A new multi-hybrid power sytem for grid-disconnected areas Wind — Diesel — Compressed Air Energy Storage

The power generation for remote areas is historically ensured with Diesel engines generators. The economical cost of energy is therefore very high not only due to inherent cost of fuel but also due to transportation and maintenance costs. The environmental cost of energy is also high as the use of fossil fuels for electricity generation is a significant source of greenhouse gas emissions. The use of hybrid systems that combine renewable sources, especially wind, and Diesel generators, reduces fuel consumption, operational cost and pollution. Adding a storage element to the hybrid system increases the penetration level of the renewable sources, which is the percentage of renewable energy in the overall production, and further improves fuel savings. Compressed Air Energy Storage (CAES) has several advantages for hybrid Wind-Diesel Systems (WDS) due to its low cost, high power density and reliability. To store and restore the CAES, we suggest doing few modifications on the Diesel engine to turn it into a Hybrid Pneumatic-Diesel Engine (HPDE) able to operate with two-stroke pneumatic motor mode, two-stroke pneumatic pump mode and four-stroke hybrid mode. We evaluate in this paper the annual fuel economy generated by this concept, function of the air storage volume and the wind power penetration rate, on a typical remote area.