Charging a 2026 Rivian R1S Performance Dual Large (20in) at home in Idaho

A 2026 Rivian R1S Performance Dual Large (20in) draws 42.9 kWh per 100 miles per the EPA; at Idaho's 12.8¢/kWh residential rate that's $5.49 per 100 miles charged at home, versus $16.02 for a 25.5-mpg gas car covering the same distance. That works out to 65.7% cheaper per mile than gasoline in Idaho — charging at home costs a fraction of what gas would here.

What a year of driving costs

Idaho owners putting 15,000 annual miles on a 2026 Rivian R1S Performance Dual Large (20in) spend about $823 on home electricity, compared to about $2,403 a gas-car equivalent would spend on fuel. Call it about $1,580 saved annually, at this mileage.

Cost of a full charge

At Idaho's rate, fully covering this 2026 Rivian R1S Performance Dual Large (20in)'s 300-mile EPA range costs about $16.46 (128.6 kWh) — the energy the EPA test actually used, not the battery's rated size.

How this compares nationally

Among all 20,400 state-and-model combinations this site tracks, charging a 2026 Rivian R1S Performance Dual Large (20in) in Idaho ranks 6,926 for cost savings versus gas — 1 being the best deal nationally. Separately, the Rivian R1S Performance Dual Large (20in) ranks 317 of 400 EV models for raw efficiency, and Idaho ranks 3 of 51 for cheapest residential electricity.

Getting set up to charge a 2026 Rivian R1S Performance Dual Large (20in) at home

Everything above is the per-mile and per-year cost once a home charger exists — getting one installed is a separate electrical job whose price depends on your panel and wiring, not the state average used here.

Ask a licensed Idaho electrician to quote the install before this math becomes a real decision.

More on how this number was built

See the methodology guide for exactly which EIA and EPA figures feed 2026 Rivian R1S Performance Dual Large (20in)'s cost in Idaho. Idaho is one of the cheapest states for home electricity — the guide to why the cost varies so much by state covers what drives that.