The idea

One decision, made every 30 seconds: charge, or coast.

Almost every home battery has a passthrough mode. Your AC plugs into the battery, the battery plugs into the wall. PeakShift only decides when the battery's input gets power. The battery's own hardware does the rest, switching over in about 10 milliseconds. You stay in control the whole time, and nothing ever pushes power back onto the grid.

01 / NIGHT

Charge when it's cheap

The battery fills overnight, when your rate or the live market price is at its lowest.

02 / PEAK

Coast through the crunch

During the expensive evening hours the AC runs off the battery instead of the grid.

03 / SAFE

Never at your comfort's expense

Low battery, any error, or a lost connection all fail toward grid power. The AC never dies to save a dollar.

What you'd pay without a battery Shifted to cheap hours by PeakShift

When the grid goes down

You don't lose the AC. Or the fridge.

The same setup that saves you money is a backup battery you already keep charged. Your appliances run through it every day, so when the power actually cuts, there is nothing to switch on and no generator to start. The battery just keeps going, in about 10 milliseconds, and your essentials stay on through the outage.

10 msCutover to battery when the grid drops, fast enough that your AC and fridge never notice

0 fuelNo generator, no gas, no wiring. It's already charged and already in line

YoursThe battery is your hardware. No one else can throttle it, meter it, or switch it off

No battery? You already own one

Your house is a battery too.

A well-sealed home holds cool air for hours. PeakShift pre-cools it while power is cheap, then lets the AC coast off through the expensive evening while the house drifts slowly back to normal. The store isn't a box in the closet, it's the building itself. Nothing to buy, and it runs on the Nest or ecobee you already have. Comfort always wins, and any error falls back to normal cooling.

And it can pay you. Utilities run demand-response events on the hottest afternoons and pay households to ease off the AC right when the grid is strained. Because PeakShift chilled the house first, you sit out the event in comfort and still collect the check. Pre-cool, coast, get paid.

$0Hardware to buy. It uses the thermostat you already own and the thermal mass of your own home

$50–150/yrTypical thermostat demand-response payment for easing off the AC at the peak, on top of your rate savings (estimate, varies by program)

NationwideWorks anywhere with central AC, including everywhere a window-unit battery can't reach

Works with your battery

Bring the battery you want.

PeakShift is brand-agnostic on purpose. Most LiFePO4 power stations with a passthrough mode work, and the universal path is a $25 smart plug on the battery's input, which works with any of them. Pick the battery that fits your home and your budget, not the one a program picks for you.

EcoFlow Bluetti Anker Solix Marstek Victron any battery + a smart plug

The full setup recipe for each battery is in the battery guide.

Works where you live

It already knows your utility's prices.

Set your peak hours by hand, look up your US time-of-use rate by ZIP, or track live market prices and let PeakShift find the priciest hours of each day on its own. It works out of the box across the US, UK, Europe, and Australia.

How it prices your power	Where
US time-of-use rate by ZIP	United States
Live wholesale market price	UK, Germany, Austria, Spain, Nordics
Live wholesale market price	Australia
Fixed peak hours you set yourself	Anywhere

Ten live price feeds across those markets, verified against their own APIs. The full list is in the project README.

What it's worth

Best in the markets with the biggest spreads.

~$1,000/yrA 5 kWh battery on UK Octopus Agile plus flexibility payments (estimate)

$600–850/yrAustralia on Amber wholesale pricing, spikes included (estimate)

$150–280/yrA 2 kWh battery on a typical US time-of-use tariff (estimate)

3,000+LiFePO4 cycles, so daily cycling still lasts 8+ summers

Estimates from published tariffs and program data. Your number depends on your rate, climate, and battery. PeakShift keeps a ledger of what it actually shifted so you can check your own.

In a funded program, you can get the battery for free. When a utility or a data center funds the hardware, a household gets the battery at no cost, keeps the bill savings above, and gets backup power. The free asset and the lower bill are the real offer, not a token check.

The DIY path

Set it up in an afternoon.

PeakShift is free and open source. Clone it, point it at your battery and your rate, and it runs on any small computer or home server you already have. You run it, so no company sits between you and your own battery.

# clone, install, point it at your battery and your rate
git clone https://github.com/steps-re/peakshift
pip install -e peakshift
peakshift test-drive   # verify the wiring
peakshift run          # saving money on every peak

At scale

One home saves money. A million becomes a gigawatt.

The same no-export load shifting, run across a whole neighborhood, shaves the local grid's evening peak without a single interconnection study. For a utility or a data center that needs power fast, it's a way to turn the community around it into an ally and free up local grid headroom the same season. Same tool, same batteries, built in months.

The utility & data center pitch Rules & limits