-Distributed Generation -

A Reliable Power Solution For The Digital Age?

-Distributed Generation -

A Reliable Power Solution For The Digital Age?

Dustin T. Smith

Power System 2002 ConferenceImpact of Distributed Generation

Clemson, SCMarch 13-15, 2002

Project Development Manager

Sure Power Corporation

2002

TodayToday

Today: Key macro-economic trend – Everything is digital (digital economy)

Components that have been addressed: IT (networks & software)/Telecommunications (networks & software)/Equipment Manufacturers (reliability of components). Components that have not been addressed: Power

What Do We Want To Accomplish?

Collectively have a better understanding of Applying DG to Mission Critical Facilities.

Reinforce the definitions of common metrics.

Challenge barriers to wide spread use of Distributed Generation. Encourage evaluating Distributed Generation as an option.

Topic Items

Appropriate Use Of Metrics – Reliability vs. Availability vs. Quality

Power Issues Of The Digital Age

Critical Elements Of DG High Availability Power – Mission Critical Applications

Example Schematic - DG Mission Critical Application

Summary - Concepts To Remember

Electric Utility

Built for the Industrial Age (light bulbs and motors).

Ability to support Mission Critical facilities is different in every location.

Facilities

Facilities supporting digital commerce are a critical component of the final product (Integrate the value of Availability into Marketing Plan).

Integration of Product Marketing and Facilitates Planning/Design Groups in conjunction with the Business Plan – Complex Project.

Demands – Volume, Availability & Quality

Scaleable, High Availability (5 9s or greater), CBEMA grade (IEEE 446-1987) power.

Vulnerabilities - Complex systems are much weaker than their weakest link.

Digital equipment power sensitivity (example: eight milliseconds outside voltage curve for microprocessors & more than a 20% voltage deviation for four cycles for semiconductor fabrication = SYSTEM FAILURE). Even short down times equals huge losses. On-Going operations & maintenance are crucial.

Power Issues Of The Digital AgePower Issues Of The Digital Age

Quality - CBEMA CurveQuality - CBEMA Curve

Typical Design Goals of Power Conscious Equipment Manufacturers - CBEMA CURVE

(IEEE 446-1987)

0%

50%

100%

150%

200%

250%

300%

350%

400%

0.001 0.01 0.1 1 10 100 1000

Time in electrical cycles - Logarithmic Scale

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ge

Ex

cu

rsio

ns

(%

)

No

min

al

= 1

00

%

Half Cycle

0.5

ReliabilityReliability

Reliability

The Probability that a system or even a component will operate for a given period of time. Quality is a component of this metric.

Over time, reliability tends toward 0 (all components eventually fail).

For complex systems: Mission length must be known and is most useful for analysis of missions during which equipment may not be repaired or down for maintenance (missions of shorter duration).

R = 1 - Pf (Probability of Failure)

Over Time - All Components Fail

0

1

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

Time

Rel

iabi

lity

Reliability ExampleReliability Example

Reliability of Emergency Diesel Generators

– Emergency Diesel Engine Generator Power System Reliability 1987-1993 Grant, G.M., et. al., Idaho National Engineering Laboratory, INEL-95/0035, February 1996

0.75

0.8

0.85

0.9

0.95

1

1/2 hour 8 hours 24 hours

Availability (Unavailability=Q=1-A)

The probability that a system will function at a future instant in time. Quality and Reliability are components of this metric.

Most useful in the analysis of complex, repairable systems with longer mission durations (does not necessarily require defined mission length).

Probabilistic Risk Assessment – Most useful tool in defining Availability (Redundancy/Spare Parts Inventory/SLAs/Staffing).

Utilizes historical performance data for individual components.

Provides specific probability of system availability in the future.

Over time, calculated results have been extremely accurate (I.e. nuclear industry).

Availability is the most useful metric for identifying power performance parameters for mission critical applications.

According to experts in the science of Probabilistic Risk Asseement1, achieving availability levels (in practice) above four 9s (99.99%), likely requires on-site distributed generation.

[1] Steve Fairfax, President of Mtechnology, Saxonville, Massachusetts, USA

AvailabilityAvailability

Application of the NinesApplication of the Nines

In The Digital Economy, Unavailability (1-Availability)

does not equal Down Time (Facility outage may be a magnitude

longer than the original power outage).

Nines Availability Unavailability

"one nine" 90% 10% 876 hours"two nines" 99% 1% 87.6 hours"three nines" 99.9% 1.0.E-3 8.76 hours"four nines" 99.99% 1.0.E-4 53 minutes"five nines" 99.999% 1.0.E-5 5.3 minutes"six nines" 99.9999% 1.0.E-6 32 seconds

Downtime

The PRA gives us an Availability Design Criteria. How do we apply it?

We must convert the system Availability/Unavailability

to a specific Probability of system failure!

Availability & Probability of FailureAvailability & Probability of Failure

0

10

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50

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99.9% 99.99% 99.999% 99.9999%

AvailabilityUnavailability

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10-2 10-3 10-4 10-5 10-6

99%

Assumptions:

16 hour mean time to repair

20-year operating life

The Traditional ApproachThe Traditional Approach

UtilitySubstations

BatteryBackup

UPSSystem

CriticalLoad

StandbyGensets

HVACSystemsHVAC

Systems

NormalLoad

EssentialLoad

Note: System availability 99.9% to 99.99%- Grid is prime source of power- Battery is short-term backup-Gensets are secondary source of power

High Availability DG SystemHigh Availability DG System

Note: Desirable System availability: 99.9999%-Prime source of power- Grid is secondary source of power

On-SitePower System

CriticalLoad

Chiller System

NormalLoad

EssentialLoad

( if available )

Utility

Chiller System

NormalLoad

EssentialLoad

( if available )

Utility

Critical Elements Of DG High AvailabilityCritical Elements Of DG High Availability

Basic elements of a high availability power system:

Redundancy

Allows system to operate when individual components fail.

Energy Storage

Maintains power flow to the critical load while additional power sources are dispatched during prime mover failure.

Switching

Detects failures in components (or even subsystems), and connects replacements (very complex and difficult).

All High Availability Designs must use these elements to achieve near-perfect operation with imperfect, real-world components.

Probabilistic Risks Assessment is a proven tool for determining the best balance of these elements and effecting the real-world system performance.

Mission Critical DG systems must be designed from the ground up with the goals, objectives and elements of High Availability in mind, not modified after-the-fact (pound-to-fit).

Additional Elements Of DG High AvailabilityAdditional Elements Of DG High Availability

Additional system performance requirements include:

Precise end user goals and objectives identified.

No single Point of failure

Example: RAID (Redundant Array of Independent Devices)

Independent redundant power paths

All generation available to all of the load, all of the time without switching.

No generation inter-dependencies

Eliminate all potential cascade failures

Design must allow for maintenance and repair (both routine and emergency) without disruption of power to the critical loads.

Benefits of DG In Mission Critical App.Benefits of DG In Mission Critical App.

Benefits of Distributed Generation in Mission Critical Applications

Dedicated operations and maintenance staff

Allows End User to manage their overall operational risk by allowing experts to handle the on-going production and delivery of Mission Critical power

True system High Availability

Efficiency (CHP Process)

Reduction in Environmental emissions

Capitol management (paying for on-site assets, not the Utilities transmission lines

Security

Autonomy/Control

Concepts To RememberConcepts To Remember

“Availability” is the most useful metric for evaluating the application of Distributed Generation power systems with respect to Mission Critical Facilities.

A formal, reviewable, rigorous design process such as Probabilistic Risk Assessment will dictate a design that ensures actual system performance meets the End Users long term system performance expectations (as well as meet business plan marketing objectives).

Table Reference: A Technical and Market Assessment of Premium Power in the Haverhill Cyber-District, Prepared For: Massachusetts Collaborative, Prepared By Planet-TECH Associates, January 2002

Concepts To Remember ContinuedConcepts To Remember Continued

“Availability” - Continued

These types of systems cost lest than the systems that do fail.

Once a system achieves High Availability in design, real-world limits such as common cause failures can be addressed.

Table Reference: A Technical and Market Assessment of Premium Power in the Haverhill Cyber-District, Prepared For: Massachusetts Collaborative, Prepared By Planet-TECH Associates, January 2002

First National Bank of OmahaFirst National Bank of Omaha

The reliability of the ‘six 9s’ computer grade electricity that Sure Power delivers isn’t a luxury for us at First National Bank of Omaha, it’s a critical difference over existing power arrangements that will substantially increase our computer uptime. The result is a tremendous leap in our competitive advantage. With Sure Power, First National can raise our customer’s service expectations while generating higher revenues.

Dennis C. HughesDirector of Property Management

First National Buildings, Inc.

© Copyright First National Bank of Omaha 1999

United States Patent 6,288,456 B1Date of Patent September 11, 2001

[Only DG - Mission Critical Installation with 3rd Party PRA Certification (Availability Higher than Grid + Back-up]

“Powering Mission Critical Enterprises”

The EndThe End

Sample Sure Power SolutionSample Sure Power Solution

Sure Power System RenderingSure Power System Rendering