Editorial - VGB PowerTech Journal 4/2017

Combining heat and power – generating double benefits

The energy and power generation industries in Germany, in Europe and worldwide are in a state of transition. The process of transformation in the energy system has reached a critical phase, characterized by the integration and dominance of renewable energy sources and the associated growing and changing requirements for the whole electricity supply system. The “three Ds” of the target triangle in electricity supply accurately describe what is happening.

While the focus of the “magic triangle” was previously on

  • security of supply,
  • cost-effectiveness – with affordable electricity prices and re-financeable assets

and

  • sustainability – with the facets environmental and climate protection,

it is now the “new 3 Ds”

  • decarbonisation,
  • decentralisation

and

  • digitisation

which are to be regarded as the driving forces and guidelines of the developments of thew future energy and electricity supply system. However, the “magic triangle” must not be lost sight of.

Totally against the trend of how it is perceived by the general public, power generation has always been subject to a continuous process of change. Even if the lifetime of plants in classical power generation of 40 to 60 years for thermal power plants, or 100 years for hydro power project a rather “static” image, our power plants, both old and new, follow important processes of innovation, including those which go hand in hand with the “new 3 Ds”.

These trends are also reflected at VGB PowerTech. Decarbonisation, certainly through our expanding expertise centre on “Renewable Energy” and its committees, and, for example, through the gains in efficiency achieved by the classic “Power Plant Technologies” committees. This includes the initiative “Energy efficiency/Energy managements systems”. The “Gas Engines” and “Distri­buted Generation” committees are examples of activities in the fields of decentralisation and digitisation, VGB Standards are in preparation as guidelines for industry as also as other activities.

The structure of the German energy supply shows considerably that the “Energy turnaround” is more than the transformation of the electricity sector. The electricity sector accounts for a share of 20 %; the transport sector uses 29 %, and in the dominant position there is heating and cooling at 51 %. Consequently combined generation of power and heat, together with the technical and economic system optimization through the combination of various generation, storage and consumption options in “virtual power plants”, are essential steps. The developments in these fields are based on technical innovations, but of course also on the commercially indicative market conditions.

In the past three years, classical combined heat and power (CHP) plants with around 4,300 MW of capacity have been put into service in Germany, although the trend is clearly decreasing. The highest capacity, central but close to consumer plants for public supply, accounting for around a third of capacity, are an important force behind this power and heat combination. In terms of numbers, the several thousand small systems with capacities below 10 kW are in the majority.

The past year, 2016, was once again a good year for combined heat and power generation. On the basis of the transitional regulations for the new German CHP Act in 2016, numerous CHP plants in the capacity segment above 100 kW were ordered at the end of 2015 and constructed during 2016. A counterproductive factor, as reported here many times, most recently by Dr. Christian Behnke in August 2016 under the title of “Reliable and adequate background conditions for CHP urgently required”, is the persistent uncertainty caused by the approval by the EU Commission of the CHP Act of 2016 together with the Renewable Energy Act of 2016 and the potential amendment in the CHP Act of 2017.

These issues have been discussed by leading experts from the industry at the recent VGB Conference on “Combined Heat and Power Plants and Virtual Power Plants 2017” in Berlin. The speakers will report in detail on their topics in the coming issues of VGB PowerTech.

All in all, the prospects for combined heat and power generation appear divided and challenging. The expected capacity additions in the field of CHP plants will probably remain on the average level of the previous years. For the operators, more stringent requirements are to be expected in several areas at the same time: increasing complexity of the environment and administrative work, increasing demands for flexibility and rising demands for emission reduction measures will exert great pressure on the technological developments. These demands will in the final analysis have to be met with solutions. In the area of funding policy, the environment also remains difficult. EU aid rules and the accumulation of subsidies in other areas have presented challenges and will continue to do so. The question also arises as to whether more regulation or more technical development and greater technically optimized operation will contribute to the achievement of the overriding aims of the energy transition.

The future in the field of combined heat and power generation therefore remains challenging and exciting. The innovations in decentralisation and digitisation offer a wide range of opportunities to further develop the reasonable, reliable and already proven coupling of the energy sectors electricity and heat also according to the further development of a secure, economical and sustainable energy supply.