Redevelopment and modernisation of existing plants
In these days of energy transition and fundamental political reforms in relation to energy generation and supply, providing reliable, efficient and cost-effective power to industrial enterprises is becoming increasingly challenging. GETEC offers planning, construction, financing and operational services for bespoke energy generation systems for the industrial sector and see ourselves as a holistic partner for everything to do with energy.
Efficient, environmentally-friendly and sustainable power supply
Much has changed since the first ever power station was built. Today, electricity, which used to be a luxury commodity for the few, influences so many aspects of our daily lives that it is almost impossible imagine a world without it. These days, it is a consumer commodity, the main power source of industry, the basis for the telecommunications industry and most services, and, above all, it is something that we take for granted.
We have come to assume that electricity simply flows reliably from the wall socket. This level of reliability that we would be loath to part with today is the result of ongoing improvements and tenacious development work over the past 3 centuries. Additional important desiderata have emerged in more recent times including efficiency, environmental friendliness and sustainability.
History of power plant construction
Before electrical power, in the form of alternating current (AC), took the world by storm at the close of the 19th century, electrical power usage had only ever been possible at the local level in the immediate vicinity of the first power generation stations. Even for the first direct current (DC) power stations, such as the famous Pearl Street Station in New York (1862), the maximum power transmission distance was limited to a few kilometres. One of the restricting factors was the voltage drop within the power grid.
The "battle of the currents" between AC and DC was settled in favour of alternating current because it enabled the transmission of power over longer distances and with lower losses than direct current. The clincher was that the voltage level of alternating current could simply be increased through the use of transformers to counteract transmission losses en route and then lowered through additional transformers at the consumer end. There was no corresponding transformer technology available for direct current. This technology enabled the construction of major centralised and efficient power stations in the vicinity of energy sources (e.g. hydroelectric power plant in the mountains or coal-fired power stations close to opencast mines) and its transmission to energy consumers in (sometimes very) distant towns and cities.
According to the laws of physics, the electricity generated must be used immediately. The standardisation of standalone power grids to the same frequency level led to the creation of continental-wide transmission grids. This pooling of networked consumers and generators means that fluctuations in any given sector of the grid are usually counterbalanced by opposite oscillations in other sections. A large system is generally more inert and therefore more resistant to fluctuations. At the same time, it proved possible to supply the main drivers of industry, but also the railway networks, street lighting and the domestic sphere whilst lowering the cost of power due to economies of scale.
Since then, the goal has always been to build ever bigger power stations in order to benefit from the economies of scale. The specific cost of power generation fell dramatically as cost effectiveness records were achieved and smashed in rapid succession. This trend is easily recognisable when one considers the average sizes of coal and oil fired power stations over the previous 60 years. In the 1950s and 1960s, the typical power plant performance was around 300 MW of electrical output, rising to 600 MW in the '70s and finally to levels in excess of 1000 MW per block unit in the 1980s. This trend continued through the 1990s with ever increasing output levels. The introduction of modern gas and steam plant, the increasing utilisation of renewable energy resources, and the effective power utilisation in industrial cogeneration plant have all resulted in a return to decentralised power generation. Thus, there has been an increase in power generation closer to the end consumer as opposed to in distant large-scale power stations and, for the first time in decades, the optimum size of power stations has decreased.
Classification of power plant types
During the 150-year or so history of power plant construction, several power generation technologies have been developed and optimised. These can be categorised on the basis of various criteria, such as:
- Operating principle
- Working medium
- Primary energy source
- Plant size
Compared with all the others, each of these technologies has various advantages and disadvantages in terms of efficiency, availability, cost-effectiveness and sustainability. The power generation type and dimensions need to be determined on the basis of the specific project parameters. The plethora of modern power plant variants available reflects this broad range of bespoke requirements.
At the global level, fossil fuels account for around 68% of electricity generation and some 30% of all CO2 emissions. The CO2 neutrality, sustainability and free "fuel" of renewable energies are countered by their heavy reliance on environmental factors such as sunshine, wind, and water availability and strength. The resulting fluctuations in energy production capacity and low utilisation levels have a negative impact on cost effectiveness.
Whilst it is true that the load profile of biomass and biogas power stations is easier to control, this advantage is countered by the limited availability of the specific fuel type.
Power plant construction & the energy transition today
The Federal Republic of Germany's energy policy has changed the power plant sector irreversibly and fundamentally. The decision to phase out the use of nuclear power generation is probably the best example of the radicalism and long-term impact of political decision-making relating to the mix of power plant technology in Germany. The objective of the energy transition involves nothing less than the restructuring and modernisation of Germany's entire energy provision plant by the year 2050. GETEC has been involved in the process since the very start and, with its innovative concepts, is playing a decisive and fundamental role in the success of the energy transition.
How is the energy transition influencing the construction of power stations in Germany and the rest of Europe?
The energy transition is based on the fundamental concept of the expansion of renewable energy sources as an alternative to nuclear power and conventional fossil fuels. Eight of Germany's nuclear power plants have been decommissioned since 2011. The nine that remain are scheduled for decommissioning by 2022.
According to the German Federal Network Agency, the renunciation of nuclear energy could result in power shortages in winter, which will need to be balanced by gas and coal-fired power stations. In addition, conventional power stations are required for grid-stability purposes, as they are able to compensate for the fluctuations that result from feed-ins from distributed renewable energy systems.
According to studies by the German Association of Energy and Water Industries (Bundesverband der Energie- und Wasserwirtschaft - BDEW), power supply security is set to worsen. The BDEW list of 20 MWel power stations (renewable and fossil fuels) that are to be constructed by 2025 includes 74 construction projects with a planned total output of 33.5 GW (as of April 2015). These do not include the renewable energy-based projects (primarily offshore-wind), which only contribute a limited amount to the overall assured power station capacity, as well as those projects that are unlikely to gain approval. Therefore, the remaining assured extension capacity is only 7.8 GW. This situation must be considered in light of the fact that the decommissioning of some 24.5 GW of assured power provision has been announced by the German Federal Network Agency (BNetzA, as of April 2015).
Not included in this BDEW list are smaller units designed for decentralised in-house power generation, which are often cogeneration systems with an electrical output capacity of less than 20 MW. These systems have the potential to bridge the energy supply gaps torn in Europe's energy topology by the decommissioning of power plant.
Power plant construction: cogeneration systems for decentralised in-house generation
There has been a steady increase in the number of cogeneration power plants constructed since 2010. The average annual growth rate for cogeneration power centres has been around 20% per annum. Cogeneration facilities with an electrical output capacity of less than 10 MW account for 41% of the 542 MWel of electrical output that were brought on-line in 2014. Due to the use of combined heat and power generation systems, the more effective utilisation level of the potential energy locked up in various fuel types is already saving some 56 million tonnes of CO2 emissions per year compared with the levels resulting from a commensurate amount of heat and power generated in separate systems. This is equivalent to an additional area of 160 square kilometres of sea ice that would not be melting each year during the summertime in the Atlantic. Cogeneration facilities are efficient, secure and more flexible, and are able to compensate grid fluctuation caused by renewable energy sources. The government of the Federal Republic of Germany regards cogeneration technology as a supportable element of the energy transition with a potential share of the German electricity production mix of 25% by 2020.