The New Homes (Solar Generation) Bill is a Step Forward – But Energy Generation Targets Make More Sense

January 15, 2025

Tom Oldfield, our Head of External Affairs, gives his views on the upcoming New Homes Bill.

Update – This bill was discussed and was not passed
but the conversation continues.

The UK government has been increasing its efforts to tackle climate change and achieve those crucial net-zero targets. Among the latest initiatives is the proposed New Homes (Solar Generation) Bill. This bill requires all new-build homes to install solar photovoltaic (PV) panels covering at least 40% of the property’s ground floor area.  

While this bill is a positive move, there’s room for smarter thinking. Instead of focusing solely on how much roof space is used for solar panels, we should be looking at how to maximise the energy they generate. Scalable, flexible, and innovative technologies—like self-consumption solutions—can help achieve this.  

The Challenges of a 40% Solar PV Mandate  

On the surface, the idea of covering 40% of ground floor area with solar panels might seem simple. In practice, however, it’s more complex.  

  • Modern Roof Designs – Today’s homes often feature Velux windows, steep pitches, or dormers. These popular features make homes more appealing and spacious but leave less roof space for solar panels.  
  • Shading Issues – Nearby buildings, chimneys, or other structures can cause shading, reducing the efficiency of solar panels—even if the 40% coverage requirement is met. 
  • Regional Differences – A home in sunny Cornwall might perform well under this bill. But for homes in cloudier parts of the UK, more panels would be needed to achieve the same energy output—leading to higher costs for developers and buyers. 

It’s less about how many panels are installed and more about how much energy they can actually produce.  

Smarter, More Efficient Energy Solutions  

Rather than focusing solely on PV coverage requirements, we should also consider how to make the most of the energy generated. This is where innovative self-consumption technologies come into play.  

  1. PV Diverters – These devices redirect surplus solar energy into heating water, reducing reliance on grid electricity. This means smaller PV systems can still be highly effective—ideal for homes with limited roof space. 
  2.  Thermal Batteries – Mixergy’s smart hot water cylinders store excess solar energy as hot water. This allows households to use solar energy during cloudy days or at night, maximising its value.  
  3. Grid Stabilisation – Encouraging self-consumption with technologies like these reduces pressure on the grid during peak solar generation, helping to balance energy networks and prepare for increased renewable energy use.  

Why Energy Generation Targets Make More Sense  

To fully unlock the potential of renewable energy, the UK needs policies that encourage innovation and flexibility. Rather than mandating a blanket 40% PV area requirement, why not focus on energy generation outcomes instead?  

This approach would give builders and homeowners the freedom to explore more creative and efficient solutions, such as:  

  • High-efficiency solar panels that produce more energy in less space. 
  • Smart storage systems like Mixergy cylinders that optimise energy usage.  
  • Shared or community solar schemes, ideal for high-density developments where individual rooftop installations aren’t feasible.  

Thinking Ahead  

At Mixergy, we’re committed to delivering solutions that empower homeowners, reduce carbon emissions, and support a more sustainable future. The New Homes (Solar Generation) Bill has great potential, but we can achieve even more with smarter energy solutions that emphasise flexibility and efficiency.  

It’s time to think beyond roof size and see the bigger picture. By combining renewable energy with innovative technologies, we can ensure new homes are not only compliant but also capable of making a real difference—for homeowners, the grid, and the planet.