Checklist: what to prepare before a feasibility study

A feasibility study is only as fast and as solid as the documents available at the start. Miss a key figure and you get follow-up questions that delay the project, or the study works with assumptions that have to be corrected later. This checklist sums up what should be ready before the start, grouped by energy data, grid connection, technical documents, contacts, and organisational constraints.

Why these documents make the difference

A feasibility study works with real measured values, not estimates. Without the load profile, an initial rough study is forced to substitute assumptions from the electricity bill or comparable figures from similar operations, and every later statement on storage size carries that caveat. The more complete the following points are at the start, the more directly the study can begin its actual analysis, instead of first requesting basics. Time lost at this point is the easiest delay in the whole project to avoid.

The following five categories can be worked through independently and do not need to be compiled by the same person. In practice, maintenance or operations staff supply the energy data and technical documents, while grid connection and contacts often sit with commercial management or facilities. Clarifying responsibility for each category in advance lets the documents be gathered in parallel rather than one after another.

Energy data

• Load profile for at least the last twelve months, at quarter-hour resolution, as a file from the metering point operator.
• For multiple connection points: load profiles per connection point, not just one combined total.
• Electricity bills for the last twelve months, broken down into energy charge, capacity charge and other grid-fee components.
• Known planned operational changes, such as new machines, additional shifts, or existing loads being dropped.
• Whether the connection point is billed on registering capacity metering or a standard load profile.
• If known: the average annual total final energy consumption over the last three calendar years, relative to the EnEfG thresholds.

Grid connection

• The current grid connection contract with the grid operator, including the agreed connection power.
• The voltage level, low or medium voltage, and the grid connection point on the site plan.
• If available: information from the grid operator on free capacity at the connection point.
• Whether a registration or feed-in commitment already exists, for instance for an existing PV system.

Technical documents

• Single-line diagram of the existing electrical installation.
• Site plans showing possible locations for a storage system, indoor or outdoor.
• Details of existing generation plants, in particular any PV system, with installed power and feed-in concept.
• Existing fire protection concepts or requirements from the local fire brigade, where they exist.
• Details of existing buildings or open areas suitable for a storage container or switchgear cabinet, including access for delivery and maintenance.
• Known site constraints, such as flood zones, noise restrictions or heritage protection requirements.

Contacts and organisational constraints

• A contact at the relevant grid operator for technical questions.
• A contact at the electrical contractor or installer already engaged, if one exists.
• A contact at the insurer for questions on fire protection and safety requirements.
• An internal decision-maker in the company who signs off the study’s results and decides on next steps.
• A contact in maintenance or operations who best knows the actual operating routines and planned changes.

• Clarity on whether the system is planned as an own investment or under a turnkey delivery model.
• Time constraints, such as an upcoming operational expansion or an expiring permit.
• Where relevant: a note on how close the project is to the §118(6) EnWG deadline, if the system is meant to reach the grid-fee exemption.
• Known internal decision processes and typical lead times, so the study can be planned toward a realistic decision date.
• Any earlier studies, quotes or reports for the same site, even if outdated or incomplete.

Checking the regulatory context

• Knowledge of average annual energy consumption relative to the EnEfG thresholds, if an energy audit or energy management system is due regardless.
• Whether the site already has an energy audit under EDL-G or an energy management system under ISO 50001 whose results can be used for the study.
• Whether a BAFA-funded energy consulting programme applies to the project, provided the relevant scheme is still open at the time of the study.
• Whether and to what extent the planned system can technically meet the conditions of §118(6) EnWG, in particular feeding back into the same grid.

Not every point on this list has to be fully in hand before a feasibility study can start. What matters more is knowing from the outset which details are missing and where they will still come from, rather than discovering them by chance during the analysis. An operator who has put these points together once can reuse the same basis later for the specification and the tender, instead of collecting it again for every step. Handing the list to a colleague in maintenance or facilities usually gets a first complete answer within days. Once the key points are in hand, a feasibility study can begin the actual analysis directly. As of September 2026.

Sources

1. §118(6) EnWG, gesetze-im-internet.de
2. §8 EnEfG, gesetze-im-internet.de
3. §8 EDL-G, gesetze-im-internet.de
4. ISO 50001:2018, iso.org
5. BAFA, federal funding for energy consulting for non-residential buildings, plants and systems (in German)