The climate and environment are increasingly suffering from people's high energy consumption - especially in industrialized nations. More and more consumers are now of the opinion that something needs to change here and would ideally like to get by without coal or oil at all. In Germany in particular, it was hoped in the past that renewable energies would lead to a move away from fossil fuels. What does reality look like and can you really live energetically independently?
According to BDEW (Federal Association of the Energy and Water Industry), the new energy sources achieved a feed-in volume of more than 145,800 GWh in 2013. The top three included wind turbines, biomass recyclers and photovoltaic systems. Nevertheless, they canRenewable energiesonly cover around 12 percent of total consumption. Is the desire for energy independence just a utopia? What options are available to a household today and are they achievable? Can energy efficiency also be practiced in your own garden?
Geothermal energy or geothermal energy is based on a simple basic principle: as the depth of a drilling increases, the heat in the drilled shaft increases. An idea can be derived from this. If you introduce cold water into the shaft, warm water can later be taken out for heating purposes.
Natural geothermal energy has several advantages over fossil fuels. This includes, among other things:
– no consumption of the energy source
– no temperature fluctuation (except in the immediate vicinity of the ground)
– Low space requirement due to deep drilling
– the provision of heat and/or electrical energy.
The advantage: At least in the context of building heating, the use of geothermal energy can also be practically implemented on a private scale. For this purpose, a system consisting of a geothermal probe and a geothermal heat pump is used. Anyone who has a garden can take advantage of many advantages and easily install geothermal energy.
The following happens: A cold liquid is circulated into the deep borehole in the garden using the geothermal probe or a surface collector and continuously absorbs heat. The liquid heats up, moves towards the heat pump and can contribute to building heating or hot water preparation.
In addition to the earth, whose usable heat comes from the time of its formation and radioactive decay, the sun is one of the energy sources that are increasingly being tapped today. The advantage: As with geothermal energy, sunlight is available without any mining or processing. The whole thing can be used, among other things, through photovoltaics.
The latter is based on the fact that the photon stream from sunlight mobilizes charge carriers - the electrons - in certain materials and can thus produce electricity. The development of solar cells has now progressed to such an extent that even everyday objects can be powered by sunlight.
In recent years in particular, Germany has experienced a boom in connection with PV systems. LoudEurObserv'ER Photovoltaic Barometer 2015The installation figures from 2010 to 2012 were over seven MW each and an easyCredit survey showed that 81% of Germans would like to generate their own electricity from solar cells. One reason for the increase was the support of the systems through feed-in tariffs. Systems that supplied electricity to the grid sometimes received more than 50 cents per kWh. The tariff rates have now fallen significantly; the fixed feed-in tariffs in August 2015 (depending on the size of the system) amounted to a maximum of 12.34 cents per kWh.
Tip: If you own a large garden house, you can also operate a small solar system on its roof. Of course, it is important to find out about the situation and other local conditions beforehand.
However, solar cells are not the only way to harness the energy of the sun's rays. When it comes to solar thermal energy, homeowners rely on another property of sunlight – the ability to heat a medium. Today, common practice in private settings is the use of flat or vacuum tube collectors.
Their basic functional principle is quite comparable. The collector is aligned towards the sun. When the sun's rays hit the collector surface, their energy heats a carrier medium (such as an H2O-propylene glycol or diethylene glycol mixture), which in turn can be connected to a heat exchanger and heats the building or produces hot water. In this respect, there are some overlaps in the principle of solar thermal energy and geothermal energy.
However, using solar thermal energy requires:
– replacing the heating system
– Construction work on the building roof
– sufficient sunshine duration
– Frost protection solutions (for the winter months)
in advance.
In principle, it is already possible today to supply yourself with thermal energy and electrical power - without relying on power plants and:
- Money
– natural gas or
– Petroleum
to be necessarily dependent. However, this only applies to property owners, as tenants can hardly implement PV or geothermal systems. With a garden, things become even easier because construction work is much easier to carry out. In this context, however, it is always problematic to weigh up the effort and benefits.
There is still room for improvement in the use of geothermal energy. Consideration is always necessary, especially given the costs, which can quickly reach five-digit euro amounts for each area. At the same time, the project should be specifically supported by experts.
Important: Anyone who wants to rely on renewable energy sources must know and comply with official regulations. It should also be clear at this point that operators are exposed to a certain level of system risk. Appropriate insurance is therefore recommended, as not every building insurance adequately covers the risks of such a system.
Challenges at a glance:
– Cost vs. benefit question
– professional installation
– energetically correct conception
– plant-related risk provision
– official regulatory measures (mining law, water law, building law, etc.).
