Italian energy storage company
About us
Heiwit S.p.A. designs and commissions sodium-ion energy storage systems in Italy for residential, commercial and industrial solar PV systems. Registered office in Varese, operational headquarters in Caronno Pertusella, with sales through qualified installers in Italy and Europe.
At a glance
Four facts, with sources
If you want to check what we say, each box shows the document the figure comes from.
- 2023Year founded: Heiwit S.p.A. was established in Varese in October 2023.The first two years
- 9.000Cycles at 95% DoD declared for second-generation NFPP polyanionic cells, with the first batch expected in stock in December 2026.The NFPP cell datasheet
- 31.972Total cycles accumulated by the installed battery fleet, as at 17 September 2026.Results in the field
- 92%Of the solar potential harnessed by systems monitored with AI-Care, real data from September 2026.The study on the systems
The product
What we make,
and what we don't
Heiwit makes the energy storage system: battery pack, BMS, control electronics and integration with the Virgo (single-phase) and Lybra (three-phase) hybrid inverters, with CEI 0-21 certification for both and VDE-AR-N 4105 for the Virgo, issued by TÜV. Up to three 10 kWh 48 V battery modules can be connected in parallel.
We do not make the electrochemical cell: we buy it from qualified sodium-ion cell suppliers and put it through acceptance testing. It is the same distinction that, in the lithium world, separates cell manufacturers from manufacturers of residential storage.
“For us the cell is a commodity: today there is no European production of sodium cells.”
Heiwit, interview with pv magazine Italia, 9 October 2026
Our method
How we work
-
We design and test in Italy
The BMS electronics and firmware are developed at our Caronno Pertusella site. Every system is tested before shipping.
The range and configurations -
We sell only through trained installers
Heiwit batteries are purchased from installers who have completed the Heiwit technical course and have access to the reserved area with price list, documentation and support.
Become an authorised installer -
We measure results in the field
The AI-Care platform collects operating data from installed systems: cycles, energy, self-consumption. We publish the results, with dates.
Real data from the systems
Manufacturing project in Italy
An assembly plant in the province of Varese, at the planning stage
The project was launched in January 2026. Construction is scheduled to start in January 2027: 2,500 m² and an initial capacity of around 12,000 battery packs a year, equivalent to around 100 MWh. The three-year target is a production capacity of 3 GWh a year.
Cells will still be bought from qualified suppliers: there is not yet any production of sodium-ion cells in Europe.
- 2,500 m²Planned plant floor area, construction expected from January 2027.
- ≈ 100 MWhPlanned initial capacity: around 12,000 battery packs a year.
- 3 GWhAnnual production capacity, three-year target.
From 2023 to today
Milestones
Each entry links to the press release or external source. The full list is in the press review.
Incorporation of Heiwit S.p.A. in Varese.
Registration with ARERA as an energy producer and seller.
Heiwit's first sodium-ion batteries for solar PV systems, for the Italian and European market.
First megawatt-hour produced by Heiwit systems.
Selected for the Zero acceleration programme by Eni and Cariplo Factory.
Confindustria Varese certificate for member companies.
The first Heiwit battery goes into operation in a residential system (pv magazine).
CEI 0-21 certification of the Virgo single-phase inverter with sodium battery (TÜV SÜD).
Best Innovation Award at Solar Solutions Torino and participation in Solar & Storage Live Verona.
Launch of the project for the Italian assembly plant.
1,000 total cycles across the installed fleet, with performance in line with forecasts.
Address to the European Economic and Social Committee, in Brussels, on the future of the European battery industry.
CEI 0-21 certification of the Lybra three-phase inverter with sodium battery (TÜV Rheinland).
VDE-AR-N 4105 certification of the Virgo inverter for the German market (TÜV SÜD).
Stand and talk at Solar & Storage Live Italia 2026; interview with pv magazine on NFPP cells and the factory.
Who it's for
Installers, customers, investors
-
Installers
Training, reserved price list, support
Technical course, reserved area with price list and documentation, support with design and commissioning. The Heiwit network covers Italy, Switzerland, Germany and other European countries.
Become an authorised installer -
Homeowners and businesses
One system for new and existing installations
The Heiwit system can be paired with new or existing solar PV systems. We will put you in touch with a qualified installer in your area.
Request information -
Qualified investors
A joint-stock company with an industrial plan
Heiwit S.p.A. has a production plan in Italy and a growing sales network. Information for qualified investors is available on request.
Contact us
Registers and associations
Where we are registered
Each label opens the body's register or list of members.
Company details
Heiwit S.p.A.
- Registered office
- Via Carlo Robbioni, 2
21100 Varese (VA) - Operational Headquarters
- Via Papa Giovanni XXIII, 126
21042 Caronno Pertusella (VA) - VAT number
- 03980400125
- REA
- VA-393186
- Recipient code (SDI)
- USAL8PV
- PEC (certified e-mail)
- [email protected]
- Phone
- 0332.1730555 (switchboard)
- [email protected]
Contact
Talk to the Heiwit team
For an energy storage project, to join the installer network or for a press enquiry: we reply from our Caronno Pertusella offices.
Italian 
English 
German 
French 
Spanish 
Polish 
Dutch 
Romanian 
Hungarian 
Czech 
Swedish 
Portuguese 
Greek