IEN: What are the major power and energy concerns facing industry in the next few years? How can they be addressed?
Loucks:
Customers are concerned about reliability of power:
- Reliability is affected by internal (inside customer facility) and external (utility) issues.
- Internal reliability is a problem because of a particular combination of situations somewhat unique to electrical distribution systems:
1. Electrical systems are inherently reliable. They have few moving parts. They withstand momentary overloads. Infrequent failures invite complacency.
2. Much of an organization''s infrastructure operates on electricity. This makes electrical infrastructure a critical component.
3. Inherent energy within electrical infrastructure invites catastrophic failures with large outlay of flash energy (refer to NFPA70E Arc Flash interest now)
4. Therefore, latent, unattended problems tend to remain benign until a final failure, which usually results in equipment damage and extended downtime.
- Good business practice demands that money be spend on most pressing issues.
- New predictive diagnostic technologies such as Partial Discharge and Gamma sensing can direct attention to areas that are escalating in importance.
- This reduces maintenance expense while improving reliability.
External reliability is an issue with utility power availability:
- Some concerns here include the considerable cost pressures placed on utilities to compete.
- Until customers complain about reliability, they continue to buy on price.
- This buying behavior makes it difficult for the utilities to spend the money necessary to improve (or in some cases maintain) reliability.
- I don''t see any market forces to change this in the near term so my prediction is that utility reliability will not improve substantially in the near term.
- Even when customers start to notice a problem and complain, infrastructure build-out takes time.
- DG is a solution until (or if) this infrastructure build-out occurs.
- Some sites will want to continue to look at DG because their reliability requirements are higher than what the utility economically can provide.
IEN: What innovations in systems, equipment & components, software, and services can help reduce energy consumption and increase efficiency in plant operations?
Loucks:
1. Neutral harmonic traps - limit harmonic current and reduce resultant losses and heating in transformers and motors.
2. Active filters - inject current into bus to remove harmonics.
3. Weather prediction - forecast to building management system how much ice storage needed, for example, in the next 24 hours.
4. SAG correction - balance phase voltages to reduced negative sequence currents within motors and resultant losses.
5. Harmonic filters - trap harmonics to limit heating in transformers and motors.
6. Higher pulse AF drives - 12 and 18 pulse drives. Not really new, but may be more cost effective to install than active filters to mitigate afterwards.
7. Wye-Delta phase shifting - phase shifting some of a facility''s load cancels certain harmonic orders.
IEN: What are the latest advances in audits, utility monitoring/analysis services, equipment diagnostics/maintenance, and HVAC retrofitting?
Loucks:
1. Meters that now transmit from behind company firewalls to central servers, simplifying deployment of energy and power quality monitoring tools for customers who want to outsource this job function.
2. Audits that look for reliability issues and provide a customer with an estimate of ''9s'' based on current condition and topology of system.
3. Services to monitor changes in utility rules and advise customers of mediation strategy (PF correction, rate change, peak shaving, etc.).
4. Industry-specific audits that understand unique requirements of companies within that same segment.
5. Partial Discharge sensing using special insulators and high frequency current transformers that are installed as standard in switchgear at time of manufacture. This permits simple connection to PD sensing equipment without needing an outage if the customer wants to wait before installing PD hardware.
IEN: How about power supplies? Power quality?
Loucks: Active filter type front end on AF drives and power supplies: draws/injects current to smooth incoming waveform.
IEN: What are some R & D hot spots?
Loucks: We have several, but they are too new to share in a public forum without an NDA. In particular, the patent I have pending deals with this subject.
IEN: Will distributed generation/onsite power, cogeneration, fuel cell technology, and isolated power play an increased role in meeting industry''s power needs? How and when?
Loucks:
1. I believe DG will play more of a role for these reasons:
- Large generation plants are difficult to site and are therefore placed in remote locations away from loads.
- This necessitates transmitting that power to the point of use using the only technology we have today, HV and EHV transmission lines.
- Transmission lines are difficult to site (aesthetics and concerns -- although unfounded -- about health problems likely reason).
- As loads increase (more electrification occurs) and the transmission infrastructure fails to increase, the transmission system is strained.
- Deregulation of transmission means any generator has access to transmission infrastructure.
- These generator sources are usually further from the loads than the incumbent (previous) generator.
- This "wheeled" power from far-flung sources now must share the same overburdened transmission system.
- Reliability suffers even more as sagging lines trip from contact to trees, voltage stability suffers as system lacks sufficient vars for load.
- One solution is to place source of power closer to load, in other words, distributed generation.
2. However, there are some issues that must be overcome:
- Lower cost sources such as reciprocating engines require periodic maintenance (filters and lubrication system).
- Maintenance contracts can alleviate some of these problems.
- Higher cost sources such as fuel cells are difficult to justify economically in many cases.
- Reciprocating engines that perform dual duty (standby and peak shaving/DG) have conflicting issues of fuel used and emissions.
- Vast majority of standby engines use diesel. Many are not allowed to operate in highly polluted cities except in emergencies.
- Natural gas or propane-fired engines are much more expensive (while still less expensive than fuel cells or microturbines) than diesel engines of same rating.
- Natural gas is not considered a reliable source for backup, so combined with higher cost of gas engine, you won''t see them on critical backup systems.
- Peak shaving can be accomplished by transferring entire facility load to backup generator, but usually not cost effective.
- Better economics occur when only a portion of the demand is shed, allowing the use of a smaller DG source.
- Peak shaving a portion of the load may imply that utility and DG source remain paralleled for extended periods, a source of concern for the utility.
- Each utility has separate rules for connecting DG in an extended parallel operation. IEEE 1547 is attempting to standardize these rules.
- Concern is potential to back-feed a dead utility distribution system, which results in safety hazard for utility workers.
- Solution is to install "anti-islanding" detection at the utility service entrance point to the customer site that disconnects customer from utility on utility fail.
- This anti-islanding detection may involve measuring direction of power flow at service entrance, rate of change of frequency or monitoring "transfer-trip" signal.
- Transfer trip is a system where the upstream utility breaker(s) send a tripping signal to the DG source when those utility breakers open, insuring isolation.
- Transfer trip is very reliable but very costly. It prevents islanding even when the DG system is exporting 0 power (worst-case condition).
- It is worst-case condition because the lost of utility may result in no change in power flow, nor a change in the frequency.
3. Fuel cell, microturbine, and photovoltaic systems offer interesting technical advantages over reciprocating engines, but those benefits come at a cost. Also, both technologies convert direct current to utility alternating current through an inverter. UL 1741 addresses some of these, along with IEEE 1547. I expect to see these newer technologies become more common.
4. Flow battery technology is interesting to watch (Sodium-Sulfur, Zinc-Bromine, Vanadium Redox, etc.) since it implies that energy could be stored during off peak times (evenings) and provided to loads during peak times. This load leveling would offer a much better utilization of the existing generation and transmission infrastructure. Sandia Labs/DOE has a good summary of these technologies; click here for more.
5. Supercapacitor and flywheel technology also continues to improve and can be used to provide energy storage for peak shaving or UPS applications.