The Comprehensive 2020 Tesla Powerwall Review and Guide

The Tesla Powerwall is a large capacity energy storage unit available for light commercial and full residential use.  Here we are in the year 2020, two decades after the turn of the century.  The long fantasized future is here and now.  Cartoons promised us flying cars, movies promised us jetpacks, novels told us we’d all be living in Utopian communities by now.

The problem with predicting the future is we always get it wrong.  Our vision of Utopian life centered on miracle breakthroughs that never materialized.  Technology marches forward but we’re still burning through fossil fuels like they will never run out.  Those flying cars were never envisioned as gasoline combustion engines, we expected the future to give us new power sources.  We didn’t develop those technologies.

Now we tread lightly into the new century and are coming face to face with the very real consequences of our inaction.  Fossil fuels are running low and it is possible our dependence on these fuels have poisoned the atmosphere beyond redemption.

This has many of us turning to alternative power sources available to us in our own backyards; solar and wind.  Both of these are good sources of power when present, but what happens when the wind dies down or you want power at night?

You need to harness excess power in a storage facility for later use.  The Tesla Powerwall is an excellent choice for your home power grid needs.  It was introduced to the market in 2015 and continued making improvements along the way.  The current version of the Powerwall2 has more than double the capacity rating of its predecessor.  Let’s take a look at the Tesla Powerwall and see what it offers us in 2020.

Tesla created the Powerwall as a way to store electricity for future use.  The company made a huge splash on the scene first with their electric cars and then the Powerwall battery systems.  Tesla may be more well known for their sexy electric cars, but these cars revolve around the same technology as the Powerwall.  Afterall, an electric car without a battery is simply a car, no matter how fancy it may appear.

There is more to the Tesla cars than simply ripping out the engine and sticking a battery in its place.  The Tesla automobiles have highly advanced gadgets and operating systems that allow the vehicle to operate efficiently on battery power.  That battery is the heart of the entire car.  Without power, the car does nothing…

Tesla took that advanced technology and introduced their Powerwall battery system to the alternative power market.  Those looking to “go green” or simply looking for a way to get “off the grid” took to Tesla’s Powerwall system because of their known reliability in the electric vehicle market and the slick streamlined design that could be compared to the other technology market dominators such as Apple.  To misquote Dr. Emmett Brown, “If you’re going to build highly advanced technology, why not do it with some style”

The “off-grid” market was a fortunate byproduct of the latest upgrades.  Depending on your power consumption and your energy generating abilities, an expanded Powerwall installation is capable of taking your power load completely off the municipal grid.  Initially, this battery system was not designed to fully supply your home with 100% of your power needs, but only to supplement your power consumption or to buffer against power outages.

Taking any degree of load off of the power grid is a step in the right direction.  Once the neighborhood sees the system, more users will take a little more off the power grid and now we’re taking a larger step in that direction.  Especially in places like California where the existing power grid infrastructure is overtaxed and causing rolling brownouts and unexpected power outages.

The Tesla Powerwall was designed for such the occasion.  It is nothing more than an uninterrupted power supply for your home.  Most of us have a battery backup plugged into the wall and powering our computers.  The Powerwall works much like that small UPS, but on a much larger scale.  As the UPS is drawing power it passes that power along to the outlets for use, while simultaneously charging the internal battery and keeping it topped off.  When the primary source of power goes out, the battery simply stops charging but continues to power your devices.  The Powerwall is a refined and scaled up version of this process.

Describing the Telsa Powerwall 2 is simple.  It is a battery system.  Understanding how it works takes a little more effort.  Battery technology has come a long way since the early inventions, but battery storage never grows by leaps and bounds.  It grows with small, incremental changes over time.  A 2% increase here, 1.5% efficiency increase there… Add them all up over the years and you have a much better battery than you started with.  Stories and anecdotes you remember about poor battery storage in general are outdated.  Soon, we will look back on today’s best capacity and call it inadequate.  Your 486 computer was amazing in its day but couldn’t run an e-mail app today.

Introduced in April 2015, Tesla’s lithium-ion Powerwall battery has 2kW output.  By June of the same year the output was increased to 5kW.  In March 2016 the output was rated at 6.4kW.  The Powerwall 1 was soon replaced with the Powerwall 2, rated at 13.5kWh.  There is never a promise when capacity will increase, only that it will, in small incremental steps.  Jumping on board the battery train can leave some users feeling like they should have waited for that next step of improvement.  The alternative is always standing by, waiting, and watching that train pass you by.

The Powerwall batteries are fluid cooled.  2.3 liters of coolant are used in proprietary operation to keep the unwanted byproduct of energy production of heat from building up and damaging the battery cells.  Though the liquid cooled battery technology is patented to Tesla, the CEO Elon Musk has announced that like the patents on his automobiles, he will not enforce patent infringements in order to foster healthy competition and to aid in the rapid development of newer and better technologies.

Meant to pair with an array of solar panels, the Powerwall draws the energy from converted sunlight to charge the batteries all day long.  On a bright sunny day, and with a large enough solar roof, you can run the appliances in your home with plenty of power left over.  Called “spillage”, this excess unused energy is placed in the battery cells for later discharge.  As the sun goes down, the solar panels feed less power into your home and as your consumption continues, the stored power in your battery steps in and supplies that extra requirement.  Without a battery storage system, the spillage from earlier in the day would not be captured and would not be available to you for the evening.  The Powerwall operation can be simplified by saying it charges up during the day so you can use it at night.  Although it would be more accurate to say that it stores the spillage for use when the source is absent.  After all, you’re going to want power during a long rainy weekend as well.

Okay, this battery system is a great idea.  What will it take to get a Tesla Powerwall 2 installed in my home?

Is it worth the cost for those looking to supplement their power consumption or use simply as a backup against brownouts, bad weather and other unexpected power outages?

Is it worth the cost for those looking to take their home’s power completely off the electrical grid?

The answer to these two questions may differ depending on your configuration.  Even among these two categories there are variations.  An installation backing up your entire home will most likely require additional battery packs.  If you don’t need to run high wattage appliances such as your air conditioner, washer and dryer, etc… the essential load backup will most likely require some additional wiring and an essential load station.

Even the basic installation consists of several components, some of which add to the overall cost.  Support hardware, backup gateway, permits, certified installations, all of these are expenses that need to be taken into consideration during the planning phase.

Installing your Powerwall as a backup may or may not be expensive depending on your requirements.  Though the initial installation can be pricey, is it worth it to you to have knowledge that whatever the conditions are of the city power, or during a natural disaster, you will have electricity?  If you don’t mind going a few days without power in the event of an emergency, maybe this system is expensive.  If you absolutely need to have power 100% of the time, this system may be worth the price for you.

If you’re taking your small home off-grid, the Tesla Powerwall could be surprisingly affordable.  After swallowing the initial investment, the system maintains itself.  Warrantied for ten years of unlimited charge and discharge cycles, the system is guaranteed to still retain 70% capacity at the end of ten years.  If you live in the city, going off-grid and waiting for the Powerwall to pay for itself may be a luxury you can afford.  However, if you’re building your home out in the wild, away from any existing power infrastructure, the cost of a Powerwall system may actually be lower than the procedure involved in getting a new power line run out to your new homestead location, if it is possible at all.

Tesla has a “certified installer network” that guarantees you will get a trained specialist completing a proper installation of your Tesla Powerwall.  Not all of these installers charge the same prices for their services, so getting multiple quotes, asking about government sponsored rebates or incentives may bring your cost down substantially.

Cost against affordability is relative to your needs and desires.  Which configuration of Powerwall is best for your use weighs against how much it is worth it to you and your power requirements.

Tesla Powerwall Review: Pros and Cons 

We can take as a given that a self contained battery system that can provide power 24 hours a day is a great appliance in any of our homes.  Let’s sum up by considering the largest pro and con of a system such as the Tesla Powerwall 2.

Pro: It grants you continuous power.

The sun dips below the horizon for half of our calendar day.  Outside of the occasional storm front, wind generally subsides at night.  On-site power generating devices such as solar panels and windmills are limited by the whims of the natural phenomena supplying the source.  We get more power than we need during the day and none at night.  The Powerwall evens this out with the capture of the daytime spillage and makes it available for nighttime use.

Con: It can be costly.

The initial purchase and installation investment can be a substantial sum.  The return on investment calculations will tell you numbers in dollars per kilowatt but that cost must be weighed against the urgency of having uninterrupted power.  The additional system components required to make the Powerwall suitable for moving all of your power consumption off the grid is an even greater investment.  And again, the cost must be weighed against the benefits.

There is no direct “yes or no” answer to the question of “is the Powerwall worth it?”  It is certainly a marvel of technology and a useful tool we would all love to have, but your demand for power can be countered by your budget.  In congested metropolis locations such as California’s rolling brownout neighborhoods, or remote isolated locations like the Outback of Australia where municipal power is out of the question, the Tesla Powerwall may be more than a desire, it may become a necessity.

Looking into the future, knowing our power consumption habits, the growing populations, deterioration of the existing power infrastructure, and the dwindling supply of readily available fossil fuels, I’m willing to say that it’s a safe bet we’ll see more systems such as the Tesla Powerwall battery system being installed in more and more homes in the near future.

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