Why do we need flexible natural gas fuelled power plants?

With the closing of large centralised power stations (particularly coal) and the increasing use of renewables associated with the move to a low carbon economy; National Grid requires access to fast response, secure and flexible generation to ensure grid resiliency.

This was recognised in the recent Future Energy Scenarios report (2019). It allows National Grid to call on demand when needed and meet requirements for peak demand, outages and unplanned events to ensure supplies are maintained to customers.

https://www.nationalgridet.com/about-us, National Grid, 2019

Do flexible power plants contribute to UK carbon emissions?

When operating our plants emit approximately 0.48kg CO2e per kWh of electricity generated. Our plants operate for around 1500 hours per year (4 hours/day) and therefore a 5MW project emits 3,600 tons of CO2 per year.

Critically though, our generators facilitate the addition of clean, zero carbon renewable sources which will generate electricity at varying levels for much longer periods. In addition, we are also displacing retiring coal plants and therefore our projects are facilitating reductions in the overall carbon footprint of electricity generation while ensuring supplies are maintained.

Do the plants help or hinder the UK move to a low carbon economy?

We will help this move. As the generation mix moves towards cleaner technologies such as large scale offshore wind farms, the overall level of carbon emitted from the power mix will reduce. In addition, as transport transitions to electric vehicles, fast response and flexible generation will become increasingly important to balance the additional demand created.

In the longer term only a small percentage of our total generation mix will need to be sourced from flexible gas-powered generators but it is a vital component that is complimentary to the growth in renewable energy.

What would happen if these plants are not built in the coming years?

National Grid is encouraging flexible generation plants because in order to balance supply and demand in an increasingly complex electricity system they need the ability to quickly turn on generation when needed.

Through market based mechanisms they are encouraging investment to allow new plants to be built. The challenge of balancing the grid network will get harder over time without this new generation, ultimately restricting the percentage of generation that can be met from renewable energy.

Why can’t battery storage provide the same function?

Battery storage technology has the potential to provide grid balancing services in the medium term as costs fall and the duration that the technology can discharge before requiring recharge increases.

In addition, batteries need to be charged and therefore high levels of renewable generation are required to allow them to be charged from clean energy sources, otherwise fossil fuel plants are generating electricity to charge batteries – a less efficient solution than we can provide with flexible gas-powered generators. In addition, National Grid have to be absolutely certain that services can be maintained and so complete dependence on variable renewable energy is not yet possible.

What kind of locations are appropriate and what are the requirements?

There are many constraints to the appropriate siting of a gas peaking plant and reflect a combination of environmental, commercial and technical issues. The key ones are proximity to viable electrical grid and gas connections. The presence of either does not necessarily mean we are able to connect so detailed studies are required.

We need to find landowners who are interested in working with us to lease the space required at viable cost. We then need to determine if the location is likely to be acceptable to the local council who will decide whether to grant planning consent.

Key factors involve ensuring noise levels are acceptable at nearby receptors, emissions studies do not demonstrate any significant increase to existing levels (generally unlikely as the plants operate to the tightest EU standards). Other factors such as flood zones, ecology, access and landscape effects may also need to be studied as part of the planning process depending on the location.

Are they noisy?

No. The level of acoustic dampening of the generator and cooling fans can be adjusted to ensure noise levels do not cause a nuisance. We undertake background noise studies so we fully understand the existing noise conditions of the location and the nearest sensitive receptors (which is generally focused on residential properties).

In some cases, we may also include an acoustic screening fence to further reduce noise levels. Projects have to operate within parameters specified in the planning consent which generally require the plant to not increase the background levels experienced at sensitive receptors.

Will they create traffic and other disruptions?

Once operational, vehicle movements are very low as the plant is operated remotely. Occasional maintenance visits are required amounting to a handful of vehicle movements per week.

During construction there is more traffic which will be carefully controlled depending on the particulars of the location. The largest movements will be the low loader trucks delivering the generators and the crane that is used to move them into position.

How are Conrad Energy projects funded?

Conrad funds its projects through a combination of shareholder equity and debt from banks.

What is the basic technology and where does it come from?

Conrad Energy utilizes reciprocating engine technology married to an electricity generator. The technology is similar to a car engine but instead of turning the wheels the engine turns the generator to create electricity.
The technology is well proven and dependable, a critical strength that allows the National Grid to call upon us. Manufacturers include Rolls Royce (MTU), Caterpillar, Cummings and Jenbacher.

How long does it take to construct a project?

Projects take 6-9 months to construct. During this period there may be times of limited activity and then busier periods when deliveries are being made.

What is the expected operational life?

The design life of the projects is 25 years but can be extended if appropriate.

What is your fuel source?

Our projects utilise natural gas from the national network in the same way a domestic boiler does. We connect to the medium pressure network.

Sometimes elements of the local gas system need to be strengthened to provide the gas we require.

This may require pipeline replacement which can require the need for temporary road works for short periods.