A rapid charging site needs a utilisation model

A rapid charging project's equipment specification is often clearer than its utilisation assumptions. That imbalance can produce a business case that looks precise while its main revenue and cost drivers remain untested. The project needs a model of who will use the site, when energy will be delivered and how the service will be maintained. Hardware choices should follow that model rather than provide a substitute for it.

Distinguish time from energy

Bay occupancy, connection time and energy delivery describe different aspects of use. A vehicle can occupy a bay after charging finishes, or deliver little energy during a short visit. Record the relationship the business case assumes instead of treating every occupied minute as productive energy sales.

For a destination with existing visitor traffic, investigate the parking and charging behaviour relevant to that location. For a dedicated charging site, examine the access and journey proposition separately. Neither model can be validated by simply importing an average utilisation figure from an unrelated place.

Test the supply assumptions

Use the proposed site's actual electricity arrangements when comparing options. Identify which costs depend on energy, capacity, timing or contractual conditions, and mark any terms that remain unresolved. Do not transfer an overseas tariff structure into a UK financial model because it appears in a technical study.

The National Laboratory of the Rockies' REopt charging work evaluates infrastructure with operating and energy assumptions. The useful lesson is to model those interactions explicitly. Storage or onsite generation may change a design, but the commercial result depends on the particular site's loads, supply and utilisation rather than on the presence of an additional technology.

Model availability as a service

Set out the maintenance, support and replacement arrangements that keep the site usable. Identify the reporting process for faults, the access required for repair and the ownership of communications or payment issues. Equipment availability and a successful customer charging session are related but distinct outcomes.

Examine how the business would operate with part of the site unavailable. The purpose is to identify practical exposure, not to invent a failure rate. A useful model can show the consequence of reduced capacity while leaving the likelihood to evidence from the actual supplier and operating arrangement.

Use scenarios with clear causes

Create cases around identifiable changes: slower initial customer uptake, different session sizes, a revised supply price or additional maintenance work. Change the relevant inputs together where they are linked. A disconnected set of optimistic assumptions can make a model look robust while never representing a plausible operating state.

The investment recommendation should show which assumptions have been evidenced, which are provisional and what observation would update them after opening. Establish the data needed from day one. That makes utilisation a manageable business variable rather than a forecast that cannot be checked, and it allows the project to compare infrastructure offers on the service and economics the site is intended to deliver.