‘Renewables are the way of the future’ – 20 years ago, this was a minority opinion. Back then, our energy supply came from fossil sources (coal, oil and gas) and from nuclear power. Power providers did not believe that solar energy could ever make up a large share of the pie and merely spoke of […]

If you want to get a lot of your heating energy from solar heat, you have to take two factors into consideration: 1 Far more heat is required for space heating than to heat service water. In old buildings, 5-10 times as much energy can be required for space heating than to provide hot tap […]

Generally, homes are energy consumers, not producers. They need heating energy and electricity, which they get from outside. But a model project in Freiburg, Germany, turns the table. The houses in the Solar Estate neighbourhood not only cover their own energy demand, but also export excess elec­tricity to the grid.23 The technologies in this residential […]

Worldwide, installed wind capacity grew from just under 20,000MW at the beginning of 2001 to around 158,000 megawatts at the end of 2009. Within eight years, installed capacity grew eightfold.16 The main markets in 2009 were China with around 13 GW, the US with 10GW, Spain with 2,5GW and Germany with 1,9GW. In 2008, the […]

The previous chapters discussed various sources of solar energy and the components within a solar energy supply. In this chapter, we provide a more holistic overview – what share of our energy supply can the various sources of renewable energy have, and how much energy can they provide? The supply of solar energy is gigantic […]

In most cases, electricity and heat from renewable sources are still more expensive than conventional power and heat for various reasons: The external costs of the consumption of fossil fuels are not included in the price (see 11.3). Some of the technologies for renewables are still being developed, and large-scale production – which would bring […]

In previous sections, we have focused on the main instruments and steps towards a sustainable energy supply in Germany. In places, we have also mentioned how impor­tant renewable energy can be for sustainable development in the developing world. As difficult as it has been for us to switch to solar energy, it is even harder […]

administration more than ever before as the country worked to make itself less depend­ent on foreign energy imports. Clearly, energy policy is in a transitional period. Renewables are quickly becoming more important. In this book, we navigate our readers through this process and provide them with facts and good reasons for this change. We also […]