Understand the role of storage
The US Department of Energy explains that storage allows energy to be used at a different time from when it was generated. It also notes that conversion and retrieval involve energy losses. The presence of a battery alone does not establish how long a particular lighting configuration can operate.
Distinguish power from stored energy
Energy capacity describes the amount of energy that can be stored; power describes the rate at which energy can be delivered. These are different quantities. A useful enquiry should therefore describe the proposed lighting demand and operating schedule, rather than asking about battery size in isolation.
Write an operating brief
Describe when the area is occupied and any periods when lighting requirements change. Include expectations for weekends, seasonal use and unusual events. This information gives the design conversation a practical basis and helps identify which assumptions need to be checked.
Request the assumptions behind the proposal
Ask what operating profile, site conditions and component information underpin a recommendation. Discuss access for maintenance and the documentation that will accompany the proposed system. Any statement about run time or availability should be supported for the actual configuration under consideration.
Bring these points to the conversation.
- Set out the intended operating hours.
- Identify changes in activity through the year.
- Ask about energy capacity and delivery requirements.
- Request evidence for any proposed run-time statement.
Source and further reading
US Department of Energy — Solar energy and storage basics ↗
This article explains storage concepts. Battery chemistry, capacity, autonomy and performance are not specified for our products.
Source checked: 25 October 2026. Our project questions and checklists are editorial guidance; they are not product performance claims.