Cost per kWh
ReliableGrid only 0.134
Solar, no battery 0.077
Solar + battery 0.071
The panels themselves 0.016
0.063 USD per kWh cheaper than the grid — a 47% lower cost per consumed kilowatt-hour.
Available now Last verified 22 September 2026
Commercial solar & battery storage in Spain
Market facts the model runs on
Primary-source values, each with its source and confidence level.
Grid tariff saved (self-consumption)
€0.170/kWh
Tarifasgasluz.com — commerciële 3.0TD-aanbiedingen voor bedrijven (TotalEnergies Clásica TE2, Contigo Energía Horas Plus) + Selectra.es toelichting IEE-belasting (pagina laatst bijgewerkt 23 juni 2026; geraadpleegd 22 sep 2026)
Export / feed-in remuneration
€0/kWh
BOE — Real Decreto 244/2019, art. 4.2.a (grens compensación simplificada) + OMIE dagmarktprijs 22 sep 2026 (RD 244/2019 (van kracht sinds 2019, ongewijzigd voor deze grens); OMIE-prijs 22 sep 2026)
Capacity tariff (monthly peak)
€21/kW/yr
Selectra.es — Calculadora de potencia eléctrica contratada (potencia-electrica-contratada) (geraadpleegd 22 sep 2026)
Fixed grid / service charge per year
€13/yr
Selectra.es — Factura de la luz: desglose y explicación de conceptos (alquiler de equipos de medida) (geraadpleegd 22 sep 2026)
Grid outage, crisis year
10h/yr
Wikipedia (EN) — 2025 Iberian Peninsula blackout (gebeurtenis 28 april 2025; pagina geraadpleegd 22 sep 2026)
Diesel generation cost avoided
€0/kWh
Solarnation assumption for reliable EU grids (2026-09-22)
Net-metering cap per installation
100 kW
BOE — Real Decreto 244/2019, de 26 de abril, por el que se regulan las condiciones administrativas, técnicas y económicas del autoconsumo de energía eléctrica, art. 4.2.a (van kracht sinds 6 april 2019, ongewijzigd op onderzoeksdatum (22 sep 2026))
High confidenceMediumTo be confirmed
Unit economics · Modelled estimate
What a kilowatt-hour costs a business in Spain
Grid electricity costs 0.134 USD per kWh. With solar sized at 120% of consumption and a battery that carries one night, every kilowatt-hour you consume costs 0.071 — grid purchase for the hours you are not covered, plus the installation written off, minus what you earn on exports.
- Grid reliability
- Reliable
- Population with grid access
- 100.0%
- Installation labour cost
- 0.54 × Belgium
- Solar yield
- 1,600 kWh/kWp
What shapes the cost here
Net saving over 25 years
1,907USD per kWp
Solar only, after deducting the installation. A 500 kWp roof: about 953,500 USD over the lifetime.
How long until it pays for itself
Against the grid tariffSolar only 5.6years
Solar + day-night battery 7.7years
Solar + three-day battery Over 10 years Three days of storage buys autonomy, not return.
Households, for reference
- Grid
- 0.255
- Solar + battery
- 0.128
- Payback, solar only
- 4.8 years
What is in the calculation
Self-consumption at the retail price and exports at 25% of it. Installation split into hardware (similar worldwide) and labour, scaled per country. Solar written off over 25 years with output declining to 85%, batteries over 15 years.
What is not included
No discounting, maintenance, financing, subsidies, import duties or price rises. Peak shaving and arbitrage are left out until we hold the tariff data per country — so a real case is usually better than this, not worse.
These are modelled averages for the country, meant for comparing markets. Your own case runs on your roof, your load profile and your tariff — the configurator computes it with the rules that apply here.
How each figure is calculated
| Figure | Unit | Definition |
|---|---|---|
| Installation labour cost | × | Cost of installation labour relative to Belgium (1.0). Eurostat construction labour cost for Europe, elsewhere derived from GDP per capita. Hardware is priced the same worldwide; only the labour part is scaled. |
| Grid access | % | Share of the population with an electricity connection (World Bank, most recent year). |
| Grid reliability | 1 = reliable (rare outages), 2 = moderate (occasional outages or regional load shedding), 3 = unreliable (frequent outages or structural load shedding). The tier decides what solar is compared against: the grid tariff, a diesel generator, or both. | |
| Grid price | USD/kWh | All-in retail price of a kilowatt-hour taken from the grid, the baseline every other figure is measured against. |
| Solar cost over 25 years | USD/kWh | Installation cost divided by everything the panels produce over 25 years, with output declining to 85 percent. The cost of the panels themselves, not of a consumed kilowatt-hour. |
| Cost per kWh with solar | USD/kWh | What a consumed kilowatt-hour costs with solar and no battery: grid purchase for the uncovered hours, plus the installation written off, minus the revenue on exported power. |
| Cost per kWh with solar and battery | USD/kWh | The same calculation with a battery that carries one night, written off over 15 years. |
| Cost per kWh against diesel | USD/kWh | Cost of a consumed kilowatt-hour where the alternative is a generator: solar with three days of storage, with the generator covering what is left. |
| Net saving over 25 years | USD/kWp | What one kWp of solar saves over 25 years after deducting the installation: self-consumption at the retail price plus exports at a quarter of it. |
| Payback, solar only | years | Years until the annual saving has paid back the installation, without discounting. Longer than ten years is reported as "over ten years": at that horizon the assumptions matter more than the outcome. |
| Payback, solar and battery | years | The same, for solar plus a battery that carries one night. |
| Payback, solar and three-day battery | years | The same, for solar plus three days of storage measured against the grid tariff. Three days of storage buys autonomy; against a cheap tariff it rarely pays for itself. |
| Payback against diesel | years | Years until solar with three days of storage has paid for itself against the fuel and maintenance of a generator. |
| Annual saving | USD/kWp/year | What one kWp of solar saves in a year: self-consumption at the retail price plus exports at a quarter of it. |
Solar autonomy scorecard · Modelled estimate
How far solar and a battery go in Spain
With PV sized at 120% of annual consumption, a battery that carries one night covers 74% of the demand in Spain; a battery holding three days of consumption lifts that to 81%.
Generation is moderately seasonal: the strongest month yields 3.9× the weakest.
In the three leanest months 15.1% of the annual consumption stays uncovered (202 kWh per kWp). Short-term storage cannot close that gap; it takes the grid, a backup source or seasonal storage.
Businesses pay on average 0.134 USD per kWh, households 0.255 USD per kWh.
The configurator for Spain calculates with 1,621 kWh/kWp, a site-specific reference (European Commission JRC — PVGIS 5.3 (PVGIS-SARAH3) (PVGIS 5.3, queried 2026-09-22)). This scorecard uses 1,600 kWh/kWp, a rounded national estimate, so that all countries are compared on the same basis. Its seasonal figures likewise come from the climate model, not from the site-specific monthly profile above.
The market facts above use the tariff a medium-sized business actually pays in Spain: €0.170 per kWh. The business price in this scorecard is a cross-country average over all business tariff classes, used only to compare countries.
- Electricity price, businesses
- 0.134USD/kWh
- Electricity price, households
- 0.255USD/kWh
- PV yield
- 1,600kWh/kWp
- Seasonal spread
- 3.9×strongest ÷ weakest month
- Three-day battery
- 11.0kWh/kWp
- Lean-season deficit
- 15.1%of annual consumption
Two battery scenarios
Both with PV sized at 120% of annual consumption.
Day-night battery
Stores the daytime surplus for the following night.
- Self-sufficiency
- 74%
- Self-consumption
- 62%
- Battery size
- 2.0 kWh/kWp
Three-day battery
Holds three full days of consumption, to ride through overcast spells.
- Self-sufficiency
- 81%
- Self-consumption
- 67%
- Battery size
- 11.0 kWh/kWp
Generation and demand through the year
Share of the annual total per month. Modelled from latitude and climate class, not measured.
- Weakest month
- 3.2%
- Strongest month
- 12.7%
- Seasonal spread
- 3.9×
- Consumption profile
- double peak (heating and cooling)
- Climate class
- Mediterranean
PV yield / Consumption — Spain
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PV yield (%) | 3.5 | 4.9 | 7.2 | 10.8 | 11.7 | 12.2 | 12.7 | 12.7 | 11.0 | 6.1 | 4.1 | 3.2 |
| Consumption (%) | 9.6 | 9.2 | 8.3 | 7.5 | 7.1 | 7.5 | 8.8 | 8.8 | 7.5 | 7.5 | 8.8 | 9.6 |
A winter deficit short-term storage cannot close
In the three leanest months 15.1% of the annual consumption stays uncovered (202 kWh per kWp). Short-term storage cannot close that gap; it takes the grid, a backup source or seasonal storage.
Every modelled value for Spain
The same fields as the downloadable dataset, with their definition.
| Variable | Value | Definition |
|---|---|---|
Continentcontinent | Europe | Continent the country belongs to. |
Countrycountry | Spain | Country name in English. |
Regionregion | — | Climate region within the country; empty when the country is modelled as one region. |
Electricity price, householdsprice_households_usd_mwh | 0.255 USD/kWh USD/MWh | Average all-in retail price for households, national average. Static average, not a dynamic or market price. |
Electricity price, businessesprice_businesses_usd_mwh | 0.134 USD/kWh USD/MWh | Average all-in retail price for businesses, national average. Empty where the source publishes no business price. |
PV yieldpv_yield_kwh_kwp | 1,600 kWh/kWp/year | Estimated annual yield of a well-oriented PV system per installed kWp, rounded to the nearest fifty. |
Weakest month shareweakest_month_share_pct | 3.2% | Share of the annual yield produced in the weakest of the twelve months (the wet season in monsoon climates, winter elsewhere). A perfectly flat year gives one twelfth per month. |
Strongest month sharestrongest_month_share_pct | 12.7% | Share of the annual yield produced in the strongest of the twelve months. |
Seasonal spreadseasonal_spread | 3.9× | Strongest month divided by weakest month. Close to one means flat generation all year; above ten means strongly seasonal. |
Self-consumption, day-night batteryself_consumption_daynight_pct | 62% | Share of the PV generation that is used on site with a battery sized to carry one night. Equals self-sufficiency divided by the oversizing factor. |
Self-sufficiency, day-night batteryself_sufficiency_daynight_pct | 74% | Share of the annual consumption covered by PV plus a battery sized to carry one night. Never above one hundred percent. |
Battery size, day-nightbattery_daynight_kwh_kwp | 2 kWh/kWp | Battery capacity needed to carry the night-time share of one day of consumption, per kWp of PV. |
Self-consumption, three-day batteryself_consumption_3day_pct | 67% | Share of the PV generation that is used on site with a battery holding three days of consumption. |
Self-sufficiency, three-day batteryself_sufficiency_3day_pct | 81% | Share of the annual consumption covered by PV plus a battery holding three days of consumption. This is the figure the energy-island assessment is based on. |
Battery size, three-daybattery_3day_kwh_kwp | 11 kWh/kWp | Battery capacity equal to three days of consumption, per kWp of PV. |
Consumption profileconsumption_profile | double peak (heating and cooling) | Assumed seasonal shape of demand for the climate: winter peak (heating), summer peak (cooling), double peak or near-flat. |
Lean-season deficitwinter_deficit_pct | 15.1% | Demand that stays unmet during the three consecutive lowest-yield months, despite the three-day battery, as a share of annual consumption. It is what remains for the grid, a backup generator or seasonal storage. |
Lean-season deficit, absolutewinter_deficit_kwh_kwp | 201.5 kWh/kWp | The same deficit expressed in kWh per kWp of PV. |
Latitudelatitude | 40.3 ° | Representative latitude used by the astronomical yield model; negative is the southern hemisphere. |
Climate classclimate | Mediterranean | Climate class that sets the monthly cloud pattern, day-to-day variability and consumption profile. |
Monthly yield sharesmonthly_yield_share_pct | 3.5 · 4.9 · 7.2 · 10.8 · 11.7 · 12.2 · 12.7 · 12.7 · 11.0 · 6.1 · 4.1 · 3.2 | Twelve values, January to December: share of the annual PV yield per month. Modelled from latitude and climate class, not measured. |
Monthly consumption sharesmonthly_consumption_share_pct | 9.6 · 9.2 · 8.3 · 7.5 · 7.1 · 7.5 · 8.8 · 8.8 · 7.5 · 7.5 · 8.8 · 9.6 | Twelve values, January to December: assumed share of the annual consumption per month. |
How the model works
Monthly PV yield comes from an astronomical model (latitude, declination, tilt) multiplied by a climate pattern for cloud and rain. Day-to-day variability follows a gamma distribution per climate; multi-day coverage is the sum of independent days. Seasonal consumption is set per climate: a winter peak for heating, a summer peak for cooling, a double peak in Mediterranean climates.
Fixed assumptions
PV sized at 120% of annual consumption; 55% of consumption falls outside direct sun hours; battery round-trip efficiency 92%.
What it is not
An analytical approximation, not an hourly simulation of your site. Prices are static national averages, not dynamic or market prices. The deficit is not a storage recommendation: it quantifies what remains for grid, backup or seasonal storage.
Sources
- Electricity prices: national averages, Q2 2026.
- PV yield: Estimates in line with Global Solar Atlas (World Bank / Solargis), rounded to the nearest 50 kWh/kWp.
- Licence: CC BY 4.0.
- Dataset updated 2026-09-22
Local partner
Installation, permits and after-sales run through our local partner; Solarnation designs, sizes and finances. Your case study is handed over to them after the last step.
Local partner to be announced.
Spain — solar autonomy in short
Can a business in Spain go off-grid with solar and a battery?
With PV sized at 120% of annual consumption, a battery that carries one night covers 74% of the demand in Spain; a battery holding three days of consumption lifts that to 81%. In the three leanest months 15.1% of the annual consumption stays uncovered (202 kWh per kWp). Short-term storage cannot close that gap; it takes the grid, a backup source or seasonal storage.
How large a battery does solar autonomy take in Spain?
Per kWp of PV, carrying one night takes about 2.0 kWh of battery and holding three days of consumption about 11.0 kWh. With the three-day battery, self-sufficiency reaches 81%.
How much does solar generation in Spain vary between seasons?
A well-oriented system yields about 1,600 kWh per kWp a year. The strongest month produces 3.9× the weakest: 12.7% against 3.2% of the annual yield.