There is a suite of innovative options available to power plant operators trying to balance the need to decarbonize with an ageing workforce, increased costs, and how to create new revenue streams. Jens Klingemann and Robin Höher of Siemens Energy lift the lid on some of the most effective service solutions.
Vienna’s Donaustadt power station in Austria is one of the world’s largest and most advanced combined heat and power plants.
Operating since 2001, it has a 350MW capacity for heat generation and up to 395MW for electricity.
In 2021, the Donaustadt power station generated electricity for around 850,000 households and heat for over 150,000.
Despite the modern CHP plant’s already impressive statistics – it has an efficiency rating of 86% – its operators must embrace change to tackle the challenges of the energy transition.
Starting in 2023, Wien Energie, alongside Siemens Energy and other partners, will start blending the natural gas fuel of one of Austria’s largest gas turbines with green hydrogen.
The first stage of this project will work with a blend of 15% hydrogen while the second will double this to 30%.
This article is part of the ‘Future Energy Perspectives’ series, in which experts from Siemens Energy share their insights into how we can move towards a decarbonised energy system.
The million-dollar energy question
With their green hydrogen trial, Donaustadt’s operators join many others worldwide in shouldering the enormous responsibility of testing vitally important future energy solutions.
Many cities and countries are committed to achieving net-zero power generation by mid-century – for example, Vienna has a target of 2040 – meaning fossil-fired plants must be converted to clean fuel generation.
They will also have to supply grid stability services and function as energy storage facilities or face being retired.
As detailed in our Future Energy Perspectives series, changes like these are necessary for the shift towards a decarbonized energy system.
So, what is the best path forward for fossil power plant operators? That’s the million-dollar question.
The majority of energy will have to come from renewables, a transition that’s already taking place in several countries around the world.
But as solar and wind are intermittent, many – though not all – thermal power plants will continue to be necessary for dispatchable energy and other services.
Leveraging insights and collaboration
In this the last article of this series, we’ll show how to build a bridge from today’s infrastructure toward a decarbonized energy future.
Firstly, let’s put ourselves in the shoes of an operator who’s wondering what the future may hold for their fossil power plant.
The paths leading to a net-zero economy are abundant, making them somewhat overwhelming to navigate. However, it’s more than possible to develop an effective strategy geared towards the future.
We aim to show that many of the solutions touched upon in this series of articles are viable options for plant operators.
We also wish to highlight the fact that, in making these decisions, no one is left behind. Smart tools, for example, can prove to be crucial in mapping out the path to net zero.
More importantly, perhaps, the collaboration and shared effort of various actors in the energy industry will play a key role in turning these visions into reality.
The potential of decarbonisation
Next to ensuring a secure energy supply, decarbonisation is paramount for all future energy generation.
Coal power plants have great potential in this regard. For example, the project for ‘Re-purposing Coal Power Plants During Energy Transition’ (RCPP), which is partially funded by the EU, has identified 835 coal-fired plants in six European countries alone, accounting for 67% of Europe’s energy generation.
Many of these have the potential to be converted into viable contributors to a future decarbonized energy system.
The most obvious choice for these plants is shifting from coal to gas. Changing a coal power plant to a combined cycle plant, for example, can reduce up to 70% of CO2 emissions and increase efficiency from an average of 38% up to 63%.
Though gas is a fossil fuel, these solutions are a necessary bridge technology that will help to smooth the transition to clean fuels, such as green hydrogen.
The decarbonization of gas-fired plants is also yet to reach its potential, and much more can be done in that space. Great gains are still possible in efficiency improvements, such as Brownfield Engine Exchange (BEX) – especially by replacing existing gas turbines with newer ones capable of hydrogen-firing.
Have you read our other Future Energy Perspectives?
Why storage is the Swiss Army knife of energy transition
Decarbonising heat: The hot topic we can’t ignore
Hybrid power plants: Tailoring technology to deliver decarbonisation
Zero Emission Hydrogen Turbine Center: A closed loop of the energy future
Kicking out coal and greening gas on the road to net zero
Auto-tuning gas turbines
The latest versions of gas turbines can achieve an efficiency of >63% in combined cycle operations.
Digital tools can enhance performance even further. For example, Siemens Energy has developed a ‘GT Auto Tuner‘, designed to optimize turbine operation.
At its core is a digital twin that uses AI to optimize the turbine’s inlet temperature and emissions with the help of reinforcement learning.
The system was implemented during a recent control system upgrade in a power plant of Dubai Electricity and Water Authority (DEWA).
The world-first combination of digital twin and artificial intelligence made it possible to compensate for age-related performance losses in real-time.
As a result, the performance of the turbines has improved, and NOx emissions have decreased substantially.
Another promising solution for reducing a gas power plant’s CO2 emissions is carbon capture. In the UK, for example, Siemens Energy, as part of a consortium, is participating in a front-end engineering design (FEED) study for carbon capture at a power plant in North Lincolnshire.
Turning to clean fuels
Moving forward, it’s clear the switch to hydrogen will be crucial for gas-fired plants – as demonstrated by the upcoming trial at Vienna’s Donaustadt power plant.
HYFLEXPOWER, an industrial power plant at a paper factory in Saillat-sure-Vienne in France, will also start co-firing hydrogen soon.
Though hydrogen is expected to be a widely-used, dominant clean fuel of the future, it’s not the only one: biofuels could also play a key role in the energy transition.
They show great potential and have already been successfully tested at the Rya CHP district plant in Gothenburg, Sweden, using hydrotreated vegetable oil (HVO).
Hybrid power plants
Another option, besides fuel switching, comes in the form of converting coal-fired power plants into hybrid power plants.
These hybrid plants integrate renewables such as wind and solar, energy storage or (co-)firing clean fuels. Crucially, if a plant operator is unsure whether it’s worthwhile to turn an existing plant into a hybrid one, there’s a tool specially made to provide them with an answer: Energy System Design (ESD).
ESD is a model-based, optimized selection of energy conversion and storage technologies tailor-made to meet a plant operator’s needs.
The process starts with essential data collection. Data collected includes a power plant’s current energy loads, options to purchase or sell energy commodities and the corresponding prices – for example, for electricity and green hydrogen.
This data is run through a modelling and optimization tool that selects and then highlights the optimal energy conversion and storage technologies.
ESD’s proprietary design enables operators to develop a plant that can contribute to making the energy transition a reality.
One of the world’s first hybrid power plants on a commercial scale is currently being built in French Guiana and is combining solar PV, batteries, an electrolyser and a fuel cell – all thanks, in part, to this technology.
Harnessing new revenue streams
Gas-fired and hybrid power plants are, of course, not the only possibilities. With thermal power plants set to face reduced revenues over time due to less usage, other possible revenue streams are worth pursuing.
One example is grid services. As the share of renewables in power generation continues to grow, volatility will also increase in the grid.
Power plants, therefore, can help with – and increase their revenue via – frequency control, voltage stability, load flow, and black start capability for the grid.
Even if power generation is shut down, one can still install rotating grid stabilizers – a solution that was applied successfully at Killingholme in the UK.
Another option for new revenue streams is Power-to-X solutions. A great example is hydrogen production for energy storage, which can eventually be used for arbitrage, storing energy when it’s cheap, and selling when it’s expensive.
E-fuel production could also be a viable option, as is the case with the Haru Oni hydrogen plant in Chile.
Finally, even crypto-mining could offer a possible path forward for a power plant.
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Automating plants of the future
Power plant automation could also play a key role by addressing the growing concern over labour shortages.
Thermal power plants, for example, face a looming workforce shortage, with skilled control room and maintenance personnel in most demand.
Plants used for dispatchable energy will also have fewer operating hours, making it costly to keep staff on-site 24/7.
With today’s digital management systems, it’s possible to operate power plants virtually autonomously.
One of the first power plants worldwide to be operated digitally from a remote location will be built by Siemens Energy in Leipheim, in southwest Bavaria.
The plant will help ensure grid stability in an emergency by supplying an electrical capacity of up to 300MW for a maximum period of 30 minutes.
That option could prove vital, for instance, when equipment in the grid is defective or not working optimally.
What’s more, this plant will operate without requiring daily onsite inspections by power plant personnel. This will greatly reduce costs at the same time as addressing the challenges of an ageing workforce.
Vital global partnerships
Regardless of the option a plant operator chooses, nothing will be possible without the contribution of supporting experts, partnerships and collaborations.
Working with partners opens up a whole host of benefits: it can help opera-tors navigate regulatory requirements and benefit from financial incentives, such as the REPowerEU programme, which promotes green H2 expansion.
For example, let’s look at the Zero Emissions Hydrogen Turbine Center (ZEHTC) at Siemens Energy Finspång in Sweden.
It has several partners: Siemens Energy, Linde Gas, a university in Sweden, one in Italy, the province Östergötland, the town of Finspång, and the EU, which partially funds the project. Also, HYFLEXPOWER is supported by numerous industrial and academic partners.
It is vital that we all work together to achieve net-zero energy generation. And it’s an initiative that goes far beyond the purview of the energy industry and drastically affects the entire world.
To make net zero a reality, regulators, intergovernmental organizations, and the majority of the public will have to collaborate on a global scale.
We’re stronger together, and, given what’s at stake, there’s no other way forward.
ABOUT THE AUTHORS
Jens Klingemann is Head of the global Marketing Strategy at Siemens Energy. In his role, he leads a global Gas and Power Generation Services team for the transformation of the Energy Service Business. His team is focused on the development and incubation of new products, solutions and business models for a sustainable tomorrow. With over 20 years of experience in the power generation business, Jens held various managerial positions within Siemens and Siemens Energy.
Robin Höher is Manager of Marketing Strategy and Business Development at Siemens Energy. He has held leadership positions in the fields of marketing, sales, business development, quality management and safety for over fifteen years. Robin has worked in different German locations for Siemens, Siemens Energy and the World Energy Council, as well as for many years in the US.