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Introducing the Enphase AC Battery

It’s been about six weeks since Net Zero Solar installed our first Enphase Energy AC Battery at our office/warehouse. Although this is a small test system, this exciting new product allows for a lot of flexibility in how energy is generated, stored, and consumed in your home. And although it’s not necessarily justified in pure economic terms at this point, the Enphase AC Battery can be a great addition to a solar electric system.

So what does it do?

It’s pretty simple—the Enphase AC Battery stores electrical energy from the sun for later use. Inside the attractive package, you’ll find a 1.2 kWh lithium iron phosphate (LFP) battery, a 280-watt microinverter, and some additional controls and safety equipment. The microinverter can convert the AC energy from your Enphase solar electric system to DC energy, which is used to charge the battery. It can also convert the DC energy in the battery to AC energy, which can be sent to the electrical loads in your home. It’s possible to install just one AC battery, most homes will need two or more to effectively store solar energy.

Net Zero Solar’s Enphase AC Battery system in operation.

The screenshot above shows operation of our system for a recent Sunday. On the left is the most important info—for this day, our only interaction with with the grid was to buy 0.38 kWh of energy. 92% of our energy came either directly from the sun, or from our two AC batteries charged from the sun!

The orange line shows how much energy was consumed in the office, with dark orange coming from either the AC batteries or the grid, and light orange coming directly from solar. Blue is solar. The lighter blue is solar production, while the dark blue is solar energy that’s either used immediately, or used to charge the AC batteries (You might be wondering why the solar output is greatly reduced in the afternoon—see below for more about this “zero export” system).

At the bottom in green, we see the state of charge for the AC batteries, or how “full” they are. From midnight on, the state of charge slowly drops, as energy from the batteries is used to power loads in the office. When the sun comes up, the solar powers the loads in the office, and then starts charging the battery too. By the time it’s 10:10am, the batteries are about 40% full. By about 2:00pm, the batteries are completely full.

Sunday night, the batteries are ready to contribute, and cover the energy use of the warehouse and office. The system is smart enough to carefully follow the load profile of the office, greatly reducing the energy used from the grid overnight. By midnight, the batteries are about 50% full. Not to spoil the story too much, but for this weekend there was enough energy stored to keep running off the batteries until 6:00am, when we came into the office and turned on lights, computers, and other loads.

You can see what happened Monday morning below. As it turns out, our weekday loads are large enough that our small solar electric system can’t both charge the battery and meet the load. We’ll be installing more solar soon to remedy this.

The system in operation Monday morning.

But Why?

So why would you want to install Enphase AC batteries? First off, it’s an amazing technology. Enphase AC batteries let you store your energy, onsite, and use it later! You’re increasing your own energy independence. You’re also buying a piece of the future, as you help build the nascent home energy storage market.

But will the Enphase AC battery save you money? Probably not. For the moment, consumers in Arizona have the ability to take advantage of net metering, which essentially allows you to use the grid as a virtual battery.

Net metering will go away later this year, as rate case hearings for TEP, UNS Electric, and SSVEC continue this summer. In fact, Trico customers already are only compensated at about eight cents for each kWh of energy they send to the grid, while they have to pay about twelve cents for each kWh they buy from Trico. So when energy is sent to the grid, rather than used or stored, they lose about four cents of value. But unfortunately, total lifetime costs for storage are currently much higher than this lost value.

Can I go “off-grid” with the Enphase AC Battery?

Well, sort of. The Enphase AC battery allows you to reduce your interaction with the utility grid, since you’ll store some or all of your solar energy on-site, and use it when you need it. But the Enphase AC battery is designed to use the grid’s voltage and frequency as a reference. If the grid goes down, the system will not provide backup (though Enphase is working on this).

What’s it like to have Enphase AC Batteries installed?

The installation is a simple process. First, we’ll find a spot to mount the batteries. Unlike microinverters, they must be mounted in an indoor space, away from the weather. A garage is ideal.

Jim and James check out the AC Battery wiring boxes in preparation for installation.

Like any other electrical infrastructure, we will obtain a building permit. Although these batteries are extremely safe, this permitting process typically takes a little extra time, because this system is new to not only homeowners and installers, but also to building departments.

When our technicians arrive on site, we’ll first install mounting brackets with wiring boxes to the wall. We’ll then install conduit between your existing electrical system and the wiring boxes, pull wire through the conduit, and connect the wires inside the AC Battery wiring boxes, and to a circuit breaker on the other end.

Rob, James, and Bobby install the Enphase AC Battery mounting brackets.

The technicians will place each AC Battery on the bracket, plug in a couple connectors, and turn on the switches. After a short commissioning procedure using a smartphone, the system will be up and running!

Bobby completes the wiring.

If you currently have an Envoy-S metered, you’re all set to go. If you don’t, we’ll need to upgrade your Envoy. Although this is an expense, the great news is this also typically adds energy consumption monitoring to your home.

Bobby and James secure the batteries to the mounting bracket, and plug in the DC connectors.

A Note on Zero Export

When looking at the first images in this post, you might have noticed that the solar electric system didn’t seem to produce as much energy as expected in the afternoon. This is partly from some clouds in the afternoon, but there’s more to the situation.

In some parts of the world, there is so much solar that utilities and policymakers have ended net metering, and systems are required to be “zero export.” This means that solar electric systems are allowed to produce energy to be used immediately in the home, or to be stored in batteries, but they can’t send energy to the grid.

This “self-curtailment” isn’t required in Arizona, but we wanted to test this zero export scenario out. So how does it work? Enphase’s Envoy-S Metered measures the energy flow in the system multiple times each second. If the energy consumption in the home or business is more than the solar is producing, things continue as normal. But if solar production is more than the loads, the Envoy-S Metered commands the microinverters to reduce power output. This architecture only works with the S280 or newer inverters.

Toward a New World in Energy

The Enphase AC Battery is just the first step toward some truly incredible technologies. In the future, we expect to have a wide variety of energy products in the home.

Yes, solar electric systems will produce energy, and energy storage will step in at night, or when it’s cloudy. But load control products will also intelligently choose when to perform various tasks in your home, such as when your heating and air conditioning should run to both keep you comfortable, and save you money. These systems might also control when your pool pump runs, or when you charge your electric car, for example.

The completed Enphase AC Battery installation!

And where’s the grid in this scenario? There are at least two possible paths. The first is that consumers minimize or eliminate their connection to the grid, running mostly from solar and storage, and using backup power source such as a generator.

The more likely path is that the grid evolves into providing a different set of services, which are much more tailored to customer needs and desires. In this world, the grid and home energy systems could communicate intelligently, helping each other as needed. For example, a home energy system could minimize the energy that they take from the grid during peak usage times. Maybe they can even send electricity from energy storage to help support the grid when needed.

Where from Here?

Are you interested in learning more about the Enphase AC battery? Please get in touch. We’d love to talk more details. We’d also like to hear your questions about the system, and your thoughts on energy storage in the future. Please share them in the comments!

Hate solar telemarketers? We do too!

I arrived home after a busy workday, and sat down for dinner. My phone rang. It wasn’t a number I recognized, but it was in my home area code. When I answered, a telemarketer we’ll call “Sam” introduced himself.

Red Flag #1: Promises of “free” solar energy

Sam launched into his script: “Do you know that right now, you can receive up to $10,000 in incentives and grants in Arizona to make your home more energy efficient, for zero down?” The game was on. The object? To act ill-informed enough that he wouldn’t hang up on me, and would share more about his questionable business practices.

Lead generation and telemarketing companies often promise “free” solar electric systems that will “save hundreds each month.” Solar can be a great investment, but it isn’t free. Solar leases may save you a few bucks a month, but they usually contain surprises in the small print, and make poor assumptions about future energy rates. Solar loans are better, but still have a cost of capital embedded somewhere. If it sounds too good to be true, it probably is.

A Tucson rooftop solar electric installation. It wasn’t free.

Red Flag #2: Promise of many “incentives and grants”

After telling Sam that my highest electric bill was $120 last year, he proceeded to admit that these “grants” were payments from local utilities. “Incentives” were state and federal tax credits. He offered to set up an appointment for an energy consultant come to my home, and have a 30-minute discussion about my options for a more “energy efficient home.”

In the past, Arizona utilities paid “up-front incentives.” These were a cash payment to a customer after solar was installed. As the solar market has matured, these programs have gone away. There haven’t been active incentives for several years in most utility territories, so the claim of available utility incentives is just plain wrong.

A federal tax credit of 30% does exist. In Arizona, we also have a 25% state tax credit with a maximum of $1,000. Both tax credits require that a homeowner have sufficient tax liability to be able to take advantage of them.

Red Flag #3: Awkward company names

As any curious customer would do, I asked him the name of his organization, and for his website address. He gave me his company name, which we’ll call “Energy Information Savings Area.”

If your company name is some random combination of “free,” “energy,” “expert,” “information,” “solar,” and “Arizona,” I’m going to guess that you haven’t been in business for long, and you might not be as much of an expert as you claim. Some lead generation companies even change names frequently to try to outrun unpaid employees or other liabilities.

Red Flag #4: Representatives are unable to tell you where they are located or tell you who will be coming to your home to talk about solar

I asked Sam where he was based. He said “Tempe.” When I noted that the area code he’d called from wasn’t correct for Tempe, he then said his company was located in “Tempe and Yuma.” Odd, since the area code he called from doesn’t cover Yuma either. At this point, I think he was tired of my questions, and transferred me to his boss to “verify my qualification for this offer.”

Lead generation companies may operate from elsewhere in the U.S., or even overseas. Does the person calling know about your town or city? Do they mispronounce local names? If they don’t even know the basics of your local area, how are they going to be able to serve your specific solar needs?

You also might not want to invite just anyone who shows up on your doorstep into your home. Any company should be able to tell you the name of the person who will be visiting your home, and what installation company they represent.

Red Flag #4: Websites with generic information and with no real people shown

While waiting for the transfer to Sam’s boss, I opened my computer. The “Energy Savings Information Area” website was real, but they weren’t located in Arizona. They claimed to have been in solar since the 1980s, but there was a conspicuous absence of any names of company founders, officers, or even employees.

The second representative introduced herself. But when I started asking a question, the line went quiet. After a couple of minutes of silence, the call was ended from the other end. With a little Internet sleuthing, I found a LinkedIn profile for her name. She apparently works as a manager for a  third-party lead generation company. They have a trail of customer complaints, unpaid workers, and similar bad press across the internet.

Solar installation is inherently local. Whether you choose a truly local company, like Net Zero Solar, or a multi-state installer, someone is going to need to come out to talk to you about your solar options, and technicians will install solar components on your home. You should be able to find at least some of those people on your solar installer’s website. At a minimum, the leadership team and sales staff should be represented. Ideally, everyone at the company should be shown on the website.

Similarly, if the information on the website is generic and doesn’t reflect information on your local market, steer clear. Another sign that a company may be “churning and burning” is the use of stock photos on their website or photos stolen from other sources (you can check using TinEye, or Google reverse image search).

Be wise when buying solar, so you end up as happy as these great Net Zero Solar customers!

Red Flag #5: Lead generators are calling you at all

Companies that are established, local, quality solar installers usually get their customers through a mix of referrals and local advertising. If a company needs to knock on your door, incessantly call, or fill your mailbox with fliers, it’s a good bet that they are focused on finding poorly informed consumers who will buy their products without careful consideration, not providing solid solar energy solutions for their clients.

Some decent companies resort to these lead generation methods because they want to grow very quickly. But this quick growth is not likely to lead to informed salespeople, quality installation, or great post-installation service.

Buying Solar Shouldn’t Make You Feel Dirty

As a long-time solar professional, this whole interaction was pretty unpleasant. Solar is a wonderful technology and investment. But in the span of five minutes, just about everything I heard from these telemarketers was either misinformation or plainly untrue.

These business practices are bound to give the solar industry a black eye. In fact, we sometimes hear from people who’ve been continually hounded by these companies, but want a second opinion. We’re happy that they’ve called us, so we can sit down, and have a low-pressure, informative conversation about solar. But some consumers might not think to contact a local business before signing a contract that will lead to sorrow down the road. This is one of the most important reasons why we are passionate about educating consumers about solar—whether here, on social media, or in person.

You now know some red flags to avoid when considering solar installation. But what are some things you should do?

Tip #1: Call potential solar installers

Instead of waiting for shady telemarketers to call you, call reputable local solar companies. Make sure you can actually talk to someone who is knowledgeable about solar, and cares to discuss your needs. How to find good solar installers? Check out the next tip.

Tip #2: Check reviews, credentials, and licensing

When looking for a solar installer, check their reviews first.  Google and Facebook are a good place to start. The specialty website Solar Reviews is even better. Talk to your neighbors and friends, too!

See if a company has NABCEP certified installation professionals on staff. NABCEP offers certification programs to renewable energy professionals throughout North America, and is known as the “gold standard” for installation certification.

You should also check the Arizona Registrar of Contractors website to make sure that any potential contractor holds the proper licensing for the work you’d like done. Residential electrical work requires a R-11 or CR-11 license. Commercial electrical work requires a C-11 or CR-11 license.

Tip #3: Meet face to face

An in-person meeting will allow you to gauge the expertise of the solar sales professional and of the company they represent. Are they knowledgeable not only about solar technology, but also about financial benefits, environmental benefits, industry trends, and policy trends? Can they answer your questions (or find out if they don’t know)? Do their company values fit with your values?

Tip #4: Don’t be pressured to sign a contract

Although the end of net metering in Arizona is approaching later this year, there’s no need to “sign today.” If a company tries to use high-pressure sales tactics to sell solar, odds are they aren’t your best choice. The cost of solar installation has declined significantly over the past few years, but it is still major purchase. It is entirely reasonable to wait to sign a contract and make a down payment until you’ve thought it over for a couple of days.

Don’t Let Unscrupulous Business Practices Discourage You From Installing Solar!

We know that dealing with shady telemarketers and wading through the solar sales process can sometimes demoralizing. But now is actually a great time to go solar! Technology has improved, prices have dropped, and we see interesting technology trends on the horizon.

When you’re ready to make your move to a clean, independent source of energy, we’d love to sit down with you.  Just remember—we are Net Zero Solar, not Energy Information Savings Area. If you want to talk to those folks, you’ll have to wait for a call. It will probably come at dinner time.

A ground mount solar electric system installed in Tucson.

What Does the End of Net Metering in Arizona Mean for Small Solar Installers?

(This post is reproduced from Originally published January 19th, 2017)

It’s been almost a month since the Arizona Corporation Commission concluded their investigation into the value and cost of distributed generation by voting 4–1 to end net metering as we know it.

The simple policy of one-to-one credit of net metering will be replaced with a scheme that includes no banking of energy credits, and a steadily-dropping compensation for any energy that homeowners send back to the grid.

As you might imagine, at Net Zero Solar, we’ve been keenly discussing what this means for solar in the state, and particularly for small rooftop solar installers like us.

The basics

The decision replaces the current net metering policy implemented by the ACC in 2009. Under the decision, rooftop solar customers will receive full retail rate benefits from energy that they produce and use at the same time, but any distributed generation will be credited at a lower rate. Initially, this lower rate will be based on the price of utility-scale solar plants.

The specific export rate for each utility will be set in each rate case. Some utilities have already completed the first phase of these rate cases. Issues related to rooftop solar will be addressed in the second half of these cases. When a customer installs solar under the new scheme, they will be “locked in” at a specific export rate for ten years.

Consumers who already have solar will be “grandfathered” for twenty years from the date their solar was installed. The Commission also clarified their December decision. A customer who submits an application with their utility to install solar will be grandfathered, as long as they apply before the conclusion of their utility’s rate case.

Solar installers will need to be leaner

The solar industry has a well-documented record of reducing their prices to consumers over the years. Much of this has been driven by aggressive reductions in module and other component costs by manufacturers. But many rooftop solar installers have also worked to lower the “soft costs” of solar, such as customer acquisition, labor, permitting, and so on.

Small installers are going to need to continue this trend, while still providing excellent products and service. Improving process and efficiency will be critical, but improvements can’t be too expensive.

Distributors will need to understand the challenges faced by installers, and provide not only product, but also share insights on industry trends and engage in state-level policy discussions.

To keep the simple payback for cash purchasers to ten years or less under the new scheme, I estimate installers will need to reduce residential installed costs by between 4-15% per year, but outcomes of utility rate cases could shift this in either direction. This will particularly put increased pressure on customer acquisition costs, and will make loan and lease products very tough (if not impossible) to justify economically.

Storage won’t save us (yet)

During the hearing, some regulators made ill-informed statements implying that solar installers needed to become competitive, and that the ending of net metering would incentivize storage. (Of course, it’s rather ironic that regulators would hector an industry that has consistently become more efficient over its short lifetime, while protecting the profits of highly-uncompetitive utilities with stagnant business models).

While we have a long history working with energy storage at Net Zero Solar, and are excited for storage for the long term, it is in no way a cost-effective solution for today. With total lifetime costs for various lithium chemistry batteries in the range 20–30¢ per cycled kilowatt-hour, it just doesn’t pencil out.

With a retail cost for electricity of around 10¢, and the initial export rate expected to be in the order of 7¢, it would be foolish to spend 20¢ per kWh to store energy that’s only worth 3¢ per kWh (the difference between retail rates and export rates). As the excess generation rate declines toward the avoided over time, it may make sense for consumer to store their energy. But unless our our generally low energy prices in Arizona increase dramatically, storage costs would need to be 25–50% of their current levels to make economic sense.

Claiming cuts to net metering will incentivize storage in Arizona in the near term makes as much sense as claiming that if you crush my old Toyota pickup, I’m sure to go out and buy a Mercedes sedan. It’s not going to happen.

Over the long term, I expect storage costs will decline. And there is value in designing systems today that will easily incorporate storage, load control, and other advanced energy technologies in the future, such as the Enphase Home Energy Solution.

Some customers will chose to do storage soon anyway — just because they think the technology is cool, or they dislike utilities, or like the independence. But this will be a few early adopters, not a major part of the marketplace.

Installers will need to up their game with modeling, storage, load control, and other building management technologies

It’s reasonably trivial to calculate the financial benefits from a net-metered residential solar electric system with two-part rates, as long as you have monthly energy usage data and can accurately model monthly energy output from the system.

With no banking of energy credits, and a differing rate for imports and exports, things get more difficult. Solar installers will need to obtain detailed energy use data for potential clients, and predict each energy flow on a second-by-second basis to understand financial payback, since maximum self-consumption will produce maximum financial benefit. This will force installers to get more savvy with energy modeling, and become proficient software such as Energy Toolbase.

Load control and other building management strategies will also play a key part. From sales through installation and follow-up, employees at installers will need to be able to offer integrated solutions that are easy for the consumer to understand and implement.

Customers will have to accept more uncertainty

With this decision, consumers will have to accept more uncertainty regarding the financial payback for their systems. First, they will only be assured of a fixed export rate for ten years from the date of interconnection. After that, exported energy may be worth as little as avoided cost. I hope that by that time, costs will decrease enough make storage installation economically feasible.

Second, specific energy use patterns will directly affect how much energy is used from solar as it is produced, and how much is sent back to the grid at a lower compensation level. For example, a consumer who leaves town for a month and turns off all electric loads will receive only the export rate for all energy produced during that time.

Utility Death Spiral? Not So Much

Arizona’s utilities are the clear winners in this decision. They have managed to stave off some of the relatively minor competition posed by the rooftop solar industry, while putting forth the unreal narrative that solar customers are “cost-shifting” to other customers. All from an industry that enjoys monopoly protections, a guaranteed rate of return, and in the case of Arizona Public Service, spends millions electing their preferred regulators.

Utilities will continue to accelerate implementation of utility-scale solar and other renewables that they can monetize, and generally advocate policies that dis-incentivize customer-owned rooftop solar.

What’s our narrative?

As we move into a new energy policy era in Arizona, it will be important to tell a clear and compelling story about our energy future. Consumers need to know that their solar installer is taking all necessary steps to meet the challenges ahead.

Even with this significant setback, I believe rooftop solar will still be an important part of Arizona’s energy mix. Clean energy choices, storage, and new energy management solutions are exciting! Small business and local jobs are critical to keeping our economy strong.

Have thoughts on the future of rooftop solar in Arizona? Please share them below.