As mentioned on my last article the new Spanish Building Regulations known as the EH1 and the EH0 relate to energy saving in buildings. The EH1limits the total amount of energy that our new and future buildings must use. It divides Spain in different zones allowing those in colder regions such as the central north regions to use more energy for heating or cooling the buildings.
It goes from 15Kw/m2 per year in warm regions like Valencia Murcia etc to 40 Kw/m2 in colder zones. On the other hand the H0 limits the consumption of energy of our buildings in a similar fashion. When I say that all buildings built from year 2020 must consume nearly 0 energy.
Yes you have read it correctly is 0 Kw. Most if not all of the energy consumed in all buildings designed from 2020 onwards must come from renewable sources only.
As a recapitulation of different sources analysed we saw the flowing two:
1. Photovoltaic panels.
We mentioned that the photovoltaic panels are best known system to collect energy from the sun, but are not the only way to harness energy.
2. Thermal: take advantage of the heat.
Thermodynamic solar technology, fruit of the union of the heat and the heat pump, takes advantage of the heat of the wind, the rain and the sun, and work also during the night.
Today we will enlarge on the rest of other renewable sources available to us.
3. Focusing the Sun's rays
The concentration of Solar power (CSP) consists of a large number of mirrors that track the sun and concentrate its heat at one point. Thus generates steam that drives a turbine to produce electricity. These facilities work even at night, since part of the heat is stored in oil or melted salt. Spain is a pioneer in this technology, with plants as a built on the outskirts of Seville.
This system can also be used on a small scale: the micro-CSP. Its design is much more simple and smaller and can be installed on the roof of a tall building, factories or malls.
Photovoltaic concentration (CPV) technology is based on solar cells more efficient than the conventional silicon materials. Being more expensive, cells are very small and mirrors, lenses, prisms, etc., that concentrate sunlight on the cells to increase their power.USA, Germany and Spain are the most advanced countries in the world in this field.
4. Solar ink
Several companies and research groups are working on the development of solar ink. They used new materials, based on nanotechnology, which can be painted or printed on surfaces which convert sunlight into electricity. Consumers could paint their roofs, walls or windows and generate their own power.
5. Solar roof tiles.
Solar roof tiles resemble conventional ones in shape or colour, but also produce electricity or heat. They function as the classical photovoltaic panels, but with new systems and materials, such as Silicon Mono-crystalline or amorphous, to be flexible and can take any form. Several U.S. and European companies are trading this material, it can be found also in Spain, several models already used in cities such as Venice. Their prices are higher and its efficiency is lower than the conventional panels so they are only recommended when aesthetics is a priority.
6. Hybrid systems
Companies around the world tested several hybrid models that unite the best of photovoltaic and thermal to be more efficient. In the Olympic village in Beijing (China). Another hybrid option is the union of photovoltaic's with other renewable systems such as the wind energy.
7. Futuristic: will someday be possible?
Drawing solar power from space? The idea would be to place solar panels in orbit and transmit microwave or laser energy attained to a station on earth for distribution to the network. Their high costs make it unworkable, but increasingly scarce and expensive fossil fuels and the advancement of technology could make it interesting in the future.
Another futuristic idea through to imitate better those life forms that produce energy from the sun: the leaves of the trees. Some researchers are already working on prototypes of artificial leaves and reproducing in laboratory the process of photosynthesis. It is not an easy task, since their apparent simplicity hides a complex system and the technological and economic challenges are great. Something to be looked at in the long term.