Shadowing Practice: The Hidden Problem With Home Batteries - Learn English Speaking with Video
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This is my electric bill from January.
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I have solar on the roof and 20 kWh of battery bolted to my garage wall.
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Even with all of that, the Eversource bill came out to $336.
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And Banked Sunshine from last summer paid $166 of it.
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Then the credit bank hit zero and my next bill came entirely out of my pocket.
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So here's the part that took me two years and a spreadsheet to work out.
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Every dollar of that rescue came from the panels on my roof, and the battery didn't help.
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12 months of my own utility bills
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and ran them against 12 months of data from the panel that meters every single circuit in my house.
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Then I ran those same 12 months again with the battery deleted.
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My battery costs me about $270 a year in electricity and has never saved me a dollar.
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Not once.
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And I'd buy it all again tomorrow.
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I know exactly how that sounds, but stick with me here, because by the end of this you'll know why
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and then you'll be able to decide whether my reasons align with your reasons.
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There's also something I realized I got wrong about my electric bill that I stated in a previous video two years ago.
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So what did I learn about home batteries after living with them across two homes over six years?
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And are they worth it?
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I'm Matt Farrell.
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Welcome to Undecided.
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This video is brought to you by Surfshark.
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A quick bit of history because it matters more than it looks like it does.
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In my old house, I had one Tesla Powerwall.
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Tesla's referral program gave me the hardware for free, but I paid for the installation costs.
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previous video.
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That meant I had to estimate the total overall costs whenever
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I talked about the calculation of payback numbers for my previous house.
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It was also a ballpark estimate because of the referral program.
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But this time I paid for the whole thing.
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Four Enphase IQ5P batteries, which means 20 kWh of storage and 15.4 kW of output. $33,407 all in before any rebates.
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The federal tax credit took 30% off and Massachusetts kicked in $1,000, so the net cost was $22,385.
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That's $1,119 for every single kilowatt hour hanging on that wall.
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I financed it with a MassSave 0% heat loan.
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It's a great program that Massachusetts runs to offer low
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or no interest loans for home energy upgrades on things like HVAC heat pumps to home batteries.
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Again, nobody sent me these batteries, so there's no sponsor.
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That's my money on the wall.
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And here's what I thought I was buying.
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Keeping those electrons generated on my roof, in my house, to help keep my electric bill low.
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Also the ability to shrug at a power outage.
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There's more to that, but only one of those turned out to be real.
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Before we get into the money, return on investment, and all the other reasons you might want to get a home battery, here's what this thing does on an ordinary Tuesday.
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Taking the last 18 months of data off my Span Smart Electric panel gives some really interesting insights.
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On a median day, the battery discharges 11.3 kWh.
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Over the last complete year, it moved 3,673 kWh into the house.
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And here's the key thing to keep in mind.
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The season decides everything.
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In January, my solar panels generate about 20 kWh a day, while my house eats 52.
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And yes, that's a lot, but remember that my house is all electric with an EV, heat pumps for heating and hot water.
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Like everything.
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There's no excess electricity generation to store, so the battery only moves about 6 kilowatt hours or so a day.
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However, in July I make 61 kilowatt hours a day and use 58, which results in the battery moving about 14 kilowatt hours.
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One quick clarification on my setup is that I keep my battery system set to 20% battery reserve, which means my total usable capacity isn't 20 kilowatt hours, it's more like 16.
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Now let's do some division, because who doesn't like some math?
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3,673 kilowatt hours a year over 16 usable kilowatt hours is 230 full battery cycles a year.
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My warranty covers 6,000 cycles or 15 years, but at my rate, I won't hit 6,000 cycles until year 26.
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It's kind of like a car warranty.
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Your car may come with a 150,000 mile warranty, but if you only drive 4,000 miles a year, the warranty will expire by its time limit first.
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I'm like that little old lady who only drives to church and back once a week.
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So this battery is going to age out long before it wears out.
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I wish I could say the same thing about my knees.
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That sounds like good news, right?
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It's actually the whole monetary problem because every dollar I spent has to spread across a very small pile of kilowatt hours.
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And that pile is smaller than I told you it was.
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Two years ago I sat here and explained how my electric bill works and I got part of it wrong.
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I didn't find out until I pulled the last 12 months of statements for researching this video.
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But hang tight because I'll show you the exact line item that proves it.
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But the reason I got it wrong was that something changed quietly and nobody told me.
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Your personal information works the same way.
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And that's where today's sponsor, Surfshark, comes in.
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I spend a lot of time thinking about protecting my home from the stuff I can't control.
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Power outages, price spikes, the grid having a bad day, and I got reminded the digital side needs the same attention recently.
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There was a massive BrightSpeed data breach that leaked personal info on more than 1 million customers.
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Things like names, emails, phone numbers and more.
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But with Surfshark you can protect yourself while online.
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When signing up for a new website account, you can use Surfshark's alternative ID to mask your name and contact info, so you stop seeding the next breach with your real info.
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They also have an email scam checker that uses AI to spot phishing attacks in your Gmail.
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It works through their Chrome extension and catches suspicious content and malicious links before you click on anything dangerous.
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It's It's really cool.
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Start your 7-day free trial and unlocks 4 extra months of Surfshark VPN.
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Go to surfshark.com slash undecided or use code undecided at checkout.
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Surfshark offers a 30-day money back guarantee, so there's no risk to try it out for yourself.
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I've been using Surfshark for years and I love it.
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Don't miss out on this great deal.
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The link's in the description below and thanks to Surfshark and to all of you for supporting the channel.
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OK, let's pull up my bill.
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Let's go slowly here.
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More for me than for you.
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My meter keeps a tab.
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One counter for kWh coming in from the grid and one for kWh going out.
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Eversource subtracts one from the other once a month and everything on my bill is computed on the difference.
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The bill makes it pretty clear.
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Consumption of 1,181 kWh, minus 143 for generation, nets 1,038.
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Then watch what happens to that 1,038 kWh.
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Both the supply and delivery chargers are computed on 1,038.
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The kWh I exported canceled the kWh I imported, delivery charge included.
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In Massachusetts that means about $0.32 of value for each one.
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That's a real one for one trade.
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And it's always worked that way here.
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So what does the battery have to do with any of that?
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Take July of last year, a month where I sent out far more than I took in.
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With the battery I imported 853 kWh and exported 1,420.
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Without it, I'd have imported 1,361kWh and exported 1,999kWh.
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The battery cut both sides by roughly the same amount.
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So my net barely budged and I came out $18 worse off.
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Now let's look at the month where I owed money.
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December of 2024.
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With the battery I paid $231.07, which is exactly what Eversource billed me.
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Without it, it would have cost $192.62, which means the battery cost me $38.
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This type of thing is happening every single month.
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Across the last 12 months, the battery cost me $207.
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The reason is almost embarrassingly simple.
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With every kWh I run through the battery, I lose about 16% as heat.
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714 kWh a year, gone.
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The cars in my garage might be slightly cozier because of that, but my wallet is not.
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Under a flat electricity rate like mine, along with basically 1 to 1 net metering, the grid is a better battery than my battery.
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It's virtually 100% efficient.
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But two years ago, I told you Massachusetts credits your exports at the generation rate only.
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So you eat the delivery charge on everything you send back.
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And I said the battery helps you dodge that.
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Many states in the country operate that way, so in those locations, that's 100% true.
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But my specific case, only half of what I said was true.
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In early 2024, my credit really was about 54% of retail, which certainly looks generation only.
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In February of 2025 it jumped to 85% and today it matches supply plus distribution plus transmission almost to the penny.
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My export terms improved by more than half and nobody told me.
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Not sure why.
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I only found it because I keep a spreadsheet.
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In case you couldn't tell, kind of a nerd.
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But the conclusion I drew was wrong back then.
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There is a haircut happening on the net metering credit for me.
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It's about 4.8 cents and it only touches the surplus
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that spills into the credit amount that builds up over the summer months.
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My battery couldn't capture it either way.
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And here's the number that nobody who's selling you a battery will put on a slide.
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So let's put a price tag on a stored kWh.
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Start with the net cost of $22,385.
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Spread it out over everything the battery will deliver in 20 years at my usage level, which is about 64,000 kWh.
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That number assumes the battery loses about 1.5% of capacity every single year, which is what the published data on this battery chemistry actually shows.
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That's $0.35 a kWh just for the hardware.
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This is not accounting for my solar panel setup, just the battery by itself.
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But when we do account for the solar I'm generating, we have to account for the cost of charging the battery.
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Every excess kWh I put into the battery is one I could have sold back to the grid for $0.28.
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Because I lose 16% in round trip efficiency, that works out to another $0.33 for every kilowatt hour I get back out. $0.68.
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That's what one kilowatt hour of my battery costs me.
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The one it replaces is worth $0.28 and I can buy one off the grid for $0.32.
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I'm paying more than double the grid price to store electricity I already own, and longer battery life doesn't rescue it.
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Stretch it to 25 years and it only falls to $0.62, because the cost of filling it never changes.
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And before you jump into the comments and try to dunk on home batteries in general, or especially on my setup, there is money in this system and it comes from exactly one place.
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My utility rents my battery.
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It's called Connected Solutions.
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Every summer between June and September, there's 40 or so afternoons that Eversource sends a signal to my battery to dump its power back into the grid.
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The sessions last for about 2-3 hours right around the 5pm crunch.
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Enphase pays $275 per average kilowatt delivered and passes 100% of that money from my utility to me.
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Some companies don't because they take a cut.
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But how's it work out?
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In 2024 I earned $1,881.38.
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In 2025 I earned $1,634.35.
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So why was one year 13% less?
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Both years my battery dumped essentially the same energy per event, about 14.5 kWh.
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What changed is how long the utility stretched it out.
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The program pays on average kW, not kWh.
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Basically, you get paid for how fast you can empty your bucket instead of how much water is in it.
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Same energy over 2 hours scores 7.3 kW.
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Over 3 hours, 4.8 kW.
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In 2024, 82% of my events were 2 hours.
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In 2025, only 55%.
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Same battery, same job, but a third less money.
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And I have zero say in it.
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Which brings us to the real question, does a home battery make financial sense?
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If you take the $207 a year my battery costs to run out of the Connected Solutions income, I'm netting about $1,550 a year if I average the first two two years.
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My enrollment runs for five years, but my understanding is that I might be able to re-enroll.
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If participation does end after five years, this battery will only recover about 20% of its cost over 25 years, and then it bleeds $200 a year forever.
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If it renews beyond the five-year period, it might pay for itself in year 15.
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The whole answer is kind of fuzzy on what's going to happen down the road.
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So when looking at the finances and ROI of a home battery, the math is saying no, it's not worth it.
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So here's the question I've been dodging for the past 10 minutes.
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Why don't I regret this?
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Why on earth would I do it all over again?
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That's because this isn't an investment decision.
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I'm not deciding what stocks to buy or where to invest my money for a financial return.
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Ask yourself, what does a battery do?
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What's its function and purpose for what you want it for?
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Do you buy a lawnmower because it's an investment or because it serves a task?
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For instance, look at my emergency backup history.
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For the past 26 months, I've had 10 outages for a total of 51 minutes.
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Out of those, the longest one lasted 11 minutes.
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On his face, it sounds like I'm spending over $22,000 for 51 minutes of backup is an insane decision.
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But here's what actually happened during those 10 outages.
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Nothing.
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We didn't notice.
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There were times we were running on backup and had no clue.
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No flicker, no beeping, no clocks blinking at us the next morning.
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I found out afterward from a log or phone notification that I missed.
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And that's the thing the spreadsheet can't see.
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Every number in this video is a money calculation, and money is not why most people buy a battery.
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So let's talk about my actual reasons for wanting a home battery.
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Contradictions included because I think the contradictions are the interesting part.
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I wanted energy independence.
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Meanwhile my utility takes the wheel 40 or so afternoons during the summer, and that's the only part of this that pays.
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My money and motivation are pointing in opposite directions.
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I wanted to use my own clean solar power power being generated on my roof.
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And To do it, I throw away 714 kWh a year as heat.
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Storing my own sunshine is less efficient than shipping it to the grid and buying it back.
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But I wanted resilience.
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I didn't size it for the worst case scenario.
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20 kWh runs my whole house about 8 hours in January, if I didn't do any kind of curtailment.
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A genuine multi-day nor'easter needs 3 or 4 times that.
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I made a rational call about how much backup I'd most likely need.
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Going off-grid was never my motivation.
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If I shut things down to just the critical loads like the fridge, the HVAC, a few lights, and with any January sun at all, I can run it indefinitely.
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That's the span panel helping me to shape my energy usage during an outage.
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Most people just install a hard-wired critical loads panel to do the same thing, but I'm able to adjust my critical loads in software.
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I can be more flexible with it depending on what's actually happening.
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The last rationale for getting a home battery tends to trip up everybody.
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Independence and resilience are two different things.
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Independence means leaving the grid.
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Resilience means the grid can stay.
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It just stops mattering when it fails.
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And I want the second one.
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Those two get mashed together constantly and they buy you completely different systems.
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EnergySage asked homeowners and installers the same question in the same survey.
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67% of installers said people buy batteries for resilience, only 11% for savings. To homeowners?
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30% said rate savings.
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A lot of people are being sold one story while telling themselves another and nobody's numbers get checked.
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And there's one benefit that the whole spreadsheet misses.
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When my battery discharges at 5pm on a 90 degree Fahrenheit day, it's shoving aside the dirtiest power on the grid.
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Peaker plants are what's running at that hour.
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Last year my battery pushed 611 kWh into the grid across 43 events.
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Every one of them timed to the filthiest moment of the day.
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My solar can't do that on its own.
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So here's where I land.
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I can't tell you this pays for itself, because in my situation, it doesn't.
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What I can tell you is what $22,000 actually bought for a nerdy homeowner in Massachusetts.
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It bought 10 power outages that I slept or worked through.
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It bought about $1,550 a year for as long as Eversource keeps renting it.
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It bought a house that holds its fridge
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and HVAC through a storm as long as the sun shows up from now and then.
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And it bought me the ability to stop thinking about winter nor'easters, which… knock on wood, hasn't impacted me in this house yet.
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It definitely did in my previous house.
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I've experienced much longer outages and it's not fun.
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Which is why I'd much rather be prepared with my energy storage backup.
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It costs me $207 a year in electricity and it will very likely never pay itself back.
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But it depends on where you live and how your electricity rates are structured.
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And this was my favorite part of digging into this topic.
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While I was pulling bills for this video, I found this.
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Eversource swapped my meter in February.
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Western Massachusetts is first in line for their smart meter rollout.
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A million and a half of them will be installed by the end of 2027.
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And the entire point of that program is time of use rates.
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Now, time of use would flip my energy math from negative $200 a year to somewhere between $170 and $800 positive,
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depending on how Massachusetts structures the rates.
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It definitely helps, but it still doesn't make it a crystal clear investment.
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The program renting my battery still does that.
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But here's the part I'm fixated on.
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A better peak rate wouldn't help my battery.
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But my utility paying me less for excess solar power I send back would.
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Right now, the grid is a perfect virtual battery for anyone that lives in my area with solar.
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It's free and never loses a thing.
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That's exactly why my battery can't win.
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The policy change I'd normally be complaining about is the one
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that would actually vindicate the purchase and honestly be more fair to all the non-solar homeowners and renters in my area.
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And yes, I'm advocating for not having a 1 to 1 net metering.
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I think it's more fair to have generation only credits for solar homeowners.
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Come at me in the comments if you disagree.
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And if you've got a battery of your own, I'd genuinely like to see your numbers and hear about your motivations on getting one.
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And for those of you that don't have home batteries, do you want them?
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Do they make sense in your area?
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Jump in the comments and let me know.
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You can also check Check out extended cuts of many of my videos over on Patreon.
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If human-written and researched videos matter to you, Patreon support helps a ton.
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The link's in the description if you'd like to join, but just watching, subscribing, and turning on notifications is awesome.
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Check out my follow-up podcast, Still to be Determined, where we'll keep this conversation going.
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Keep your mind open, stay curious, and I'll see you in the next one.
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Vocabulary and speaking notes for this lesson
This B2 speaking lesson is built on the video “The Hidden Problem With Home Batteries”. The speaker keeps coming back to these words: battery, kwh, hour, grid, cost. This video has 273 sentences and 3307 words to shadow. The speech runs for 17:54. The speaker talks fast, about 185 words per minute, so expect linked and reduced sounds. Only 81% of the words are among the 3,000 most common in English, so the vocabulary is demanding.
Key vocabulary in this video
The 15 most advanced words in the video, with pronunciation and meaning:
| Word | Pronunciation | Meaning |
|---|---|---|
| grid noun | /ɡɹɪd/ | A rectangular array of squares or rectangles of equal size, such as in a crossword puzzle. |
| kilowatt noun | /ˈkɪ.ləˌwɒt/ | One thousand (10³) watts, an amount of power large enough to power such things as a typical home appliance (e.g., a microwave oven, a toaster, or a hair… |
| outage noun | /ˈaʊ.tɪd͡ʒ/ | A temporary suspension of operation, especially of electrical power supply. |
| homeowner noun | Someone who owns a house. | |
| spreadsheet noun | /ˈspɹɛd.ʃit/ | A computer application for organization, analysis, and storage of data in tabular form. |
| resilience noun | /ɹɪˈzɪl.ɪ.əns/ | The mental ability to recover quickly from depression, illness or misfortune. |
| warranty noun | /ˈwɔɹ.ən.ti/ | A guarantee that a certain outcome or obligation will be fulfilled; security. |
| meter noun | /ˈmitəɹ/ | A device that measures things. |
| undecided adjective | /ˌʌndɪˈsaɪ̯.dɪd/ | Open and not yet settled or determined. |
| metre noun | /ˈmiːtəɹ/ | The basic unit of length in the International System of Units (SI: Système International d'Unités), equal to the distance travelled by light in a vacuum in… |
| import noun | /ˈɪm.pɔɹt/ | Something brought in from an exterior source, especially for sale or trade. |
| mathematics noun | /mæθ(.ə)ˈmæt.ɪks/ | An abstract representational system studying numbers, shapes, structures, quantitative change and relationships between them. |
| compute verb | /kəmˈpjuːt/ | To reckon, calculate. |
| contradiction noun | /ˌkɑːntɹəˈdɪkʃən/ | The act of contradicting. |
| installer noun | One who installs. |
Phrasal verbs you will hear
| Word | Pronunciation | Meaning |
|---|---|---|
| check out verb | To record the departure or withdrawal of someone or something (such as guests, employees, books, etc.). | |
| find out verb | To discover, as by asking or investigating. | |
| send back verb | To return (something) to its origin. | |
| work out verb | /ˌwɝk ˈaʊt/ | To calculate. |
| work through verb | To get past a difficult or stressful situation by thinking or talking about it. | |
| come out verb | /ˌkʌm ˈaʊt/ | To be discovered; to be revealed. |
| follow up verb | To take further actions remaining after an event; to continue, revisit, or persist; especially, to maintain communication or verify. | |
| go off verb | To explode. |
Sentences worth repeating
Short, complete lines from the video that you can reuse in everyday conversation:
- That's my money on the wall.
- In case you couldn't tell, kind of a nerd.
- Why don't I regret this?
- What's its function and purpose for what you want it for?
- Do they make sense in your area?
Grammar in this video
The structures the speaker uses most, with the exact words from the video:
| Structure | In the video |
|---|---|
| Present perfect continuous have/has been + -ing — an action that started earlier and is still going on | I've been using · I've been dodging |
| Passive voice be + past participle — the focus is on what happens, not who does it | is brought · is computed · are computed |
| Present perfect have/has + past participle — a past action that still matters now | has never saved · have imported · hasn't impacted |
| Relative clauses who / which + clause — extra information about a person or thing | batteries, which means · reserve, which means · level, which is |
Pronunciation to watch
The speaker uses 52 contractions and reduced forms, such as I'm, I'd, can't. Say them the short way, as you hear them.
- The “sh” and “zh” sounds: spreadsheet /ˈspɹɛd.ʃit/, contradiction /ˌkɑːntɹəˈdɪkʃən/, calculation /ˌkælkjuˈleɪʃn̩/, notification /ˌnoʊtɪfɪˈkeɪʃn̩/, sunshine /ˈsʌnʃaɪn/
- Long words — get the stress right: resilience /ɹɪˈzɪl.ɪ.əns/, undecided /ˌʌndɪˈsaɪ̯.dɪd/, mathematics /mæθ(.ə)ˈmæt.ɪks/, contradiction /ˌkɑːntɹəˈdɪkʃən/, notification /ˌnoʊtɪfɪˈkeɪʃn̩/
How to practise with this video
- Listen to the whole video once without speaking and note the words you do not know.
- Start at 0.75× speed, shadow it sentence by sentence, then go back to normal speed once it feels easy.
- Record yourself and compare with the original, paying attention to words like grid, kilowatt, outage.
What is the Shadowing Technique?
Shadowing is a science-backed language learning technique originally developed for professional interpreter training and popularized by polyglot Dr. Alexander Arguelles. The method is simple but powerful: you listen to native English audio and immediately repeat it out loud — like a shadow following the speaker with just a 1–2 second delay. Unlike passive listening or grammar drills, shadowing forces your brain and mouth muscles to simultaneously process and reproduce real speech patterns. Research shows it significantly improves pronunciation accuracy, intonation, rhythm, connected speech, listening comprehension, and speaking fluency — making it one of the most effective methods for IELTS Speaking preparation and real-world English communication.