Solar Batteries Required to Disclose Where They Obtained Electricity After Dark

By our Energy Compliance Correspondent · November 1, 2026

Battery operators supplying solar electricity after sunset have been instructed to account for its whereabouts during the intervening hours, after a routine review found substantial quantities entering the grid at times when no sunlight was being produced. The new guidance permits storage in principle while requiring operators to explain each instance in which the principle has been used.

Facilities must provide a receipt showing when the electricity arrived, the compartment in which it was held and the official responsible for releasing it into the evening. An initial form asked for the sun's forwarding address. That field has been made optional following representations from the industry.

‘We are satisfied that this was solar electricity at the point of collection,’ an inspector said. ‘What we need to establish is the basis on which it continued being solar electricity at eight forty-five. The sky was examined at that time. The conditions ordinarily associated with the product were not present.’

Operators have offered charging records showing that batteries take in power during the day and discharge it later. The department said those records explain the sequence but do not establish whether the delay was authorized. A separate application allows a battery to hold electricity overnight, provided it identifies a reasonable opportunity to return it to circulation.

The distinction has caused difficulties for one household whose kitchen light remained on after dinner. Its supplier traced the power to a battery charged that afternoon, but the household could not say which afternoon appliance it would otherwise have used the electricity in. The matter has been referred for an assessment of displaced daytime activity.

Grid engineers warned that matching every unit to its original conditions of production would also require wind farms to account for power delivered after the wind had moved elsewhere. The department said wind was outside the scope of this review. A request to clarify where wind ends has been assigned to a different team.

An industry proposal to classify the stored supply as daytime electricity delivered late has received provisional support. Under the proposed arrangement, customers would acknowledge receipt against the date of generation rather than the time they switched on a lamp. Suppliers would send the acknowledgment the following morning, when its source could be inspected.

Existing batteries may continue operating during the consultation, but must retain a sample of the electricity under review. Inspectors will visit between ten and four. Facilities unable to produce the sample at that time should leave the relevant light on and provide directions to the room.