Integrated Systems + Principles Approach

Source: California Energy Commission (2000) Manufacturing Energy End-Use Breakdown

Energy Systems –Lighting –Motor drive –Fluid flow –Compressed air –Steam and hot water –Process heating –Process cooling –Heating, ventilating and air conditioning –Cogeneration

Principles of Energy Efficiency  Inside Out Analysis  Understand Control Efficiency  Think Counter-flow  Avoid Mixing  Match Source Energy to End Use  Whole-system, Whole-time Frame Analysis

Integrated Systems + Principles Approach  Integrated systems + principles approach (ISPA) = Systems approach + Principles of energy efficiency  ISPA is both effective and thorough.

1. Inside-out Approach

Inside-out Approach

Inside-out: Amplifies Savings Reduce pipe friction: Savings = 1.00 kWh Pump 70% eff: Savings = 1.43 kWh Drive 95% eff: Savings = 1.50 kWh Motor 90% eff: Savings = 1.67 kWh T&D 91% eff: Savings = 1.83 kWh Powerplant 33% eff: Savings = 5.55 kWh

Inside-out: Reduces Costs  Original design: 95 hp in 14 pumps  Re-design: –Bigger pipes:  p = c / d 5 (doubling d reduces  p by 97%) –Layout pipes then equipment shorter runs, fewer turns, valves, etc… –7 hp in 2 pumps

Avoid Outside-in Thinking Traditional Analysis Sequence for Reducing Energy Use Traditional Analysis Sequence for Reducing Waste Result: Incremental improvement at high cost

Think from Inside Out! Inside-Out Analysis Sequence for Reducing Energy Use Inside-Out Analysis Sequence for Reducing Waste Result: Significant improvement at minimal cost

2. Understand Control Efficiency  Systems design for peak load, but operate at part-load  System efficiency generally changes at part load  Recognize and modify systems with poor part- load (control) efficiency

Control Efficiency

Air Compressor Control FP = FP 0 + FC (1 – FP 0 )

Power and Flow Control

Chiller Control

Boiler Control

Data Scatter Indicates Poor Control

3. Think Counter Flow  Heat transfer  Fluid flow

Counter-flow Improves Heat Exchange Q T T x x Q Parallel Flow Counter Flow

Stack Furnace Pre-heats Charge Reverb Furnace Stack Furnace

Molten Glass Transport: Each Exhaust Port Is A Zone

Counter-flow Within Zones Increases convection heat transfer by 83% Contact length = 2 x ( ) = 30 feet Contact length = ( ) = 55 feet

Tile Kiln (Counter flow?) Tile Exit Tile Entrance

Counter Flow Cooling Enables Cooling Tower Cross-flow cooling of extruded plastic uses 50 F water from chiller

4. Avoid Mixing  Availability analysis… Useful work destroyed with mixing  Examples –CAV/VAV air handlers –Separate hot and cold wells –Material reuse/recycling

HVAC Applications Cooling Energy UseHeating Energy Use

Cooling Applications Separate hot and cold water tanks

5. Match Source Energy to End Use

Match Source Energy to End Use

Utilize Current Daylighting Wright Brothers Factory, Dayton Ohio

Replace Colored / Fiberglass Windows with Corrugated Polycarbonate

Employ Skylighting Skylights: –Highest quality light –Reduce lighting energy costs –Increase heating/cooling costs

6. Whole System Whole Time Frame Design  Design heuristic derived from natural evolution  Nothing evolves in a vacuum, only as part of a system  No optimum tree, fan, …  Evolutionary perspective: ‘optimum’ synonymous with ‘perfectly integrated’  Optimize whole system, not components  Design for whole time frame, next generation

Whole System “ Lean ” Manufacturing

Whole System Energy Engineering Optimum Pipe Diameter  D opt = 200 mm when Tot Cost = NPV(Energy)+Pipe  D opt = 250 mm when Cost= NPV(Energy)+Pipe+Pump  Energy 250 = Energy 200 / 2

Whole System Accounting  Budgeting and capital processes separate from operational processes  Organizational structures within companies constrains optimum thinking  Enlarge system boundary to include entire company

Whole-Time Frame Accounting “Efficiency Gap”  “Numerous studies conclude 20% to 40% energy savings could be implemented cost effectively, but aren’t…..”  Discrepancy between economic and actual savings potential called “efficiency gap”.  Puzzled economists for decades: “I can’t believe they leave that much change lying on the table.”

Don’t Eat Your Seed Corn  SP = 2 years is ROR = 50%  SP = 10 years is ROR = 10%