Is it better to store solar or export it?

Almost always better to store (self-consume). Self-consumed solar saves 24.5p/kWh; exported solar earns only 4–15p/kWh. However, the battery cost means the FINANCIAL benefit of storing depends on battery price, tariff, and consumption patterns.

How much extra does a solar battery save?

A 10kWh battery with a 4kW solar system saves approximately £200–£400/year more than exporting. With a smart tariff (Octopus Flux), the additional saving can reach £400–£700/year through tariff arbitrage.

Should I get more panels or a battery?

If you have unused roof space, more panels offer a better ROI per pound than a battery. Each extra panel costs £200–£350 and returns £50–£100/year (payback: 3–6 years). A battery costs £3,000–£6,000 and returns £200–£400/year (payback: 10–19 years). Panels first, battery second.

What is the best SEG tariff for solar export?

For fixed rates: British Gas (~5.6p/kWh) or E.ON (~5.5p/kWh). For variable rates with a battery: Octopus Flux (8–24p/kWh, time-dependent). Octopus Flux with a battery earns the most but requires active management.

Solar Battery vs Exporting: Which Makes More Money?

Last updated: 18 March 2026

Independently written

Solar panels vs battery storage — comparing export vs self-consumption strategies — Every kWh you use saves 24.5p. Every kWh you export earns 4.5p. The maths is clear.

Is it better to use a solar battery or export to the grid?

Using solar electricity yourself (self-consumption) is worth 5–6x more than exporting it. Self-consumed solar saves 24.5p/kWh (the grid rate you avoid paying). Exported solar earns only 4–15p/kWh via SEG. A battery captures surplus daytime solar for evening self-use, converting 4.5p exports into 24.5p savings. The question is whether the battery's extra savings (£200–£400/year) justify its cost (£3,000–£6,000).

The Value Gap: Self-Use vs Export

Every kWh of solar electricity has two possible destinations:

Self-consumption (use it yourself): - Value: 24.5p per kWh (you avoid buying from the grid) - This is the grid electricity rate you do NOT pay

Export to grid (SEG): - Value: 4–15p per kWh (depending on your SEG tariff) - Typical fixed SEG: 4.5p/kWh - Best variable SEG (Octopus Flux peak): up to 24p/kWh for 3 hours/day

The gap: Self-use is worth 1.6–6x more than export, depending on your SEG tariff.

Without a battery: - You self-consume approximately 50% of solar generation - You export approximately 50% at the low SEG rate - Many valuable kWh are 'wasted' at 4.5p instead of saving you 24.5p

With a battery: - You self-consume approximately 80% of solar generation - You export only 20% (mainly in summer when generation exceeds even battery + home needs) - Far more kWh are captured at the high self-consumption value

Source: Ofgem Q1 2026 price cap; SEG rate data.

Battery storing surplus solar for evening self-consumption instead of exporting — A battery converts 4.5p exports into 24.5p savings — a 5x value increase per kWh.

The Financial Case for a Battery

4kW system — Export-only strategy (no battery): - Self-consumed: 2,000 kWh × 24.5p = £490 - Exported: 2,000 kWh × 4.5p = £90 - Total value: £580/year

4kW system — Battery strategy (10kWh battery): - Self-consumed: 3,200 kWh × 24.5p = £784 - Exported: 800 kWh × 4.5p = £36 - Total value: £820/year

Battery adds: £240/year in extra value

Battery cost: £4,500 Battery payback: 18.8 years standalone

With Octopus Flux tariff optimisation: - Export stored energy during peak (16:00–19:00) at 15–24p/kWh - Recharge from grid overnight at 7.5p/kWh - Additional tariff arbitrage: +£100–£250/year - Effective battery payback: 11–15 years

Key insight: A battery's pure solar self-consumption payback is long (~19 years). But combined with smart tariff arbitrage, it drops to 11–15 years — within the battery's 15–20 year lifespan.

Source: Ofgem; Octopus Flux tariff; Energy Saving Trust.

Energy flow showing battery capturing surplus before export — The battery sits between panels and grid — capturing surplus before it reaches the low-value export.

When a Battery IS Worth It

You are on a time-of-use tariff (Octopus Flux/Go) — tariff arbitrage dramatically improves battery ROI
You use most electricity in the evening — a battery shifts free solar to when you need it
Electricity prices rise — every 1p/kWh increase adds £32/year to battery savings (on a 4kW system)
You want backup power during outages — some batteries provide emergency power supply
You value energy independence — even if the pure financial ROI is marginal, energy autonomy has psychological value
Battery prices fall further — if replacement costs drop 30–50% by year 13, the lifetime ROI improves significantly
You have a large solar system (5kW+) — more surplus to capture = better battery utilisation

When Exporting Is Better (Skip the Battery)

You are on a high fixed SEG rate (12–15p/kWh) — the value gap between export and self-use is smaller
You are home during the day (retired, remote worker) — you already self-consume 60–70% without a battery
Your budget is tight — the £3,000–£6,000 battery cost could go toward more panels instead
You have a small system (2–3kW) — less surplus means less for the battery to capture
You plan to add an EV — a smart EV charger (Zappi) diverts surplus to your car at full 24.5p value, acting as a 'battery on wheels'

Battery adds total savings but reduces percentage ROI — A battery increases total savings but at a higher cost — the percentage ROI is lower than panels alone.

The Smart Compromise: Battery + Smart Tariff

The best battery strategy combines solar self-consumption with tariff arbitrage:

Daily cycle on Octopus Flux:

06:00–15:00: Solar charges battery + powers home. Export surplus at standard rate. 16:00–19:00: Battery exports to grid at PEAK Flux rate (15–24p/kWh). You earn the highest possible export value. 19:00–02:00: Home uses grid at standard rate. 02:00–05:00: Battery charges from grid at CHEAP Flux rate (7–10p/kWh). Full recharge at minimal cost. 05:00–06:00: Battery powers home until solar kicks in.

Result: You earn 15–24p/kWh for peak exports AND pay only 7–10p/kWh for overnight charging. The 8–14p/kWh arbitrage margin per kWh, across 10kWh per day, earns £300–£500/year in pure tariff profit — on top of solar self-consumption savings.

This is the strategy that makes batteries financially compelling today.

Source: Octopus Flux published rates; battery cycling calculations.

Smart tariff management with battery — maximising value from every kWh — Smart tariff + battery = optimal value extraction from every kWh you generate or buy.

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