Solar is Helping Islands Ditch Diesel
From a utility and engineering perspective, the transition from diesel to solar power on these islands sets a critical precedent.
Halfway between Hawaii and New Zealand, there is a small group of atolls called Tokelau. To get an accurate idea of just how remote Tokelau is – it’s a full 24-hour boat ride from Samoa, which is itself a six-hour flight from Auckland, NZ.
Given its isolation and population of just 1500 people, it’s hardly a surprise that Tokelau has the smallest economy in the world. After all, the entire region’s landmass is a paltry 3.9 square miles. Nevertheless, it is one of the most important island chains in the world right now, thanks to its widespread adoption of solar energy.
In November of 2012, Tokelau ditched its diesel generators for good, becoming the first territory in the world to utilize 100% renewable energy. Because of the low population and reduced energy demands, this impressive transition was accomplished via just three solar power stations, with a total generation capacity of 930kWp.
In the following decade, the Tokelau solar project has proven such a success that the trend is already spreading to places like Guam and the Marshall Islands. Of course, such efforts are not only pivotal for the islands that accomplish the switch, but they could serve as models for implementing solar energy in other regions – remote or otherwise.
In this article, we’ll explore the successes and challenges related to these initiatives, as well as what they might mean for the future of solar engineering.
Even Today, Most Islands Remain Reliant on Oil
Prior to 2012, the islands that make up the Tokelau Atoll were importing around 2,000 barrels of diesel per year. Given its location, transporting this fuel was both logistically challenging and expensive. This led to uncomfortably high energy costs in a region with a per capita GDP of just US $6,275 per person per year.
Though electricity demand has changed somewhat since the island achieved energy independence, solar still supplies around 75% of total power. More importantly, diesel imports have been reduced by 80%.
Unfortunately, other islands worldwide continue to rely heavily on imported petroleum products. In the Solomon Islands, 97% of the country's electricity is generated from diesel, with only 12% of homes being connected to the grid. The situation is similar on Tonga, where high energy costs from imported diesel lead many homeowners to avoid using electricity unless it is absolutely necessary.
The story is the same in Antigua, Saint Vincent, and the Grenadines, as well as the Maldives, Seychelles, and Falkland Islands. However, thanks to the rapidly increasing viability of renewables, many of these islands are making at least some investments in solar or wind. As of 2023, El Hierro, a small island in the Canaries, is about halfway toward its stated goal of abandoning fossil fuels, while at least six Caribbean islands have pledged to make similar strides.
As far as United States territories are concerned, all eyes are currently on Guam and the Marshall Islands. These landmasses have been critical to U.S. military strategy in the Pacific for decades. However, as with all the previously listed territories, their distance from the mainland presents unique challenges in energy supply. Even for an economically powerful and innovation-focused country like the U.S., connecting these areas to more extensive power grids would be highly impractical, leaving them heavily reliant on diesel.
Why the “Great Island Solar Project” Matters
According to Aaron Burkhart, VP at utility-scale solar engineering firm Doman Energy, the so-called “great island solar project” is one of the most important aspects of the modern solar energy revolution. “It has a lot more to do with perception than anything else,” he says. “A small rural town goes 100% solar, and it’s seen as a minor achievement. A whole island or island chain does the same, and suddenly, you’ve got a major news story – even if the island has a smaller area and population.
It's an important distinction. Because while solar energy seems to have overcome the negative public perceptions that plagued its growth in recent years, there are still challenges in getting people to see it as a “big picture solution.”
“Solar is a key solution to global energy security problems,” says Burkhart. “It can power anything reliably, cheaply, and effectively.” Yet too many people still think of solar as something you put on your roof. Because of years of only being exposed to solar on roofs, they fail to see that solar as capable of powering cities, countries, and continents.
However, each island that transitions to solar energy provides another micro-grid" use case for solar’s ability to ensure large-scale energy security – even if the scale only appears large.
“Nowadays, I could get an island the size of Tokelau up and running in 10 months with a relatively small investment,” says Burkhart. “They’d never have to turn on a generator ever again when you couple solar with modern BESS.”
As previously mentioned, Tokelau’s entire land mass is just 3.9 square miles. Now consider the fact that Vatican City is just 0.19 square miles, and Monaco is just 0.78. Tokelau proves that either of these regions could easily be converted to 100% solar energy in months, for very little cost. This is why the ongoing projects in Guam and the Marshall Islands are so critical.
At 70 square miles, the Marshall Islands are larger than the entire country of Lichtenstein. At 210 square miles, Guam is equivalent to some of the world’s biggest cities. It’s not difficult to see Burkhart’s manner of thinking. As more (and larger) islands transition to solar, the more people who live in other territories, cities, and countries will say, “Why not us?”
A New Plan for Guam and the Marshall Islands
Because of all of this, it’s fair to say that a lot of people have their eyes on Guam and the Marshall Islands right now. But to truly understand the scale of these solar initiatives, we need to take a closer look at the unique situations these island chains are in.
With just 169,000 permanent residents, Guam’s population is akin to that of Providence, Rhode Island, or Tempe, Arizona. However, it is also home to significant U.S. military installations – enough to cover roughly 29% of its land area. These bases and their respective ships can house tens of thousands of military personnel at any given time, and require vast amounts of energy to operate.
As Doman Energy previously pointed out, the United States Department of Defense is one of the largest proponents of renewable energy solutions in the world. Over the years, military personnel at all levels have come to realize that energy infrastructure is perhaps the most important factor in both conflicts and peacekeeping efforts. From a cost and transport logistics standpoint, it’s safe to say that diesel fuel is now one of the biggest liabilities of any military installation – land, sea, or otherwise.
Minus the fact that their population is much lower, the Marshall Islands are just as integral to U.S. Pacific policy as Guam. However, they are also more widely dispersed. In total, the islands consist of 29 atolls and five individual isles, all spread over a large ocean area. Though the military presence varies depending on the time of year, the islands are home to a major missile defense test site and vital tracking equipment, requiring that about 1,300 full-time personnel remain in place.
But the military is only one part of the story. Both Guam and the Marshall Islands have a sizeable tourist economy. In fact, aside from catering to stationed military personnel and their families, these territories are almost completely reliant on tourism to keep their economies afloat. At present, no two things threaten their long-term economic success more than the cost of power and climate change.
Unfortunately, the Marshalls have already seen a significant impact from the latter, specifically in the form of rising sea levels and stronger typhoons. In fact, studies indicate that the sea around the islands has risen roughly 0.13 inches per year since 1993, which is more than twice the global average. Guam is facing similar threats, as well as an increased risk of flooding and a reduction in freshwater availability.
Not only is the islands’ reliance on diesel literally fueling their climate problems, but the rising cost of petroleum is too much for their tiny economies to bear. Renewables represent both a long and short-term option. As such, the Marshall Islands have committed to becoming net zero by 2050, with substantial interim targets for reducing greenhouse gas emissions. Guam, meanwhile, has set a goal of achieving 100% renewable energy by 2045.
Like the leaders of Tokelau, the governors of these territories see solar as integral to achieving their goals. However, even working on such a small scale, making the transition is no simple undertaking.
Let There Be Light (and Power)
Whether it’s on land or on an island, there’s no getting around the fact that transitioning to renewable energy necessitates significant investment in grid infrastructure, not to mention the transport and installation of the photovoltaic systems themselves. On top of that, most islands have limited land, much of which is needed for agriculture, housing, or tourism.
So, while the island solar experiment is an ideal engineering petri dish in terms of scale, the unique problems also make it much more difficult.
And, as is often the case, the only real way to overcome these problems is with more funding. Fortunately, Guam and the Marshall Islands do not have to face these costs alone. In Guam, the U.S. Department of the Interior’s Office of Insular Affairs has allocated $5,218,185 in 2023 Technical Assistance Program grants to support renewable energy projects, which include solar-plus-storage systems as well as 30 MW of low-income community solar gardens.
Such gardens represent a pioneering approach to renewable energy, allowing individuals, businesses, and communities to access solar power without installing panels on their properties. This not only makes solar energy more accessible and inclusive; it helps to break down barriers like unsuitable rooftop space, upfront costs, or rental living. Though there have been setbacks in Guam’s efforts, the Guam Power Authority is still on track to meet, and potentially beat, its green energy targets.
In the Marshall Islands, the Asian Development Bank and the government have signed agreements for a $7 million grant to develop renewable energy, supplementing an initial $12.7 million approved in 2018 as part of the Energy Security Project. This funding has gone a long way toward supporting the Marshalls Energy Company in strengthening the country’s energy network and preparing it for renewables.
From a utility and engineering perspective, the transition from diesel to solar power on these islands sets a critical precedent. By demonstrating the feasibility of renewable energy in isolated and resource-limited environments, they make it almost impossible to argue against implementing more widespread utility-scale projects back on the mainland. So, while it’s true that the growing success of projects like Tokelau and potentially Guam and the Marshall Islands can offer valuable insights for similar transitions in other remote areas, it is a much larger shot in the arm for solar energy as a concept.
The truth is that wherever you find solar energy, you not only find environmental sustainability but also enhanced energy security and resilience. While it’s easy to point at remote island communities and say “they are at risk,” the time must come when we all recognize the benefits of having a more secure energy future, and that everyone is at risk without it.