Solar Panels & Your Electricity Bill: What Changes

When you install solar panels, your electricity billing changes in two ways:

1. Your import bill drops: During daylight hours, your home uses free solar electricity instead of buying from the grid. Your smart meter records fewer imported units, so your bill falls. How much depends on how much solar you use directly (self-consumption rate).

2. You earn export income: When your panels generate more than you use, the surplus flows to the grid. Under the Smart Export Guarantee (SEG), your energy supplier pays you for every kWh exported. This appears as a credit or separate payment.

Your electricity bill does NOT disappear entirely. You still buy grid electricity: - At night (panels produce nothing) - In winter evenings (low generation + high consumption) - During heavy usage periods (cooking, electric heating, EV charging) that exceed panel output

Typical bill reduction: - Before solar (average UK household): £900–£1,100/year - After solar (no battery, 50% self-consumption): £400–£550/year - After solar (with battery, 80% self-consumption): £150–£300/year

Source: Ofgem Q1 2026 price cap (24.5p/kWh); Energy Saving Trust.

Before solar (3-bed semi, 2 adults): - Annual electricity use: 3,800 kWh - Cost at 24.5p/kWh: £931/year (£78/month) - Standing charge: £365/year (£30/month) - Total annual bill: £1,296 (£108/month)

After solar — 4kW system, no battery: - Solar generated: 4,000 kWh - Self-consumed (50%): 2,000 kWh (free) - Exported (50%): 2,000 kWh (earning SEG at 4.5p = £90) - Grid import needed: 3,800 - 2,000 = 1,800 kWh - Grid import cost: 1,800 × 24.5p = £441 - Standing charge: £365 (unchanged) - SEG income: -£90 - Net annual bill: £716 (£60/month) - Saving: £580/year (£48/month)

After solar — 4kW system + 10kWh battery: - Self-consumed (80%): 3,200 kWh (free) - Exported (20%): 800 kWh (earning £36) - Grid import needed: 3,800 - 3,200 = 600 kWh - Grid import cost: 600 × 24.5p = £147 - Standing charge: £365 - SEG income: -£36 - Net annual bill: £476 (£40/month) - Saving: £820/year (£68/month)

*Note: You still pay the standing charge regardless of solar. This is typically £1/day (£365/year) and is unavoidable while grid-connected.*

Source: Based on Ofgem Q1 2026 price cap and typical domestic consumption.

With a smart meter (required for SEG), your meter tracks two separate flows:

Import: Electricity you buy from the grid (charged at your standard tariff rate) Export: Electricity your panels send to the grid (paid at your SEG rate)

Your in-home display (IHD) shows real-time usage and generation. During the day, you may see your import reading drop to zero or near-zero when solar is covering your needs.

What your smart meter does NOT show: - How much solar you use directly (self-consumption) — this is not metered separately - Total solar generation — you need an inverter monitoring app for this - Whether your battery is charging or discharging

To get the full picture, use your inverter's monitoring app (GivEnergy, SolarEdge, Enphase etc.) alongside your smart meter data.

Source: Ofgem smart meter guidelines.

Yes. The standing charge (approximately £1/day or £365/year) is a fixed daily fee for being connected to the grid. It applies regardless of how much electricity you use or generate.

The only way to avoid the standing charge is to disconnect from the grid entirely (go off-grid), which is impractical and not cost-effective for most UK homes.

Some suppliers offer zero-standing-charge tariffs, but these typically have a higher unit rate that may cancel out the benefit — especially for solar homes that import relatively little.

Source: Ofgem standing charge guidance.

If your electricity bill has not dropped after installing solar, investigate these possible causes:

1. Your usage has increased — did you buy an EV, add electric heating, or work from home? Higher consumption offsets solar savings. 2. System fault — check your inverter for error lights. Check your monitoring app for output data. Zero output on a sunny day indicates a problem. 3. Wrong tariff — some tariffs have high unit rates that undermine savings. Switch to a competitive tariff. 4. Low self-consumption — if nobody is home during the day, most solar is exported at low SEG rates (4p) instead of used directly (saving 24.5p). A battery or smart appliance scheduling helps. 5. Estimated readings — if your supplier estimated your usage rather than reading the smart meter, the bill may not reflect actual (lower) imports.

Contact your installer if your monitoring shows normal generation but your bills remain high — there may be a metering or billing error.