You might be interested in the following issues with which I am assisting Shoreline :
ALTERNATIVE ENERGY EVALUATION SITES
Under the guidance of His Royal Highness, Crown Prince Tupouto'a, Chairman of The Board Shoreline Power, studies have been underway for many years to evalute the feasibility of electricity generated from renewable energy sources.
The top of Mt. Talau (130 mtrs AMSL), at the entrance to Vava'u harbour, is one location of a wind recording station for Shoreline Power. Data collecton started in October 2004 and the results since then are promising as the average wind speed has been 8m/sec.
For comparison the long term, average wind speed at Nuku'alofa Harbour is only 3.9 m./sec. Even though the wind speed on the mountain is only double that of normal sea level winds in The Kingdom, the amount of power available from the wind on the mountain is 8.5 times higher than that at sea level.
Power options being evaluated are direct windpower generation or, pumping seawater to a reservoir on the top of the mountain and then generating electricity using hydropower. A large seawater pumped storage hydro-electric station has been operating on the island of Okinawa since 1999.
Wind data has already been collected on Lifuka and Tongatapu Islands but unfortunately, wind speeds are too low for economical wind power generation.
A recording anemometer has also been installed at 300 metres height on 'Eua Island where initial measurments are also promising. Under evaluation there is the feasibility of a pumped storage hydroelectric scheme. Windpower would pump sea water into a large storage reservoir. Water flowing from the reservoir through turbines, at the bottom of the eastern 300m high cliffs, could generate 5 MW of power to be transported by an 11 km submarine cable to Tongatapu Island.
Recent improvements in the technology for harnessing wave power allows us to re-evaluate its potential for electricity generation in the Kingdom.
Other alternative energy sources such as solar, fuel cells and biomass power are not forgotten but unfortunately not cost effective yet.
Any technical comments or suggestions may be made to me.
Peter P. Goldstern
Consultant to Shoreline Power for Feasible Alternative Energy Systems
B.Sc. Hydraulic Engineering, Massachusetts Institute of Technology
M.Sc. Hydraulic Engineering University of Washington
M.Sc. Management Massachusetts Institute of Technology