Why grid reform CMP446 can unlock more solar value for your buildings

A new UK rule changes mean you may soon be able to export more solar energy — and get connected faster.

If you’ve considered installing solar panels on your commercial or industrial property, and you've been convinced to up-size your installation you may have heard something along the lines of:

“We can only get 950kW of export to the grid — otherwise we’ll be stuck in the queue for years.”

That’s been a frustrating reality for anyone trying to maximise their solar installations and monetise on the excess. But from May 2025, that’s changing.

A new rule — called CMP446 — is being introduced to raise the cap for transmission level grid assessments from 1 megawatt to 5 megawatts.

That means that sites that were previously held back on export by the local DNO at 950kW to avoid triggering a 10 year transmission level grid assessment, can now get approval for up to 5MW by DNO decision alone.

💡 What this means for your building

• Bigger solar systems: No more squeezing in just enough panels to stay under the old grid threshold to avoid the long transmission assessment wait times.

• Faster grid connections: Less red tape = quicker installs.

• Better economics: More export capacity can unlock higher returns and bigger energy savings — especially for C&I tenants that are electrifying their operations.

  
  

🏢 Who benefits?

• Landlords of logistics parks, retail centres, and warehouses.

• Tenants looking to reduce daytime electricity bills or meet carbon goals.

• Energy buyers like data centres that want to access to purchasing the excess from these sites.

  
  

⏳ When does this take effect?

The new rules apply from May 2, 2025, across England and Wales. If your project was previously limited due to grid rules — or paused altogether — now is the time to reassess what’s possible.

✅ What should you do now?

• Ask your solar partner whether your site could now qualify for more export capacity.

• Review old quotes that were based on the 950kW cap — especially if your building could support more.

• Explore shared savings models where increased export improves payback, even with tenant turnover.

  
  

⚡ Bottom line

This may be one of the most important regulatory changes for solar in years — especially for commercial property owners with large, underused roofs or estates. If your project was previously stuck at the 950kW ceiling, May 2025 may be your moment to go bigger.

InRange is creating a new energy asset class from the built environment, unlocking new revenue streams for landlords and saving energy costs for tenants. InRange provides guaranteed 10-year fixed export tariffs, selling surplus energy to buildings within their network through the InRange Marketplace. InRange’s AI-powered platform simplifies the entire energy process, empowering landlords and tenants to roll out solar and storage, fast.