05-19-2008, 05:08 AM
Hawaii is unique in the world in that it is so near to cold deep ocean water that can be used to generate electricity (Ocean Thermal Energy Conversion) or that can at least be used to displace air conditioning loads for large scale users. However, everything depends on the cost of energy. Eventually energy costs will make many alternative energy sources viable.
However, implementation of OTEC, wind, geothermal, hydropower, etc. is not a trivial challange. There is no way around the fact that fossil fuels are wonderfully easy to obtain and use compared to the alternatives. OTEC would require huge pipes. The originally cold and now only cool water, once cooled, is still a different temperature than the near shore surface waters. It is a waste product that must be disposed of properly in accordance with an NPDES permit. You can no longer get permits to dispose of anything, even cool seawater, into any bay or harbor so the Hilo hotels and condos would face a particularly expensive installation. OTEC would be an excellent baseload like geothermal but would have high initial costs for infrastructure and installation.
Wind is intermittant. I don't buy the line about windmills killing lots of birds unless they are in a migration corridor or other unique circumstance. The big deal is that us energy addicts are so consistantly hungry for a fix that intermittant sources such as wind, solar, wave power, even tidal power, not being continuous and controllable, aren't able to supply our needs. No matter what we will need to modify our needs. The power companies already offer preferred rates for off peak use and even interruptable use, meaning you agree that they can pull the plug on you for short periods without any notice. That's fine if you are filling a water tank in the middle of the night but not so cool for grandpa's iron lung.
Wave power has so far been hard to harness economically. The ocean beats the hell out of things and is notorious for being, if nothing else, highly variable. Also, I would think that surfers would object to draining waves of their energy.
Hydropower is intermittant unless you have a reservoir. Reservoirs are not environmentally benign. They have even been implicated in global warming because they usually replace forest and they generate methane gase in their bottom sediments.
Hawaii doesn't have big shallow tidal flats and doesn't have widely varying tides. I don't see wave power as being a candidate for Hawaii.
Solar is good both for direct heating of water and for PV electricity. I don't know how much energy it takes to produce a solar panel but I understand that now PV panels actually produce more energy over their lifetime than was consumed when they were manufactured. I think that in the past this was not always so. Obviously it is a consideration. Also, for a stand alone system you will need batteries for night time. Batteries are full of lead and acid and are not good for the environment.
I am sure there are other sources I have left out. As you can see, there is no really easy answer. Even burning wood causes deforestation in undeveloped nations. The most green policy for Haiti would be to make sure everyone has a propane stove to cook with. Conservation must play a huge part but will not be the only answer. Imagine going skydiving but forgetting your parachute. You can stick your arms and legs out and slow way down, but unless you can slow down enough..... More than anything conservation will allow us to fit our energy use to the supply that is available.
However, implementation of OTEC, wind, geothermal, hydropower, etc. is not a trivial challange. There is no way around the fact that fossil fuels are wonderfully easy to obtain and use compared to the alternatives. OTEC would require huge pipes. The originally cold and now only cool water, once cooled, is still a different temperature than the near shore surface waters. It is a waste product that must be disposed of properly in accordance with an NPDES permit. You can no longer get permits to dispose of anything, even cool seawater, into any bay or harbor so the Hilo hotels and condos would face a particularly expensive installation. OTEC would be an excellent baseload like geothermal but would have high initial costs for infrastructure and installation.
Wind is intermittant. I don't buy the line about windmills killing lots of birds unless they are in a migration corridor or other unique circumstance. The big deal is that us energy addicts are so consistantly hungry for a fix that intermittant sources such as wind, solar, wave power, even tidal power, not being continuous and controllable, aren't able to supply our needs. No matter what we will need to modify our needs. The power companies already offer preferred rates for off peak use and even interruptable use, meaning you agree that they can pull the plug on you for short periods without any notice. That's fine if you are filling a water tank in the middle of the night but not so cool for grandpa's iron lung.
Wave power has so far been hard to harness economically. The ocean beats the hell out of things and is notorious for being, if nothing else, highly variable. Also, I would think that surfers would object to draining waves of their energy.
Hydropower is intermittant unless you have a reservoir. Reservoirs are not environmentally benign. They have even been implicated in global warming because they usually replace forest and they generate methane gase in their bottom sediments.
Hawaii doesn't have big shallow tidal flats and doesn't have widely varying tides. I don't see wave power as being a candidate for Hawaii.
Solar is good both for direct heating of water and for PV electricity. I don't know how much energy it takes to produce a solar panel but I understand that now PV panels actually produce more energy over their lifetime than was consumed when they were manufactured. I think that in the past this was not always so. Obviously it is a consideration. Also, for a stand alone system you will need batteries for night time. Batteries are full of lead and acid and are not good for the environment.
I am sure there are other sources I have left out. As you can see, there is no really easy answer. Even burning wood causes deforestation in undeveloped nations. The most green policy for Haiti would be to make sure everyone has a propane stove to cook with. Conservation must play a huge part but will not be the only answer. Imagine going skydiving but forgetting your parachute. You can stick your arms and legs out and slow way down, but unless you can slow down enough..... More than anything conservation will allow us to fit our energy use to the supply that is available.