Household Tariff Arbitrage Analysis

Best EV / Super Off-Peak Rate

5.99c/kWh

Pinergy Lifestyle Night Time (2 AM - 5 AM). No EV required. Inc. VAT.

Biggest Same-Supplier Spread

45.73c/kWh

Energia EV Smart Drive Plus: 11.03c (night, with 10% disc.) vs 56.76c (peak)

Best Practical Spread

37.80c/kWh

Bord Gais EV Smart: 8.45c (EV) vs 46.25c (peak). No EV ownership required.

Dynamic Pricing Mandate

1 June 2026

Top 5 suppliers must offer dynamic tariffs. Rates update every 30 min based on wholesale.

Best Payback Period

~5.7 years

Budget 10 kWh system on Bord Gais EV plan. No SEAI grant for standalone battery.

Smart Meter Penetration

80%+

Over 2 million installed (Sep 2025). ~87% of Irish households. Required for TOU tariffs.

Night / EV Rate Comparison (c/kWh inc. VAT)

Effective Annual Cost: Night Rate + Standing Charge

Peak vs. EV/Night Price Spread (c/kWh)

Hypothetical 10 kWh BESS Annual Revenue Breakdown

Supplier Comparison Table

Click column headers to sort. All rates c/kWh inc. VAT. Standing charges EUR/year inc. VAT. Verified 2026-02-13.

Supplier ▲▼	Plan ▲▼	EV/Night Boost (c/kWh) ▲▼	Night (c/kWh) ▲▼	Day (c/kWh) ▲▼	Peak (c/kWh) ▲▼	EV Window ▲▼	Standing (EUR/yr) ▲▼	Spread (c/kWh) ▲▼	EV Required? ▲▼

Arbitrage Savings Calculator

Model annual savings from battery storage tariff arbitrage. Adjust inputs or use supplier presets.

Battery Size (kWh)

Common sizes: 5, 10, 13.5 (Tesla Powerwall 3)

Peak / Day Rate (c/kWh)

Night / EV Rate (c/kWh)

Cycles per Day

Typically 1 cycle/day (charge at night, discharge during peak)

Round-Trip Efficiency (%)

Lithium-ion: 85-95%. Lead-acid: 75-85%.

Operating Days per Year

Account for holidays, downtime, low-demand days (typical: 330-350)

System Installed Cost (EUR, inc. VAT)

Budget 10 kWh ~EUR 6,150. Tesla Powerwall 3 ~EUR 14,760. No SEAI grant for standalone battery.

Results

Gross Spread --

Effective Spread (after efficiency loss) --

Daily Saving --

Energy Arbitraged per Year --

Annual Saving --

Saving per kWh of Battery --

Simple Payback Period --

10-Year Net Return --

10-Year ROI --

Dynamic Pricing: The June 2026 Mandate

CRU-mandated dynamic tariffs will reshape the Irish electricity market.

DEADLINE
1 June 2026

The five largest Irish electricity suppliers -- Electric Ireland, SSE Airtricity, Bord Gais Energy, Energia, and PrePay Power/Yuno -- must each offer at least one standard dynamic tariff by this date.

Prices will update every 30 minutes based on the Day-Ahead Market (DAM) wholesale price. Rates are known 12-24 hours in advance, enabling intelligent battery scheduling the evening before.

Four-Component Structure

1. Standing charge (fixed daily)
2. Base unit rate (fixed or variable, known ahead)
3. Dynamic unit rate (varies every 30 min, DAM-based, capped at EUR 0.50/kWh)
4. Taxes & levies (VAT 9% + PSO EUR 1.46/month)

Consumer Protection

Price cap of EUR 0.50/kWh on the dynamic component limits exposure during extreme price events. CRU recommends bill protection and restricted early termination fees during a phase-in period.

Battery Arbitrage Impact

Negative wholesale prices (common during high-wind periods) could create charging opportunities below 0c/kWh. Less predictable than fixed TOU but potentially much larger spreads. Battery scheduling software becomes critical.

Key Caveat

This is NOT a pure wholesale pass-through like UK Octopus Agile. Suppliers have discretion over how much of the rate is "dynamic" vs "base." No supplier is yet offering a dynamic tariff. Octopus Energy has NOT launched in Ireland as of Feb 2026.

Key Claims & Confidence Tiers

C1 Verified (multiple sources) C2 Well-sourced (single reliable source) C3 Inferred (calculated) C4 Anecdotal

Pinergy Lifestyle Night Time: 5.99c/kWh inc VAT (2 AM - 5 AM). Not EV-specific. All other hours 41.77c/kWh. Standing charge EUR 283.46/year.

Source: Pinergy Tariffs (verified 2026-02-13). Cross-verified with Selectra, Kilowatt.ie.

Bord Gais EV Smart: 8.45c/kWh (2 AM - 5 AM), peak 46.25c, day 33.16c, night 25.02c. No EV ownership required. Standing charge EUR 325.52/year.

Source: Bord Gais Compare Plans, EV Price Plans (verified 2026-02-13).

Energia EV Smart Drive Plus: 12.26c/kWh (11.03c with 10% disc.) during 2 AM - 6 AM (4-hour window). Peak 56.76c -- highest of all suppliers. Standing charge EUR 265.01/year.

Source: Energia Tariffs (verified 2026-02-13).

Electric Ireland Night Boost EV: 10.52c/kWh (8.84c with 16% DD disc.) during 2 AM - 4 AM (shortest window: 2 hours). Day 36.34c. Highest standing charge: EUR 328.58/year.

Source: Electric Ireland Night Boost EV (verified 2026-02-13).

SSE Airtricity Smart EV Charge: 8.58c/kWh during 2 AM - 5 AM.

Source: Selectra - Best EV Tariff Ireland (2026-02-11). Single source, not cross-verified.

Dynamic pricing mandate: Five largest suppliers must offer a standard dynamic tariff by 1 June 2026. Rates update every 30 minutes, based on Day-Ahead Market, capped at EUR 0.50/kWh.

Sources: Kilowatt.ie, Energia, CRU Decision Paper.

No SEAI grant for standalone battery storage. Solar PV grant (EUR 1,500 from Jan 2026) applies to PV only. Batteries qualify for 0% VAT only when installed with solar PV.

Sources: SEAI, GreenTech Review.

Non-EV owners CAN access EV tariff rates. Bord Gais explicitly confirms. Pinergy's plan isn't even EV-specific. This means 5.99c-8.45c super off-peak rates are accessible for pure battery arbitrage.

Sources: Bord Gais FAQ, Kilowatt.ie (verified 2026-02-13).

Best payback ~5.7 years (budget 10 kWh at EUR 6,150 on Bord Gais EV, 37.80c spread, 90% efficiency, 330 cycles/year). Conservative case: ~11.2 years (EI night vs day, 18.42c spread).

Calculated from verified supplier rates and battery installation costs.

EV tariff plans yield EUR 110-150/kWh/year arbitrage -- roughly 2x the ~EUR 62/kWh/year from conservative night-vs-day spreads. Choice of tariff is arguably more important than choice of battery.

Calculated from verified spreads. Original ~EUR 62 estimate from LessWrong analysis confirmed as reasonable for conservative case.

Battery installed costs: 5 kWh EUR 3,000-5,600; 10 kWh EUR 4,500-7,000; Tesla Powerwall 3 (13.5 kWh) EUR 11,000-13,000. Add 23% VAT for standalone (no solar PV).

Sources: Solar Energy Broker, GreenTech Review.