Once you get past the tried and true options like hydro and geothermal, the new options that are figuring the most at present are wind turbines and solar cells. This brief article is about solar cells. They are not a new option. Solar cells have been in use around the world for some time. Like many renewables the key problem is that they only work when the sun is shining so there have to be back up options.
The most usual backup options are:
- Storage of some type, the most obvious is the use of batteries. Another storage option (which to come extent we have already in New Zealand though our hydro system) is water storage which is at a sufficient height for power to be generated using a turbine or similar device.
- The ability to draw on the national grid, i.e. our national power system, when solar cells can’t supply what is needed. Some households are already set up to do this – using power from the system when there is not enough sun to operate the solar cells completely, and also being able to feed power back into the system when the solar cells are generating more than it needed.
Solar cells are particular suitable for remote locations where the power demand is relatively small so not too much back up storage is required, and it would be very expensive to run in a line from the distribution network.
Solar cells are also a good option for our Pacific Islands, where the alternative is probably a diesel generator, as diesel generation is so costly. For example when you fly into Rarotonga, the solar cell arrays you can see are very impressive.
Cost is still an issue with solar cells. They are expensive when you calculate the true cost against the normal supply however, for households who are able to swallow the installation cost, the cost is probably not a huge factor. For many people it is part of a life style choice. If you are building a new house then that is the cheapest time to add solar cells into the roofing design. Certainly once the cells are in place there is no operating cost to speak of.
Something I don’t know, and it may be to soon to ask the question, is that of what the life of a solar cell array will be. For sure there will be a limit somewhere.
What about the future? Of all the renewable options (except/hydro and geothermal) it is the one I think has the brightest future and I think a lot effort is already going into the dual questions of lowering the cost and improving efficiency. I think the effort going in will pay off eventually and then solar cells will really come into their own.
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This is another of Bas Walker’s posts on GrownUps. Please look out for his articles, containing his Beachside Ponderings.