax credit is around $18.5k (assuming $25k quote). No reason to pay $13k for just a gateway with no storage. Just a waste of time/money. If someone gets SGIP, that makes it less than $15k which is a no brainer compared to this $13k (which could be $9.62k with tax credit).
For folks considering more flexibility, I'd still suggest getting more $$ or refi/cash out or get some other loan, but set it up correctly instead of doing it piecemeal (which other installers don't want to deal with later). Going off-grid can't be expected to be cheap.
doghousePVD
My grandfather’s car
I live off grid on an island in Maine. 15 kw ground mounted panels, 100 kwh batteries (not Tesla, installed before before Tesla was available).
Passivhaus, all heat passive solar and firewood, no propane or generator. Sophisticated hot water system from combination of heat pump, wood stove circulation, and electric resistance, runs dishwasher easily. "Smart house" (Homeseer) controls electric loads by priority. Induction cooking, Starlink communications. Energy "splurge" in summer includes hot tub (sunny days only). The Tesla is on the mainland, so no EV charging.
It can be done, but definitely is not a simple plug and play nor cheap. Not much sunlight in foggy, dark December, and have to scrape snow off the panels.
Proselytizers claiming easy off-grid are lying or incredibly uneducated, probably both.
Passivhaus, all heat passive solar and firewood, no propane or generator. Sophisticated hot water system from combination of heat pump, wood stove circulation, and electric resistance, runs dishwasher easily. "Smart house" (Homeseer) controls electric loads by priority. Induction cooking, Starlink communications. Energy "splurge" in summer includes hot tub (sunny days only). The Tesla is on the mainland, so no EV charging.
It can be done, but definitely is not a simple plug and play nor cheap. Not much sunlight in foggy, dark December, and have to scrape snow off the panels.
Proselytizers claiming easy off-grid are lying or incredibly uneducated, probably both.
skepticcyclist
Member
No one here is saying it is easy. The question was do we generate enough to go off grid in the winter and the answer is yes for some of us, myself included.
There are many variables for some of us, including myself, that are much different than for yourself (climate, latitude, and resources being three huge ones.) I have gas for all appliances. I live in SoCal which has much milder climate (very little heating is needed), many more sunny days in the winter, and much longer winter days with a higher sun angle than that of Maine (which is further north than southern Canadian border). As I showed in previous posts that even with my current setup, it is possible for me as long was we do not have a lot of rainy days in a row. It will not be easy by any means.
CrazyRabbit
Active Member
I have 56 panels installed with emphases iq7+ inverters and another 7 panels in garage to go up later. Waiting on 8 powerwall install with another 12 panels, engineering plans are done and just waiting on install.
Got a 12kw generator, dual fuel, with three 100 lb bottles of propane. Installed generator interlocks on both circuit panels.
Got two propane Mr heaters. Uses two 1lb bottles each, got refill adapter for the 1lb bottles. Pro tip, found out tracker supply in Texas sells propane by the gallon.
Got model Y on order, just deferred until 2023.
Cut down two trees this year, so got about a cord of wood. Really want to get a wood stove fire place insert, double burning. That will come after powerwalls are installed.
Really would like a solar injector to charge the AC connected batteries, like powerwall, from a generator. 2kw would be enough, would like the load on the generator to be adjustable. This would be really easy to develop.
How are you guys preparing.
Got a 12kw generator, dual fuel, with three 100 lb bottles of propane. Installed generator interlocks on both circuit panels.
Got two propane Mr heaters. Uses two 1lb bottles each, got refill adapter for the 1lb bottles. Pro tip, found out tracker supply in Texas sells propane by the gallon.
Got model Y on order, just deferred until 2023.
Cut down two trees this year, so got about a cord of wood. Really want to get a wood stove fire place insert, double burning. That will come after powerwalls are installed.
Really would like a solar injector to charge the AC connected batteries, like powerwall, from a generator. 2kw would be enough, would like the load on the generator to be adjustable. This would be really easy to develop.
How are you guys preparing.
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90 panels, 7 batteries, 22kw generator connected to a 500 gallon propane tank. I am ready for anythingI have 56 panels installed with emphases iq7+ inverters and another 7 panels in garage to go up later. Waiting on 8 powerwall install with another 12 panels, engineering plans are done and just waiting on install.
Got a 12kw generator, dual fuel, with three 100 lb bottles of propane. Installed generator interlocks on both circuit panels.
Got two propane Mr heaters. Uses two 1lb bottles each, got refill adapter for the 1lb bottles. Pro tip, found out tracker supply in Texas sells propane by the gallon.
Got model Y on order, just deferred until 2024.
Cut down two trees this year, so got about a cord of wood. Really want to get a wood stove fire place insert, double burning. That will come after powerwalls are installed.
Really would like a solar injector to charge the AC connected batteries, like powerwall, from a generator. 2kw would be enough, would like the load on the generator to be adjustable. This would be really easy to develop.
How are you guys preparing.
CrazyRabbit
Active Member
Also I’m all electric. Resistance heat, Rheem hybrid hot water heater. When rest of solar is installed I will have 56+7+12=75 panels.
320X56+340X7+400X12=25.1Kw
The seven panel were replaced when I got hit by lightning. Solar installer and emphases said it was the inverters, turned out it blew the by pass diodes which I replaced and repotted with silicone potting compound. So seven are freebies.
320X56+340X7+400X12=25.1Kw
The seven panel were replaced when I got hit by lightning. Solar installer and emphases said it was the inverters, turned out it blew the by pass diodes which I replaced and repotted with silicone potting compound. So seven are freebies.
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