Yesterday, I noted how rooftop solar is badly out of sync with heat pump demand. The solution is remarkably simple but it requires a change in how we think about solar deployment
The Efficiency Gap: Fixed vs. Tracking
Ground-mounted systems offer a 5–10% efficiency gain over static roof panels before you even account for tracking, simply by allowing for optimal orientation.
When you add tracking, the numbers are game-changing, particularly in the spring and autumn which accounts for 50% of additional heat pump demand:
> Fixed Solar: In spring, a panel in an optimum orientation meets 33% of daytime demand for a home with heat pump.
> Latitude40 Tracking: Meets 46% of that same spring demand.
> The Difference: a 13% lost opportunity
The Planning Blocker
A simple fix is to update permitted development for ground-mounted solar. At just 9m2, it is currently barely enough to meet 3 large panels – this won’t deliver the demand from any of heat pumps, EVs or batteries.
Around 20% of buildings are unsuitable for rooftop (e.g. structurally weak, poor orientation, too shaded, multiple small roofs, listed, etc) – that’s millions of roofs. Many outside built up areas have suitable ground space.
Our Proposal for Reform:
We could cut this problem down to size by just amending planning, closing the demand gap at source
> Domestic planning: ~25m² would allow 5-6kW of generation to meet the demand of a modern, electrified home.
> Businesses: 50m² of ground mount solar would let rural SMEs and farms win an immediate economic benefit.
Talk to installers – they don’t want the hassle of planning. Let’s grasp the simple solutions to deliver this challenge.