Hybrid power generation systems can combine solar, wind, battery and generator power to keep your island hideaway running around the clock and around the year. In many parts of the world, the peak operating conditions for solar and wind power occur at different times of the day or even during different seasons, so a hybrid system is more likely to deliver electricity when you need it. Reserve power (up to three days worth) can be stored in battery banks and a diesel or gasoline generator can be added to the system for those rare island days when there is neither wind nor sunshine.The diagram to the right, from the U.S. Department of Energy’s Energy Efficiency and Renewable Energy (EERE) site shows a simplified Hybrid design.

Hybrid systems are designed to be operated “off the grid” (i.e. not connected to a commercial power distribution system) which makes them ideal for stand-alone operation. Sophisticated electronic controllers manage the multiple power sources and monitor the status of the batteries. If the reserve runs low, the controller automatically starts the generator to supply power and charge the battery bank.

The EERE Web site at http://www.eere.energy.gov/ provides a wealth of information about alternative energy sources, including information on hybrid solar lighting (HSL) - a new technology that harnesses the sun by collecting sunlight and routing it through fiber optic cables where it is combined with electric light in special hybrid light fixtures to provide interior lighting. The Department of Energy estimates that HSL systems will deliver an equivalent amount of light for about 25% of the cost of a completely electric solution.

Many island owners use gas generators as a back-up source of energy on their islands. Gas generators are great for temporary usage and supplying energy for essential needs such as heating or electricity. Before purchasing a generator it’s important that you know what your will need to power and for how long you wish to power it. You may also want to consider the ease of transporting the generator to your island and the amount of fuel you will need to transport to the island for the generator. These two factors may influence the type of generator you purchase. Typically a 900 W generator will power a small refrigerator, seven 60W bulbs and a 200 watt fan. This generator will require 2.53 gallons of gasoline every 24 hours and sells for approximately $790. A 4000W generator can power a coffee maker a full size refrigerator (725 watts); lights a fan and a 750 Watt microwave. Alternatively it could power a well pump. This type of generator would require 11.7 gallons of gasoline every 24 hour and costs approximately $1,000 dollars. An 8000W generator can run a well pump, a coffee maker, a refrigerator, lights, a fan, a microwave, a sump pump and heating equipment (up to 1800 watts). Alternatives the system could run a 32,000BTU air conditioning unit. This type of generator requires about 25 gallons of gasoline every 24 hours and costs about $1,250.