Why CHP Was Used for Triad Avoidance

✅ Why CHP Was Used for Triad Avoidance

• Under the old Triad system, large electricity users were charged Transmission Network Use of System (TNUoS) fees based on their average demand during the three highest winter peak half-hours (November–February). These charges could reach £40–£60 per kW in high-cost regions like London, adding tens or hundreds of thousands of pounds annually.
• Businesses with on-site generation, such as CHP, could reduce grid import during predicted Triad windows, dramatically lowering their TNUoS bill for the entire year.
• CHP was ideal because it runs continuously for heat and power, so during Triad alerts, companies could maximize CHP output and minimize grid draw without disrupting operations.

✅ How CHP Was Operated During Triads

• Pre-Triad Forecasting: Energy consultants and suppliers issued Triad warnings based on demand forecasts. Companies prepared to ramp up CHP output during these windows.
• Load Displacement: CHP supplied site electrical demand, reducing reliance on the grid. Some sites even exported surplus power back to the grid.
• Heat Utilization: Waste heat from CHP continued to serve heating or process loads, so the system delivered dual benefits during avoidance periods.
• Integration with DSR: Many CHP-equipped sites also participated in Demand Side Response (DSR) programs, earning revenue while avoiding Triad charges. 

✅ Financial Impact

• Savings were significant: avoiding Triads could cut £50k–£250k per year for large industrial sites.
• CHP operators often negotiated embedded benefits with suppliers—payments for generating during Triads because it reduced supplier exposure to TNUoS charges. This was known as the Triad Avoidance Benefit, which reached £40–£45 per kW before Ofgem reforms. 

✅ Why It Changed

• Ofgem’s Targeted Charging Review (TCR) ended Triad-based residual charging in April 2023, replacing it with fixed daily charges based on capacity bands.
• This removed the incentive for CHP-based Triad avoidance, as residual costs are now unavoidable. CHP remains valuable for efficiency, resilience, and carbon reduction, but not for gaming TNUoS.