How to Sell Excess Solar Power in the UK: Export Tariffs Explained

riter focused on practical UK home solar decisions, installation economics, and policy changes that affect payback.

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When UK homeowners crunch the numbers on solar panels, the export income often gets treated as an afterthought.

That's a mistake.

For a typical 4kW south-facing system in the Midlands, export payments can contribute £150–£250 annually—roughly 15–20% of the total financial benefit.

Get your export arrangement wrong, and you're essentially giving away electricity you paid to generate.

The good news: the UK export market has become genuinely competitive.

The Smart Export Guarantee (SEG), introduced in January 2020, replaced the Feed-in Tariff's generous but closed scheme with a market-driven approach.

Some SEG tariffs now pay over 15p per kWh—more than many households pay for imported electricity during off-peak hours.

Understanding how export tariffs work, what rates are available, and how to optimise your system for export income can meaningfully improve your solar investment returns.

The Smart Export Guarantee: How It Actually Works

The SEG requires licensed electricity suppliers with more than 150,000 domestic customers to offer an export tariff to small-scale generators.

Crucially, suppliers set their own rates—the government only mandated that the tariff must be "above zero." This created immediate variation: when the SEG launched, some suppliers offered 1.5p/kWh whilst others pushed above 5p/kWh.

By 2024, the spread had widened dramatically, with some tariffs exceeding 16p/kWh.

Unlike the old Feed-in Tariff, the SEG pays only for electricity you actually export.

There's no "generation tariff" paying you for everything your panels produce.

This means your export income depends entirely on what you don't self-consume—making battery storage and consumption timing critical factors in overall economics.

To qualify for SEG payments, your installation must be MCS-certified (Microgeneration Certification Scheme).

This isn't optional—suppliers will reject your application without an MCS certificate number.

The MCS requirement ensures your system meets safety and quality standards, but it also means using a certified installer is essential from day one.

SEG Eligibility Requirements

The SEG applies to installations up to 5MW capacity—far beyond typical domestic needs.

For most homeowners, the relevant thresholds are straightforward:

• Solar PV systems up to 50kW capacity (domestic systems typically 3–6kW)

• MCS certification for both the panels and the installation

• A smart meter capable of measuring export (SMETS2 or dedicated export meter)

• Permission from your Distribution Network Operator (DNO) for the connection

• Energy Performance Certificate (EPC) rating of D or above for some supplier tariffs

The EPC requirement catches some homeowners off guard.

Whilst the SEG itself doesn't mandate a minimum EPC rating, several suppliers—including British Gas and EDF—require EPC D or above for their best export rates.

If your home has a poor energy rating, you might need to improve insulation or heating controls before accessing premium tariffs.

Current Export Tariff Rates: What's Actually Available

Export tariff rates have risen substantially since the SEG's introduction, driven by wholesale electricity price increases and genuine competition between suppliers.

However, the best rates often come with strings attached: requirements to import electricity from the same supplier, time-of-use variations, or capacity limits.

The table below shows representative SEG tariffs available in early 2024.

Rates change frequently—always check directly with suppliers before deciding.

The standout option for many homeowners is Octopus Energy's Outgoing Agile tariff.

Rather than a fixed rate, it pays a variable price that tracks wholesale electricity markets—meaning you can earn significantly more for exporting during peak demand periods.

On winter evenings when wholesale prices spike, export payments can exceed 30p/kWh.

Conversely, on sunny summer afternoons when solar generation floods the grid, rates can drop below 5p/kWh.

The Export Process: From Panels to Payment

Understanding the practical mechanics of export helps avoid delays and maximises income.

The process involves several parties: your installer, the DNO, your energy supplier, and the MCS certification body.

Step 1: DNO Approval (Before Installation)

Your installer must notify your local Distribution Network Operator before connecting your solar system to the grid.

For most domestic installations under 3.68kW per phase, this is a simple notification process using a G98 form.

The DNO has 28 days to object, though in practice most approvals are automatic.

For larger systems (3.68kW–50kW), a G99 application is required.

This is a more detailed process requiring the DNO to assess whether the local network can accommodate your export.

In areas with high solar penetration—particularly in parts of Devon, Cornwall, and East Anglia—DNOs may require export limiting equipment or network upgrades at your expense.

Always confirm DNO approval before committing to a larger installation.

Step 2: Smart Meter Installation

Export measurement requires a smart meter capable of recording both import and export separately.

SMETS2 meters (the current standard) can do this, but many older SMETS1 meters cannot.

If you have an older smart meter, your supplier may need to replace it—usually at no cost, but this can delay SEG payments.

Some installations use a dedicated export meter separate from the main smart meter.

This is more common in commercial installations or where the main meter position makes export measurement difficult.

Your installer will advise on the appropriate setup.

Step 3: MCS Certification and Paperwork

After installation, your MCS-certified installer provides a certificate confirming the system meets required standards.

This certificate number is essential for your SEG application—suppliers will not process payments without it.

Keep this certificate permanently; you'll need it if you switch SEG suppliers.

Step 4: SEG Application and Payment Setup

Once your system is installed, metered, and certified, you apply directly to your chosen SEG supplier.

The application typically requires:

• MCS certificate number

• Proof of address

• Bank details for payments

• Smart meter details (MPAN number)

• DNO approval confirmation

Most suppliers process applications within 2–4 weeks.

Payments are typically made quarterly, credited directly to your bank account.

Some suppliers offer the option to credit your electricity bill instead—this can be useful if you're also an import customer with the same supplier.

Legacy Feed-in Tariff: Should You Stay or Switch?

Approximately 800,000 UK households remain on the Feed-in Tariff (FiT) scheme, which closed to new applicants in March 2019.

If you're among them, the decision to stay on FiT or switch to SEG requires careful calculation.

The FiT provided two payments: a generation tariff (for all electricity produced) plus an export tariff (for deemed or metered export).

Generation tariffs varied based on installation date, ranging from over 40p/kWh for early adopters to around 3–4p/kWh for late entrants.

The export element was initially "deemed" at 50% of generation for systems under 30kW—meaning you got paid for exporting half your production regardless of actual export.

From 2012, larger FiT installations were required to have export meters, and from 2022, all new FiT applicants (before closure) needed metering.

If you're on FiT with deemed export, you're being paid for 50% of generation regardless of actual export—even if you self-consume everything or have battery storage.

For FiT participants with generation rates above 15p/kWh (common for installations before 2012), staying on FiT is almost always better.

The guaranteed generation payment alone exceeds what any SEG tariff offers, and the deemed export payment adds further value.

These legacy rates are index-linked and guaranteed for 20–25 years from installation.

Battery Storage: Transforming Export Economics

Battery storage fundamentally changes the export calculation.

Without storage, you export whatever your panels produce that exceeds immediate household consumption—typically 50–70% of generation for a system sized to annual demand.

With storage, you capture most generation for self-use and export strategically.

The economic logic shifts from "export what you don't use" to "export when prices are highest." This is particularly powerful with variable-rate export tariffs like Octopus Outgoing Agile.

A typical pattern might be:

• Daytime: Solar charges battery; minimal export

• Evening peak (6–9pm): Battery discharges to household; excess exported at premium rates

• Overnight: Battery charges from grid if on cheap overnight rate (e.g., Octopus Go at 7.5p/kWh)

• Morning: Solar resumes charging

This "arbitrage" approach—buying low, selling high—can generate £300–£500 annually from a 5kWh battery paired with 4kW solar, compared to perhaps £150–£200 without strategic timing.

The battery cost premium (roughly £3,000–£4,500 for a 5kWh system) can be justified on export income alone over a 10-year period, before considering the self-consumption benefits.

However, battery storage for export optimisation requires active management.

Automated systems help—some inverters can be programmed to discharge at specific times—but you'll need to engage with your tariff structure and adjust seasonally.

For homeowners who want a "fit and forget" system, the battery premium might not deliver full value.

Tax Implications: When Export Becomes Income

For most domestic solar households, export payments are tax-free.

HMRC treats small-scale domestic generation as outside the scope of taxation, provided the system is primarily for household use rather than commercial generation.

There's no requirement to declare SEG income on tax returns for typical installations.

This changes if you're generating commercially or if export income becomes substantial.

If you're considering a large system (over 10kW) specifically to generate export income, or if you have multiple properties with solar installations, seek professional tax advice.

The boundary between domestic generation and commercial activity isn't always clear.

Planning Permission and Permitted Development

Most domestic solar installations in England, Scotland, and Wales fall under permitted development rights—meaning no planning permission is required.

However, there are conditions:

• Panels must not project more than 200mm from the roof surface

• Panels must not be installed above the highest part of the roof (excluding chimneys)

• Listed buildings require full planning permission

• Properties in Conservation Areas or World Heritage Sites face additional restrictions on street-facing elevations

• Ground-mounted systems must not exceed 9m² in Conservation Areas

Northern Ireland has different permitted development rules, generally requiring planning permission for solar installations.

If you're in Northern Ireland, factor planning costs and potential delays into your project timeline.

Even where permitted development applies, it's worth contacting your local planning authority to confirm.

Some authorities have specific guidance or Article 4 directions that remove permitted development rights in certain areas.

A quick phone call can prevent enforcement action later.

Choosing Your Export Tariff: A Framework

With multiple suppliers and tariff structures available, choosing the right export arrangement requires honest assessment of how you'll use your system.

The optimal choice depends on three factors:

1.

Self-consumption level:

If you're home during the day and use most of your solar generation (perhaps with a heat pump or electric vehicle), your export volume will be low.

In this case, chasing the highest export rate matters less—prioritise your import tariff instead.

If you're out during the day and export heavily, the export rate becomes more significant.

2.

Battery storage:

With storage, variable export tariffs become attractive because you can time your exports.

Without storage, a fixed-rate tariff provides predictable income regardless of when generation occurs.

3.

Willingness to engage:

Some tariffs require active management—checking half-hourly rates, adjusting battery settings, timing appliance use.

Others are entirely passive.

Be realistic about whether you'll actually engage with the system over the long term.

"The best export tariff is the one you'll actually use effectively.

A variable-rate tariff that pays 15p/kWh at peak times is worthless if you export everything at 2pm when rates drop to 2p.

Match your tariff to your lifestyle and engagement level, not just to the headline rate."

For most households without batteries, a fixed-rate SEG tariff in the 5–7p/kWh range provides decent income with zero effort.

Octopus Outgoing Fixed at 15p/kWh is the current market leader for fixed rates, but requires switching your import supply to Octopus.

For households with batteries and willingness to engage, Octopus Outgoing Agile offers the highest potential returns—but requires understanding wholesale market patterns and adjusting behaviour accordingly.

The tariff can pay 30p/kWh on winter evenings but 1p/kWh on summer afternoons.

If you can shift your export to high-price periods, annual income can exceed £400 for a 4kW system with 5kWh battery.

The Role of Energy Performance Certificates

Several SEG suppliers require a minimum EPC rating for their best tariffs.

British Gas, for example, requires EPC D or above for its Export and Earn tariff.

This isn't a legal requirement for the SEG itself—it's a commercial decision by suppliers who want to encourage energy efficiency alongside generation.

If your home has a poor EPC rating, improving it before applying for SEG can unlock better rates.

Common improvements include:

• Loft insulation (typically £300–£500, improves rating by one band)

• Cavity wall insulation (free or subsidised under ECO4 for eligible households)

• LED lighting throughout (minimal cost, contributes to rating)

• Heating controls and thermostatic radiator valves

The ECO4 scheme provides grants for energy efficiency improvements to households receiving certain benefits or with low incomes.

If you qualify, you might receive free insulation and heating upgrades that improve your EPC rating—making better SEG tariffs accessible and reducing your overall energy consumption.

Future Outlook: Where Are Export Tariffs Heading?

The UK export market has matured significantly since the SEG's 2020 introduction.

Competition has driven rates upward, and the gap between the best and worst tariffs has widened.

Several trends suggest where the market might go next:

Time-of-use export will become standard. As the grid manages increasing renewable generation, paying different rates for different export times makes economic sense.

Variable tariffs like Outgoing Agile are likely to multiply, creating opportunities for engaged households with batteries.

Local flexibility markets are emerging.Some areas with grid constraints are developing "flexibility markets" where households are paid to reduce export or increase consumption at specific times.

This could provide additional income streams beyond standard SEG tariffs.

Smart systems will automate optimisation.

New inverter and battery systems increasingly offer automated export optimisation, responding to price signals without manual intervention.

This reduces the engagement burden on households while capturing much of the benefit.

However, export rates could also fall.

The record highs of 2022–2023 reflected wholesale electricity prices that have since moderated.

If wholesale prices decline further, export tariffs will follow.

The long-term sustainable rate for solar export is probably 8–12p/kWh—above the early SEG rates but below the peaks of the energy crisis.

Getting Started: Your Export Tariff Checklist

If you're installing solar panels or already have them, use this checklist to ensure you're set up to maximise export income:

• Confirm MCS certification for your installation (required for all SEG applications)

• Check your smart meter can measure export (contact your supplier if unsure)

• Obtain your EPC rating and improve if necessary for premium tariffs

• Compare current SEG tariffs (check Octopus, British Gas, EDF, E.ON, Scottish Power)

• Decide whether to use your import supplier or a separate SEG supplier

• Consider whether a variable-rate tariff suits your lifestyle and system

• If you have battery storage, programme it to export during high-price periods

• Set up quarterly payments to your bank account (not bill credit, for clarity)

• Keep records of all export payments for comparison and future switching

• Review your tariff annually—rates change and better deals emerge

Final Thoughts

Export income alone won't justify a solar installation—the payback period based purely on export would exceed 20 years at current rates.

But as one component of overall solar economics, export payments matter.

Getting £200 rather than £80 annually from the same generation adds £1,200 over a decade.

That's real money, and it requires only choosing the right tariff and understanding how it works.

The UK solar export market has improved substantially since the SEG launched.

Competition exists, rates have risen, and options are available for different household circumstances.

The key is matching your export arrangement to your system, your consumption patterns, and your willingness to engage with tariff structures.

For most households, this means a straightforward fixed-rate SEG tariff with a reputable supplier.

For those with batteries and interest in optimisation, variable-rate tariffs can transform export from a minor bonus into a meaningful income stream.

Whatever you choose, don't leave export as an afterthought.

The panels are on your roof; the electricity they generate is yours to use or sell.

Selling it well is simply good household economics.