The energy revolution is underway

At first sight, today's buildings are not very different from those of yesterday. However, in the laboratory and in businesses a genuine change is taking place: with their sophisticated communication devices, their optimized energy efficiency and their increased comfort, these dwellings and offices of tomorrow will offer a radically new living environment.

Responsible for 45% of our energy consumption and 22% of greenhouse gas emissions*, building has become the number one target in the fight to reduce waste. Driven by a formidable stream of innovations (and strongly incentivizing regulations), it is heralding significant changes to our way of life.

Market shares have risen very quickly
Forgotten are the heat sieves of the 1970s: by 2020, legislation will require new dwellings to produce more energy than they consume. Photovoltaic systems will be compulsory! This is not all: the building of the future will adjust its operation in real-time ? it is pointless to heat and light empty rooms. Such a building will be fitted with electronic sensors to measure, regulate and, take care or our comfort and will deploy new automation able to combine different energy sources. Sustainable development will be addressed through the use of recyclable materials... “This will not be a spectacular revolution, because the rate of housing renewal is less than 3% per year, explains Jean-Louis Six, manager of the Smart Building programme at the CEA. But for all the businesses involved the excitement is intense: it is necessary to react quickly to capture market share, which requires discovering new, not well known skills at the CEA". This is the case, for example, in the rapidly rising integrated solar energy market (see page 5). The CEA is well-equipped to meet this challenge thanks to the complementary efforts of three of its institutes. In particular, at the LITEN, the French National Solar Energy Institute (INES) has abilities, which are unrivalled in France, for addressing problems in the fields of energy production, lighting, heat management and the energy consumption of buildings. Through the test bench for solar powered water heating in its life sized, experimental house, it possesses an exceptional set of platforms (see pages 14 and 15). Added to this, the LETI is an authority on sensors, embedded intelligence and communications systems. Inside the building, everything is measured and a response provided: temperature, humidity, lighting level, air quality and air flows and the presence or absence of people. This well exploited raft of data makes it possible to optimize energy management. In order to make all of this discreet, reliable, accessible and effective...

Buildings, energy, telecommunications... global partnerships
Finally, the LIST brings to the table its expertise in algorithms and software tools as well as their integration into systems. Modelling is indispensable for predicting thermal and air-flow phenomena within dwellings, for analysing old buildings before renovation and for comparing technical solutions. Similarly, intelligent management of the raft of data discussed above is achieved using complex algorithms, which form the cornerstones of regulating programs capable of finely tuning energy supply and consumption. “Up until recent times, we have progressed in a rather opportunistic way, remarks Jean-Louis Six. Today, however, efforts are being structured. We assess the skills and test-facilities available, we identify the experts and we prepare a technological roadmap. We are creating a platform, named Helios, which brings together all the issues for buildings. It makes it possible for us to offer certain industrialists a one-stop shop for R&D and design”. But above all, this is not a single monolithic offer: many enterprises, which have already collaborated with the CEA, have brought a wide range of problems. Firstly, industrialists from the construction industry are keen to innovate. They are manufacturing sliding roofs and insulation materials as well as heating, airflow and electrical equipment, or even complete buildings; and they want to integrate more intelligence and/or new energy sources. Then, more unexpectedly, there are the industrialists affected by the economic crisis who are on a quest to find new markets: The CEA has notably provided advise to automotive equipment suppliers on possible adaptations that could be made to their industrial tooling so that it could be used to produce sub-assemblies intended for use in buildings. To these can be added energy producers, who want to choose the correct materials for future solar-power units, or telecommunication companies seeking new applications and services such as ecologically-friendly control of residences, real-time calculation of energy cost or optimisation of the resale of kilowatt-hours produced by the building. And finally, insurers and venture capitalists, who come to the CEA to determine the parameters of this new market. “In the current difficult economic phase, we offer assistance to our industrial partners, whatever their size, by complementing our collaborative R&D proposals with financial and engineering instruments (access to research tax credits, preparation of documents for Oseo Anvar, Fui, etc.) and market analysis, all of which can help them in their approach to innovation. In this respect, our financial strategy expert is often involved in preparation of dossiers. Another shared concern is competitiveness research. The concept of positive energy houses, such as those marketed in Germany for example, is not only of interest to one fortunate customer. Our objectives, in phase with the market, are targeted at around 1,000 euros per m²”, quantified Jean-Louis Six.

A positive energy house for 1 000 €/m2
The priority focus of the CEA work is on the overall performance of the building: energy efficiency, optimal management of electrical and thermal energy, solar devices integrated into the building, sustainable and recyclable materials, etc. This is more difficult than it seems! Hence, the building of the future will have to offer the user simple strategies for energy production and consumption, which take account of local meteorological constraints in the short or medium term as well as his planned consumption of electricity and heat. Another issue is how to best produce, store and use electricity from solar panels on the roof, or forming part of a network, depending on the time and use? How, for example, could we best link solar heating with a gas boiler during the day and night, or during times of moderate or intense cold (see opposite)? “Nothing is simple. everything must be compared, combined and optimised on a case-by-case basis”. The second priority direction for the work is the quality of indoor environments: thermal comfort, air quality and lighting quality. Here again there is no simple approach. Thermal comfort, for example, depends on factors such as temperature, humidity, ventilation and passive contributions from the sun. The automobile industry has a great depth of knowledge on the subject of improving comfort inside a vehicle. One such expert on these matters has recently joined the LITEN to apply his expertise on the scale of buildings.

Sophisticated technologies ... but easy-to-use
Indoor air quality is also a subject with multiple inputs. Indeed, heat, cold, pollutants and humidity are all transported by the air; controlled mechanical ventilation (VMC), which is indispensable, may be responsible for 15% of the thermal losses of a building. “The importance of the air as a carrier it emphasised more each day. We want to make it a speciality”, explains Jean-Louis Six. Finally, lighting quality involves both the developing area of LEDs (see preceding page) and the management of natural light using light-well systems. The third direction for improvement “Buildings suitable for the needs of the occupants”, addresses a vital requirement: the new technologies included in buildings must be usable by all! “We must not forget that the population ages and that everyone wishes to live in their own home for as long as possible, even when they are not well. The building of the future must make life easier” the scientist stressed. Some examples? CEA's laboratories are working on program interfaces which cover the full range; they are working on programs capable of automatic control of the heating functions in a residence so as to improve control of its heating equipment as a function of the weather; on systems to measure and modulate the light intensity of a room according to the requirements at any specific moment; on CO2 sensors and the presence of rapidly installed “plug and play”, etc. The more complex the "hidden" technology becomes, the more simple will be its exposed face: this is certainly the most ambitious challenge for the building of the future.