Green Energy for Samoa – Why not the obvious?

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By Kevin Hartin Asaga Savai’i

All the talk about being totally green by 2020 is a wonderful sentiment that will have no one arguing against, but how are we going to get there?

Reports of wind farm in the hills of Upolu and the visible evidence of the Solar farms out next to the Airport show that the Samoan Government and EPC is trying to go green, however why has there been no discussion about harnessing the power of the ocean that surrounds our beautiful islands?

One of Samoa’s most popular tourist draw cards are the Blowholes at Alofaaga and various other sites around Samoa’s volcanic coastline. 

Did you know that there is a Green Power Generating technology based on the Blowholes, already in operation for more than 15 years in other parts of the world?  Welcome to the world of the “Oscillating Water Column” (O.W.C).

Imagine if you had a long open pipe and put half of it vertically in the ocean where waves can go past, alternatively raising and lowering the sea level, both outside and inside the pipe.  

The water going up and down inside the pipe would be like a piston pushing air out the top then drawing it back in, just like the blowholes blow and suck with every wave that hits the shore. 

Instead of throwing a coconut in the hole to launch into the air for the pleasure of the tourists, how about we could put a special turbine in the hole and use the alternating airflow to spin this turbine? This special turbine is called a Wells Turbine, which spins in the same direction irrespective of the flow of air over it.  Connect this turbine to a generator and viola, you have a totally Green Power generating solution, modeled of our beloved blowholes.

The most famous O.W.C site is on the Isle of Islay in Scotland called LIMPET, which has been operating for more than 15 years and generates 750kW of electricity.  To put that into perspective, I believe the total electricity being generated in Savaii is about 4MW, so a 15-year-old installation is capable of generating almost 15% of Savai’i’s peak power needs.  Using today’s technology, where it is possible to generate 1.5-2MW from such an installation, a single station could potentially produce 30-50% of the needs of our big island.

With large parts of our coastline not protected by reefs and the waves breaking up against the lava rock, we have many perfect locations for Q.W.C installations like that of the LIMPET.  Consisting of a concrete collector chamber built on the edge of the shore, extending out into and underneath the surface of the water, with a turbine and generator up out of harm’s way on the lava rock, we could have these high tech, man-made blowholes producing electricity 24 hours a day, 365 days a year, for little more than the cost of maintenance.

But I hear you say that we already have all these solar panels, so why would we need another form of green energy?  The big problem with Solar technology, apart from the very high installation cost is that they don’t product any electricity at night, nor do they work at even close to their peak when there is cloud cover or heavy rain.  Solar panels are also highly susceptible to damage in cyclones and may prove to be unreliable after a few years in our harsh tropical environment.

If you really wanted to spend some money, you could always install large bank of batteries to store the electricity generated by the Solar arrays, for use at times when it is needed, however, as fast as battery technology is progressing, it still has a massive cost of installation, requires constant maintenance and will require scheduled replacement every few years due to the daily cycles of charge and discharge. 

 

 This fact alone makes it somewhat impractical as the key to Samoa’s green power goals.

With so many proven technologies available, Samoa should look at deploying a number of these to reach our goal.  We already have about 50% of Upolu’s power generated by the existing Hydro infrastructure, which supplemented by the current and planned Solar installations and possibly the proposed Wind Turbines, may enable the Diesel generators to be turned off, most of the time.

Savaii is slightly different, without the Hydro and planned Solar installations.  With many miles of uninhabited, rugged coastlines, there is an opportunity to look at a few OWC installations to get us from the current 100% reliance on Diesel generation at Salelologa to the 100% Green by 2020.  If a solar installation can generate, say 1MW during the day when air-conditioners and workplace load demands more power, then three OWC installations around the coast could easily generate a base load of 3 or 4MW to handle Savaii’s current and future needs.

One of the more recent countries to conduct research into OWC is our primary development partner in China.  With such a close relationship and the funding available in China for development projects in countries like Samoa, it would surely be a more positive and long serving addition to Samoa’s infrastructure than another office building or upgrade to our sports facilities.  A good news story for China, not usually known for their Green stance, helping their partner in the Pacific meet a key goal of the Samoan Government, 100% Green Energy by 2020.

This sort of Green solution can also be a boost to Samoa’s very important and growing Tourism sector.  Many of our current visitors are drawn to Samoa’s natural and unspoiled environment, with many very interested and motivated by Green initiatives. 

Imagine the marketing spin the Tourist Authority can put on the promotion of Samoa as a Green energy producer with something like OWC being pitched as based on our natural Blowholes.  It is a good news Green energy story with a difference and relevance unlike most anywhere else.

So, I challenge the Samoan Government to at least look at this as a part of the solution to the goal of being 100% Green Energy by 2020.

 


© Samoa Observer 2016

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