Panels too grimy to catch the light

Serious flaws have been revealed in the management of Palmerston North’s struggling solar farm.

The farm on the roof tops of the civic administration and convention centre buildings is only generating about a third of the returns expected, while its panels are lying flatter than recommended and uncleaned.

City council finance and performance committee chairwoman Susan Baty has blasted management for taking three years to report on the problems.

Originally, the farm was expected to generate 118,000 kilowatt hours of electricity per year.

It came close in the first year, dropping back to just over 100,00kwh in the second year, but has generated just 53,997kwh eight months into the 2016-17 year.

General manager for City Networks Ray Swadel presented the figures in a report on how savings from solar generation are well down on projections to the committee’s meeting on Monday.

Earlier projected to save the council $27,000 a year and pay back the $200,000 installation costs within 10 years, the savings so far were just under $12,000 in the first year, nearly $11,000 in the second, and under $6000 to the end of February this year – a total of about $29,000 in its lifetime.

Swadel said low sunlight hours this summer contributed to the low performance, but another reason was a lack of cleaning.

The 400 panels were laid flatter than the recommended 40 degrees because of the risk of wind damage.

They lie on a 10 degree angle, allowing dust and dirt to build up, and it did not get washed off in the rain.

No cleaning and maintenance programme was put in place at the start.

Baty said she was ‘‘very perturbed’’ problems had been brewing for three years without councillors being told.

‘‘Eighty-one-thousand dollars was supposed to be the saving so far and we are only meeting onethird of that.

‘‘To be sitting here three years later and not know we are not getting the productivity, and that maintenance has not been done, shows there are serious flaws in our system.’’

Swadel said he could only apologise. There had been a change in staff looking after the solar farm and he had not been aware of the issues.

He said the maintenance work should have been in place from the first day and a $4000-a-year programme starting now would help to enhance performance.

He was not aware changing the angle of the panels would have affected the generation and savings potential so much, but said it would not be prudent to change the angle and risk wind damage.

The electricity from the civic administration building panels is used only within the building, with none sold into the national grid.

Another smaller-scale generation project is based at the Esplanade depot, which exports all of the energy it makes, worth $779 in 2015-16. Its 26 panels had also suffered through lack of cleaning, an oversight that would be fixed.

A more successful council power-generation scheme is at the water treatment plant, which in the 2015-16 financial year generated $177,855 of electricity, about half of which was used to power the plant, with the balance sold.