There will be times when the electricity your solar system generates is more than you can use at the time it is being produced; for example, when you are away from home because of work or on holiday. In such instances, a battery storage system would be very useful because your power controller would normally divert the surplus electricity into the battery to store it for future use. Once the battery is fully charged, any further electricity generated would be exported to the Grid.

The Smart Export Guarantee (SEG)

From the 1st of January 2020, energy suppliers with over 150,000 customers have to offer an export tariff to homes and small businesses for each unit of electricity they sell to the grid, as measured by their smart meter.

The energy suppliers will pay for electricity exported to the grid based on readings taken from a suitable meter such as a smart meter capable of providing export readings every half an hour, even if the tariff is not paid on a half hourly basis.

Renewable energy installations eligible for SEG

The following renewable energy installations are eligible for the smart export guarantee:

  • Solar PV systems, onshore wind, anaerobic digestion, hydro; up to 5MW
  • Micro-combined heat and power; with an electrical capacity of up to 50kW

Any typical domestic system would be well within these size limits.

The technology and installer used by householders must be certified under the Microgeneration Certification Scheme (MCS) or equivalent. Energy suppliers may ask you to provide an MCS certificate to prove your installation meets this standard.

Exported power must be metered using a meter capable of reading exports on a half hourly basis, even if half hourly readings are not required for the tariff. Meters must also be registered for settlement. Unlike the Feed-In Tariffs scheme, EPC standards will not be applicable.

It is possible that the legislation might allow energy suppliers to pay people for exporting electricity to the grid at times of peak demand, that they have imported earlier; whether or not it was renewably generated.

There is not a minimum rate for the tariff, only that the payment should be ‘more than zero’. It means that all the energy companies are free to pay whatever they choose.

Combining SEG with other grants and financial support

You cannot receive both a Feed-in tariff and SEG payments, although you can choose to opt out of your Feed-in Tariff and receive SEG payments instead.

SEG payments are not linked to other financial support around renewable energy installations. This means, if eligible, you could combine SEG payments with other financial support offered by Energy Saving Trust such as the Home Energy Scotland loan for example. You will not be able to receive SEG from more than one supplier.


SEG and energy storage

Some solar PV or wind turbine installations will have energy storage systems attached to them. In these cases, the battery could store electricity imported from the grid (known as brown electricity) before exporting it later.

Energy suppliers are not obliged to pay you for brown electricity exported to the Grid, but they may choose to do so.

Some suppliers may only pay the SEG for green electricity i.e. the electricity your low-carbon system generates itself. If this is the case, the supplier may ask you to show how you separate out the green electricity you generate from any imported brown electricity.

There are some companies who started paying quite a reasonable export rate, even before the legislation was enacted and one worthy of note is an energy supplier called Social Energy; who as of August 2020 were still paying the largest amount for exported energy from residential houses. There are certain other interesting things about Social Energy; they deal only with ‘green energy’, they do ‘energy trading’ and pay 70% of such profits back to the consumer. This 2 minute video gives a pretty good explanation about Social Energy… Video Explanation