On­line tool re­veals so­lar sav­ings

Home­own­ers can see how much they can save or make

The New Zealand Herald - - NEWS - Jamie Mor­ton

How much so­lar en­ergy could your home cap­ture? A Univer­sity of Auck­land re­searcher has cre­ated a new on­line tool for city res­i­dents to find out whether in­stalling so­lar pan­els on their roof could help them make or save cash.

Dr Kiti Suo­ma­lainen un­veiled a 3D model last year that mapped the best places in Auck­land to har­ness so­lar en­ergy, find­ing that sub­urbs in­clud­ing Botany Downs, Shelly Park, Massey and Flat­bush could po­ten­tially har­vest nearly 4000 kilo­watt hours (kWh) each year.

She built this us­ing Auck­land Coun­cil’s LiDAR data, which is col­lected by planes emit­ting light pulses and tim­ing how long it took for the re­flected pulse to re­turn.

Ul­ti­mately, the model suggested that if 250,000 houses had 36sq m of so­lar rooftop pan­els, they could to­gether meet Auck­land Coun­cil’s low-car­bon tar­get of pow­er­ing the equiv­a­lent of 176,565 homes with the sun.

Suo­ma­lainen has since used that model to develop an on­line cal­cu­la­tor that crunches the so­lar rooftop po­ten­tial of half a mil­lion Auck­land build­ings down to one square me­tre. This po­ten­tial de­pended on such things as the roof’s slope and as­pect, and shade from sur­round­ing build­ings and trees.

“So­lar gen­er­a­tion is rapidly ris­ing in New Zealand, with homes lead­ing the trend,” said Suo­ma­lainen, a re­search fel­low at the Univer­sity of Auck­land Busi­ness School’s En­ergy Cen­tre. “We wanted to of­fer an ed­u­ca­tional tool that is im­par­tial and re­al­is­tic to help peo­ple work out if so­lar is eco­nomic for their house­holds or work­places.”

New Zealand’s to­tal in­stalled so­lar ca­pac­ity rose five­fold over the three years to 2017, and Auck­land Coun­cil has a goal of 970MW in­stalled ca­pac­ity of so­lar pho­to­voltaics by 2040.

The cal­cu­la­tor al­lows users to zoom in on their rooftop for a colour-coded view of its so­lar en­ergy po­ten­tial, which high­lights the best spots to place pan­els.

Home­own­ers could also en­ter the size and qual­ity of so­lar panel they pre­fer, how much so­lar power they would use and how much they would sell back to the grid, along with sev­eral other val­ues.

The cal­cu­la­tor, which is now at the stage where users can test it, of­fered the to­tal value of the in­stal­la­tion over its life­time, sug­gest­ing that so­lar pan­els were a good in­vest­ment if the re­sult was pos­i­tive.

“Self-con­sump­tion rate — the per­cent­age of so­lar power that you use your­self, rather than sell back to the grid — is the main thing that will af­fect your eco­nom­ics,” she said.

“If you’re at home all day, you will prob­a­bly use more power than some­one who is at work or school most of the day.

“For ev­ery kilo­watt-hour of so­lar power you use, you save about 27c.

“The buy-back rate at the mo­ment is around 8c — so the more you use, the greater the over­all value of your so­lar gen­er­a­tion.”

Picture / Daily Post

Home­own­ers can save 27c with ev­ery kilo­watt-hour of so­lar en­ergy they use.

Newspapers in English

Newspapers from New Zealand

© PressReader. All rights reserved.