Hydro energy’s potential may be overlooked because; it is “old” renewable energy, or because like nuclear energy, some hydro electric schemes have been criticized by environmental groups, but most importantly a perception by many, that most hydro electric potential in North America has already been exploited. Hydro electricity deserves more scrutiny because;
1) North America has significant undeveloped potential,
2) the technology is well understood, although technical improvements continue to be made, especially for low head and small hydro,
3) hydro has a very high energy return on energy investment (ERoEI),
4) additional hydro can enable more wind and solar energy capacity to be absorbed by the grid,
5) hydro potential is more geographically dispersed than wind and solar, and finally,
6) the cost of developing additional hydro capacity is moderately low and has very low technical and financial risk.
Energy Net on 25 May 09Jeff Vail has started a series looking at what I've long called the "EROEI hole" problem - making sure we don't leave the transition to renewables too late and find ourselves stuck in a situation where we have shrinking production of fossil fuels which are produced at ever lower EROEI values, thereby making constructing an alternative energy infrastructure a lot more problematic than it would be today - The Renewables Hump: Digging Out of a Hole. In the first post in this series, I introduced the general notion that renewable energy requires an up-front investment of energy, and that this may dramatically impact our ability to transition to a renewable-energy economy because the transition effort will initially exacerbate the very energy scarcity that is its impetus. Beyond this general notion that the transition to renewables first requires exacerbating our current energy scarcity, the time that it takes a renewable source of energy to return the up-front energy invested in it becomes especially critical. Here's a quick example (for the simplicity of these examples, I'm assuming that 100% of energy requirement is up-front with no maintenance requirement):
