Powering the future Guernsey has a decision to make
As an island we have pledged to reach net zero by 2050. Where our energy comes from and how we use it will play a leading role in achieving this goal.
We’ve come so far. We used to rely entirely on our fossil-fuelled power station for all our electricity.
We have made great progress, but, we need to act fast to provide the best possible solutions to suit our island’s needs. This year the government will be making decisions. Decisions that will affect us all. Before then, we want to share the facts, so you can have your say on this important topic.
In 2000, we installed a subsea cable which is now our primary source of electricity. Importing energy has decarbonised our electricity and has delivered a significant part of the islands’ 37.5% decrease in emissions from 1990 levels. But we still have some way to go before Guernsey is net zero. Our subsea cable provides up to 60MW of electricity to the island. When demand exceeds this, we make up the difference by using the fossil fuelled power station. This comes with environmental and financial costs.
Demand is predicted to increase. Phasing out petrol vehicles and fossil fuel heating, means the phasing in of electric-powered alternatives. At the moment, this would mean using the power station more. A decision needs to be made on how we provide this additional electricity.
No decision, will leave us no choice. We’ll be forced to invest in replacing and upgrading the fossil-fuel power station.
60MW GJ1
France
Subsea cable N1 N2
Jersey N3
Guernsey has a decision to make. Want to know more? Visit www.electricity.gg/electricfuture *States of Guernsey, Energy Policy
Timing is critical. This key decision about Guernsey’s future electricity sources will be explored in the island’s Electricity Strategy which is due to be debated by the States of Guernsey later this year. To maintain the momentum that we’ve started towards net zero, we need to act fast to provide the best possible infrastructure to suit our island’s needs. This is a decision that will affect us all. For over 10 years research has been conducted into alternative energy supplies on and around the island, including sources such as wind and tidal. While our unique island provides opportunity, it also presents unique challenges.
Fossil Fuel Power Station
Subsea Cable
0MW
10MW
20MW
30MW
40MW
50MW
60MW
70MW
80MW
90MW
How do we provide this predicted increase?
150MW
Guernsey currently demands between 25MW and 95MW of electricity
Guernsey currently demands between 25MW (megawatts) and 95MW of electricity. We expect peak demand to increase in the future to 150 MW by 2050 so we need to ensure that we can always keep the lights and WiFi on, and our homes warm.
While our unique island offers opportunity, it also presents unique challenges.
What are the options?
Tidal
Solar
Offshore Wind
Wave
+ Predictable
+ One of the most advanced technologies
+ Commercially viable
- Technology is still in development
+ Guernsey has a large tidal range
- Only generates power in the day
+ Promising local resource
- Waves are unreliable
- Environmental impact
- Unreliable, can produce too much/ little power
+ Sustainable low carbon energy
- Potential impact to marine industries
- Needs lots of land/roofs
- Unreliable, weather dependent
- Not currently commercially viable
- Requires battery storage and alternative supply
- Potential marine environmental impact - Potential to impact marine industries
Tidal energy is predictable, and we have one of the largest tidal ranges in the world which could be harnessed via tidal stream, barrage or lagoon. The local potential has been investigated but there are limited installation sites. It is expensive, there are environmental impacts and the power produced does not always match up with energy demand. Battery storage or a second subsea cable would be needed for when supply exceeds demand, to make the most efficient use of the energy generated.
Whilst one of the more advanced technologies, the intermittent nature of solar energy (only generates in the day) limits the availability. On very sunny days, Guernsey would generate too much, so we would need batteries or the ability to export via a subsea cable. To provide 70MW of electricity from solar, 175,000 solar panels are required. 1MW requires about 2.5 acres of space. That’s around 40 tennis courts. 70MW would provide around 20% of today’s demand.
- Requires battery storage and alternative supply
Wind energy is commercially viable, and research has shown a promising local resource for an offshore development. Consideration would be needed around impacts to the environment, fisheries and shipping for example. The fluctuation in wind would require battery storage or a second subsea cable to export energy.
Technology is still developing, and waves are an unreliable and unpredictable energy source. Research has identified three potential locations but there are no technologies which are at a commercial scale.
What are the options? continued...
Additional subsea cable
Fossil Fuel Power Station
Energy Storage (Batteries)
+ Secure diverse supply from Europe
+ Reliable
+ Store energy for when its needed
+ Affordable low carbon energy
+ Controllable
+ Provides a flexible on demand resource
+ Diesel power station only needed as a back up
- Large carbon emissions
- Expensive
+ Provides security to support local renewable development
- Expensive upgrades required to ageing equipment
- Requires large space and/or complex and costly infrastructure
+ Potential to sell excess generated locally
- Cost of imported fuel can vary significantly - Geo-political risks and dependency
- Geo-political risk and dependency
A 100MW cable would provide enough electricity for the island and allow for the decarbonisation of heating and transport in Guernsey, meaning the power station would no longer be required, for top up purposes but may be retained for emergencies. It would also provide the security to enable more local renewables and the ability to export and sell any excess energy.
Generating from the power station is dependable, but significant upgrades are required imminently. As one of the most carbon emitting sources, it brings significant financial and environmental costs, threatening our ability to meet net zero.
Energy storage comes in various forms and can be used to smooth out the variable supply from renewable sources. Batteries are one form, and are becoming cheaper and more readily available but only provide short term (daily) storage options, and remain expensive despite falling costs. For energy security, longer term forms of storage are required. There are many technologies available and hydrogen is rapidly developing, but all options will increase the cost of energy for customers.
Local renewables alone cannot provide the electricity we need today, let alone in the future. There is no simple solution. Using a mix of sources will offer reliability and security.
How do the options compare?* Technology
Technology cost (per MW installed)
Energy cost (per MWh)
Availability
Carbon intensity***
Thermal Power Plant
£1m
10-14p/kWh
>95%
600-700 gCO₂e/kWh (direct)
Solar Photovoltaic
£1m
6-10p/kWh
12-14%**
40 gCO₂e/kWh (lifecycle)
Offshore Wind
£2-3m
6-9p/kWh
30-40%**
5 gCO₂e/kWh (lifecycle)
Tidal Power
£8-10m
20-25p/kWh
20-25%**
Unknown
Additional Subsea Cable Interconnection
£0.85m
6-8p/kWh
>95%
4-40 gCO₂e/kWh (lifecycle)
*These are indicative figures based on Guernsey Electricity’s market research relevant in the Guernsey context. **This is the amount of energy we could expect the technology to deliver as a percentage of its theoretical continuous maximum output- referred to as ‘capacity factor’. ***Direct refers to the emissions related only to the creation of the energy. Lifecycle refers to the energy creation emissions as well as the emissions of all stages of production including construction and decommission.
Frequently Asked Questions We have the largest tidal range in the world, why aren’t we focusing on tidal power? This is becoming more commercially viable, but at the moment it is not affordable for the island.
Why aren’t we being more self-sufficient? We need to have a secure supply and local renewables alone cannot provide the affordable electricity we need today, let alone in the future. Using a mix of sources will offer reliability and security for a sustainable supply. Importing electricity today is the bridge to tomorrow’s technology and will enable more local renewables. A second cable also opens up the opportunity to sell electricity to Europe.
Buying renewable energy certificates for the energy we import doesn’t mean we are getting renewables through the cable. ‘Guarantee of Origin’ certificates (GoO’s) are the current market mechanism for driving investment in renewables. We are using our market power to drive investment to the right places. By increasing the demand for renewable and sustainable electricity, we reduce the investment into fossil fuels. The more communities that make this same choice, creating more demand for energy from sustainable energy sources, the more generators will invest in these technologies.
Why have we printed this? We understand the environmental and financial impact of printing. Usually, we focus on digital communications but because this future decision will impact all customers and islanders now and in the future, we want to make sure we reached you, and that the information was available to everyone.
Please visit www.electricity.gg/electricfuture for more information.
How do you want to power your island? The government’s Electricity Strategy is developing plans to meet our future electricity needs. Later this year the States will be making decisions, and at this point we encourage you to express your views.