Installer guide · 12 min read

Commercial Solar Prospecting: Build a Target List from UK Public Data

Short answer: the best commercial solar prospects own their building, use electricity in the day and have a roof or land big enough to matter. You can find most of that before you pick up the phone, from free UK registers: Companies House for the business, the EPC and DEC registers for the building, HM Land Registry for the owner and SECR reports for energy use. This guide shows how to use each one and how to turn the results into a ranked list.

What makes a good commercial solar prospect

Every outbound channel, whether that is cold calling, cold email or LinkedIn, is only as good as the list behind it. A strong prospect passes four tests. It owns the building, or the landlord will consent. It uses a lot of electricity in daylight hours. It has a roof or land that is big enough, unshaded and not due for replacement. And you can reach the person who signs off the spend.

Those are the same checks a good lead has to pass at qualification (see how to qualify commercial solar leads). Prospecting simply moves them earlier, so your caller spends their time on sites that could become projects. For the size of the market by system band and region, see the UK commercial solar market in numbers.

Seven sources at a glance

Source 1: Companies House and SIC codes

Companies House advanced search is free and filters companies by status, SIC code, registered office location and incorporation date. Every company picks one or more SIC codes from the Companies House condensed list of the 2007 classification when it files. That makes the code a quick way to pull, for example, every active warehousing company with a registered office in your county.

Three things to watch

• The registered office is often not the site. Accountants' offices and head offices are common. Find the operating address from the company website or the EPC register.
• Companies choose their own codes. Some use a vague code; a food manufacturer might be filed under wholesale. Use codes to filter, not to exclude.
• The filing tells you more. Directors' names are public, and filed accounts show whether the company is small, medium or large, which hints at budget and who decides.

Source 2: the non-domestic EPC register

Business premises that are built, sold or let generally need an Energy Performance Certificate. GOV.UK's find an energy certificate service covers homes, business properties and public buildings in England, Wales and Northern Ireland, searchable by postcode, street name and town, or certificate number. Scotland has a separate register.

For prospecting, the certificate is useful in three ways. It confirms the building type at a specific address. It gives the floor area, a rough proxy for roof size on single-storey sheds. And it gives the energy rating. For lists rather than single lookups, MHCLG publishes bulk non-domestic EPC data for England and Wales as CSV downloads and an API. You need to sign in with GOV.UK One Login to download it, and the service notes licensing restrictions you should read before using it.

Why the rating matters on let buildings

Under the minimum energy efficiency standard, since 1 April 2023 privately rented non-domestic property in England and Wales must have an EPC rating of at least E, unless a valid exemption is registered. A let unit rated F or G gives its landlord a reason to talk about energy improvements. Ask an accredited assessor what solar would do to that building's rating rather than promising an improvement yourself.

Source 3: Display Energy Certificates for public buildings

A Display Energy Certificate (DEC) is needed for a building in England or Wales that is at least partly occupied by a public authority, has a total floor area over 250 m² and is frequently visited by the public: councils, leisure centres, colleges and NHS trusts, for example. The DEC rates the building from A to G on its actual energy use. It lasts one year for buildings over 1,000 m² and ten years for buildings between 250 and 1,000 m², so large public buildings are re-certified every year.

DECs are searchable through the same certificate service and in the bulk data. They give you a ready-made list of large public buildings and how much energy they use. Public bodies usually buy through procurement, though, not after a cold call. Read commercial solar tenders and frameworks before you contact one.

Source 4: who owns the building

Ownership is where most commercial solar projects die, so check it before the call, not after the survey. HM Land Registry publishes data on freehold and leasehold titles in England and Wales whose registered owner is a company or other corporate body, updated monthly. You need an account and must accept the licence before you can download it.

Match the title address to your prospect. If the occupier owns the freehold, they can sign off solar themselves. If a different company owns it, you are talking to a tenant: you will need the landlord's written consent, and the landlord may be a better first call. For a single property, you can buy the title register from HM Land Registry.

Source 5: SECR energy disclosures

Under the Streamlined Energy and Carbon Reporting (SECR) regulations of 2018, large unquoted companies that used more than 40,000 kWh of energy in the UK must include energy and carbon information in their directors' report. That covers annual UK energy use in kWh (gas, purchased electricity and transport fuel at least), the related emissions, an intensity ratio, the measures taken to improve energy efficiency and the previous year's figures. Companies using 40,000 kWh or less are exempt as low energy users.

The directors' report is filed with the accounts at Companies House, so for larger prospects you can read their energy use and what they say they are doing about it before you call. A company that writes about cutting energy use or reaching net zero has already put the subject on the board's agenda.

Source 6: check the roof from above

Satellite and aerial imagery in free mapping tools shows the roof's shape, rough size, pitch direction, shading from trees or taller buildings, rooflights and plant, and sometimes obvious wear. Many tools have a measuring feature for a rough area. It will not show asbestos or structural capacity, but it rules out the obvious non-starters in seconds, and a note such as "large south-facing pitch" makes a better opening line.

Score and prioritise the list

Put every prospect in one spreadsheet or CRM with a column for each check, then score it. Call the sites that pass most checks first, and keep the rest for email or a later pass.

Once your list is scored, the next job is turning it into conversations. The solar lead generation guide compares the channels, and our guide to commercial solar lead costs shows how to cost your time per signed project.

UK rules for using the data

Data being public does not mean you can use it however you like. A summary, not legal advice:

• Each bulk dataset has its own licence. Read it before you build a marketing list from it.
• Under PECR you can make live sales calls to business numbers that are not on the TPS or Corporate TPS and have not objected to your calls. Screen against both registers and your own do-not-call list.
• You can send marketing emails to corporate addresses if you say who you are and give a simple way to opt out. Sole traders and some partnerships are treated like individuals and need consent.
• A named director or manager is personal data under UK GDPR, so you need a lawful basis (usually legitimate interests for B2B) and must honour objections.

The cold calling guide and the cold email guide cover the rules for each channel in more detail, with the ICO sources.

What it really takes

Compare it with the full cost of an in-house team in in-house vs outsourced lead generation.

Do it yourself vs have it done

Building your own list makes sense when someone has the time to work the registers and a caller is ready to use it. If not, having qualified, exclusive site meetings booked for you is simpler: TNW Marketing is paid per qualified, attended appointment, with no retainer and no minimum spend. See how pay per appointment works, read about appointment setting for solar installers, compare commercial solar lead generation companies and pay per lead vs retainer, or see installer case studies and video reviews.