QUOTE(Ol Sarge @ Jan 24 2005, 04:04 PM)
I do believe hydro could make a significant impact, not a replacement for major power production but help. Low impact mini power plants as simple as water wheels could do little to affect the flow of water downhill. Work is being done when water flows down hill equal to the work to pump it uphill. Corps of Engineers could capture the work in many locations in levies and use water collection similar to that used in cities collection from reservoirs to create low impact energy reclamation. The simple process of placing water in a pipe at one elevation to a lower elevation creates pressure to produce power. Adequate filtration, like stone and sand traps used in city water purification collection would return the water to the lower elevation without impact. Water under pressure of gravity could run a steam engine in place of steam. To create pressure simply contain the clean water in a pipe to a lower elevation and return it to nature after extracting the energy with no more impact than underground water table.
Unfortunately, it's never that simple. Hydroelectric power generation has arguably been the most ecologically disruptive power generation system humans have ever devised. Changing the patterns of rivers & streams and creating artificial lakes & underground aquifers has had a major disruptive influence on local and regional ecologies. Of course, some of these changes may have been beneficial yet they are not without costs. That said, I agree that there are some clever things which could be done with small, point-source hydroelectric generators. It's important though to consider that you don't get something for nothing. Yes, you could hook turbines to waste water run-off but this will slow down the flow rate of that waste water. This may be a problem on both the front-end and back-end of the system. If the flow rate is too slow, it could pool causing all sorts of problems.
We can get useful energy from gradients in temperature, pressure, volume, radiation, chemistry and gravity. Renewable energy is any energy which we get for "free". We can "intercept" the energy source to use for our needs without significant deleterious effects.
This is the cutting edge to low technology I can relate to. Basic cave man common sense says you won’t freeze in a cave, nor will you get too hot. Residential heat and cooling energy requirements could be reduced to the difference between ground temperature below frost level and outside temperatures with an effective heat exchange system. The initial cost outlay would be great but if you only had to heat from 66F or cool from 66F instead of the outside temperature little energy need would exist.
Yes, we could be much more clever about managing waste heat. Better & smarter materials which insulate our homes could solve some of these problems "passively". For example, if the house is too warm, then shunt the heat into the ground either conductively (heat sink) or convectively (heat pump).
3. Geothermal/hydrothermal power generation. Any time you can get a significant temperature differential, you can get useful energy.
Available sources are on national parks and trial lawyers are keeping the possibility out of sight.
You don't need active geothermal vents to get good geothermal power. In fact, you want to avoid areas like this because of instability. Instead, dig a really deep hole in a tectonically stable area. Run a hose down. Cycle a "working fluid" though the hose (like air or water). Use cool liquid at the start which flows to the bottom and gets hot; it then "boils" back up. Sort of like the opposite of a refrigerator.
On the other hand, hydrothermal power would work like a refrigerator. Build a platform in the middle of the ocean. Run a hose down really deep. Cycle a working fluid through the hose which would cool at the bottom. This creates a temperature gradient.
It all comes down to: PV = kT. Increase pressure: temperature increases and/or volume decreases. Increase temperature: pressure and/or volume increases.
5. Individual/home solar power. Tax incentives would help seed the market here. The idea is to get more home owners to generate at least some of their power locally. Solar tends to help during peak demand hours (like during the summer months).
They have federal law requiring power companies to buy back excess home produced power already. Prez Carter introduced such initiatives and worked until the Iran hostage put people in lines at the gas station and as the door hit him in the butt the solar water collectors panels on troop barracks for the 82nd Airborne Div. were removed and sold for scrap. I use solar hot water and PV panels and battery bank for power outages but the cost of storage batteries and PV panels eliminate consideration as an energy source. BP, British Petroleum of all sources uses solar power for all of their gas stations in Europe and sells the PV systems. Go figure?
Yes, the power companies must buy back the power. Unfortunately, this doesn't seem to be enough incentive for most people to outlay the costs of installation. Tax incentives help smooth this out. Of course, once the market is sufficiently "seeded", then remove the incentives as they will be no longer necessary. Keep in mind, that power companies benefitted from massive government funding in the early and mid-20th century.
2. Hydrogen fuel. Convert other types of energy into hydrogen fuel. Keep in mind that it takes energy to produce hydrogen fuel. A renewable energy source to create hydrogen is what we want.
I think hydrogen fuel could be economically produced with waste power. Like water flowing down hill we have millions of vehicles hauling millions of tons of cargo traveling down hills. The same energy is wasted in brake HP as is used in going up the hill with the heavy load. Trains and transport trucks could have breaking HP capture energy with generators resistance controlled by a rheostats instead of friction or engine back pressure the “work” of slowing the load would be transferred to the energy grid similar to a cable car to produce energy for hydrogen production. Think Rocky Mountains! Hydrogen production with oil is still almost an equal trade off.
Regenerative power is a good thing, however generating hydrogen from it is probably not the most efficient means of storing that power. It's much easier to store the regenerative power as electrons inside batteries or as mechanical energy inside flywheels. Generally, for transportation related power regeneration you're going to use that energy right away (on the next hill). Not only is hydrogen production is too lossy to make this viable but you'd have to carry water along to generate the hydrogen. That extra weight would make such a system highly inefficient.