Google wants to save your energy

The technology giant is investing in the development of technology that will make the use of renewable energies much more efficient and economical. Will she change the world again?

By Dr. Daniel Mader, Zivata, Science and Environment News Agency

In recent years, Google's parent company, Alphabet, has been operating an experimental department that has won the promising name "Company X". The department engages in research in technological fields "outside the box" - that is, those that have low current chances of feasibility but with the ability to greatly influence life and the world. Well-known studies of the Google X-Men include, among other things, Google's autonomous car project and the project to establish a global wireless Internet network whose transmitters are placed on balloons.

In addition to that, Department X also deals with development Energy storage technology, which should solve the main problem of the global electricity sector: the very limited ability to store energy. Although, even today there are small-scale products in this field, such as batteries that convert electricity into chemical energy that is available for conversion back into electrical energy for simple use. However, still There are no means of storing electricity on a large scale (at the level of a city or state). Therefore, the electricity sector relies on the production of electricity in a volume slightly larger than the volume expected for use, in order to avoid situations of usage that exceeds the expectation - in such a case there is a danger to the stable and continuous supply of electricity to all customers. This stability of the electricity grid is almost taken for granted in developed countries, and great efforts are made to maintain it. A significant disadvantage of this method is that, on a regular basis, excess electricity is produced that is not used and is actually wasted.

Dependence on the weather

One of the biggest problems of successful implementation of renewable energies is the fact that most of them do not provide energy in a stable and known amount in advance, because most of them depend on the weather (sun, wind, etc.). Therefore, it is not currently possible to plan the energy economy relying on renewable energies only. New technologies for energy storage seek to solve this problem and prevent the waste of excess electricity that is produced every hour by storing it and using it when needed.

The numbers speak for themselves: in 2013-2010, approximately6.5-11.5 A percentage of the electricity produced each year in Israel. This is unnecessary electricity that is produced on a scale that is roughly equal to all the electricity produced by the Hagit power plant in Carmel (~1400 MW installed, as of 2013) for a year.

Class X focuses on energy storage in the form of thermal energy (heat and cold). The project, called Malta project, including a heat pump that creates temperature differences (potential energy): the heat is stored in molten salt, and the cold is stored in coolant. These materials are kept in thermally insulated containers that prevent the loss of heat/cold to the environment and thus prevent the loss of stored energy. Later, when electricity is needed, the temperature difference between the molten salt and the coolant is used to drive a heat engine that produces electricity from the potential energy and the electricity is fed into the electricity grid.

The principle of operation is similar to a dynamo/alternator in a car, which converts kinetic energy from the rotation of the engine (motion energy) into electrical energy, which is stored in a battery (in the form of chemical energy). Standard batteries make extensive use of precious metals, some of which are not particularly common (like lithium), and some of which are very toxic (like lead) and therefore cause environmental problems. Also, the batteries lose a significant percentage of their efficiency after a few years of use.

Materials are available and cheap

Google's thermal energy storage technology is able to store energy at a high density, and uses available and cheap materials (normal salt and refrigerant) that do not create significant environmental hazards. Also, the system can be recharged with energy in a large number of cycles for decades without a decrease in function. The new system is flexible and the storage capacity of an existing system can easily be increased by adding additional containers.

The main challenges in this technology are maximum prevention of heat/cold loss from the system, the system's resistance to the conditions in which it operates, designing an efficient system with minimum energy loss, and that the complete system will have an attractive price.

Department X built a small prototype to prove the technological feasibility of the project, and its people are currently working on improving the system and connecting it to other systems in order to establish a pilot facility on a larger scale, to prove economic feasibility.