Quick start

1) You can move around the screen and select option as shown in the Tutorial picture.

2) The app opens with a 60 MW a sub-sea interconnection cable providing all the Isle of Man's electricity at 31 p/kWh (pence per unit) – the cost of purchasing and importing the power from the UK.

3) Go to Energy Storage & Export-Import and change Interconn. from 60 MW to 0 MW. You will see there is now an Electricity Demand Shortfall* of 358 GWh per year at the top of the screen meaning that none of the Island's demand is being met. One of the goals is to get this number to 0 GWh. You can easily do this by changing interconnection back to 60 MW.

4) You will see that there is enough interconnection (green light) but Carbon emissions are still too high (red light). You can get further information by scrolling down to RESULTS.

5) Add some Power Generation e.g. 40 MW solar. In this case, see how the Cost of Electricity falls from 31 to 29 p/kWh as you are now generating a small amount of relatively cheap power on the Isle of Man. You can see the Proportion of costs in RESULTS. Note also that there is still Sufficient capacity of interconnection. If there is no interconnection and no energy storage, the Isle of Man grid would easily become overloaded with too much renewable energy when there is minimum electricity demand (c.20 MW).

6) Move the dials on Your Electricity Bill e.g. Quarterly Units of 500 kWh. In RESULTS, you will see that you will be paying £20 more per year (Annual penalty on your electricity bill, shown in red) compared to the current Manx electricity price of 28.5 p/kWh (look in Settings – gear icon near the top of the window). Even 28.5 p/kWh is high because the gas which is used to generate electricity at Pulrose power station is relatively expensive.

7) Add more Power Generation e.g. 120 MW wind. In this case, the Cost of Electricity falls from 29 to 17 p/kWh as you are now generating a significant amount of relatively cheap renewable power on the Isle of Man. Nonetheless, it is still necessary to export excess power (when the wind is generating more than is being used on the Isle of Man) and import power (when there is insufficient supply of electricity from wind and solar to meet demand). You can see the shortfall (99 GWh per year) by temporarily switching Interconn. to 0 MW. You will see in RESULTS that 60 MW interconnection is now Insufficient capacity (red light), which you can solve by increasing the capacity of Interconn. to 180 MW. The cost of this extra or larger subsea cable has to be paid for, as does the imported electricity, so the Cost of Electricity increases, in this case to 22 p/kWh.

8) One effective way of dealing with the mismatch between power supply (from variable wind and solar) and electricity demand (fluctuating on-Island consumption) is by adding some Energy Storage, e.g. 240 MWh (batteries and pumped hydro). Although storage requires investment this can be spread over, for example, 20 years. At the same time, very little expensive electricity has to be imported. Therefore, with 240 MWh storage the Cost of Electricity falls to 16 p/kWh. You can now reduce the amount of interconnection to 120 MW which in turn lowers the electricity cost to 14 p/kWh. You will see in RESULTS that the Isle of Man has achieved greater than 100% Energy Self-Sufficiency, that the Annual saving on your electricity bill is £282 and that Carbon Emissions are now only 7000 tonnes CO₂ per year, significantly less than present day (227,000 tonnes CO₂ per year from burning gas at Pulrose).

9) Now try out other combinations of Power Generation, Storage and Interconn. to see if you can achieve better results. For example, you can reduce the amount of wind and solar power and then try adding other sources of power. The goals are to get to 100% or more self-sufficiency, as well as 22 p/kWh or less and no more than 15,000 tonnes CO₂ emissions per year. Further information on the different sources of power and the power capacities available can be found in a dropdown by clicking on the question mark located between Tutorial and Sponsors near the top of the page**.

*It is important that there is no Electricity Demand Shortfall (i.e. 0 GWh is showing) otherwise the Cost of Electricity will be incorrect as the missing power has not been accounted for. The easiest way to ensure there is no a shortfall, is to import electricity by choosing sufficient Interconn. capacity – 60, 120 or 180 MW.As you add renewable energy, you can reduce the size of interconnection by increasing the amount of Storage. The balance between these two options - Energy Storage & Export-Import - is a crucial part to finding the best solution for costs, emissions and energy self-sufficiency.

It is worth noting that the results from this sort of modelling are not always intuitive because of the complex way that variable amounts of renewable power interact with fluctuating demand, grid restrictions, energy storage and export-import decisions. The app is a simplification of the results of hundreds of thousands of numerical simulations ('energy system models') which require inputs in the form of hourly data over a full year of weather, daylight, electricity consumption and market prices. A simple example of the issue is that all power from a 20 MW wind farm on the Isle of Man can be used whereas a large part of the power from a 100 MW wind farm will be surplus to requirements and will have to be exported or, better still, stored for when it is needed. Even with a sizeable wind farm there will be times when insufficient electricity is being generated to meet demand, which is when power has to be regenerated from storage or it has to be imported.

A 10 MW wind farm on the Isle of Man will typically generate an average of 3-5 MW power or 20-45 MWh energy per year, as the strength of the wind varies. In this case, '10 MW' refers to the maximum power the turbine or turbines can generate – when the wind is blowing hard. The ratio of the average power to the maximum power is known as the capacity factor (23%-51% in this example). Although somewhat cheaper to build, a 10 MW solar park will produce only on average 1 MW or 10 GWh per year because it has a lower capacity factor (11-12%). Strong sun is relatively rare and there is no sunlight at night. Each power source shown in the app has a different capacity factor, except for hydro, biomass and nuclear plants which can run at maximum power, provided there is sufficient water or fuel and whilst no servicing or maintenance is required.

**Additional documentation can be requested from dquirk@dtu.dk. Alternatively, please refer to the Knowledge Hub and News sections of this website where more information is available.

Abbreviations used

MW – megawatt (the sames as 1000 kilowatts, kW)

MWh – megawatt hours (the same as 1000 kilowatt hours, where 1 kWh is a 'unit' of electricity)

GWh – gigawatt hours (1 million kWh)

CO₂ – carbon dioxide

Credits

The Island Power App has been developed by David G. Quirk and Behzad Hosseinzadeh in 2024/2025 on behalf of the Energy and Sustainability Centre Isle of Man (ESC) and with the financial support of the Manx Lottery Trust. The app software is powered by Webstartiom.

Island Power App

Introduction and background

The Island Power App has been developed by David G. Quirk and Behzad Hosseinzadeh in 2024/2025 on behalf of the Energy and Sustainability Centre Isle of Man (ESC) and with the financial support of the Manx Lottery Trust.

The motivation behind the app is to show you the different options to generate affordable electricity on the Isle of Man and which combinations work or don't work. One can choose between alternative sources of power and different sizes of installations, plus energy storage and import-export (interconnection) capacities. You will then see how the price of electricity and CO₂ emissions rise or fall on the basis of your choices. You can also try to get the Island to be self-sufficient in power.

The emissions of carbon dioxide (CO₂) produced directly on the Island in 2022 were approximately 700,000 tonnes of CO₂ or 8.3 tonnes per person per year (83,000 bin bags full). 77% of this comes from power – electricity, transport and heating – by using oil and gas. Such carbon emissions are causing a severe rise in global temperatures. For this reason, the Isle of Man Climate Change Act 2021 commits the Island to achieving net-zero emissions of greenhouse gases by 2050 and the Government has an interim target of net-zero CO₂ from electricity by 2030.

Slightly more than one-quarter of the Island's power demand is for electricity. Pulrose power station can generate 20-85 MW (megawatts), sufficient to provide all of the Island's electricity, although some electricity is generated from burning waste as well as a small amount from water turbines (hydro-electricity). Every year Pulrose power station burns more than 80 million m³ of natural gas (methane) emitting approximately 227,000 tonnes of CO₂. The power station will reach the end of its life before 2035 and will actually have to be replaced entirely by low-carbon sources of power by 2030.

Low-carbon electricity generation

The Island Power App (IPA) only considers current electricity demand. Heating and transport using gas and oil products account for three-quarters of the power demand on the Isle of Man and will be incorporated in a future version of the app. It is worth noting that the consumption of electricity is likely to double as heating and transport are electrified.

Reflecting the Island's commitments to net-zero emissions, the app does not allow the continued use of conventional fossil fuels so Pulrose power station and oil-powered generators are not included. The energy sources that users can choose from are largely renewable, those which do not directly produce carbon dioxide.

The main advantages with renewable power are lower costs and energy security. Local generation does not depend on imported oil and gas - thus avoiding unpredictable prices and issues of supply. The difficulty with most renewable energies is that the power varies with natural conditions like wind and sunlight which are out of sync with the fluctuating electricity demand of Manx electricity consumers. This means that there can be times when too much power is being generated and other times when there is insufficient. Without a way of dealing with oversupplies and undersupplies of electricity, the grid can become destabilised whilst individual cables can become overloaded. Like food, it is best to store energy surpluses for times when there is not enough. The most appropriate forms of energy storage for the Isle of Man are lithium-ion batteries (expensive but easily installed) and pumped hydro storage (most cost-effective but involving large-scale civil engineering).

An alternative to storage is using sub-sea cables (interconnectors) to the UK or Ireland to export surplus power and to import when there is a deficit. However, on the whole the British Isles experiences similar weather patterns, light conditions and fluctuations in electricity demand, so the price of electricity tends to be low at times of strong wind and sun on the Isle of Man and high when there is little, meaning that trading power to match supply to demand would be expensive for the Isle of Man. Therefore, choosing the right amount of on-Island energy storage is one of the main challenges you can try to solve with the app.

The amount of power that can be generated on the Island from waste, biomass and hydro-electricity is limited. In the case of waste material, the limitation is the quantity of rubbish available, in the case of biomass it is the area of land that is required to grow the fuel and with hydro it is the amount of water. Hence, they are all restricted to 10 MW in the app. Neither wind nor solar have such restrictions and, in addition, wind power can be sited offshore.

Certain renewable energy technologies have not been included, either because they are not feasible on the Isle of Man, such as geothermal power, or because the technology is far from being commercial.

Regarding geothermal power, unfortunately the geology of the Isle of Man is not suitable. Firstly, the sub-surface temperature does not increase quickly enough with depth (the so-called geothermal gradient is low), secondly, there is insufficient water in the sub-surface (there are no aquifers or hydrothermal systems) and thirdly, the rocks are hard and convoluted (making drilling difficult and expensive).

When it comes to commerciality, it should be noted that tidal energy generators, wave energy converters and small ("modular") nuclear reactors are still under development and it is uncertain whether they will ever compete in terms of price with solar, wind and hydro. They have nonetheless been included in the app for completeness. Large areas of sea are required for tidal and wave energies so, for pragmatic reasons, they are limited to 10 MW in the app. In contrast, nuclear power plants tend to built at large scale and even small modular nuclear reactors are unlikely to be built in units less than 60 MW in size, despite the word 'small' in their name.

Energy storage

Two options for energy storage are used in the app: 1) lithium-ion batteries (up to 120 MWh, megawatt hours) and 2) pumped hydro storage (for more than 120 MWh). The split is because batteries (chemical storage) are essential for keeping the grid stable over short periods of time (milliseconds to minutes) but they are expensive. Pumped hydro storage, which utilises the potential gravity of water between two different elevations, is much cheaper and is the appropriate technology for hours to days of energy storage. Furthermore, it does not have the water restrictions of traditional hydro-electricity projects because the water is recycled between two reservoirs.

Another potential form of energy storage is "green" hydrogen, produced by electrolysis using surplus renewable power. The incentive for green hydrogen comes from countries like Denmark and The Netherlands, who do not have the elevation for traditional pumped hydro storage. The large-scale electrolysers which are required are now coming to market. However, the storage of hydrogen is difficult and the economics of using hydrogen in power production are somewhat challenged. Nonetheless, there is significant investment in green hydrogen projects and there is a certain attraction in using the technology to promote energy self-sufficiency on islands, as it is one way of replacing fossil fuels used in transport and heating. But for now it is really just a case of "watch this space".

There is added export value with Manx energy storage which is not calculated in the price of electricity on the app. Extra money can be made by 1) selling stored energy via interconnectors when the price of electricity is high in the UK and Ireland; 2) keeping an energy reserve to be called upon when extra power is needed to maintain frequency or restore power on the British or Irish grids. Providing these services would in theory make electricity on the Island even cheaper.

Other options to decarbonise power?

Another way of dealing with CO₂ emissions is to capture them from the air. At present, the only affordable option is natural sequestration, for example by growing new woodland or establishing new peatland. Although such projects have other environmental benefits, the amount of carbon that can be captured is relatively small, particularly in consideration of the amount of land that would be available for this on the Isle of Man. In fact, it would be difficult to offset more than a few percent of the Island's current emissions from power. Disposal or "permanent storage" of CO₂ in the sub-surface is also not an option because of the Island's geology. So carbon capture and storage ("CCS") is not offered as an option with IPA, at least not with this release of the app.

Data sources and calculations

The information underpinning the app is based on research and energy system modelling from 2019 to 2025. Some of this work has been published by Quirk et al. (in 2023 and 2024) and some of the data have also been used in playing cards (Quirk et al., 2021; Quirk et al., 2022; Quirk, 2023; Quirk, 2024).

The energy system modelling involves digital simulations with EnergyPlan, software which has been developed by Aalborg University, originally to assist government decisions with the energy transition in Denmark. The inputs to the models come in two forms:

1) Hourly electricity supply-demand, wind and solar data for an average year – which in IPA were obtained from the Manx Utilities Authority, Global Wind Atlas, Global Solar Atlas, Renewables Ninja, IRENA and IEA.

2) The technical specifications, energy performance, capital costs and operating costs of power generators, interconnector cables and energy storage installations, as well as electricity prices, fuel costs and carbon emissions from the Danish Energy Agency (saved under the heading 'technology data'), the UK Government Department for Energy Security and Net Zero ('electricity generation costs'), the UK National Grid ('data groups'), as well as other UK, Manx, EU and international sources noted in Quirk et al. (2023; 2024) and at www.energysustainabilitycentre.im/knowledge-hub.

Where there is a range of uncertainty, average values have been used. Up-front (capital) expenditure has been spread over 20 years. For simplicity, 0% discount (interest) rate, 0% cost of capital (borrowing rate) and 0% profit have been assumed. Overheads of 25% are used to cover private and public sector costs (e.g. those of the Manx Utilities Authority) and a 7.5% overhead is also included for new infrastructure costs.

The database was built by David Quirk and John Boucher and the simulations were carried out by Francesco Piovesan and David Quirk. As the number of options in IPA lead to almost 1.7 million permutations, Francesco also built a batch mode tool in Matlab to carry out multiple runs simultaneously with which a matrix of results was built and then added to an 'SQLite' database, whilst David developed formulae to simplify the results. Behzad Hosseinzadeh built the app utilising the results matrix and formulae which were combined using the open-source graphical user interface 'Qt QML'. The source code is available at https://github.com/behzaadh/IoM_APP for users to analyse further.

Artwork was designed by Amalie Quirk.

The actual data, the calculations and other material can be requested from David Quirk – dquirk@dtu.dk – who is also responsible for any inaccuracies or errors. Suggestions for new technologies and improvements to the app can also be made to David. In addition, a paper is being prepared explaining how the calculations have been made, with pre-prints available on request.

Abbreviations used in the Island Power App

avg – average

Hydro – traditional hydro-electricity power plant

MW, MWh – megawatt (1000 kW), megawatt hours (1000 kWh)

kW, kWh – kilowatt, kilowatt hours (or 'units' of electricity)

GWh – gigawatt hours (1 million kWh)

Nuclear – nuclear fusion power plant using small modular reactors

CO₂ – carbon dioxide

Acknowledgements

Without research funding from the Manx Lottery Trust, this app could not have been made and we greatly appreciate their valuable support. Thanks are also due to the Energy and Sustainability Centre's main sponsors – Zurich Isle of Man– for their invaluable support.

Help and advice has come from numerous sources including Manx Utilities Authority, United Renewables, Best Energy, Peel Group, Capital International, Chris Gledhill, Poul Østergaard, Henrik Lund, Filipe da Silva, Felipe Camara, Terji Nielsen, Helma Tróndheim, Tórfinn Simonsen, Henki Ødegaard, Bjarne Børresen, Filipe Mendonça, Agostinho Figueira, Marjo Lahtimo, Torben Jørgensen, Søren Hermansen, Michael Kristensen, Christer Nordberg, Luke Fraser, Gareth Davies, John Caldwell, Chris Caldwell, Chris Reed, Richard Madden, James Curran, Steve Forden, Ken Milne, Paul Craine, Jane Poole-Wilson, Clare Barber, Daphne Caine, Mike Newby, Maurice Faragher, Lorraine Rostant, Amalie Quirk, Mike Quirk, Tracey Fuller, Steve Jones and colleagues at DTU Offshore. Last but far from least, we are as always grateful to Ralph Peake, Adrian Cowin, Kimberley Moughtin and Rebecca Keeley from the Energy and Sustainability Centre for their tireless efforts to advance the green transition on the Isle of Man.

Bibliography

Quirk, D.G., 2023. Future Energy System Builder: Sustainable Power Cards. DTU Offshore, Denmark, 56 cards.

Quirk, D.G., 2024. Future Energy System Builder: Green Power Cards. DTU Offshore, Denmark, 58 cards.

Quirk, D.G., Boucher, J.B. and Peake, R., 2021. Energy System Builder Cards. Energy and Sustainability Centre Isle of Man, Douglas, 47 cards.

Quirk, D.G., Boucher, J.B., Peake, R. and Bates, T., 2022. Energy System Builder Cards (northern European island). Energy and Sustainability Centre Isle of Man, Douglas, 58 cards.

Quirk, D.G., Mendonça, F., Henriques, F., Jørgensen, T., Lahtimo, M., Figueira, A., Tróndheim, H., Nielsen, T., Nordberg, C., Davies, G., Fraser, L., Østergaard, P.A., Lund, H., Kristensen, M., Hermansen, S., Cowin, A. & Peake, R., 2024. Energy transition league: A comparison of islands' paths to net zero emissions. Proceedings of 8th International Hybrid Power Plants & Systems Workshop (HYB 2024), Azores, pp.65-74. 10.1049/icp.2024.1820

Quirk, D.G., Boucher, J.D., Østergaard, P., Lund, H., da Silva, F., Camara, F. & Peake, R., 2023. How to quickly transition from 0% to 100% renewable energy on an island in the northwest corner of Europe? Proceedings of 7th International Hybrid Power Plants & Systems Workshop (HYB 2023), Faroes, pp. 19-19. 10.1049/icp.2023.1429

Keeley, R. and Quirk, D.G., 2025. Guide to the Power System of the Isle of Man. Energy and Sustainability Centre Isle of Man report, published online, 10 pages. 10.13140/RG.2.2.18142.55361

Users are also referred to www.energysustainabilitycentre.im/knowledge-hub where other relevant information can be accessed.