Renewables in the UK - Part 4 Channel Islands
Back by popular demand! By request we have extended our Renewables in the UK series to have a specific look at the Channel Islands.
Fundamentally the availability of resources is not different to that of the UK, but the relative levels of each do vary for this location.
- Solar radiation is slightly better than for the main body of the UK due to the southerly latitude and offers a good option to local residents concerned about decarbonisation of heat and power.
- The wind resource on and around the islands is best described as “OK”. The onshore mean of ~6m/s and offshore ~8.6m/s are not exceptionally good sites, but could be used to generate electricity.
- The positioning within the English Channel and exposure to the Atlantic means that the wave and tidal resource is significant, with the islands providing natural channels for the tidal flows. The tidal resource particularly in Alderney Race is one of the best in the world and a number of developers have looked to make the most of this. Currently SIMEC Atlantis have plans to develop this site as part of the TIGER programme.
Larger islands like Jersey and Guernsey are powered by an undersea cable to France. There is a power station (La Collette – oil fired) on Jersey and one on Guernsey, but today these are for emergency back-up supply in case of power interruption. That is not to say that no renewable energy is generated locally; this represents ~5-20% of the energy generated with solar PV being the main contributor. For example, Guernsey Energy owns a 100kW solar array; this is supported by over 500kW of privately owned panels.
There are smaller islands than Guernsey and Jersey that are permanently inhabited, such as Sark, Alderney and Herm. These islands are predominantly reliant upon diesel generation for their power supply. That is not to say that the inhabitants of these islands have not pursued or considered renewable sources as options for power generation. Given the smaller populations on these islands one of the biggest challenges with integrating renewables is balance of plant requirements. The outputs from renewable sources are inherent transient when compared to the diesel generation and thus require control and modulation to output consistent frequency AC power.
Perhaps the simplest solution is “behind the meter” solar PV, which puts the onus on local residents. Given the variability in wind and wave energy the remaining candidate is tidal energy. We have been involved with a number of tidal energy ideas in and around the Channel Islands and can see a strong case for the usage. The most optimal application would be tidal energy combined with energy storage which could provide both a stable base load and have the capacity to deal with daily variations in demand. One of the major advantages of tidal energy is the predictability which facilitates a simpler design and integration of the storage system making it a cost-efficient option across the Channel Islands, not just the smaller isles reliant on diesel generators.
It has been noted that the governance system on the islands (typically consensus-based decision making) is inherently slow and can make commitment to renewable energy projects more challenging. In parallel, we can appreciate the challenging balance of plant issues compared to importing power from France via the interconnectors. However, we think there is a renewable solution for the Channel Islands, most likely with tidal at its core. It will start on the smaller islands and once demonstrated begin to spread. That gives me an idea for an interesting little piece of modelling…