SUNLIGHT INTO STORED ENERGY

A year of sunlight.
A clearer recharge plan..

Explore seasonal production, energy for your loads, and the surplus that could recharge a battery.

A LOCATION, A SURFACE, A WEATHER RECORD

Start with the solar resource.

Enter approximate coordinates for your location. North is 0°, east 90°, south 180° and west 270°. A tilt of 0° is flat; 90° is vertical. Coordinates stay on this page until you explicitly request a model estimate.

Approximate latitude (° north)Approximate longitude (° east; west is negative)Panel tilt from horizontal (°)Orientation clockwise from north (°)Silicon module mounting

Use at most two decimal places for latitude and longitude (roughly a kilometer). A roof-integrated module and a ventilated roof rack have different temperature assumptions. This model is for monofacial crystalline silicon, not a bifacial gain estimate.

The request contains no project name, notes, equipment list or battery inputs. The server caches this resource geometry to reduce repeat requests. Loading an example or saved project does not contact PVGIS.

Follow the energy through your system.

Array DC nameplate (kWp)Additional nearby shading loss (%)Other collection losses: wiring, soiling, etc. (%)Inverter efficiency (%)Daily AC load before charging (kWh/day)

DC nameplate is the sum of panel ratings at standard test conditions. PVGIS models temperature, reflection, spectral and terrain-horizon effects for a 1 kWp surface. Your additional nearby shading and collection losses apply to that output; inverter losses then produce the AC energy estimate.

What would you like to recharge?

Battery capacity (kWh)Capacity basisAssumed usable share of nominal capacity (%)Starting charge (% of usable capacity)Target charge (% of usable capacity)Charging pathCharge-path efficiency to stored energy (%)Charge-path input ceiling (kW)

Use battery-side energy, before discharge conversion. If capacity is already documented as usable, usable share is not applied again. Start/target percentages refer to that usable energy window. Charging efficiency includes losses from the selected charge-path input to energy actually stored.

ARRAY DC NAMEPLATE

Power rating at test conditions; not daily energy.

MODELED ANNUAL AC ENERGY

ENERGY TO STORE

The seasons change the budget.

Month	AC kWh/month Mean (modeled low–high)	PV DC / AC kWh/day	Stored surplus kWh/day	Equivalent generation days Mean (fast–slow)

Equivalent generation days are an energy budget, not a calendar-time promise. Monthly averages do not model cloudy sequences, hourly load/charging overlap, clipping, snow cover, battery temperature, charge taper, equipment compatibility or outages. The charge-path power floor is separate. Without enough surplus the battery does not recharge in this budget.

Low–high spans the same month across complete modeled years, not a confidence interval or a guarantee. Annual bounds are complete annual totals, not the sum of individual monthly extremes. All months use UTC.

Resource, coverage and calculation assumptions

PVGIS’s additional system efficiency is set to 100% so conversion and collection losses are applied visibly here, once. Additional shade is a constant energy reduction; actual nearby obstructions require a site-specific shade study. Storage degradation, controller/inverter power limits, degradation and battery discharge conversion are not modeled in the seasonal table.

PVGIS photovoltaic model documentation · Official resource API

Connect your saved assumptions.

Project

Importing a load treats its Wh/day as AC load before charging. A runtime capacity must state a battery-side boundary; delivered AC capacity cannot be silently treated as battery energy. These buttons change only the stated inputs, which remain editable.

Or new project name

Your projects Load planner Runtime calculator