Exploring Tesla Powerwall and home batteries – worth it?

this episode is brought to you by squarespace from websites and online stores to marketing tools and analytics squarespace is the all-in-one platform to build a beautiful online presence and run your business i just got a tesla powerwall well more like i've got a tesla wall that's ready to be installed it's laying on my garage floor but with home batteries like this being so expensive why would anyone want one it goes beyond a simple return on investment discussion in fact there's some really interesting programs that are launching right now that could help drive adoption so let's get into it i'm matt farrell welcome to undecided [Music] my tesla powerwall isn't doing much laying on my garage floor at the moment but once it's installed i'm planning on future videos to dive into my experiences with it and how it's integrated into my non-tesla solar panel setup so be sure to subscribe to not miss that but given how expensive these battery systems can cost i thought it was worth diving into why you'd want one how they can make sense financially and some of the intangibles that go beyond a return on investment we're actually seeing more and more people jump into residential battery systems just like this it's not too surprising why when you consider recent events like the california wildfires that knocked out power for millions of people or tropical storm isaias that left almost 3 million homes without power here in the northeast of the u.s traditionally when there's a power outage solar arrays have to be de-energized to protect utility workers that may be sent to fix something like a downed power line you don't want your excess solar production keeping grid power lines electrified when adding a battery to a home it has the ability to island itself off from the grid so your home is consuming both stored and self-generated electricity basically your solar panels stay on and are controlled by the battery control system here's a good example from a homeowner here in massachusetts that has a sonam battery paired with solar when tropical storm is hit our area it took out a tree causing a 36 hour outage the blue line is how much energy they were using the yellow line is their solar production the red line is when the battery was discharging power to the home and the purple line shows the battery's state of charge all the way the top is 100 charged and down at the bottom is zero percent you can see exactly when the battery kicked into gear and powered the home for the first 14 hours then during the next day it recharged itself and powered the home from solar for the next 26 hours an interesting note is the sawtooth pattern that you see in the purple line as well as the solar power looking like it's being shut on and off the battery control system automatically turns the solar panel system off when the battery is near full and there's too much power being generated for the house to use the system alternated between powering from the battery and recharging from solar to manage that load it's it's really pretty cool resiliency is a big perk of a home battery storage system like this it may be a little tricky to calculate the return on investment this way but keep in mind that this homeowner still had his lights on at night and didn't lose food from a refrigerator losing power during the height of the new england summer it's also worth mentioning that many people install permanent gasoline or natural gas backup generators for situations just like this and those can cost an average of thirty seven hundred dollars to install but power during an outage is not the only reason that you want a battery system if you have solar power installed in your home you might benefit from having energy storage to capture your overproduction during the day for use at night with or without solar you can shift your grid energy use to avoid expensive time of use rates pay for grid energy when it's cheap and pull from the battery when it's expensive and i'll get into more detail about this in a bit but you might be able to make a little money directly from your utility by letting them use your battery as part of a larger virtual power plant system and speaking of making money if you're looking to build out your company website online store or portfolio you should check out today's sponsor squarespace this one is pretty personal to me because i've been using squarespace for years and i use it for the undecided website i've got over 25 years experience building on websites so i know it's a full-time job to build and maintain a website squarespace takes care of all of it and lets you focus on the other work that matters for your business i absolutely love the content management system for publishing my articles and videos you can customize and fine-tune the look and feel to get something that fits your personality and your company's brand and you don't have to worry about software updates web servers or anything like that the all-in-one platform is my favorite part if you want to build out a beautiful web presence without the hassle head over to squarespace.com for a free trial and when you're ready to launch go to squarespace.com matt farrell to save 10 off your first purchase of a website or domain thanks to squarespace and to all of you for supporting the channel and when trying to choose a battery it can be difficult to navigate all of the different battery types brands installation costs and incentive programs the most prominent option out there and it's what i've got laying on my garage floor is tesla's powerwall it's an nmc battery pack which means that it's using lithium-nickel manganese cobalt oxide chemistry it tends to have a higher specific energy or energy density compared to other chemistries so it can store more per kilogram however it has a slightly lower power rating than other chemistries so there is a small trade-off the power well has a usable capacity of 13.5 kilowatt hours and a continuous power supply of 5 kilowatts or up to 7 kilowatts peak when you first turn on an electric device there's sometimes a brief spike of a power draw and that extra peak in the battery will cover that you can think of power supply of a battery like water flowing through a hose the diameter of the hose limits how much water can come out at once the power supply has the same kind of limiting effect so in my setup with one power wall my backup is able to handle about five kilowatts or 5000 watts of power draw at once that means i wouldn't be able to run an electric stove and ac at the same time considering they use way more than 5000 watts my hose just isn't wide enough i need to add a second power wall to make sure i could cover that situation now kilowatt hours are how many watts you're using over time if i ran a thousand watt oven from my power wall i'd be able to run it for about 13.5 hours because the battery pack is rated for 13.5 kilowatt hours the other important thing to consider when choosing a battery are the depth of discharge round trip efficiency and what the warranty it comes with the depth of discharge is how much you can drain the battery before the manufacturer recommends recharging in the case of the power wall it has a 100 depth of discharge meaning that you could theoretically drain it completely but that's generally not a good idea for the long-term battery health the round-trip efficiency is the amount of energy that can be used as a percentage of the amount of energy it took to store it this comes in at 90 efficiency which is excellent and for a warranty tesla provides a 10 year or 70 percent of original capacity warranty an alternate to the nmc battery chemistry is lfp or lithium iron phosphate and examples of that format are the sonen eco and end phase and charge lfp batteries have a slightly lower specific energy but higher power output the sony eco comes in configurations that range from 5 to 20 kilowatt hour capacities and between 3 and 8 kilowatts of continuous power output it has 100 depth of discharge rating and an 86 round trip efficiency and as for the warranty the desonant has a 10-year 10 000 cycle or 70 capacity warranty there are even more batteries like the generac power cell the lg cam resi the panasonic evervolt and the electric power pod i'll provide a link in the description to my website that has more details on different batteries and their stats it's not a comprehensive list but it covers some of the bigger options that are out there but there's still a big looming question which is cost no matter what route you go all of these options are expensive right now the power wall costs between nine thousand six hundred dollars and fifteen thousand dollars to purchase and install and sonan starts around ten thousand dollars and can be expanded by 2.5 kilowatt hour increments which would increase the price accordingly now like i said it's expensive but remember a backup generator can cost you thousands of dollars and is only used during a blackout where home batteries can provide value 24 7.

And this is also where incentive programs can really come into play to make not only the economics make sense but to also help the broader community in california there's this self-generation incentive program or sgip which is a budget of one billion dollars to fund the program through 2024. single-family homes are eligible for 850 per kilowatt hour as a rebate now this should cover about 85 percent of the cost of the average energy storage system and if you live in a multi-family home or qualify for additional help the program will cover a thousand dollars per kilowatt hour or about a hundred percent of the cost now in massachusetts where i live there's a solar massachusetts renewable target program or smart which pays participants based on the amount of energy that they produce the program has a battery storage adder which depends on the size of the solar panel system and the battery that it's paired with but it can add between two cents and seven cents back per kilowatt hour of electricity and while there's not a rebate payout like california there's a mass save heat loan program that you can use to pay for the battery system which will get you a seven year loan up to twenty five thousand dollars at zero percent interest and the utilities in the new england area which are eversource and national grid have created their own incentive program called connected solutions this is a really cool program that's creating a virtual power plant by using thousands of home battery installations as one massive battery to handle peak loads on the grid i've applied to get my power wall included in the system which will pay 225 dollars per kilowatt of your battery's average contribution during summer events and 50 per kilowatt during winter events tesla does take a 20 cut for managing and dispatching of the power wall but sonan manages their service free of charge for their customers utilities limit the number of events to 60 in the summer and five in the winter and each event is about two or three hours long for a typical battery that's capable of five kilowatts continuous contribution that could earn you about 1 375 dollars per year while enrolled in the program for a single powerwall that would almost cover the cost of the powerwall itself over five years and going back to that massachusetts homeowner with that sun and battery he's enrolled in this system and on this chart you can see what it looks like when the system taps into the battery the utility made sure his battery was fully charged and then started to drain it at the beginning of the peak event which was 4 pm this tapped the battery out by the end of the event which was around 7 pm and the grid filled the battery up to about 20 charge until the next day when his solar panel system filled it up the rest of the way the most interesting part of this program is that it was created by the utilities in an effort to save themselves money and the payouts are coming from the benefits the program provides pilot programs like this have shown a lot of promise green mountain power launched a similar program in vermont that paid back in a big way in 2018 the network of batteries reduced consumption during new england peak hour and saved about six hundred thousand dollars in capacity fees in 2019 after adding more batteries to the system for about 10 megawatts of capacity it saved about 900 000 from a single hour of operation in late july peak so you can start to see why utilities are willing and able to pay customers to contribute to systems like this in fact national grid in rhode island offers 400 per kilowatt during summer events and connected solutions program maybe i should move to rhode island well building under that basic concept is a broader standard called clean peak that's starting to get rolled out in some governments massachusetts is the first state in the united states to enact the clean peak standard and it looks like arizona might be next in a nutshell it's a mandate that requires a certain percentage of a state's energy to come from renewable sources during peak demand the nuance there is peak of clean peak just adding solar panels won't cut it because they won't provide direct power during peak events which usually occur in the early evening when people start turning on lights and cooking dinner in order to hit those mandates states will need methods to store that renewable energy to use during peak which is where the battery storage comes into the picture programs like connected solutions are laying the groundwork for utilities to start building up those energy stores as part of the mix one study has shown that after the initial setup costs of clean peak that massachusetts looks to save over 400 million dollars this coming decade for rate payers not to mention the massive savings in co2 emissions in germany there's a solar storage incentive for systems below 30 kilowatts that can cover 30 of the battery system's cost and in the uk you'll find the smart export guarantee which will earn you money for exporting stored electricity back to the grid how much you'll get and if you can get it depends on the supplier but you might see somewhere between 4 and 6p per kilowatt hour two factors are going to play a big role in battery adoption in the home continuing to drive down battery prices and smart utility and government policies and programs as more pilot programs like connected solutions start to show the value that home energy storage can bring to the community we'll start to see greater adoption it's going to be interesting to see how this evolves over the next few years so what's your take jump into the comments and let me know what you think about home batteries like this and if you're interested in seeing a follow-up video about my tesla powerwall be sure to hit the like button and i'd like to give a big thank you to matthew tuttleman who helped me with the research and scripting of the video he's an expert in energy storage systems and has a lot of professional experience with virtual power plants so his insights were incredibly helpful and as always a special thank you to all my patrons all of your support is really helping to make these possible if you liked this video be sure to check out one of the ones i have linked to right here and be sure to subscribe if you think i've earned it and as always thanks so much for watching i'll see you in the next one

You May Also Like