{"name":"Unit economics by country — Solarnation","description":"What a consumed kilowatt-hour costs per country: from the grid, with solar, with solar plus a battery, and against a diesel generator where the grid is unreliable. Plus payback and the net 25-year saving, for households and for businesses. Modelled estimates, not measurements.","url":"https://global.solarnation.be/countries/belgium","updated":"2026-09-22","licence":"CC BY 4.0","currency":"USD","assumptions":{"diesel_usd_kwh":0.35,"export_value_fraction_of_retail":0.25,"pv_lifetime_years":25,"battery_lifetime_years":15,"pv_output_at_year_25":0.85,"pv_oversizing":1.2,"price_escalation_in_escalated_irr":0.035,"capex_eur":{"pv_residential":[700,400],"battery_residential":[400,150],"pv_commercial":[450,200],"battery_commercial":[230,70]},"excluded":"discounting, maintenance, financing, subsidies, import duties and price escalation"},"reporting":{"payback_horizon_years":10,"note":"Paybacks longer than 10 years are reported on the site as \"over 10 years\"; this dataset carries the computed value."},"market_streams_rule":"Peak shaving and arbitrage are counted only for the markets where tariff data is available; elsewhere those fields are zero, which means missing data rather than a market without value. Curtailment reduces the export remuneration by the share of exported solar that earns nothing.","return_rule":"IRR is for solar without a battery over its full life at today's price; the escalated variant adds 4% a year. Battery cases carry no IRR.","reference_rule":"Grid reliability tier 1 → the grid tariff, tier 3 → a diesel generator, tier 2 → both.","columns":[{"field":"labour_cost_multiplier","csv_header":"Labour cost multiplier (Belgium=1)","unit":"×","label":"Installation labour cost","definition":"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."},{"field":"grid_access_pct","csv_header":"Grid access (% of population, World Bank)","unit":"%","label":"Grid access","definition":"Share of the population with an electricity connection (World Bank, most recent year)."},{"field":"grid_reliability_tier","csv_header":"Grid reliability tier (1-3)","unit":null,"label":"Grid reliability","definition":"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."},{"field":"curtailed_export_pct","csv_header":"Worthless PV export share (%, curtailment)","unit":"%","label":"Export that earns nothing","definition":"Share of the exported solar that is worth nothing because prices are negative or an export cap applies. Already deducted from the export revenue in the cost columns."},{"field":"grid_usd_kwh","csv_header":"Grid price <segment> (USD/kWh)","unit":"USD/kWh","label":"Grid price","definition":"All-in retail price of a kilowatt-hour taken from the grid, the baseline every other figure is measured against."},{"field":"solar_lcoe_usd_kwh","csv_header":"Solar PV cost 25y <segment> (USD/kWh)","unit":"USD/kWh","label":"Solar cost over 25 years","definition":"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."},{"field":"mix_pv_usd_kwh","csv_header":"Mix cost PV only <segment> (USD/kWh)","unit":"USD/kWh","label":"Cost per kWh with solar","definition":"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."},{"field":"mix_pv_battery_usd_kwh","csv_header":"Mix cost PV + day-night battery <segment> (USD/kWh)","unit":"USD/kWh","label":"Cost per kWh with solar and battery","definition":"The same calculation with a battery that carries one night, written off over 15 years."},{"field":"mix_pv_battery_market_usd_kwh","csv_header":"Mix cost PV + battery incl. market streams <segment> (USD/kWh)","unit":"USD/kWh","label":"Cost per kWh with solar, battery and market income","definition":"The same cost per consumed kilowatt-hour, minus what the battery earns on the monthly peak charge and on the daily price spread. Only for the markets where we hold the tariff data; elsewhere this equals the figure without market income."},{"field":"mix_pv_3day_vs_diesel_usd_kwh","csv_header":"Mix cost PV + 3-day battery vs diesel <segment> (USD/kWh)","unit":"USD/kWh","label":"Cost per kWh against diesel","definition":"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."},{"field":"peak_shaving_usd_kwp_year","csv_header":"Peak shaving value (USD/kWp/year) <segment>","unit":"USD/kWp/year","label":"Peak shaving value","definition":"What shaving the monthly peak saves per kWp of solar per year, in markets where the grid bills a measured peak rather than a contracted capacity."},{"field":"arbitrage_usd_kwp_year","csv_header":"Arbitrage value (USD/kWp/year) <segment>","unit":"USD/kWp/year","label":"Arbitrage value","definition":"What charging cheap and using expensive earns per kWp per year on the spare battery capacity, after deducting battery wear."},{"field":"net_saving_25y_usd_kwp","csv_header":"Net 25-year saving PV only <segment> (USD per kWp)","unit":"USD/kWp","label":"Net saving over 25 years","definition":"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."},{"field":"payback_pv_years","csv_header":"Payback PV only <segment> (years)","unit":"years","label":"Payback, solar only","definition":"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."},{"field":"payback_pv_battery_years","csv_header":"Payback PV + day-night battery <segment> (years)","unit":"years","label":"Payback, solar and battery","definition":"The same, for solar plus a battery that carries one night."},{"field":"payback_pv_3day_years","csv_header":"Payback PV + 3-day battery <segment> (years)","unit":"years","label":"Payback, solar and three-day battery","definition":"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."},{"field":"payback_vs_diesel_years","csv_header":"Payback PV + 3-day battery vs diesel <segment> (years)","unit":"years","label":"Payback against diesel","definition":"Years until solar with three days of storage has paid for itself against the fuel and maintenance of a generator."},{"field":"irr_pv_pct","csv_header":"IRR PV only <segment> (%, flat prices)","unit":"%","label":"Return (IRR)","definition":"Internal rate of return of solar without a battery over its 25-year life, at today’s electricity price. The rate at which the savings exactly pay back the installation — comparable with any other investment. No maintenance, financing, subsidies or price rises, so a real project usually does better."},{"field":"irr_pv_escalated_pct","csv_header":"IRR PV only <segment> (%, prices +3.5%/yr)","unit":"%","label":"Return with rising prices","definition":"The same return with the electricity price rising every year by the rate in the metadata. Solarnation uses this rate as its house default in payback work; it is a single assumption applied to every country, so treat it as a direction, not a forecast."},{"field":"annual_saving_pv_usd_kwp","csv_header":"Annual saving PV only <segment> (USD per kWp)","unit":"USD/kWp/year","label":"Annual saving","definition":"What one kWp of solar saves in a year: self-consumption at the retail price plus exports at a quarter of it."}],"country":"Belgium","iso2":"BE","continent":"Europe","reference":"net","regions":[{"continent":"Europe","country":"Belgium","region":"","labour_cost_multiplier":1,"grid_access_pct":100,"grid_reliability_tier":1,"grid_reliability_label":"reliable","curtailed_export_pct":7,"households_grid_usd_kwh":0.406,"households_solar_lcoe_usd_kwh":0.051,"households_mix_pv_usd_kwh":0.254,"households_mix_pv_battery_usd_kwh":0.231,"households_mix_pv_battery_market_usd_kwh":0.218,"households_peak_shaving_usd_kwp_year":4,"households_arbitrage_usd_kwp_year":6.5,"households_mix_pv_3day_vs_diesel_usd_kwh":0.485,"households_net_saving_25y_usd_kwp":3162,"households_annual_saving_pv_usd_kwp":193,"households_payback_pv_years":6.2,"households_payback_pv_battery_years":7.5,"households_payback_pv_3day_years":18.2,"households_payback_vs_diesel_years":24.6,"households_irr_pv_pct":15.1,"households_irr_pv_escalated_pct":18.5,"businesses_grid_usd_kwh":0.263,"businesses_solar_lcoe_usd_kwh":0.03,"businesses_mix_pv_usd_kwh":0.161,"businesses_mix_pv_battery_usd_kwh":0.14,"businesses_mix_pv_battery_market_usd_kwh":0.126,"businesses_peak_shaving_usd_kwp_year":4.8,"businesses_arbitrage_usd_kwp_year":6.5,"businesses_mix_pv_3day_vs_diesel_usd_kwh":0.315,"businesses_net_saving_25y_usd_kwp":2116,"businesses_annual_saving_pv_usd_kwp":125,"businesses_payback_pv_years":5.6,"businesses_payback_pv_battery_years":6.7,"businesses_payback_pv_3day_years":15.6,"businesses_payback_vs_diesel_years":13.6,"businesses_irr_pv_pct":16.8,"businesses_irr_pv_escalated_pct":20.2}],"all_countries_url":"https://global.solarnation.be/data/unit-economics/all.json"}