Are renewables a viable alternative for ports?

Ports looking to upgrade their power supply might be tempted by heavily hyped green alternatives, but should they jump feet first into these murky waters?

Probably not, advises Julia Bradley, Peel Ports' head of marketing. She suggests that other options should be considered first, specifically targeting energy conservation and efficiency to reduce existing consumption.

“Whole life cost, the environment and customer needs have to be central in considering any solution to energy requirements,” she says.

Alstom Grid's Akash Middya points out that ports work 24/7 all year round, so require uninterrupted power, making reliability of power quality important.

“Wind mills,” he says, “normally provide seasonal power, although there are some regions where this would be constantly available.”

Jürgen Moser, senior expert for power electronics at Siemens, is similarly cautious. “Windturbines or, sometimes even better, solar power modules, are a good solution when a port of terminal wants to reduce the power bill, but they are not a good solution when the main aim is to increase the overall power supply,” he says.

Both technologies have their advantages and disadvantages, he claims. Windpower, for example, produces high power density (compared with its footprint); produces free energy once capital costs have been accounted for; and has a more stable in-feed compared with solar. On the downside, maintenance is required; the moving shades of the blades disturb workers at the terminal; there is the possibility of ice strike from the blades; and the amount of power generated is not predictable.

As for solar, it also produces free power once investment is amortised, requires no maintenance and has a relatively predictable in-feed of power. However, cloudy skies mean there is no guarantee that power will be available when needed. “Regenerative power has to be seen as variable and something which you cannot rely on and is not necessarily available when operations in the harbour need it.

"So, first the power supply to the port has to be increased to meet the needs of the production process. When this is covered, the price for electric power can be reduced by using the port's own production, which is free of cost after return on invest has been secured.”