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Show HN: We built a Plug-in Home Battery for the 99.7% of us without Powerwalls

pilaenergy.com

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Re: Show HN: We built a Plug-in Home Battery for the 99.7% of us without Powerwalls

#191

Post by chadconway »

VectorLock wrote: post #159
the__alchemist wrote: post #122

Earlier quoted context omitted.

Given these stats and the price in the sister comment, this costs $24,400 for a day of backup. This makes the LCD displays on the front page of the website listing "5 days 6 h ours" and similar on a single unit very misleading. That amount of backup would cost $128,000.

I assume it least has enough smarts to only show the battery capacity for whats in it. It can't run a whole house, so comparing it against an entire household's average load might be unrealistic.

Correct, 1 can’t run your whole house, but you can get 1 per room and backup your whole house that way.

Re: Show HN: We built a Plug-in Home Battery for the 99.7% of us without Powerwalls

#192

Post by chadconway »

CharlesW wrote: post #54

From your site: "For homes with electricity prices that vary throughout the day, Pila optimizes charging to help manage your utility bills." Based on experiments like https://www.youtube.com/watch?v=jtNq-0kV8YM , I'm extremely skeptical. Can you back this claim? Also, why are people going to spend $1,300 on this when a good UPS is a fraction of the price, and (for example) an Anker SOLIX F3800 Plus is $3,200?

A UPS can usually only power 100W, not enough for most fridges. Pila can do 2.2kW, enough for fridge, microwave, internet, and coffee maker.

Re: Show HN: We built a Plug-in Home Battery for the 99.7% of us without Powerwalls

#193

Post by nikodunk »

bigtimesink wrote: post #169
nikodunk wrote: post #156

Earlier quoted context omitted.

Great points! This is meant as whole room backup - so it’ll keep your fridge (and a few other small devices like wifi, etc) running for 2-3 days - a pretty long outage. It’s basically a huge, 21st century UPS. It can also do arbitrage and charge when it’s cheap and deploy the power when it’s expensive. The main problem with a powerwall is it doesn’t work for renters, and costs 20,000+ (and permits, etc) if you do own…

> Great points - however this can keep your fridge running for 2-3 days (a pretty long outage). $1,000 buys a lot of groceries. It's cheaper to to have a small supply of shelf stable food for outages. > It can also do arbitrage and charge when it’s cheap and deploy the power when it’s expensive. This has the same problem. It takes a long time to make back the $1000.

Definitely! It’s primarily backup, and secondarily an arbitrage device :)

The average fridge loss is estimated at $300 per outage, and the average fridge outage insurance claim is $600 I just learned today from an insurance agent at SXSW at our booth (apparently a lot of lobster is bought the day of the outage :P).

Re: Show HN: We built a Plug-in Home Battery for the 99.7% of us without Powerwalls

#194

Post by chadconway »

Nextgrid wrote: post #101
CharlesW wrote: post #54

From your site: "For homes with electricity prices that vary throughout the day, Pila optimizes charging to help manage your utility bills." Based on experiments like https://www.youtube.com/watch?v=jtNq-0kV8YM , I'm extremely skeptical. Can you back this claim? Also, why are people going to spend $1,300 on this when a good UPS is a fraction of the price, and (for example) an Anker SOLIX F3800 Plus is $3,200?

That video's conclusion is misleading - he's only shifting his fridge's energy consumption. That's not actually much in the grand scheme of things - it's a well-insulated box that is already a thermal battery. In fact, he only discharged his power bank to 64% at the end of the day, so he didn't even use up his full capacity (that he paid for and is factored in his spreadsheet). Batteries can provide significant savin…

100% Pila can charge from your home solar or cheap electricity and discharge when power is expensive.

Re: Show HN: We built a Plug-in Home Battery for the 99.7% of us without Powerwalls

#195

Post by happyopossum »

dharmab wrote: post #186
crazygringo wrote: post #144

It looks beautiful. But I honestly don't understand what the market is. OP answered in one of the comments that it will run a single fridge for 32 hours. I understand the benefits of a UPS that will run your desktop computer during a brief power outage of a couple of hours. And I understand a generator that will keep your house running for 10 days after a natural disaster. And I understand a Powerwall that can suck u…

> it'll stay cold enough on its own for a day without power as long as you don't open it much. Food in an unpowered fridge will be unsafe within 4 hours: https://www.foodsafety.gov/food-safety-charts/food-safety-du...

> will be unsafe

That is absolute BS - food is considered unsafe after the food itself spends 4 hours above 40*f, so the website you’re linking to assumes a fridge and everything in it immediately warms to 41+* upon losing power? Physics doesn’t work that way….

Re: Show HN: We built a Plug-in Home Battery for the 99.7% of us without Powerwalls

#196

Post by chadconway »

rtkwe wrote: post #104
CharlesW wrote: post #54

From your site: "For homes with electricity prices that vary throughout the day, Pila optimizes charging to help manage your utility bills." Based on experiments like https://www.youtube.com/watch?v=jtNq-0kV8YM , I'm extremely skeptical. Can you back this claim? Also, why are people going to spend $1,300 on this when a good UPS is a fraction of the price, and (for example) an Anker SOLIX F3800 Plus is $3,200?

That conclusion all depends on how much extra power the UPS uses while acting as a pass-through. I think the SOLIX doesn't directly pass through the power so it's having the inefficiencies of conversion to and from AC-DC-AC, maybe this version has a more efficient pass-through system?

Correct, this does direct feed-through no conversion losses for pass through because it uses a relay rather than an inverter to connect to the grid.

Re: Show HN: We built a Plug-in Home Battery for the 99.7% of us without Powerwalls

#197

Post by a_square_peg »

This is fantastic to see - I've been thinking about the need for something like this for a while.

I think there are two markets for this and I feel like you are already addressing the homeowners. Have you reached out to utilities who are looking to shave peak loads with DER?

Re: Show HN: We built a Plug-in Home Battery for the 99.7% of us without Powerwalls

#198

Post by barbazoo »

dharmab wrote: post #186
crazygringo wrote: post #144

It looks beautiful. But I honestly don't understand what the market is. OP answered in one of the comments that it will run a single fridge for 32 hours. I understand the benefits of a UPS that will run your desktop computer during a brief power outage of a couple of hours. And I understand a generator that will keep your house running for 10 days after a natural disaster. And I understand a Powerwall that can suck u…

> it'll stay cold enough on its own for a day without power as long as you don't open it much. Food in an unpowered fridge will be unsafe within 4 hours: https://www.foodsafety.gov/food-safety-charts/food-safety-du...

That’s much too conservative in opinion, at least around eggs, cheese and dairy.

Re: Show HN: We built a Plug-in Home Battery for the 99.7% of us without Powerwalls

#199

Post by cantrecallmypwd »

As far as I know, backfeeding is illegal and not allowed by the NEC because of how dangerous it is to linepeople without a disconnect switch. A local transformer when energized by backfeed creates high voltage on lines that should be deenergized.

Re: Show HN: We built a Plug-in Home Battery for the 99.7% of us without Powerwalls

#200

Post by chadconway »

amluto wrote: post #65

Two questions: 1. Have you considered building a “microgrid interconnection device” to go with this to allow the batteries to backfeed a house in the event of an outage? (This would require native 240V split-phase capability and/or an auto-transformer.) 2. Have you considered removing the fade-in-when-scrolling abomination on your website?

Pila team designed the Powerwall & SPAN microgrid interconnect device (MID) / relay that disconnect the home from the grid. So we could, but we believe the value to be the 0 install cost. Installing an MID can cost anywhere from $2500-15,000 depending on complexity.
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