The small African island nations scattered around the continent are notable for their diversity. Some, such as Mauritius, a hub for financial services, and Cabo Verde, a hot spot for tourists, are relatively wealthy. Others like Comoros and Madagascar are among the poorest people in the world. The Seychelles are made up of lowland islands that are extremely vulnerable to sea level rise, while the Saonme and Principe are made up of towering volcanic peaks.
Although each African island nation is unique, its small size and relative isolation creates several common challenges.
James Ellsmoor, CEO of consulting firm Island Innovation, said that when generating electricity for an island grid, the cost per unit is “very high.” “The smaller the island, the higher the cost per unit due to the economy of scale. And it has a knock-on effect on the entire economy, putting the entire island economy at a real disadvantage.”
The African Islands rely heavily on small power plants that burn imported diesel or heavy fuel oil (HFO). The reliance on these facilities makes the island particularly vulnerable to international oil price fluctuations.
“The costs are now very high,” says José Maria Gomes Lopes, an energy researcher at Cabo Verde, who spends around 7.5% of GDP imported fuel according to IMF figures. He added that the need to redistribute imported fuels around the archipelago will increase costs. There are no transmission cables between the 10 islands of Cabo Verde and mainland Africa. This means that they are forced to maintain multiple small power plants for a total population of over 500,000.
However, Burning Diesel or HFO was the only viable option for isolated islands where the small market cannot commercially implement the upfront costs of more modern power generation methods.
However, the ever-growing number of renewable energy technologies offer new options for African islands. The energy revolution may be trying to take shape, but because there are no two islands that share the same characteristics, it becomes a revolution that takes many different shapes.
Alternative energy
“In my opinion, the sun and storage are the biggest opportunity, far apart,” Elsmoor says. Solar panels can be placed on a scale that suits the needs of each island. And as the cost of the sun continues to drop, many islands have already made considerable advances in deploying technology. According to statistics from the International Renewable Energy Agency, Cabo Verde commissioned the largest solar park in Africa, sub-Saharan Africa.
Meanwhile, the Seychelles are trying to overcome space constraints by developing a floating solar installation. The government signed a power purchase agreement with French developer Qair in 2023 for a 5.8 MW floating facility, and was built in the country's largest island, Mahe.
Wind energy is also an option, but this technology tends to require economies of scale to become viable. As a general rule, wind speeds are usually close to the equator, with only a modest possibility of wind power on African islands.
Meanwhile, the island is looking to reduce its dependence on imported fuels, so it is taking great care in storing its batteries. Curacao, a Dutch Caribbean island, aims to use the sun and wind in combination with storage to increase 70% of its electricity needs from the current 30% by 2027. The energy utility signed a deal with technology company Wärtsilä last month, with the Swedish company planning to install storage and use software tools to maximize renewable energy use at the expense of HFOs.
The 70% goal is “very exciting for us,” says Anders Lindberg, president of Wärtsilä Energy. “It takes years to do this in a big power. Of course, what's interesting about an island like this in the Caribbean is that it can make this quite fast.”
Wärtsilä is currently building a battery storage system on the island, and should be ready later this year. The software helps optimize how power is used and stored, and only kicks in when renewable energy or storage is unavailable.
Lindbergh says the Curacao Project has a broader lesson. “I think it's very possible to replicate,” he says, noting that the project could become a “showcase and blueprint” for other islands. “And I don't just mean physical islands,” he adds. “I mean Electric Island.”
Lindberg points out that, for example, mining companies operate remotely where grid power is not available, and usually rely on HFOs to meet their electricity needs. They need to learn a lot from Curacao as they are trying to reduce electricity costs while reducing emissions.
Will it become zero?
However, the opinion on whether islands should aim to be fully dependent on renewable energy is especially when intermittent sources like solar and wind make up the majority of the power mix.
Ellsmoor highlights how Tokelau, a group of Pacific atolls, has relied entirely on renewables since 2012, but electricity is usually unavailable for 24 hours. But this is an extreme example. “I'm an advocate of economic optimality, and sometimes 100% is not the most economically feasible,” says Erzumur.
“The economic optimality of renewable energy can be between 40-90%,” he adds. Beyond this level, he warns and stops renewable energy from becoming more cost-effective due to the cost of installing enormous amounts of battery storage.
It can also be questioned whether the renewable energy goals set by some island governments are truly supported by true commitments.
Cabo Verde has the goal of reaching 50% renewable energy penetration by 2030, with a goal of hitting 100% in 2040. However, Lopez describes this as “very ambitious.” He points out that the government had previously set a goal of achieving 100% renewable energy by 2025. Its goal is very overly optimal, with renewables making up only about 25% of today's power mix.
“Now, I'm not looking at the amount of investments being made across the country so that I can believe it's a realistic goal,” says Lopez. “There are a lot of technical capabilities that need to be developed here so that we can ensure that this goal is met over the next 15 years.”
Cabo Verde has the potential to produce hydroelectric power. A storage hydroelectric power plant pumped on Santiago Island is set to open in 2028. This allows you to generate 20 MW for up to 8 hours. The government says it will help reduce the island's fuel consumption by 22%. However, hydropower resources, particularly on small and low islands, are often limited in hydropower improvements.
Geothermal energy, first deployed on the massive scale of New Zealand and Icelandic island nations, is another possibility for some islands as a source of baseload power. However, the best geothermal resources are largely confined to volcanic regions. Also, even when resources are present, geothermal power plants are expensive to develop and require a reasonable, financially viable market. However, on the island, looking for better options involves not only looking towards the land, but also towards the ocean.
I use the ocean
Several marine energy technologies have already been tested and tested. The tide barrage built over the mouth of the river operates in a similar way to a hydroelectric dam, with water held behind the tide walls being released to drive the turbine. On the other hand, tidal currents are like underwater wind turbines driven by the decline and flow of rapidly moving flows.
A variety of vibration energy technologies have also been developed, but no one has yet reached a commercial scale.
An approach that appears to be particularly suitable for the African Islands is marine thermal energy conversion. “OTEC is essentially a sea heat pump,” said Dan Grech, CEO of Global OTEC, who is trying to pioneer technology. “The temperature difference between warm surface water and cold deep seas is used to run the turbine and generate energy.”
Grech has identified Samme and Principe, archipe, archipe, which rises sharply from the seabed of the Gulf of Guinea, as ideal locations to run the pilot 10 MW project. “You don't have to go very far to get into 2,000 metres of water, meaning you can access the temperature difference between warm surface water and cold deep seas.”
And San Tome and Principe are desperately in need of new energy technologies as they take on the weight of the fuel import bill.
Conditions are not ideal for the sun or wind. But the 10 MW OTEC facility “provides all the baseload power the country needs,” says Grech. This can be replenished with solar power to remove diesel generators. “Our mission is to make the history of diesel generators for these island states from a utility scale perspective.”
Climate funding issues
But the challenge is to find a financial institution in one of the small and poor countries of the world that is ready to take the risk of funding pilot projects for early technology.
Marina Melo, project manager for Aler at Lusophone Renewable Energy Association, said: She warns that access to funding is a “major limit.”
Ellsmoor agrees. “The problem with investing in infrastructure and small island states is that money is too expensive. If you want to get a loan, you'll pay a much higher interest rate than you would if you were in Europe or North America.”
He adds that insurance costs are another major obstacle to a small island. “All of these financial barriers have come together in countries in Europe and North America, perhaps not repeated ways to create economically viable projects. The islands at the forefront of climate change tended to rely on multilateral financial institutions, but have long complained about the lack of support as they seek to strengthen their infrastructure. On behalf of small island developing countries, Sids Group has staged a strike in opposition to the commitment of wealthy countries to fundraising targets sufficient to meet their needs, from last year's COP29 at Baku last year.
Many have expressed their support for the Barbados-led Bridgetown Initiative aimed at reforming global finance architecture.
Compared to the size of the issue, the amount of funds currently accessible to SIDS certainly appears modest. One option is to rely on the Global Environmental Facilities (GEF), a funding group established under the United Nations Climate Process to support climate adaptation in developing countries. Classified as “most developed countries,” SIDs are eligible to access up to $20 million in GEF's current four-year funding round. For example, São Mé and PrÃncipe have been allocated over $10 million under the 2022-26 GEF program.
GEF recently created a new “window” to fund projects in SIDS that are not classified as developed countries (LDCs), at least in a category that includes Cabo Verde, Mauritius, The Seychelles, and more. These countries will have access to at least $3 million.
“Well, you're going to say, 'Well, that's not enough,'” admits Jason Spenceley, senior climate change specialist at GEF. “It's not, but it's something, and if you use it really, really well, $3 million could be the catalyst.”
“The question for multilateral funders like ourselves is, “How do we use valuable public resources to catalyze much larger-scale private investments, a precious public resource, unfortunately, a finite resource?” He emphasizes that blended financial mechanisms do not provide a panacea, but may help attract private capital by providing initial loss guarantees. Multilateral funders could help reduce capital costs by covering some of the interest payments SIDS private lenders demand.
It remains to be seen whether these types of mechanisms can offer global OTEC solutions as they aim to unleash the ocean energy of the Samme and Princesipes.
Grech argues that the Global OTEC project is “Shovel Ready,” and in theory could have moved the island's home within two and a half years. In the long term, it suggests that OTEC could be used in more than 100 countries.
If this vision were to come true, OTEC is another example of the technology developed in the island setting that will eventually expand globally.
