Vast oceans separate remote island communities who are often faced with energy poverty. The International Renewable Energy Agency (IRENA) calls these locations Small Island Developing States (SIDS). IRENA supports these communities to reduce their reliance on costly fuel imports by harnessing renewable energies to accelerate their Energy Transitions. There are no long-distance, submarine electricity transmission lines from any mainland grids, so these remote communities have had to rely on Distributed Power Generation which was historically Coal, Heavy Fuel Oil (HFO), or mainly Diesel powered. With the Energy Transition, these remote communities are considering their Renewable power options. Hybrid Microgrids are an attractive option to increase the use of Renewables whilst maintaining grid stability and reliability. For purposes of this article, I will concentrate on the example of remote island communities in the Western Pacific Ocean.
The Pacific Ocean contains the largest number of remote island communities. It is a diverse region with a range of climates, economies, and living standards. Oceania (including Melanesia, Micronesia, and Polynesia) has ~10,000 islands with about 12 million inhabitants (excluding Australia) with many Indigenous cultures. Oceania ranges from 28 degrees north latitude to 55 degrees south latitude. The islands include continental islands, high islands (volcanic), coral reefs, and uplifted coral platforms.
A Western Pacific Climate Projection Map illustrates climatic features which influence varying amounts of cloud cover, precipitation and wind energy distribution. Higher wind speeds are located farther from the Equator.
There does appear to be some technical solutions to increase Renewable power generation with Solar radiation somewhat more favourable than the low Wind energy prevalent near the Equator, but farther away (e.g. Fiji) the wind energy increases, particularly on higher ground.
The Federated States of Micronesia is a country spread across the western Pacific Ocean comprising more than 2100 islands. The geographical spread is across an area of 7,400,000 km2. Micronesia has several island states including Federated States of Micronesia (607 islands including Yap, Chuuk, Pohnpei, and Kosrae), Kiribati (32 islands), Nauru, Palau, and Republic of the Marshall Islands. There does appear to be some technical solutions to increase Renewable power generation with Solar radiation more favourable than the low Wind energy prevalent near the Equator.
More than 1,000 islands, some aligned with countries including Australia, France (e.g. French Polynesia), New Zealand, UK, and US, but others independent like Samoa, Tonga, and Tuvalu. The region is spread across a rough triangle with sides of ~6,000 km. There does appear to be some technical solutions to increase Renewable power generation with Solar radiation somewhat more favourable than the low Wind energy prevalent near the Equator, but farther away (e.g. Pitcairn or Kermadec) the wind energy increases.
Remote Island Communities
These remote islands face some of the highest fuel costs in the world due to their location and logistical challenges. It has also been noted that some of these communities have electrical load restrictions due to inadequate and aging (~20 years old in many cases) Conventional Power Generation equipment. Load restrictions mean constraints on further economic development, including housing, commercial establishments, education, and improved sanitation facilities. There are hundreds of existing Diesel-based electrical power generators in public use combined with thousands of private units. The cost of Diesel is significantly increased with the logistical challenges of transport and storage in these remote areas. In addition to reducing these high costs, mitigating GHG Emissions (from inefficient older Diesel machines) are good reasons for increased deployment of Renewables. A positive note is that the existing electrical distribution networks for Diesel-based electricity can readily be used to distribute electricity from Renewables, thus mitigating the connection costs.
Renewable Power for Remote Communities
The preceding maps of Solar radiation (Solargis) and Wind energy (Global Wind Atlas) show that Oceania is able to be roughly split into regions close to the Equator and those farther away with different amounts of Solar radiation and ranges of Mean Wind Speeds. Solar Power appears to be the most significant source of Renewable Energy at this time. Wind Power is not so common here at this time.
From experience, the intermittency of these Renewables means that hybrid solutions with both types, combined with Energy Storage Systems (e.g. Lithium-ion or Lithium Iron Phosphate (LFP) batteries for short duration storage and grid stability) may be the best solution. With minimal seasonal climate patterns, long-duration energy storage may not be required (e.g. Hydrogen P2G2P) in these islands.
A review of Solargis’ Photovoltaic Electricity Potential (PEP) maps gives relevant Solar Power data. Solargris’ maps provide long-term averages of daily/yearly potential electricity production from a 1 kW Solar PV power plant. The assumed PV system configuration consisted of ground-based, free-standing structures, with crystalline-silicon PV modules mounted at a fixed position with optimum tilt to maximize yearly energy yield. The use of high efficiency inverters is assumed in their maps.
A review of Global Wind Atlas wind maps gives some relevant Wind Power data. Global Wind Atlas’ maps provide Mean Wind Speeds able to be used with a typical Wind Turbine Power Curve – in this example it was assumed to be a small Enercon E-53/800 kW Wind Turbine (commonly used on Greek islands). The assumed number of Wind Turbines can be calculated from this information.
For an assumed medium sized remote community with residential and commercial users, the assumed power demand requirement would vary over the course of the 24 hours. For this example, the nominal demand and supply targets could be as follows (below left). Normal intermittency is not shown in these curves but it is factored into the Photovoltaic Energy Potential maps. Wind energy appears low in these areas, so Solar PV Power is a higher percentage.
- Assumptions: Peak demand ~2.5 MWp; Average demand ~2 MW x 24 hours x 365 days = 17,520 MWh = 17,520,000 kWh total power needed= MWhreqd (split in some percentage between Solar and Wind);
- Mixed Solar Scenario: assume Solar 9 MWp x Annual PVOUT = MWhSolar (day time);
- Assume 1 MWp plant requires 2632# x 380 W Solar PV panels; and 1 hectare for 1 MW;
- Cost of PV panels ranges, but $0.37/W for a 380 W panel delivered is conservative;
- Cost of Solar PV panels is assumed to be ~1/2 of the Gross Cost of a Solar PV Farm (on this scale);
- Mixed Wind Scenario: calculate MWp required (from MWhreqd-MWhSolar, all day and night);
- Wind Only Scenario: calculate MWp required (from MWhreqd, all day and night);
- Assuming the required number of turbines is MWp/(Turbine Applicable MWp @ Mean Wind Speed);
- Mean Wind Speed for this example to be assumed to correspond to “50% of windiest areas”;
- Wind Farm Size varies according to land topography and access constraints, but an average value of 1 hectare / Wind Turbine has been suggested;
- Market cost of Wind Turbines have been changing rapidly, but $1MM for a Enercon E-53/800 kW Wind Turbine delivered is used (~$1.1MM/MW);
- Delivered Cost of Wind Turbines are assumed to be ~1/2 of the Gross Cost of a Wind Farm;
From the preceding assumptions and data for Oceania some approximate values were selected:
Local topography and wind data could also be investigated to see if mountain or hill ridgelines are available for siting Wind Turbines in areas of even higher wind speeds. Solar Power seems to be the most important energy solution for these regions, given the challenges of low and intermittent winds. Both solutions could be installed to improve resilience, e.g. the 550 kW Wind Turbine (2 x 275 kW) site below in Samoa could easily have Solar PV panels installed on the same site to help provide electrical power in cases of wind lulls. Extinct volcanoes on some Pacific islands may also provide the necessary topographical elevation to access higher wind speeds as seen on some of the Solargis maps.
Added to these costs may be the cost of a high capacity, long-duration Energy Storage System (e.g. Hydrogen P2G2P). With less daily and seasonal variation close to the Equator, the need for long-duration Energy Storage Systems may not arise however.
It is also possible that a hybrid power generation system for some locations could include small amounts of existing or renewed Conventional Power Generation. Diesel fired engine power generators cost ~$1-2MM/MW (~$2.5-5MM for this 2.5 MW example). Conventional Power Generation would have OPEX costs including fuel, increased maintenance costs for the rotating equipment, and increased numbers of operations and maintenance personnel. Also not considered in this cost comparison is any Regulatory costs associated with the GHG emissions of Conventional Power Generation. ESG considerations may be part of the decision to adopt hybrid Renewable solutions, in order to improve access to funding and finance.
Remote Pacific Island Renewable Project Example:
Role of Clean Gas Power Generation in Remote Island Energy Transitions
Clean Gas Power Generation may have an important role in the Energy Transition from other more carbon intensive fuels like Coal, Heavy Fuel Oil (HFO) and Diesel – but for these remote islands it would be impacted by transportation and storage logistical factors. Clean Gas Power Generation emits fewer GHG and other pollutants and it has been characterised as a “bridge” in the Energy Transition and a key part of the “energy mix”.
The transport of liquid fuels may be able to be replaced by Clean Gas. Clean Gas for these islands could be Liquified Natural Gas (LNG) or more likely Liquified Petroleum Gas (LPG) including bottles or tanks of Butane and/or Propane. Hybrid Microgrids are a good solution to combine Clean Gas Power Generation with Renewables. The Clean Gas component could mean ocean vessel transported LNG or LPG to Distributed Power Generation plants on these islands. These plants would be linked, as shown below, to the Renewables in Hybrid Microgrids to support Industrial, Commercial, and Residential users. Investors need to support these hybrid solutions to deliver better environmental, health, and developmental outcomes, particularly for remote Indigenous communities in Oceania.