Staff members of the Innovation Center of the Physical Institute named after P. Lebedev, RAS (FIAN), under support of the Fund of Assistance to Development of small forms of enterprises in scientific-technical sphere have worked out an autonomous hybrid mini power system MIP-SK, which can provide with electric energy small economic and social objects: villages, settlements, small enterprises and individual residential houses. Andrei Chervyakov, Cand. Sc. (Tech.), a specialist in FIAN commercialization, told about a concluding phase of the project to the Agency of Scientific Information "FIAN-Inform".

The necessity of such sources is most acutely felt by owners of buildings, which are located rather far from basic energy mains. Connection of the house to the general transmission line is a process involving much trouble for owners, while for energy suppliers it results in significant expenses. The matter is that consumption of electricity by population has a vividly expressed "peak" character. Each inhabitant of Russia on average spends approximately 2 kWh of electric energy a day, while in working evening hours almost 10 times more than other time. It turns out that the energy supply company must provide each house with, say, 10 kW electric energy for each inhabitant to be able to use it to fully only twice a day. Such uneven rhythm of consumption tells badly on the service term of the equipment of electric power stations, as in peak hours it functions in maximum modes and so it wears out more rapidly, while for the rest of time the figure is 10 percent.

It is certainly possible to obtain an autonomous electrogenerator, set in motion by an internal-combustion engine. But its functioning under uneven loading is also uneconomical. Besides, parameters of noisiness of such aggregate are, as a rule, rather critical.

There exist advocates of "green technologies", who propagate use of wind generators and solar batteries. However, the former producing electric energy, let out unacceptable noises, especially unpleasant in the infrasound part of the spectrum. Besides, they can be use only in mountains or near the sea, where the wind is constantly blowing. The latter possess low efficiency and also completely depend on weather conditions. Consequently both sources lack stability.

According to Chervyakov, a good example of stable energy supply can become an autonomous hybrid system MIP-SK. "Such installation,-he explained,-can provide electric energy for remote places, without exposing the owners to extreme conditions of life near it. In addition we tried to solve a problem of effective use of resources: the system should produce exactly so much energy as it is required for the consumer in the given moment to avoid charging, say, a mobile phone using the power necessary for the refrigerator, microwave oven and a washing machine in the aggregate."

MIP-SK is designed according to the block-module principle and consists of a direct current accumulator battery with a voltage of 24 V and from 100 to 1,000 A/h capacity (depending on the needs of the consumer)-it is the "nucleus" of electrosupply of the object, 9.9 kW generator of electric energy, actuated by a modernized double-cylinder four-cycle engine of internal combustion air cooling Honda GX-610 with 6.6 horsepower capacity and heavy-current (9 kW) multifunctional inverter.

The main generating force of MIP-SK is a multifuel engine of internal combustion. "It is our pride,-said Chervyakov.-If the existing in the market multifuel power systems really require replacement of one type of fuel by another, depending on its availability, our engine is "omnivorous". It can work using both gasoline and gas

(main or balloon). Besides, according to the results of trials, transfer to balloon gas takes place without a loss of engine capacity as compared with gasoline regime, while transfer to main gas results in power drop by not more than 20 percent. For comparison: a majority of standard engines show in some cases a power drop by 50 percent and more.

Management of the work of energy resources is carried out by means of a controller. "If, for example, for some reason, delivery of main gas is terminated,-explained Chervyakov,-the system automatically transfers the engine to balloon gas. If gas has finished in the balloon (or it is out), the system will automatically passes to gasoline. And backwards-as soon as reserves of balloon gas are refilled or delivery of main gas is renewed, the engine will return to economically advantageous variant of fuel."

Such "omnivorous" character of MIP-SK increases reliability of providing objects with electric energy in case of arising of emergency situations.

The systems of control and management worked out by the staff members of the Innovation Center are today solving a pressing problem of effective use of electric energy and allow to additionally lower fuel consumption. MIP-SK automatically follows consumed power at the exit of energy system. If the load is light, the system works using storage batteries. When the load increases and the battery capacity is not enough, the engine is triggered. When the resource of the storage battery is exhausted, the system automatically sets it to be charged and starts the engine. So, the owner of such equipment will never find himself in a deenergized house.

At the expense of periodization of the engine work and giving up the idea of its constant functioning, its resource is "expanded" and ecological safety of its exploitation is increased. Besides, due to the intellectual and accumulating principle of the unit, it can become a base for use of additional energy sources-the same wind generators or solar batteries. But they will be not main, but auxiliary resources expanding the potentialities of energy system. This will result in maximum decrease of their negative characteristics and will accentuate their indubitable advantages-getting "free" energy, literally from the air.

MIP-SK, weighing ~140-160 kg, has rather modest parameters: 700x600x1,200 mm, i.e. it is a quite mobile module, not requiring special means of delivery. It can be exploited at a temperature from -40 °C to +45 °C.

At present the inspection of efficiency of the existing mockup of the unit is in progress, which will be followed by field trials. The developers are at the same time solving a problem of cleaning up of the worked out fuel, in order to make its characteristics and composition meet the requirements of the standards of Euro-4 and Euro-5. This will increase ecological safety of the aggregate.

In 2012 the Hybrid Mini Power System was highly assessed at the International Industrial Exhibition "Development of the Infrastructure of the South of Russia-IDES".

Ye. Lyubchenko, Energy to Order-Scientific Information Agency "FIAN-Inform", May 2014 Illustrations from the site of FIAN and other Internet sources

Prepared by Marina KHALIZEVA