Chemical plants suffer from inadequate power supply

London - Energy costs are an increasingly significant burden for the chemicals sector. Whilst the pricing of already high costs for oil, natural gas, and electricity are out of the sector’s control, the cost of energy does not stop at signing the annual energy contract.

Electrical power is perfect for end users if voltage and current are correctly balanced and describe a pure sinusoidal waveform. This can be distorted by disturbances such as interruptions, dips or surges, harmonic pollution, and interference, which can degrade power quality.

According to the European Copper Institute, many chemical plants incur significant financial losses due to electrical power systems that cannot cope with commonly experienced irregularities in the power supply. These unplanned losses can represent the difference between profit and loss, particularly as short interruptions to power supply, even as short as a millisecond, can stop a production plant and for some chemical plants.

ECI, for example, cites how at one chemical plant, a contactor failed for just under 6 seconds. Controls and operational equipment were affected, leading to an entire week’s production being halted. The losses included lost production, staff downtime, wasted raw materials, equipment damage and penalties to the electrical network operator. The aggregated cost to the company was just under Euro7.8 million.

These impacts can also trigger a wider range of penalties – environmental, utility, client contract, and personnel claims. These unexpected stoppages disrupt production planning and usually result in delivery delays, loss of reputation for reliability and consequently loss of business.

Moreover, sudden voltage surges can can cause control equipment to overheat with potentially disastrous consequences for the integrity of the plant. These in turn can lead to damaged capital assets and often as not to serious environmental or health & safety incidents.

A recent ECI survey found that electrical power systems in the chemical sector were not adequately designed to withstand such common power interruptions and disturbances and identified many losses and much wastage due to poor PQ throughout the industry.

Average costs by type of poor power quality event

- Surge or transient: €120,000 — 180,000

- Long interruption: €90,000

- Short interruption, service sectors: €18,000 — 36,000

- Short interruption, industry: €7,000 — 14,000

- Voltage dip: €2,000 — 4,000

Whilst current investment into PQ solutions for the companies interviewed was 3.5% of the average turnover, the average losses caused by unresolved PQ issues accounted for over 10% of their annual electricity bill. Another problem is that these losses tend not to be assessed as a totality, relating as they do to different cost centres and occurring at different moments in time.

The solutions to these problems lie very much in the industry’s own hands, according to ECI, which recommends a holistic approach to review all the issues at hand, based on three operational pillars:

- Correct measurement, to assess the full impact of power quality events, and why they are happening.

- Appropriate design for the electric installations, ensuring reliability and resilience.

- Considered investment justified by assessing system renovation cost set against the accumulated losses