Reducing overnight energy waste in manufacturing doesn’t require large investments—just smarter management. Idle equipment, inefficient HVAC use, and hidden losses can account for 10–25% of total energy costs, but targeted interventions can deliver immediate savings.
This guide outlines practical steps, from eliminating phantom loads and optimising HVAC systems to leveraging real-time data and reviewing supplier tariffs. By implementing these strategies, manufacturers can cut costs, enhance efficiency, and reinvest savings into long-term upgrades. The quickest way to reduce energy consumption is to prevent waste—starting today!
Why It Matters
Idle equipment can account for 10–20% of total energy use in manufacturing (Carbon Trust, 2023). Immediate savings are achievable by targeting “phantom loads” — energy consumed by machinery in standby or inactive modes.
How to Implement
Automated Shutdown Protocols:
Programmable Logic Controllers (PLCs): Integrate PLCs with SCADA systems to schedule automatic shutdowns of non-essential machinery (e.g., conveyors, HVAC in non-critical zones).
Example: Toyota reduced idle energy use by 15% by automating shutdowns across 12 production lines.
Lighting Optimisation:
Replace legacy lighting with PIR (passive infrared) sensors in low-traffic areas (e.g., warehouses, offices). For high-risk zones (e.g., forklift routes), use microwave sensors to avoid false triggers.
ROI: A £5,000 investment in sensor lighting typically pays back in 8–12 months (Energy Savings Trust).
Action Steps:
Conduct a 24-hour energy audit using submetering (e.g., Schneider Electric PowerLogic) to identify idle loads.
Prioritise shutdowns for equipment with >5 kW standby draw (e.g., hydraulic presses, CNC machines).
Why It Matters
Heating/cooling empty facilities wastes 25–35% of total HVAC energy (CIBSE, 2022).
How to Implement
Setback Strategies:
For process-critical areas (e.g., clean rooms), maintain temperatures within ±1°C of daytime settings.
Non-critical zones: Reduce heating by 3–5°C or raise cooling setpoints by 2–4°C overnight.
Ventilation Management:
Adjust air changes per hour (ACH) from 6–8 (daytime) to 2–3 (night) in storage areas.
Install motorised dampers to isolate unused zones (e.g., offices) from main HVAC loops.
Case Study:
Unilever saved £120,000 annually by reducing HVAC runtime by 30% across 4 UK factories using BMS-driven setbacks.
Why It Matters
A single 3mm air leak in a compressed air system costs £700/year in wasted energy (British Compressed Air Society).
How to Implement
Compressed Air Leaks:
Use ultrasonic leak detectors (e.g., UE Systems UltraProbe 9000) to identify leaks during quiet night shifts.
Apply aerogel pipe insulation to reduce heat loss in steam lines by 60%.
Motor Efficiency:
Check vibration levels with Fluke 810 analysers: Motors exceeding 4.5 mm/s RMS indicate bearing wear.
Clean motor windings with dry compressed air to prevent 5–10% efficiency losses from dust buildup.
Action Steps:
Create a nightly checklist for lubrication (ISO VG 68 oil for gearboxes), belt tension (deflection <12mm per 300mm span), and filter changes.
Use thermal imaging cameras (FLIR T540) to spot overheating in electrical panels.
Case Study:
Bosch reduced compressed air costs by 12% in 3 weeks through nightly leak detection at its Worcester plant.
Why It Matters
30% of manufacturers lack visibility into overnight energy use (EMEX, 2023).
How to Implement
Submetering:
Install DIN-rail meters (e.g., Carlo Gavazzi EM24) on high-load circuits (>50 kW).
Use Modbus TCP to integrate data into existing SCADA or ERP systems.
Data Logging:
For SMEs: HOBO UX120-006M loggers (£250/unit) track kWh consumption at 15-minute intervals.
Analyse night-time baseload: >10% of daytime usage indicates wasted energy.
Action Steps:
Benchmark against industry standards:
Plastics Moulding: 0.8–1.2 kWh/kg.
Machining: 0.3–0.6 kWh/kg.
Set alerts for abnormal consumption (e.g., >5 kW outside production hours).
Case Study:
Siemens saved 18% on night-time energy by identifying a faulty chill water pump drawing 22 kW idle via submetering.
Why It Matters
UK manufacturers on outdated tariffs overpay by £0.03–0.05/kWh (OFGEM, 2023).
How to Implement
Half-Hourly (HH) Data Analysis:
Use your MPAN number to access 30-minute consumption data via Elexon Portal.
Shift batch processes (e.g., oven preheating) to 00:30–04:30 off-peak windows (rates as low as £0.12/kWh vs. £0.35/kWh peak).
Demand Response:
Enrol in National Grid’s Demand Flexibility Service: Earn £3,000/MW for reducing load during peak events.
Negotiation Tactics:
Leverage 10% consumption reduction from overnight fixes to demand lower unit rates.
Consider blended tariffs combining fixed and index-linked pricing for volatile markets.
Case Study:
Jaguar Land Rover cut energy costs by 22% by shifting 15% of its Castle Bromwich plant’s load to off-peak hours.
Why It Matters
Organisations with dedicated energy roles achieve 2.5x faster savings (Carbon Trust).
How to Implement
Role Definition:
Large Sites: Assign shift engineers to audit 3–5 critical zones nightly (e.g., compressors, HVAC plant rooms).
SMEs: Train a lead operator to conduct 15-minute shutdown walks using a digital checklist (e.g., SafetyCulture iAuditor).
Performance Incentives:
Tie 10–15% of the champion’s bonus to measurable kWh reductions
Case Study:
Nissan’s Sunderland plant reduced overnight energy waste by 27% within 6 weeks by empowering 12 “energy champions” with real-time dashboards.
Why It Matters
Every £1 saved via quick fixes funds £4–5 in long-term upgrades (Energy Institute, 2023).
Next Steps:
Reinvest savings into voltage optimisation (10–15% reduction) or heat recovery (e.g., Heliex Power’s steam-to-electricity systems).
Align with ISO 50001 to institutionalise energy management.
Explore Energy Performance Contracts (EPCs) for LED retrofits or CHP installations with zero upfront cost.
Case Study:
A Midlands-based SME redirected £50,000 of annual savings from overnight measures into solar PV, achieving 40% energy independence.
Immediate energy savings in manufacturing require neither capital nor complex overhauls. By methodically targeting idle loads, optimising HVAC, and leveraging real-time data, leaders can achieve 10–25% cost reductions within 30 days. These actionable steps — grounded in technical protocols and market mechanisms — provide a springboard for sustainable, long-term efficiency gains.
Top tip:: The fastest kWh is the one never used. Begin tonight.