Meet the new invention of the 21st century. It is a solar heater. The basic principle is pretty simple: water is stored in a bed-sized floating bag, which looks like this:
The Sun’s light passes through the transparent plastic, heats up the water inside the black tubes, and then it’s passed on to the heating devices in your home, like in the schematics below. Words are not necessary, since an image values all of them:
An English company, IDC, has announced plans to mass-produce this inflatable solar panel and make it commercially available for less than 100 pounds ($200). The SolarStore panels, which inflate from a backpack into a 2 meter square, are designed to replace hot water heaters, one of the primary consumers of power in most households. This means that you could just heat water anytime you want using these instantly inflatable solar panels.
While other heating systems can take up to 20 years to cover their investment, this one covers itself in about 6 months. They are meant to be used in developing countries, where energy economy is really an issue (where isn’t energy an issue nowadays?)