Photo voltaic + Battery Storage = Energy Grid Independence

Two Enphase IQ 10 Batteries had been put in in my storage

These of you who’ve been round me or this weblog for the previous few years know that I’m a fan of tech, inexperienced power, electrical automobiles, and naturally solar energy. On the finish of 2019, I went photo voltaic and documented it right here. My electrical invoice dropped by greater than half and I’ve been very pleased with my system. No complaints. It simply works! Nonetheless, there was one thing that I knew I’d in the end wish to full the system and I discussed it again then. battery storage!

A photo voltaic system with out battery storage will solely go to this point

Photo voltaic solely, no battery storage. Extra energy goes again to the grid

Including photo voltaic panels to your property will nearly instantly begin paying off by lowering and even eliminating the facility you want from the grid. That’s the upside! Nonetheless, except your system is PERFECTLY designed to match your power wants AND you’re on a Internet Metering Plan, you’re going to both overproduce or underproduce energy. There shall be instances all through the day when you might even be doing each.

For instance, let’s say it’s a particularly sunny day and no one is residence. That implies that your system is probably going producing extra energy than your property is consuming at that second. The place does that extra power go? Again to the grid. Relying in your energy firm you might or might not be capable to make the most of that extra energy. You’d must test to see in case your energy firm presents Internet Metering.

What’s Internet Metering?

Internet metering (or web power metering, NEM) is an electrical energy billing mechanism that enables shoppers who generate some or all of their very own electrical energy to make use of that electrical energy anytime, as an alternative of when it’s generated. That is notably necessary with renewable power sources like wind and photo voltaic, that are non-dispatchable (when not coupled to storage). Month-to-month web metering permits shoppers to make use of solar energy generated through the day at evening, or wind from a windy day later within the month. Annual web metering rolls over a web kilowatt-hour (kWh) credit score to the next month, permitting solar energy that was generated in July for use in December, or wind energy from March to August.

If you happen to can make the most of Internet Metering then producing extra energy than you employ isn’t an enormous deal from a monetary standpoint. It’s going to work out on the invoice.

What occurs when Internet Metering is just not supplied?

If Internet Metering isn’t supplied (and it isn’t supplied by my energy firm). then your energy firm might merely pay you for the power you ship again to the grid. The issue with that is that the quantity they pay you is pennies on the greenback in comparison with what they charged you for the electrical energy you employ. Subsequently, in case you don’t have Internet Metering you shouldn’t construct a system that can consistently overproduce UNLESS you add battery storage!

Battery Storage presents two huge benefits

Photo voltaic is producing sufficient to run the home (with one AC operating besides) and the surplus goes to the battery! Successfully off-grid

The primary benefit is that when you add battery storage to your system, any extra energy that’s generated by your panels is shipped to the batteries as an alternative of the grid. Because of this your property will then use this energy throughout instances of low or no photo voltaic manufacturing.

The second benefit is that the batteries act as an influence backup throughout grid outages. They’re even sensible sufficient (since they’re related to the web) to answer climate alerts by routinely charging the batteries to 100% in anticipation of an upcoming storm. Consider it or not, in case you don’t have battery storage that even on a brilliant sunny day if the grid goes down, so does your property. It is because energy firms don’t need their line personnel in peril of electrocution from the power that your photo voltaic system might ship again to the grid whereas they’re engaged on the outage. With battery storage, the facility to your property is coming from the battery throughout an outage and nothing goes to the grid. Additionally not like a generator, the swap over from grid to battery throughout an outage takes a millisecond. You’ll by no means know the grid was down. You set a minimal reserve proportion of storage so that you simply at all times have that quantity for surprising outages. The default is 30%.

(NOTE: Enphase’s new IQ8 Microinverters can create a self-contained grid to energy your property from the solar even throughout an influence outage with no storage. There are limits although. It will solely provide as a lot energy as your panels can produce throughout an outage and shut off as soon as the solar goes down.)

What system did I am going with and the way does all of it work?

I positioned an order on August 3, 2020, for 2 Tesla Powerwalls. I just like the design of the Powerwalls and so they provide about the most effective worth/efficiency ratio of all of the options on the market. I’d have cherished to have ordered these from Higher Tomorrow Photo voltaic (a very nice firm), the identical firm that put in my photo voltaic panels, however alas Higher Tomorrow Photo voltaic wasn’t but licensed to promote Powerwalls (they’re now!). My analysis led me to Artistic Photo voltaic and my order was positioned. This was a time that Tesla merely couldn’t sustain with the demand. I attempted ready, however in the end gave up and switched my order to Enphase IQ Batteries on Could 20, 2021. Higher Tomorrow Photo voltaic does promote Enphase batteries, however I had already put down a deposit with Artistic Photo voltaic, so I caught with them.

The rationale I selected Enphase is that my photo voltaic inverters are additionally Enphase (IQ7+). On the time this was a good higher match than Tesla Powerwalls as a result of the Enphase batteries would discuss straight with my Enphase photo voltaic inverters and supply a couple of extra advantages.

The wait continued….

My two Enphase IQ 10‘s simply obtained put in on June 22, 2022. That’s nearly two years of ready attributable to provide chain points.

Let’s undergo the system and the way in which it really works in all of the totally different eventualities

It’s a sunny day!

A superb photo voltaic day, batteries are nearly full from the solar!

The photo voltaic panels both produce sufficient to run the home or overproduce to additionally cost the batteries. Yay! – little to no grid use

The solar goes down

Not sufficient solar to provide, the home is operating off the batteries.

The batteries kick in and energy the house till they’re drained all the way down to the reserve proportion. – little to no grid use

The solar is gone AND the batteries are all the way down to the reserve quantity

The grid powers the house till the solar comes again up.

The photo voltaic panels should not producing sufficient to energy the house

The facility comes from the photo voltaic panels, the batteries, and the grid if essential.

There may be little or no coming from photo voltaic, however mixed with the battery it’s sufficient to energy the house.

There’s a extreme storm coming

Enphase has a characteristic referred to as “Storm Guard.” The system switches to the 100% Backup Profile. Photo voltaic manufacturing goes straight to the battery and OPTIONALLY you may activate a characteristic that will even cost the batteries from the grid.

There’s an influence outage and the solar is up

that is what grid-down would seem like if the solar is up.

If there’s sufficient photo voltaic manufacturing and you’ve got the newest IQ8 microinverters, the home is powered by the photo voltaic panels, and if not it’s powered by the panels and or the batteries. When you’ve got the older microinverters like my IQ7+s then your own home will solely be powered by the batteries.

There’s an influence outage and the solar is down

That is what a grid outage would seem like for my system with the Enphase IQ7+ Microinverters and Enphase IQ 10s for storage.

The home is powered by the batteries.

The entire eventualities above are utterly managed by the system. There’s nothing you’ll want to do however get pleasure from your system.

Now for a couple of “What Ifs”

Electrical Automobile plugged in however charging is not going to begin till the Tremendous Off-Peak Charges are in impact

What if the solar is down and the outage is extended? As soon as the batteries are drained and there’s no solar or grid, you go darkish like the remainder of your neighbors.

What if the batteries are full and your system continues to be producing greater than the house wants? Any extra energy is shipped again to the grid.

Why not simply get a generator? It’s less expensive than battery storage.

I had a complete home pure fuel generator after I lived in Michigan and it was GREAT the one time the facility was down for 3 days. With a generator, it simply sits there 99% of the time doing nothing if there isn’t any energy outage.

My energy goes out quite a bit and for a number of days, will batteries work for me?

It will depend upon the scale of your system vs. the quantity of energy you employ. I’ve an 8.2 kW photo voltaic array and 20 kW of battery storage. The photo voltaic produces sufficient by itself even when one AC is on to run my residence. If each ACs are on then photo voltaic doesn’t produce sufficient and energy both comes from what’s saved within the batteries or the grid. To unravel this and be capable to run each ACs on photo voltaic, I’d want so as to add extra panels to provide extra energy. Throughout an influence outage, I can management whether or not or not or for a way lengthy I run the AC. Much less AC implies that my home would keep up a lot for much longer on batteries. Since I haven’t had a protracted outage (we hardly ever have outages that final various minutes), I haven’t seen how lengthy the batteries would final on a 100% cost. For outages that final for days, you’d need sufficient battery storage to energy your property for a minimum of 16 hours/or lengthy sufficient for the solar to return again up.

It’s been cloudy for days attributable to rain, however nothing critical sufficient to trigger a climate alert. What now?

Even on this very overcast day with nearly no solar, the system produced 22.5 kWh of energy and achieved 46% Power Independence.

Consider it or not, it doesn’t must be sunny for the system to provide energy. It simply received’t be as a lot energy as it could be on a sunny day. Consider it this manner, on a cloudy day don’t you continue to see daylight? The panels nonetheless get solar too. Right here’s an instance, for about 10 days we’re anticipated to see any solar right here within the Atlanta space:

Can I take advantage of a generator too?

Truly, I used to be pleasantly stunned that Enphase added generator help to their system for people who have extended outages. You need to use a generator to seamlessly recharge the batteries throughout a protracted outage. The generator would kick on when the batteries are at a stage you specify and switch off as soon as the battery is charged again up. You’ll by no means know the facility was out your entire time.

Can I add to the system if it’s not large enough to run my home?

Yep! If you happen to discover that you simply’re not getting sufficient photo voltaic manufacturing to run the home and cost the batteries to 100%, then you might add extra photo voltaic panels.

If you happen to discover that the house doesn’t run lengthy sufficient on charged batteries, you may add extra batteries (or a generator).

All of this comes at a price because the panels and batteries aren’t low-cost. You’d must weigh your payback over the time you propose to remain in your house to see if it’s really cost-effective for you. Most often it’s, however your scenario could also be totally different.

How does TOU (Time of Use) have an effect on all of this?

Time Of Use is one other issue. I additionally simply switched to my energy firm’s Electrical Automobile Time of Use Fee and the Enphase app may be set as much as make the most of this.

As an alternative of simply charging up through the day and operating on battery when the solar goes away, the batteries cost up and begin powering the house through the TOU On-Peak ($0.203 per kWh) hours (2 PM – 8 PM Monday by Friday) which is when the electrical energy is the costliest. Off-Peak ($0.060 per kWh) is from 7 AM to 2 PM and eight PM to 11 PM. Tremendous Off-Peak ($0.040 per kWh) is from 11 PM to 7 AM the place the charges are the most cost effective and the most effective time to run all of your huge home equipment (dishwasher, washer, electrical dryer, and many others.) in addition to any electrical car charging.

How a lot does it value and the way lengthy is the payback/break even? Utilizing a typical 6.2 kW photo voltaic system estimated at $18K earlier than the Federal Tax Credit score and battery storage at $10K earlier than tax credit, it could look one thing like this;

Instance: Calculating your payback interval with and with out battery storage

Payback interval = Whole value of your photo voltaic system/yearly financial savings

U.S. Common power utilization in 2020: 893 kWh per thirty days

U.S. Common utility value of electrical energy: $0.13 per kWh

Month-to-month financial savings: 893 kWh * $0.13 = $116.09

Yearly financial savings: $116 * 12 months = $1,392

Payback interval with photo voltaic battery: $20,720/$1,368 = 15.15 years

Payback interval with out photo voltaic battery: $13,320/$1,368 = 9.7 years

The Backside Line

It’s too early but to see what influence the batteries have on my electrical invoice. My objective is to get it all the way down to nearly nothing, It’s most likely not doable (with out including extra panels and extra storage) for me to get rid of it utterly and be 100% off-grid since we earn a living from home and are right here all day, however I can already see each day that the batteries are powering the home at instances I’d be pulling from the grid. I can’t wait until my TOU billing kicks in as nicely. Additionally, understand that there’s nonetheless a 26% Federal Tax credit score for U.S. residents that may offset a major quantity of the system value.

In case you are fascinated with getting photo voltaic and storage you may’t go mistaken with Higher Tomorrow Photo voltaic and Artistic Photo voltaic. They’re each right here in Georgia. If you happen to’re not in Georgia get a minimum of three quotes.