New Awareness of Energy – Against the Current

Photovoltaik

The previous article focused on some of the well-known technologies that could cover human energy needs without destroying our planet. Today, we will look at the possibilities of decentralized energy production and the overall increase in energy efficiency. Again, the technologies used are by no means always “high tech”.

Home Sweet Home

Opportunities to use regenerative energies for the homestead are abound. The most practical method, as mentioned in the last article, has proved to be solar energy production. But not only electricity for domestic use can be generated by the power of the sun:

Solar thermal heating (heating of water) for houses or residential buildings is common in the southern regions. House roofs without solar panels are an absolute exception in countries such as Greece. In our latitudes, however, conventional solar collectors, especially in the winter months, are not usable.

Efficient through Vacuum

But here, too, there are possibilities, such as the so-called vacuum tube. This version of solar thermal is highly efficient. An absorber, usually made of dark-coated copper, is surrounded by a vacuum tube. These tube elements lie on so-called CPC mirrors, which can exploit even the diffuse from a cloudy sky in order to heat up a carrier liquid.

These systems can be used in conjunction with a solar-driven boiler inside the building, to provide hot water and to support of the heating system.

Depending on the building type and insulation, 60-90% of the energy costs can be saved. Even in the deepest winter, there are sufficient installations to save about 20% of the required heating energy.

Cooling with the Heat

Clearly, in the summer there is a huge surplus of heat energy through the collectors. Here, too, there are ingenious possibilities to use this excess energy meaningfully.

The absorption refrigeration machine, designed by Edmond Carré as early as 1850 and presented in the Paris World Exposition in 1878, is able to use the heat energy to cool water (or some other carrier material).

Thus whole houses can be cooled in summer. The “Wien Energie” company, offers the so-called “Fernkälte”(remote cold), based on this principle.

Eletricity Generation by Heat

It is technically not a big challenge to convert heat energy into electrical energy. There are several possibilities:

The generated heat can be used to drive a steam engine. Stirling engines, as they are sometimes already used in block heating or biogas plants, converting some of the heat energy generated by combustion engines into electric current, would be another possibility.

Thermoelectric generators can also make use of the heat generated. The efficiency of these technologies is low, but irrelevant in view of the inexhaustible nature of solar energy.

Wind Energy – Wind of Change

Wind generators are part of the landscape. But even in small, these generators can accomplish great things. Wind generators for the home, the residential settlement or in cities in general, would be a further contribution to sustainable energy generation. In this area as well, prices have decreased dramatically in the last 20 years.

Small wind turbines with an output of about 0.5 to 5kW are already available in a variety of different designs. Such a small-scale plant, in favorable conditions on-site, could produce a considerable amount of electricity in the annual average, more than a 4-person household would need.

Newer constructions are partly no longer audible. So there is nothing to prevent the use of these devices.

Heat Pumps

The energy gained from the sun or wind can also be used to operate heat pumps. The principle here is basically very simple, and similar to that of a conventional refrigerator. These devices are capable of making ambient heat usable for heating.

Thus, e.g. the warmth in the ground or ground water can be used to heat whole houses with it, and this is as environmentally friendly as can be.

Here too, cooling in the summer would be absolutely no problem, as heat pumps can be used as air-conditioning systems just as well. In the summer, they pump the heat from the building, and in winter they conduct the heat into the building. Heat pumps also play a key role in the recovery of heat from our wastewater and sewage systems.

Mini Biogas Plants

Small biogas plants could also help to produce energy in the near future. Industrial small-scale plants can produce methane from wastewater, food residues, garden waste and other biological material by adding bacteria.

This gas may e.g. be used for cooking, heating or even as an automotive fuel. The remnants of the converted material may also potentially be used as fertilizer for the garden or agriculture in general. The cycle would be perfect.

In China, such mini biogas plants are even partially subsidized by the state.

Smart Grids – The Networks of the Future

A key challenge of the future will be to use and distribute regenerative energies efficiently. So-called smart grids would be able to provide a kind of “peer to peer” network for electricity. Sensors at various node points measure the utilization of the networks, as well as the current energy requirements in the sub-areas, and regulate the current distribution automatically.

To illustrate this: if a household, for example, is currently consuming less energy than its regenerative energy sources could provide, the system recognizes this excess and makes it available to other network participants.vEven today, energy-self-sufficient communities would be possible with this technology.

There are indeed villages, for example. In Germany or the Netherlands, who practice it.

It is not an absurdity by any means, to claim that in the foreseeable future, we would have to pay for the upkeep and maintenance of these energy systems only, while the actual net energy costs will move more and more towards zero.

It is up to us to campaign for this future. A future in which no global players dictate, but where we are increasingly returning to self-organized structures, meaning that the value chain remains local and the environmental destruction can be put an end to. This is all technically and organizationally possible. All the reasons standing against it, are purely ideological or political.

According to recent estimates, the cost of the Iraq war – which was lead for the country’s energy resources – would be enough to convert the entire US to renewable energies almost completely, thus solving such conflicts once and for all. These dimensions of absolute madness are a blow in the face for all those who use “Wherever would we take the money for this conversion?” as an argument.

It is also a sad mirror of our society that we accept such a cynical, murderous, destructive and contemptuous system and generally perceive it as “normal”. It is our duty to strive for a better future, meaning each and every one of us within their respective possibilities.

Translation into English: Serena Nebo

Credits

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Photovoltaic technology Photovoltaic technology Sakaori (talk) CC BY-SA 3.0