Adding battery storage to Ellon solar, without losing a penny of your 50% export payment.

Not if you are on deemed export, which most domestic FIT households are. Ofgem's guidance on storage installed alongside generation states at paragraph 3.4 that for accredited FIT installations with a capacity of 30kW or less, export "may be deemed as a percentage of the amount of electricity generated", and for solar PV "the percentage is 50%". Because the payment is calculated from the generation meter reading rather than from what actually leaves the property, paragraph 3.18 confirms that "this remains the case for FIT installations with co-located storage", and Ofgem's worked scenario for a standard domestic retrofit concludes "deemed export payments are unaffected". Your generation payment is also untouched, provided the battery sits downstream of the generation meter.

Yes. Ofgem's guidance at paragraphs 3.31 to 3.33 says co-locating storage "should be reported to the FIT Licensee, in accordance with the requirement within the Statement of FIT Terms", and Appendix 1 of that guidance contains example declarations for domestic scale installations. They may ask for an updated single line diagram showing how electricity reaches the storage and how the metering is arranged. We produce that as part of the job and hand it over with the rest of your paperwork.

Yes, in two specific situations. First, if the battery can be charged from the grid and is installed upstream of your generation meter, that meter is no longer measuring only solar, and Ofgem is clear at paragraph 3.16 that in that case "the generator will not be entitled to receive generation payments". Second, if you are on metered export rather than deemed, a grid chargeable export capable battery means the export meter cannot separate solar export from battery export, and Ofgem's scenario 4.2 concludes "no metered export payments can be made". Both are avoided by design decisions taken before anything is ordered.

It can, and SEG households need to be more careful than FIT households. Ofgem's Appendix 3 allows storage at A3.1 "as long as the export meter is still able to measure the amount of electricity generated/exported from the installation separately from any other source". The distinction is between green export, which came from your panels, and brown export, which you bought from the grid and sent back out. Where a meter records brown export and cannot separate it, A3.4 states "a SEG licensee is not obliged to make SEG payments". Ofgem's own instruction is that generators should check with their SEG licensee about intended changes, so if you want the battery to charge from the grid overnight, ask your supplier first.

Usually yes, and this catches people out. The threshold is 16 amps per phase, and MCS MIS 3012:2025 is explicit that "the 16 A per phase threshold is the total aggregated AC output of all generators", giving the worked example that a 3kW solar system plus a 3kW battery storage system on the same single phase supply "gives a combined maximum theoretical output greater than 16 A. In this case EREC G99 applies." So a 4kWp array notified years ago plus a 3.6 to 5kW battery inverter clears the threshold together. In Aberdeenshire that application goes to SSEN, whose G99 Fast Track route aims to respond within 10 working days, with Form A3-2 returned within 28 days of commissioning.

Yes with an AC coupled retrofit, which adds a dedicated battery inverter alongside your existing one and leaves the roof and DC wiring untouched. No with a DC coupled retrofit, where a hybrid inverter replaces the existing unit and runs both the panels and the battery. The deciding factor is usually the age and warranty status of what you already have: an inverter from the early FIT years is outside every manufacturer warranty period we are aware of and is a reasonable candidate for replacement now rather than in two years, whereas a recent inverter still under warranty almost always stays.

Only on a DC coupled retrofit. A hybrid inverter has a defined voltage window and a set number of strings per tracker, so an older array split across more strings than the hybrid supports, or one whose voltage climbs beyond the ceiling on a cold Aberdeenshire morning, can rule out a particular unit. It is a datasheet check against your actual array rather than a guess. On an AC coupled retrofit the question does not arise, because the battery inverter connects at the consumer unit rather than to your panels.

The battery is treated separately from the solar. Since 1 January 2025 there has been a dedicated MCS standard for storage, MIS 3012, covering electrical energy storage systems up to 50kW in permanent buildings, to be read alongside the IET Code of Practice for Electrical Energy Storage Systems, and it covers both AC coupled and DC coupled retrofits. Your original solar certificate covers the solar and does not stretch to the battery. Every installation we complete is fully MCS registered through our Q-Smart partnership, so the battery gets its own registration alongside your existing solar record.

Technically it is straightforward, but the answer depends on your scheme. For a FIT household on deemed export with the battery correctly installed downstream of the generation meter, grid charging does not disturb the deemed export payment. For a SEG household it is a different question, because electricity bought from the grid and later exported is brown export, and Ofgem is clear that a licensee is not obliged to pay SEG on it. Ask your supplier before enabling it.

A 10kWh battery AC coupled to your existing array is £3,500 to £5,000 fully installed. A 15kWh unit is £5,000 to £7,000. A hybrid inverter swap, where DC coupling is the right answer, is specified and priced at survey. All battery work is zero rated for VAT until 31 March 2027, after which the rate becomes 5%. A consumer unit upgrade, where the existing board cannot take the new circuit, starts at £550 + VAT, and the G99 application and your single line diagram are included.

PAS 63100:2024, the fire specification for battery energy storage in dwellings, says a battery should not go in a room intended for sleeping and should not go on a means of escape that is not a protected escape route, which rules out most landings, staircases and hallways, and it sets provisions for loft spaces. PAS 63100 clause 6.1.3 caps stored energy at 20kWh per enclosure. On a retrofit this sometimes conflicts with the obvious spot, which is usually wherever the existing inverter is, so we resolve it at survey.

No. Part P is a section of the Building Regulations for England and Wales. Scotland has Building Standards, administered by the local council, and the mechanism is a building warrant rather than a notification. There is no Building Control body to notify here. Ellon sits within Aberdeenshire Council. Separately, the distribution network operator for AB41 is SSEN, not National Grid and not the operator covering central and southern Scotland.