Questions, answered plainly.
The short answer first, the detail underneath. Can’t find yours? Write to hello@orza.co.uk and a person will answer.
Getting started
Free, with nothing to install, and nothing sent to your battery until you choose.
Does Orza cost anything?
Not right now. Everything in Orza is free, with no card, while we spread the word. Paid tiers will come later, and we are committed to always keeping a free version. There is nothing to pay for today, so we hold no payment details at all.
Can I look round before connecting anything?
Yes. The demo opens with no account, and every account opens with an example home to look round. Connect your own battery later, or never.
Which batteries and suppliers does it work with?
The UK’s popular makes, through each maker’s own cloud. Each has a page saying what you need first: AlphaESS, Fox ESS, GivEnergy, Sigenergy, SolarEdge, SolaX, Solis and Tesla Powerwall.
Any supplier works. Octopus connects with an API key, so Orza reads your tariff and usage itself; for British Gas, EDF, E.ON Next, OVO Energy, ScottishPower and the rest you enter your tariff.
Do I need to install anything?
No. No hub, no box and no software on your network. Orza reaches your battery through its maker’s cloud, the way your maker’s app does, and that app keeps working as it does now. On Sigenergy, while Orza holds the battery in Automatic control, modes can’t be changed in mySigen until you hand back.
How long does setup take?
A few minutes. Pick your battery’s make and sign in to its cloud or paste its key, add your supplier, and tell Orza where your home is. The first reading arrives within five minutes, and the first plan soon after.
Do I have to let Orza control my battery?
No. Every home starts in Monitor only, where Orza reads and plans and sends nothing, and shows what its plan would have saved. Automatic control is a separate step only you can take, and you can step back from it at any time.
The cloud connection
Orza talks to your maker’s cloud, never to anything in your home.
How does Orza reach my battery?
Through the cloud your battery’s maker already runs, with the login or API key you already have. About every five minutes Orza reads your solar, grid, home and battery power and the battery’s charge, which sets the detail of everything it shows.
Nothing is installed in your house: no hub, no Raspberry Pi, no always-on computer, no software on your network and no port to open. Your inverter sits behind your router where no server can reach it, and we don’t try.
Why the cloud, and not a local connection?
So you never have to keep a computer running to save money. A local link is faster and more precise, and we built one before deciding never to ship it: it is a support burden, a security risk and a thing that breaks while you are on holiday. The cost is a coarser connection, five minutes instead of seconds, and only what each maker chooses to publish.
What can the cloud not tell Orza?
It depends on the make. Some makers’ clouds leave out pack temperature, battery health or alarms, which the inverter knows but doesn’t publish. Orza records, for each make, exactly which readings are genuinely reported, and where one is missing the app says why. It never estimates one and presents it as measured.
What happens when a reading fails?
It is recorded as a failure, never as a zero. A half hour with no reading behind it is marked missing, and a day that contains one is left out of your savings headline rather than quietly averaged. The gap stays visible.
The plan
Every half hour Orza works out the cheapest way through the next day and a half.
Why plan ahead instead of running a timer?
A timer only ever sees one night. It can’t know that tomorrow is sunny, or that tomorrow evening is three times dearer. Orza plans every half hour it can see at once, so cheap charge tonight isn’t spent before the evening that needed it.
How far ahead does it plan, and how often?
Up to 36 hours ahead, remade every 30 minutes. It plans on every price your tariff has published, and estimates the half hours not published yet from the same half hour over the last seven days. Each new reading, forecast and set of prices changes the next plan.
How does the planner decide?
It finds the cheapest way through the half hours it can see, as a linear programme solved with the open-source HiGHS solver:
Cost = ∑ (grid import × import price) − ∑ (grid export × export price) − value of the charge left at the end
within the battery’s physics: the sun covers the house first, charging and discharging stay within the battery’s power limits, the charge stays between your reserve and full, and each way in and out loses energy at its own efficiency.
Will it wear my battery out for pennies?
No. Every kWh that goes into the battery and back out loses some energy, and the plan pays for that loss. So it only moves energy through the battery when the price gap covers it, and a fraction of a penny never does.
How the saving is scored
Your own battery, against the same battery following Orza’s plan, half hour by half hour.
What is the saving measured against?
Your own battery, never a house with no battery. Orza runs a copy of your battery that follows the plan, using only what was known at the time, and costs both with your home’s own readings. The saving is what your battery really cost, less what the copy would have. Both sides go through one costing function.
What does “never with hindsight” mean?
Each half hour is judged on the forecast Orza had at the time, not the weather that arrived. The easy way to a big number is to wait until the day is over and work out the perfect plan with what actually happened. No plan could have known that, so Orza doesn’t score itself that way.
What happens on a day Orza’s plan would have lost?
It is shown, in red. When Orza’s plan would have cost more than your battery did, Savings says so for that day. It isn’t averaged away or left out.
Safety and control
Orza plans. Your battery, its own settings and its maker’s app always outrank it.
What happens if Orza goes down?
Your battery keeps running. Orza is not in the path your power takes and there is nothing of ours in your house to fail. The half hours it missed show as gaps, and your electricity works exactly as it did before you signed up.
Can Orza override my battery’s safety limits?
No. In Monitor only and Assisted it sends nothing at all. In Automatic control its only route in is the maker’s own cloud, which accepts a narrow set of instructions, and your battery’s own management system applies its limits for voltage, current and temperature underneath anything Orza asks for.
Can I take back control?
Always, in one click. Choose another mode at the top of the app. Handing back is never blocked. Before Orza changes anything your battery’s own settings are noted, and they are put back when you leave, or where a maker’s cloud handles the hand back itself, the battery returns to its maker’s own self-use mode.
What if my battery does something I didn’t expect?
Take control back first, then tell us. Choose another mode at the top of the app, which takes one click and is never blocked. Then use “Talk to a real person” in the app, which reaches us straight away by email. Can’t sign in? Email hello@orza.co.uk with Urgent in the subject. What to do if something looks wrong.
Does Orza affect my battery’s warranty?
Your warranty is between you and your maker. Orza works through the maker’s own cloud, in the modes it offers, and your battery’s own management system applies its limits underneath. Warranties usually set a number of years, and some also limit cycles or energy through the battery, so check yours. How many cycles a planned battery does.
How often does Orza send instructions to my inverter?
At most once each half hour, in Automatic control. Each goes through the maker’s own cloud and inside the limits it sets. Fox ESS, for example, allows 1,440 calls a day. In Monitor only and Assisted, nothing is sent.
What if readings stop arriving?
Orza stops sending. In Automatic control, with no fresh reading for 25 minutes, nothing is sent until one arrives. Orza never acts on a battery it can’t see.
Tariffs and prices
The more your price moves through the day, the more there is for a plan to find.
Which tariffs work best with Orza?
Ones whose price changes through the day, for import and export. Dynamic tariffs such as Octopus Agile are where Orza is worth most, because prices can swing from below zero to over 30p within a day. Tariffs with fixed cheap windows work the same way: Orza takes any half-hourly price.
Can I use Orza with Octopus Charge Pack?
Not both at once. Octopus says Charge Pack can’t be combined with other providers’ battery optimisation, so choose it or Orza’s Automatic control. Its page lists Intelligent Octopus Go, Octopus Go, Flexible and Fixed with Outgoing Octopus, not Agile or Flux, so on those there is nothing to choose between. On Go with Outgoing Octopus the two come out close: over a year of 40 modelled homes, Orza’s plan saved £404 on average against the battery left alone, and a simple routine (fill in the cheap window, then run the house) saved £263, or £407 with Charge Pack’s £144 a year minimum. Charge Pack can pay more than its minimum. Monitor only sends nothing, so it can show you what Orza’s plan would have done on your own home first.
When are new plans made?
Every 30 minutes, and as soon as new prices land. Octopus publishes tomorrow’s Agile prices each afternoon, usually between 16:00 and 16:30, and Orza remakes the plan with them straight away. In Monitor only the plan is recorded and scored, not sent anywhere.
Security and privacy
Your battery login is encrypted, and your data is yours to take or delete.
How is the login I connect stored?
Encrypted with AES-256-GCM the moment you save it, with the key kept in a separate vault, never in the database. No browser can read that table at all, and the login is never written to a log or sent back to a page. If the key is missing, Orza saves nothing at all rather than save it unencrypted.
Who owns my data?
You do. Your readings, plans and savings are never sold and never used for advertising. You can read and export all of it from the app, and deleting your account deletes it from the live database at once.
Can Orza’s staff see my home?
They can see what you see, and change nothing. Staff can view your account, readings, plans and savings, to answer you and to catch problems early. Your battery login is never visible to anyone, staff included.
Where is my data kept?
In London. Your data and sign-in are stored in London, and the planner that reads your system runs in Amsterdam. The privacy notice lists everyone who sees anything, and why.
See what Orza would do with your battery.
Free, with no card. Look round an example home first, and connect your battery when you’re ready.