How to get an energy project costed

Costing versus feasibility

Feasibility tests whether the idea holds: site, grid, building, use case. Costing estimates what it would cost to deliver a defined scope. You can need both. You should not treat a feasibility memo as a quote, or a quote as proof that the project is possible.

If the technical questions are still open, costing may be premature — or it may be a high-level budget only, labelled as such.

Information a costing usually needs

A provider cannot price a blank. They need the site or building, what you want installed, constraints you already know, and whether the estimate is a budget, a quotation, or a range.

Missing items should stay in the brief as missing. Filling them with assumed kWp, MW or bay counts to “get a number” produces a number nobody can use.

• ▢Location and who controls the site
• ▢Technology and intended outcome in plain language
• ▢Any drawings, bills, grid letters or surveys you already have
• ▢Known constraints: access, tenants, roof, power, planning
• ▢Whether you want a budget, a firm quote, or a scoped range

Scope is the brief

Scope says what is in and what is out: equipment, civils, grid works, design, commissioning, exclusions. Two quotes that look comparable often are not, because one omitted the upgrade or the scaffolding.

Ask providers to state exclusions. A cheap figure that ignores connection works is not cheaper; it is incomplete.

Quotations and what they are not

A quotation is an offer to do stated work for a stated price, on stated conditions, for a stated period. A budget estimate is looser. Neither is a funding commitment, and neither survives unchanged if the scope changes.

WattFund does not generate a price. Where a project needs a delivery estimate, it can connect you with relevant service providers against a structured brief.

Service providers

Installers, EPCs, designers and specialists cost different slices of the same project. Match the request to the capability: a heat-loss model is not an install quote; an EV civils price is not a DNO application.

Providers respond to a requirement. WattFund does not sell ranked placement and does not guarantee that anyone will quote.

Why costings matter for funding

Investors and lenders cannot usefully discuss a figure that has not been established. Owner-funded projects still need a number to approve internally. If costs do not exist yet, the honest next step is often to get the project costed — not to invent a round-number raise.

A costing does not make a project “investment ready”. It removes one class of guesswork.

Why costs change

Scope change, grid conditions, roof or ground surveys, equipment lead times and exclusions that later come into the works all move the number. That is normal. What is not useful is presenting an early budget as a fixed capex in a capital conversation.

Label the estimate: date, provider, scope, and whether surveys are still outstanding.

Technology differences

Solar costing usually needs a design envelope and roof or land constraints. BESS costing is sensitive to duration, civils and connection. EV charging is sensitive to power, bay count and civils. Heat pumps start from building demand and electrical capacity.

The operating model is the same: a structured brief, a relevant provider, a labelled estimate. The inputs are not the same.