Page 304 - 360.revista de Alta Velocidad - Nº 6

Berrios Villalba, Antonio. Martínez Acevedo, José Conrado. Tobajas Guerra, Carlos. Gómez Alors, Antonio.

KEYNOTE

• Increase the availability of renewable sources (solar, wind, etc.). (Applicable in this
project)
• Increase the efficiency and the rational use of energy in industrial processes

2.4.2 Electrochemical batteries

Devices capable of accumulating power by electrochemical processes. This energy is then
returned almost in its entirety. This cycle will be repeated a number of times, given by the
useful life of the device. There are various types of batteries with different characteristics (lead
batteries, alkaline batteries of manganese, nickel-cadmium, nickel metal hydride, lithium ion,
polymer lithium, etc). This type of battery energy density varies between 30 and 130 WhKg. It
is a secondary electrical generator. Does not produce electricity, but it frees up that has been
previously stored during its load. The number of uploads and downloads will be limited by its
useful life.
ADVANTAGES: higher density power against other geostructural.
DISADVANTAGES: low upload speed and download allowed. (they are not devices capable
of absorbing large ends of power loads or provide downloads without that do not impact
negatively on its useful life). His performance is not very high, on the order of 80, due to
its internal resistance, which is remarkable in the processes of loading and unloading of the
device. Another unfavorable feature is the own self-discharge over time due to the leakage
resistance. Some types of batteries are the so-called "memory effect", in which each refueling
is limited voltage or storage capacity, due to high current, high temperatures, the ageing of
the device, making impossible the use of all its energy. A no less important disadvantage is the
high toxicity of heavy metals taking part in some types of batteries, which constitute a serious
environmental problem. You are trying to reduce this toxicity with replacement by new less
polluting substances. The main existing battery technologies are:

• Lead-acid
• NaS
• NI-CD

• Ni-Mh
• Li-ion

Batteries used in sources of energy energy storage systems renewable are stationary batteries.
They are low content of antimony lead-acid batteries. They have approximately 2,000 life
cycles when the depth of discharge is a 20 (i.e. that battery will be with your load 80) and some
1,200 cycles when the depth of discharge is 50. These batteries have one self-discharge less
3 and an efficiency of 75. They can withstand 80 downloads and have a life of about 15 years.
They are used in installations of great powers. You can get the operating voltage required by the
Association in a number of these devices. Of Li-ion, whose highest densities of power, energy
and higher yields make them more attractive for these applications. In the case of lithium-ion
batteries industrial, have capacities ranging from 4 Ah to 400 Ah, although their prices are well
above the stationary lead-acid batteries.
The main characteristics of these devices are listed below:
• Energy density: 20-100 WhKg

• Power density: 20-200 Walter Kissling GAM

302 360.revista de alta velocidad