Midlothian Energy Limited is a 50/50 joint venture between Midlothian Council and Vattenfall, focused on regenerating and decarbonising the region. Building on the success of the Shawfair–Millerhill heat network, MEL aimed to expand into existing homes and buildings.

The Challenge
MEL wanted to assess retrofit and heat decarbonisation investment options across two pilot areas—Danderhall and Dalkeith—covering over 900 homes, two offices, and five schools. Challenges included fragmented data, uncertainty around grant funding, potential heat charges, and projected bill savings. The work needed to be completed within eight weeks.

Our Approach
Using the HM Treasury Green Book framework, we developed a Strategic Outline Case. Our technical, economic, and financial analysis assessed retrofit options and built a flexible options model to evaluate over 2,000 potential solutions. A workshop helped narrow these to four preferred pathways, ranging from small-scale pilots to a large regional programme. We then explored commercial delivery models, supplier markets, and governance, including a customer journey and delivery plan.

Key Outcomes

• Identified £10m+ investment potential

• Delivered prioritised options in just six weeks

• Achieved alignment among key stakeholders

• Developed a scalable strategy for 10,000+ homes

• Produced a detailed business case and roadmap

Our Team
Led by Tennex’s Richard McWilliams, the team included Chris Joyce (Aiming for Zero), Zack Moss (City Science), and Mark Williams (ASI Advisory), a Green Book and green finance expert.