This kind of growth is natural at early stages of an innovation. We are at early phases of an S-curve for solar power.
This growth, however, will face some challenges in the years ahead. This is, because:
- Generation of wind/solar power is typically far away from the areas, where the higher population densities are.
- Generation does not happen at the times, when electricity would be most needed in the area, where generation takes place.
A good example of the challenges is the gigantic plan to build solar power plants in Sahara and other location with high solar radiation levels /1/. A relatively small area in Sahara could supply all energy, that Europe needs. The biggest challenge in that project is not, whether the generation capacity can be build. No. Solar power technology exists. There is more, than enough energy. The challenge is, how to transfer the energy from Sahara to the the cities and factories in Europe.
A well known technology to transfer larger amount of electrical energy longer distances is High Voltage Direct Current (HVDC). Technology is relatively mature and big plans exist to build, for example, a European Electrical Superhighway /2/. Longest long distance power line is 1700 km (in Kongo). This technology, however, may not make it possible to reach the goals as set out by the rapid proliferation of geographically distributed large scale solar power production plans. This is, because HVDC is very expensive, it has high amount of losses in very long distances (albeit considerably smaller, than in AC transmission).
Building high capacity DC grids is also important from the point of view of market efficiency. When electricity production and consumption can be further away geographically, trading of electricity becomes more competitive, and ultimately prices to end-users get lower.
The possibility to build low-loss transmission DC lines using superconducting cables has been investigated for a long time. The invention of high temperature superconductors in the late 1980’s was a major step, as it made it economically feasible to build the cryogenic environment needed.
Electric Power Research Institute has made an interesting feasibility study related to the implementation of superconducting DC cables /3/. The present a cable design as follows:
The paper presents quite a convincing story:
- The authors envision a single superconducting cable system, which can achieve 10 GW power capacity. It operates on 100 kV and carries 100 kA. These are huge numbers. Perspective to this is, that a single nuclear power plant can typically produce 1 GW. Thus, a single cable system can take care of the transmission of several nuclear power plants. In deed, huge amount.
- A lot of benefits are seen: less environmenal impact (less pylons in your neighborhood), significantly lower losses, considerably smaller costs, higher reliability.
- The technology seems at such level, that large-scale manufacturing should be possible within the next few years.
My bet is, that by 2020 we see several long distance ultra high capacity superconductive power lines.
/1/ http://www.desertec.org/
/2/ http://www.friendsofthesupergrid.eu/
/3/ http://www.smartgridnews.com/artman/uploads/1/new_epri.pdf
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