Alternative Energy at Work

The problem with electrical energy is it cannot be stored in large quantities,economically. So we can store compressed air from compressors driven by wind power and use to drive air motors and generators as well. Another way is to reduce energy consumption by reduce,reuse,recycle water and electricity. Also by harvesting rainwater we can reduce energy used in water treatment plants. In rainwater downpipes in buildings as well as in storm water even in sewerage mains we can install micro hydro/mini hydro generators. Switching off "vampire power" will save a lot of energy. Generating in small quantities by wind/solar locally is more economical as there are no transmission and distribution losses as in HV lines,substations,cables etc.

"The problem with electrical energy is it cannot be stored in large quantities, economically."

Perhaps this is true when using chemical storage; but when considering large scale pumped storage this is not the case; especially where the geographic location allows close access to any large body of water and close proximity terrain with significant elevation in relation to the body of water.

Pumped storage solves the variable supply problem for solar, wind and tidal generation. Variable production is no longer an issue when power can be produced at a constant average rate by pumping to the storage reservoir during peak production and using the pumped storage to drive turbines at a constant output.

In a few small scale applications, pumped storage has been used in the US for decades. In large scale applications, where stream flows are adequate, the reservoirs can also be used for irrigation, recreation, and other purposes.

The motors, pumps, and water turbine generators used in pumped storage processes are relatively high efficiency devices; much higher than the heat engines used to power our transportation conveyances and power production facilities.

As it has always been; the best way to improve the economics and global dynamics of energy use is to increase end use efficiency.

An example of this is in kinetic recovery - regenerative capable transportation processes. When looking only at the kinetic recovery the radical increase in end use efficiency can be easily overlooked. Why - Because the relatively low efficiency of the power production is not factored into the equation.

Let us assume a high overall efficiency for an internal combustion engine based transportation or electrical generation system. We will use the figure of 25 percent for the overall efficiency. We will calculate this efficiency factor as the applied energy (w) / the input energy (E) where the efficiency factor EF = W/E. Since we are using combustion fuels in our Internal Combustion Engine or Electrical Power Plants the Energy input is equal to the combustion energy of the fuel.

Because the efficiency factor is given as .25; for each 1 unit of work performed 4 units of combustion energy must be consumed. It then follows that in Kinetic Recovery processes for each unit of kinetic or gravitation energy recovered 4 units of combustion energy is saved. It is for this reason increasing end use efficiency gives such a good return on investment.

The return multiple is even greater for electrical lighting because of even lower "at the plug" efficiencies.

Gavilan

Pumped storage is possible only if there are rivers,how many regions,countries have rivers?.

Water usage in pumped storage can be limited to evaporative losses and seepage losses only.

You are correct; pumped storage would probably not be practical in arid regions where there is not enough seasonal runoff to support evaporative losses; or where variations in elevation do not allow for efficient application. Those areas are few. There are many more areas where pumped storage would work splendidly.

There are also a number of recent projects using rotational kinetic storage (flywheels) for peak demand applications. These systems could be used anywhere.

As always - economics drives technology. I pay 12 cents per KWH for my electricity. On one of the islands I visited the cost was 38 cents per KWH. That is a huge variation in price. Although a channel tidal turbine with small scale pumped storage or Rotational Kinetic Storage may not make economic sense where electricity is cheap; it might be quite competitive in places where electricity is very expensive.

Tidal power is a very predictable and dependable type of hydro-kinetic power in both scale and time, and makes the design of the pumped or rotational kinetic storage much less problematic.

The great thing about grid based electrical power is its "portability." Solar power could be produced in a desert and then used to power pumps in a pumped storage facility many miles away where a single season's runoff of a relatively small stream or river could supply the water for several years of use. Again; where the power and supply reservoirs are used solely for pumped storage the only water "use" is the evaporative and seepage losses.

The challenges of variability in solar, wind, and hydro-kinetic power production processes can be met. Although quite expensive (now) on the front end, the operating costs over the long term are far more favorable than Coal, Oil, Gas or Nuclear Power; and the total potential power is huge.

The challenges are more political than technical.

Gavilan

I have been sure there are better ways to save Rain water... I See the Water ways in Los Angeles, Near Flooded, every time it rains... going to the ocean!