Questions we may ask ourselves are: Do I need a car? Home much gasoline is consumed by my car on a 100 km? Could I take my bike to work? How much energy do I use for my heating? Are the walls of my flat insulated? Could I use a renewable source of energy for my heating and warm water demand? Where does my food come from? Do I need to eat apples in May when they are only growing on the other half of our planet? Do I spend my vacation far away and travel with airplanes?
Whenever we are moving, whenever we are eating, whenever we are heating - we always consume energy.
We drive approximately 10.000 km with our VW camper every year. We decided to live close to the city to have a short commute and I take the bike to work nearly every day. I have invested in a pedelec which allows me to reach work quickly and without pollution. We buy our vegetables and fruits form a local farmer who brings the food every week by bike (this service is quite unique in Freiburg I believe). We avoid eating very much meet. In 2014 we moved into our new house which was build on the principles of sustainability. The walls are from aerated concrete which provides a high insulation. Lightning is by LEDs, the washing machine and fridge follow high energy efficiency standards. The house has a geothermal heating system. Water is pumped 190 meters below the ground to capture natural heat and transfer it to our floor and wall heating system by the use of a heat pump (highly efficient heatpump from the company Waterkotte). As can be seen on the left photo, this heatpump uses 1 kWh of electricity to create 6.4 kWh of heat for the floor heating and 4.3 kWh of heat for warm water. The electricity is provided by our own photovoltaic modules on the roof and again the picture on the left shows that between July 2014 and September 2016 a total of 7619 kWh where delivered to our house and 9031 kWh were fed back into the grid. In other words, the house produces more energy than we consume. In summer we use the comfort of floor cooling by running the heating system in the opposite direction and transferring heat energy into the ground. This house has a very high living comfort at low consumption and there is no chimney which pollutes the air of our neighborhood.
But we also sometimes take a plane to enjoy seeing other countries and cultures. I believe that suffering can not be a prerequisite for a responsible and sustainable living. We should use our brain and knowledge to avoid wasting resources and create technological solutions to provide sufficient power to our dreams and desires.
Saving energy in our homes can also save significant amount of money. Insulation of walls and windows pays back in short period of time. If you have some money to invest, think about saving energy. Energy prices will increase but reducing your consumption will make you independent. We have invested 20.000 € additional for the PV and heating technology of our house compared to the standard of gas heating. This results in low running costs which are below 100 €/month. Taking into account how important it is for our children to reduce emissions, this investment is definitely worthwhile.