[Brian]

Very valid observations.

I know nothing of the details, nor can I be considered conversant with Li batteries, but the concept appears interesting except for the fact to make economic sense the billing for electric usage has to change.

As I understand the reason for installing a bank of batteries for home use is to charge the batteries when electric cheap, such as at night, and power the house via the batteries and inverters during the day when electric would be more expensive. Right now my cost for electric does not reflect different costs based on the time of use so from an economic perspective there is no justification for installing the needed system.

But like any puff pieces put forth by the PR people the cost of the battery is a small element in the system cost. I suspect the price reflects some wishful thinking in that as volume goes up the costs may get down to that level. The whole story hasn’t been told either. I have a 200 amp panel for example and that means I would need 6 4000 watt inverters to start with. Then I would need some form of transfer switch to automatically determine the source of power, either from my batteries or from the grid, depending on the cost of electric, my demand, or my battery state of charge.

With winter electric bills on my house running $140 to summer bills running $290 or a total cost annually of $2580, if my electric bills went to zero it would still take me more than 10 years to recover the investment, and by then I would have to replace the batteries and likely repair or replace the inverters.

[Andre]

To me the charm of this is not to reduce the cost of my electric power but to deal with the loss of it. Sure I can put in a generator, but that really makes sense if the power outage goes on for a long period of time. Most of our power outages are fairly short. Maybe an hour or two. It would be nice to have a backup that could keep my non-electric heat, refrigeration, a few lights and maybe a TV or 2 running. Sort of like our bus over night. If Elon Musk gets the price down we might also see these batteries in our busses.

[Greg]

We have Lithium Ion technology in our bus. I’m not really sure how much it is like Tesla’s but I sure like the whole idea.

What I like about Li batteries is that they can go to almost zero (or zero) before loss of power (much like a cell phone).

This is what is installed in our Elegant Lady… (from the spec sheet) 4 – 3500 watt -24 volt OutBack Sine Wave Inverters‚ 3- Lithium Ion 24 volt Mastervolt Batteries interfaced to the Mastervolt Network for
complete monitoring of battery history. Battery life expected to be 10 years.

My understanding is that we will rebuild these batteries at a much cheaper cost than replacement when the time comes.

Our home in the Southern California desert can sure make the electric meter spin (digital now). We don’t have solar yet, thinking pretty hard on getting that as many friends and neighbors have bit the bullet and had them installed. Many of them have zero electric bills. With twenty-six tons of air, I think it would be advantageous to consider it.

Mark

[Greg]

Probably goes well with tesla (elon musk) other business Solar city.

[George]

If you own a coach you never have to worry about power outage in your home.

I have mine set up so the generator is my standby power and I plug into my buddy plug with shore power cords and my house has power.

[Archived]

I’m asking about using the Tesla battery pack as a replacement for the house batteries in my bus. Other than changes to or replacement of the inverters becuase the Li batteries need to be charged differently, what else would be needed? Would it be possible to keep the present inverters but use them only for inverting and not charging? I assume charging from the engine alternator would not change, and a stand-alone charger for gen/shore power would not be terribly expensive. This assumes the Tesla battery is 24 volts, which I do not know to be the case. Other than that, am I missing something?

[Archived]

Bryan,

The best I’ve seen is Volta Power that Panterra is working with, here’s my post from Feb:

Volta Power

There’s a whole lot more to it than just replacing components. Their approach is a complete integrated system so the coach functions as you are used to.

[Tommy]

Thanks, Tom. I missed that thread and appreciate the link. It seems like we are in interesting times, and Li replacements for AGMs may be in our future, but perhaps quite not the present.

[Archived]

I considered what would be involved in making the switch and the short version is a bale of Benjamins would be needed.

The inverters might actually be OK, but if you have a 12/24 volt house system it starts to get expensive because of the converters involved, plus there are a lot of other components required to make the system function. Part of the problem or benefit depending on how you look at this is Li batteries provide the exact same voltage from when fully charged until they just shut down. No warning, they reach a certain point of charge, and then they shut themselves down. Obviously with an AGM the voltage drops slowly until some point at which the auto-start for example will kick on and recharge them. They require a system and devices that will function with their operating characteristics.

[Bill]

The immediate criticism of the Tesla presentation centered around a distortion of the actual costs of the product being prersented to the public. The media sources discussed the undisclosed installation and maintenence costs, etc. One either believes in this company and its alleged products or they do not… As stated in an interview this morning on CNBC, it is a culture thing….you either buy into this fellow’s philosophies or you don’t….. From my view, based on his presentation and apparent initial inaccuracies, there are significant issues yet to be resolved. He personally has made hundreds of millions on paper and cash but has yet to produce a profit….. the first net income is expected to be in 2017 ???

I understand that the car itself is outstanding …. the new twin engine has a competitive quarter mile to the Corvettes, etc. I guess I am soured on some of these situations like a local LNG facility here in the Gulf Coast where the CEO was recently paid $140 million for twelve months of performance….the LNG company has lost about two billion or more so far…

I’ll get off of my soap box. My 40 years of investment banking/brokerage background makes me super suspicious.

Pres

[Ken]

I’m with Pres on this one. Any time someone in business makes promises basedon incomplete or inaccurate information it makes me question everything. To suggest you can slap a Li battery on the wall of your garage and power your house for $3500 is nowhere near the truth. Maybe the battery cost can be $3500, but that isn’t even close to what it will cost by the time a system that will work is functional.

Going further I would like to see real world figures on return of investment.

[Bryan]

But ignoring the undisclosed cost to set it up and make it work at home or in a bus, isn’t a 10KWh lithium ion battery pack an amazing bargain at $3500? That was the whole point of my post. This battery technology may be available to us at reasonable cost in the relatively near future.

[Deleted User]

That was my point………I don’t believe $3500 or 10KWH.

Without a doubt however the battery industry is going to be turned on its head by high volume production of batteries and that will at some point be clearly an advantage to us.

[Andrew]

I believe it is called the Tesla Powerwall and is designed to be installed vertically. The problem could be the dimensions. It is over four feet tall by three feet wide by seven inches thick. The listed voltage is 350 – 450 volts and can only be installed by certified technitions.

[Brian]

Tesla’s massive Powerwall battery promises to be able to take homes and businesses off the grid. Here’s a sanity check on how realistic it is, and what it means for the energy market.

Tesla’s new Powerwall battery.

Image: Tesla

As usual, Elon Musk was extremely convincing in his most recent announcement about Tesla’s new Powerwall battery. Imagine: in a matter of months, you could be weaned off fossil fuels and start participating in the clean energy ecosystem of the future. Your home or business could be off the grid completely.

As solar energy is more widely adopted, a dedicated battery to store the energy makes a lot of sense. Without one, that excess power generated during peak sun hours is often sold back to utility companies, then purchased back when customers need it. That actually adds demand on power plants, increases carbon emissions, and overall, it’s not sensible or efficient. The utility providers can end up making money off of the power you generate.

So Tesla made the Powerwall, which works like most other renewable energy storage systems. You may recognize names like Alevo or Enphase Energy, if you’re familiar with the clean energy industry. This battery stores electricity from solar panels and helps balance loads from the grid. It charges during non-peak energy usage hours, when the rates are lower — like the middle of the day or middle of the night — then provides you energy during morning and evening demand, when rates are higher.

However, there is still no great economic return because the market hasn’t matured enough and installing a whole system of solar panels and massive batteries remains incredibly expensive, even though the Powerwall was announced at a much lower price point than the industry expected.

More on that in a minute. First, here’s a rundown of the key takeaways from the announcement:

1. Telsa’s plan is to remain agnostic: Tesla is seemingly willing to work with any company to install and utilize these batteries. That doesn’t lock them into anyone, so third party developers, installers, and software companies can access the storage systems at a much lower price, and it gives the company the ability to scale and work with providers around the world.

2. They’ll begin installing this summer: “I was surprised they said next year [they will be] scaling significantly,” said Brian Warshay, an analyst with Bloomberg New Energy Finance, noting that the Gigafactory will be complete in late 2016 or 2017. “So it sounded awfully optimistic.” The Gigafactory, which is the world’s largest battery factory, is being built with Panasonic, which will manufacture lithium-ion battery cells for Tesla car batteries. Customers can reserve a Powerwall on Tesla’s website, and installations — done by third party installers — will begin this summer.

3. Tesla Energy is a new division of the company: Tesla is officially no longer just an electric car company. Tesla will offer Powerpack, sold in 100-kilowatt-hour modules at $25,000 each. According to CNET, Tesla has already started working with industrial customers on these installations.

4. Low price point: The price for the residential battery is much lower than most experts anticipated — upwards of $10,000. Musk announced Powerwall at $3,500 for the 10 kilowatt hour (kWh) battery and $3,000 for the 7 kWh model. However, that’s not including the installation costs, or costs for an entire solar outfit on your home or business, which can rack up quickly. “The fact they openly announced pricing… will put pressure on competitors,” Warshay said.

Here’s how it works: The Powerwall comes in a 10 kWh weekly cycle — for backup applications — and 7 kWh for daily cycles. If a home/business has a greater energy need, multiple batteries can be stored — up to 90 kWh total for the 10 kWh battery and 63 kWh total for the 7 kWh battery. The Powerwall generates 2 kW continuous and 3.3 kW during peak usage. It weighs 220 pounds and can be installed indoors or outdoors. The battery technology is lithium ion.

Many companies offer lithium-ion battery solutions, though there are other types out there like compressed air energy storage or flow batteries, but those are still in the nascent stages of R&D. Tesla is also the first large company to plan to manufacture energy storage and it’s offering a 10 year warranty.

Musk’s enthusiasm would have you believe it’s incredibly easy and cheap to go off the grid. Soon, it will be much easier, and it continues to be more cost effective as the price of solar panels and installations plummet, with the help of SolarCity where Musk also serves as chairman. But as of right now, the ROI still takes too long to reach break-even for people to view it as an economic benefit.

Why? Basically, it boils down to how much you pay per kWh put into the battery, which is then retrieved later. And if you don’t already have a big enough photovoltaic system to get off the grid, paying the estimated $0.30/kWh for electricity through the Powerwall may not make much sense. On average, grid prices for electricity in the US are about $0.12/kWh. Rooftop solar PV is estimated to reach grid parity in most places by 2016, but it’s not quite there yet.

“It’s much more likely people have a PV system, a few kilowatt hours of storage here and there, and self supply 70-80%, but not 100%,” Warshay said. “As you get up closer, there are significant diminishing returns.”

The batteries are already big with early adopters — engineers, renewable energy professionals, and avid Tesla or Musk fans — but they’ll have to show a significant economic benefit to catch on in the mainstream. The utility scale batteries, on the other hand, show a lot of promise, as Tesla already has pilot programs and partnerships to deploy the systems, and it will probably be the cheapest option for commercial storage.

The way to do that is to create an ecosystem, so that renewable energy makes sense from all angles. Musk, as usual, already seems several steps ahead of everyone with this. According to Greentech Media, Peter Rive, CTO of SolarCity and Musk’s cousin, said that the solar company plans to offer shared grid revenue services by allowing SolarCity customers to use Tesla’s batteries as grid resources and make some money off of the revenue they share with other grid users. SolarCity will install Tesla’s batteries for $5,000 (which is on top of the $3,500 price tag for the battery itself).

Just days after the Powerwall announcement, Tesla announced it will sell used electric cars at lower prices, and there’s a four year (or 50,000 mile) warranty on pre-owned vehicles. Since the first-generation Model S is reaching its three year mark, people who leased the vehicle will be returning it soon, which means there will likely put more electric vehicles on the roads.

Bringing the attention back to the cars — and especially, to the move toward more affordable cars — was a smart move by Musk. He’s expanding the ecosystem for Tesla and for sustainability, and pushing back against the idea that renewables are too expensive to invest in. That’s the primary argument people have at this point, and it’s quickly fading — even if it’s not quite as rosy as the picture Musk painted in the Powerwall announcement.

Also see:

• What Tesla is about to announce about gigantic batteries, and why it matters
• 10 awesome reads about cleantech on TechRepublic
• Green tech: The most eco-friendly cities in the world
• The recycled plastic filament that could set a new standard for 3D printing

About Lyndsey Gilpin

Lyndsey Gilpin is a Staff Writer for TechRepublic. She covers sustainability, tech leadership, 3D printing, and social entrepreneurship. She’s co-author of the upcoming book, Follow the Geeks.

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