It is broadly accepted that current energy systems should become more sustainable in both a global and local context. However, setting common goals and shared objectives and determining the appropriate means by which to get there is the subject of heavy debate. Therefore, the American Society of Mechanical Engineers (ASME) and the German Association of Engineers (VDI) initiated a joint project aimed at providing a young engineers’ perspective to the global energy conversation. The young engineer project teams set a common goal of assembling a completely sustainable energy system for the U.S. and Germany by 2050. This includes not only the electricity market, but the overall energy system. Based on the current global energy paradigm, a completely sustainable energy system seems very ambitious. However, multiple analyses show that this path is possible and would in the medium to long run not only be desirable, but also competitive in the market. This future ‘energy puzzle’ consists of many important pieces, and the overall picture must be shaped by an overarching strategy of sustainability. Besides the many detailed pieces, four main critical issues must be addressed by engineers, politicians and everybody else alike. These challenges are:
i) Rational use of energy:
This uncomfortable topic is rather unappealing to communicate, but is a key issue to reduce energy demand and to meet the potentials of renewable energy carriers.
ii) Balancing of electricity demand and generation:
This is a challenge to the electricity markets and infrastructures that are currently designed for base-load, mainly fossil power plants. The overall mix of renewable energy generation, storage technologies, grid infrastructure, and power electronics will decide how efficient and reliable a future energy system will be.
iii) Cost efficiency and competitiveness:
It is a prerequisite for industrialized countries to stay competitive and to establish RE in the market. Developing economic technologies while at the same time establishing a strong RE market is the secret of success.
iv) Acceptance of the system and its consequences:
The best energy strategy cannot be realized without broad public acceptance for it. Therefore, the understanding of the energy technologies and an objective discussion must be promoted — without old fashioned emotionalizing of certain risks.
The paper will present details on the four mentioned aspects, compare the situations between the U.S. and Germany, and propose solutions for appropriate political frame conditions to achieve a sustainable energy system.