reservolt

A battery that knows tomorrow's electricity price.

Reservolt controls your Deye or Solis inverter through the manufacturer's cloud: it buys in the cheapest hours, keeps energy for the expensive evening and, in summer, makes room for solar ahead of time. No extra hardware.

Join the pilot See how it works

Today's exchange price in Lithuania

ct/kWh excl. VAT, every 15 min

Loading prices…

Quarter-hours a 15 kWh battery would charge in Other quarter-hours

How it works

  1. Connect your inverter's cloud

    Deye Cloud or SolisCloud API keys. We show you where to find them, step by step.

  2. Describe your system and ESO plan

    Battery size, connection and export power, time zones, net-metering method, system cost.

  3. Watch the dry run

    For a few days Reservolt only shows what it would do. Nothing changes on the inverter.

  4. Switch control on

    The schedule is written to the inverter and updated when next-day prices come out (around 14:00).

Planned around your contract, not an average

Storing energy in the ESO grid?

While you still have stored kWh, buying at night doesn't pay: every kWh from the grid just draws your balance down. Reservolt tracks the balance from your inverter's readings and starts buying in the cheapest hours only once it runs out.

Summer mode

If your permitted export is small, say 1 kW, the midday solar surplus is simply cut off. Reservolt empties the battery by 10:00 just enough to fit the day's surplus.

Exchange prices and time zones

Exchange-linked plans, fixed prices, 1, 2 or 4 ESO time zones, public supply: every kWh is priced the way your bill prices it, VAT included.

What your battery cost

With your system's price and warranted cycles, Reservolt knows what one battery cycle costs and doesn't buy when the price gap wouldn't pay for it.

What it's worth

It depends on your contract more than on the size of your battery.

Exchange plan, no stored kWh at ESOabout €200–300 a year with a 15 kWh battery
Net metering, balance still leftclose to €0 from buying; less curtailed solar in summer
Fixed price, one time zoneclose to €0: there is no price gap to use

Estimate from 2025–2026 Lithuanian exchange prices, with about 10% losses and battery wear included. Not a promise: the dashboard works out your real result every day against the inverter's usual mode.

Shaped by the systems of 24 Lithuanian battery owners: typically 10–15 kWp solar, a 15–32 kWh battery, an 11 kW connection, and one in six runs several inverters.

What happens when something breaks

  • Reservolt only changes the inverter's time-of-use schedule: when to charge from the grid and how far to discharge. Protections, battery limits and backup power stay with the inverter.
  • If the internet or our server goes down, the inverter keeps running the last schedule, and a schedule never buys above the price limit you set.
  • One button puts back the schedule you had before Reservolt.
  • Credentials are encrypted (AES-256). We don't keep your Deye password, only the hash Deye's API asks for. Data stays in the EU.

Supported inverters

Deye

Hybrid inverters through Deye Cloud, parallel systems included.

Supported

Solis

Hybrid inverters through SolisCloud. Beta.

Beta

Others

Sungrow, Huawei, GoodWe, Growatt and others. Leave your e-mail and we'll let you know.

Questions

Do I need extra hardware?

No. Reservolt uses the manufacturer's cloud API. A separate module is only needed for the balancing (mFRR) market, which Reservolt doesn't do.

How is this different from time windows in the inverter app?

In the app you set the windows yourself and they repeat every day. Reservolt re-plans every few hours from next-day prices, the weather forecast and your own consumption.

My installer registered the plant under their account. Will it work?

Only the owner's account, or one with control rights, may change the schedule. Ask your installer to transfer the plant to your account or grant control rights.

How much does it cost?

Free during the pilot. We'll announce pricing in advance, and it will only ever be a share of what you save.

Can I switch it off any time?

Yes. Dry run, pause and putting back your original schedule are one button each, and you can delete your account with all its data yourself.

Is this connected to ESO?

Not yet: you enter your ESO plan and stored balance, and we keep the balance estimate up to date from your inverter's readings. A direct ESO data connection is in preparation.

Join the pilot

We're inviting Deye and Solis owners in Lithuania. Free, no commitment.

Join the pilot