Tangible plan for the green course

SEV announced its plans to reach 100% green energy on shore in the Faroe Islands by 2030, when the company officially opened the Húsahagi wind farm on 9 October 2014.

The Government agreed with the green course in the coalition agreement in 2015, laying a very strong foundation for the green course for both SEV and the Faroe Islands as a whole. The prerequisites for embarking on the green course are hereby met.

The wind farm at Húsahagi is, with its revolutionary battery system, which in terms of minutes and seconds balances the energy output to the grid, the first concrete step on the green course. The battery system enables higher yield from wind energy.

– This is breaking new ground in energy production and all effort will be put into finding the optimal technical solutions for sustainable energy sources in the Faroe Islands. Still, further ground-breaking solutions are required to reach the target, says Terji Nielsen, SEV’s Manager of Development.

Terji Nielsen is leading the work to prepare a tangible plan for the green course, and the following details some aspects of the plan that Terji Nielsen and others are preparing.

The choices to be made between the different technologies and solutions have to be based on environmental impact, economical viability, and security of supply.

One example of a road map is shown in figure 1 below. The figure shows that total energy demand in the Faroe Islands increases both due to normal economic growth and due the changes in energy usage, which is envisaged within domestic transport and heating when the switch from oil and petrol to electric energy takes place in years to come. Electric energy demand is expected to increase from around 350 GWh in 2017 to around 600 GWh by 2030.

Figure 1.

The tangible long-term plan will be a combination of the available energy sources in the Faroe Islands and various energy storage options, yet will also have flexibility built in to adapt to changes in technology and financial circumstances.

One of SEV’s greatest challenges in the future will be to ensure a balance between demand and production. The challenge grows with increasing production from unstable sustainable sources – such as wind, hydro, and solar. It is therefore important to develop systems to secure a balanced, sustainable production every hour of the day, all year round, while maintaining security of supply.

In the short term, the thermal plants – such as Sund power plant – will secure supply and balancing the grid, when supply from green sources is insufficient. With developments in technology, the green sources in conjunction with energy storage will be able to take over the security of supply from the thermal plants for longer periods of time, such as in the summer period.

Wind energy

The Faroe Islands are surrounded by plentiful and unstable winds, and the average annual wind speed exceeds 10 m/s in several locations. Energy production from wind is unstable and closely correlated to the changeable weather patterns in the Faroe Islands. The challenge is that wind alone cannot be the sole source of supply, rather the wind needs to be coupled with more stable production sources, such as hydro.

Wind farms are easily and quickly built, as well as being an inexpensive form of production, and more energy from wind is certainly a part of the plan. This will most likely happen in conjunction with energy storage that can store excess wind energy, and then release the stored energy onto the grid, when wind production is low.

Aside from the fact that wind energy production is unstable in the very short term – minutes and seconds – there is also great variation across seasons – summer and winter. From experience we know that wind energy production in June and July is only a quarter of the production in December and January. The summer period is therefore a challenging time for wind production.

Hydro

The Faroe Islands are also rainy. Ever since the first hydroelectric plant started production on 18 July 1921, hydro energy has been a very important part of Faroese energy production.

But like wind, hydro is dependant on the weather. Again our experience shows that there is a great difference between summer and winter production, such that the production in a summer month can be as little as 15% of a winter month.

Despite the large seasonal variations in Faroese hydro production, hydro is still a very stable and secure production source when reservoirs are full. This type of production plant runs for many years after the initial investment in turbines, dams, and tunnels. Some of the hydro plants in the Faroe Islands are from the mid-fifties and the sixties, and with on-going maintenance they will continue to produce electricity for many more years.

The summer is, as earlier stated, a challenging time for hydro production. SEV aims to fill reservoirs before the summer period to provide backup production capacity in the event of a breakdown on one of the thermal plants.

Solar

Solar power is not presently used in the Faroe Islands, but this will most likely change as the cost of solar plants has reached a level to make them interesting and viable for a small island community in the North Atlantic.

A solar plant in the Faroe Islands will naturally not measure up to the production from a plant in more sunnier climates, yet it is interesting to look at how such systems perform in the Faroe Islands with the limited sunlight available – and not least how such systems stand up to the harsh weather conditions on the islands.

There are two primary reasons for solar being an interesting option in the Faroe Islands. One reason is the steadily decreasing cost of solar technology, which has fallen by more than 75% since 2006. This decrease means that solar will in time be a less expensive form of production than thermal.

The other reason is the seasonal interaction between wind, hydro, and solar, whereby the greatest solar energy potential is during the summer, when less is available from hydro and wind, see figure 2 below for an illustration. Another advantage with solar systems is that they are quick to build and come on-line, and there is very little maintenance once installed.

Figure 2.

Tidal

Tidal turbines are a new and exciting technology. There are several large enterprises around the world currently developing the technology. Commercial availability, though, is anticipated to take a further 5-10 years.

On a global scale, experts have estimated tidal energy potential to 80 GW, and around the Faroe Islands the potential is a total of 1GW, of which 15-20% can be reasonably utilized, equal to 150-200 MW. In comparison, the current maximum demand in the Faroe Islands is 45 MW. Although there are very large amounts of tidal energy flowing around the Faroe Islands, the drawback with tidal energy is its variability and direction of flow.

On the other hand, the major advantage is that tidal energy is available all year round, and the strength and direction of flows is entirely predictable.

The inherent stability of tidal energy is therefore a great advantage when compared to the instability and weather dependency of hydro, wind, and solar. An added advantage in the Faroe Islands is the time difference between peak flows in the different sounds, which means that by installing turbines at different locations, tidal energy is always available from at least one of them.

Tidal energy is not weather dependent, and is therefore an energy source available all year round.

Interaction between energy sources

Precipitation and wind speeds decrease as we enter the summer period, but sunlight increases towards the month of May, which is the best month on average in terms of hours of sun. Tidal power is much more stable, and while the output is variable, it is available throughout the year.

The Faroe Islands are very well situated to take advantage of sustainable energy sources, and with well-planned and considered investments, these varied sources can be brought to interact through the seasons.

Wind and hydro can be the mainstay of winter production, and excess production stored by pumped-storage systems to fill reservoirs, which will supplement wind and hydro during the summer months.

Although tidal power is variable, it is predictable compared to the other sustainable sources, and it is not unthinkable that tidal energy will be an important part of total energy production as we near 2030. By employing a mix of the aforementioned sustainable sources along with storing energy in batteries and pumped-storage reservoirs, the Faroe Islands can become independent from oil in 2030.

Energy storage

An electricity system in the Faroe Islands based on sustainable sources which all are variable in time and strength, will entail a large excess production at times, such as a winter’s day with rain, wind, and strong currents. At other times, such as on an overcast, dry, and calm day, the sustainable sources will be insufficient to meet demand.

The changing weather conditions therefore require an energy storage system, that can save energy from times of excess production for use in those periods when sustainable sources are not sufficient to produce green energy.

The requirement is for long-term storage with the ability to store significant amounts of energy to be used in periods, when production from hydro and wind is low – especially the summer months of May, June, and July.

There are not many ways to store such large amounts of energy. The most obvious solution is a pumping system where fresh or seawater is pumped up into reservoirs using excess green energy. When the energy is required, the water will be released to a turbine, which will produce the necessary energy.

Economy and technology

Regular review and adaptation of the tangible course are necessary to make use of advances in technology while also considering the economic viability going forward. Great advances have been made in solar energy production in recent years, with improvements in both yield and cost. As solar is a relatively new technology, care has to be taken to implement the best solution, but this is true also for other sustainable sources, such as with tidal.

The work to reach 100% green energy on shore in the Faroe Islands by 2030 is based on three main principles. First, the security of supply must be maintained unconditionally, and second, all investments must be financially viable, and third is the consideration for the environment. To make the right decisions at the right time is crucial on the green course.

The tangible plan for the green course is a flexible project with the aim to securely and with great care to select the best and least impacting green solutions for the Faroe Islands.