INTEGRATED SOLAR-WIND SYSTEM FOR GENERATION OF ELECTRICITY

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I. INTRODUCTION

Geothermal power plants are an established technology to provide base load electrical power generation. In a northern climate, there are two annual peak electrical usage periods, in the summer due to air conditioning and in the winter due to structure heating and low daylight hours. Direct solar systems match the summer electrical load, but they provide almost no output during the cold and dark winter months.

Power is generated while heating this thermal storage in the summer and becomes a very efficient geothermal power system in the winter due to the close location of the thermal storage versus a deep geothermal source and the cold winter climate.



II. CYCLES AND IMPLEMENTATIONS

Due to difference of temperatures in the various seasons, the air flow pattern follows certain changes which change the air cycles.

The cycles studied are:

1) Hot air cycle
2) Cold air cycle

These cycles also vary according to the location. The two implementations studied are:

1) Tropical implementation
2) Arctic implementation



III. CONSTRUCTION
• A tower is built to allow large quantities of air to move across heat exchangers by natural convection due to buoyancy.
• Solar thermal or deep geothermal heat is used to power a heat pump which moves a much larger amount of heat from the air.
• Both the heat from the air and the heat powering the heat pump are stored in shallow heat storage.
• The thermal storage is used to exploit the difference in temperature changes due to day time heating between the air and shallow underground, either day/night or seasonally. In effect this creates a local geothermal source and the low media transfer energy allows for an efficient geothermal power generation system. This source is reliable and may be used for base load electrical generation and structure heating.



VI. ADVANTAGES

• The system is base load electrical generation.
• The solar energy collected is used to move a much larger amount of heat from the air.
• The heat pump system can be powered from multiple sources (solar, geothermal or waste heat).
• This system will be available in sub-zero temperatures and can generate as much power when it is really cold as when it is really hot.
• Due to the reversible cycle, the energy stored or removed from the earth is used in the opposing cycle.


VII. CONCLUSION

Renewable energy sources are mainly concentrated on wind, solar and hydro power. This technique provides a new insight into a lesser used resource. A base load power plant using renewable resource is the need of the hour. The economy of the system may be under question, just as the rest of the renewable energy systems. In the long run, it is definitely to provide continuous generation with low maintenance and conservation or natural resources.