A local resort has successfully set up a solar system – letting the owners achieve their dream of getting off the national power grid.

Muri Beach Resort owners Paul and Jane Pearson have always believed in alternative methods and thought Rarotonga the perfect place for solar energy because of its long sunshine hours.

When the couple first thought about getting off the grid the technology was not available, but since then advancements have been made to make their dream viable.

Paul Pearson says they have watched the water quality of Muri Lagoon change over the years and wanted to make sure they were taking the environmentally friendly approach. On top of their latest switch to solar, they use aerated septic systems and reduce and recycle waste.

“The only way this island can move into the future is to go green. People are looking at clean, renewable places to stay in.”

His wife agrees. “Tourists put that on their checklists when deciding where to stay. Going green could be a huge feature for the island.”

Esben Torget started design work on the resort’s solar system a year ago. The Norwegian – who has an electrical engineering background – lived in the Cooks a number of years ago where he met his local wife. They have lived in Norway for the past 10 years where Torget has been designing yachts.

On their return to the Cooks last year, Torget set up Sunshine Solar Solutions, a solar design and installation business. He has set up a number of smaller solar systems around the island but this is the largest one to date. With his engineering background as a base, he trained in solar systems with SMA Solar Technology – which is the system he uses and deems the “world leader”.

The installation was done by Torget, Pearson and resort maintenance staff, with help from John Koteka and his team at Koteka Electrical.

One room at the resort is used to house 96 large batteries which weigh 250 kg each. They store excess energy not used throughout the day, which is converted from DC in useable AC current by solar invertors.

The resort has a generator which kicks in automatically when needed as back-up. They might use it for one hour during the night if there has not been much sun that day.

Torget says the only limitation on the system is roof space. There are 406 panels at 250 watts each, which cover 700 square metres of roof space. Muri Beach Resort also built another structure out the back of the hotel to hold extra panels.

They cover each unit roof in the 20-room resort surprisingly subtly, giving off an obsidian gleam – and in Torget’s opinion, make for a more pleasing aesthetic than the previous roofing.

He said if the system is installed correctly then maintenance is easy– there is none. The panels are cleaned by the rain and dried by the sun. They do need to be placed on roofs that can handle the load in a cyclone, but most houses can.

Trees must be kept trimmed so branches do not shadow the panels – but Torget uses a handy technical web-based tool provided by SMA which monitors exactly which panel is being shadowed and a team can be sent to trim the branch. This free tool allows Torget and resort owners to log in from anywhere in the world to check what is happening with the grid and make sure everything is performing as it should.

Graphs show energy produced and used, battery fullness and power levels the invertors are producing. Other graphs show what happened to the battery banks overnight, what the sun is doing and what the grid levels are.

This real-time monitoring of the system allows the resort to plan daily energy activities. They do all their washing, and run septic and pool pumps when the battery levels are at their highest. The resort uses 40 kilowatts per hour, on average, and uses most of its energy on hot days when guests run air conditioning in their rooms.

The project was not cheap – costing the resort somewhere between $600,000 and $650,000 – but it is an investment deemed extremely worthwhile by the Pearsons.

Before putting in the system, the resort’s power costs per month were around $6000 to $10,000 per month. Now they are totally off the national grid – and didn’t even know about the recent island-wide power cuts until someone told them later.

This project looks impressive and the statistics show it is. It is the fifth largest off-grid system in the Pacific Ocean, and three times bigger than the government solar project in Rakahanga.

The government has a much publicised renewable energy target of 50 per cent by 2015 and 100 per cent by 2020. It has recently secured a funding injection from New Zealand and the United Arab Emirates after the Pacific Energy Summit in Auckland. But there has been recent public doubt the ambitious objectives will be achieved on time.

Torget and Pearson think storage is the biggest problem Rarotonga faces in the quest to becoming fully solar powered. There is not enough space to store the batteries needed – so they think storing the energy in water, using hydro dams in the mountains, is the way to go.

Muri Beach Resort does not feed back into the national grid, despite approaching Te Aponga Uira to ask them if they could. They have had some discussions with the energy company but at this stage TAU does not have the technical capacity to deal with excess energy coming in and then stopping suddenly. The resort could be potentially feeding in 100 kw/h when it is sunny and its batteries are full, but would stop feeding in energy once it got dark.

Once TAU has made adjustments to their system the parties will discuss again – the resort is keen to help out as they produce more energy than they can use and there is only so much energy the batteries can store.

The Pearsons are pleased with how the system has turned out and encourage more people to follow suit.

“There’s a mentality that it’s for people that have money because of the upfront investment. But they don’t think about how it pays itself back.”

Torget agrees. “Solar is definitely the way to go. The payback time is about five years for houses and just a bit longer for resorts.

“Muri Beach Resort wanted to go green. Tourists appreciate the eco side of things, and it’s cool to think all the energy used is from the sun. Any resort on the island could do it.”

Calida Smylie