Renewable energy (wind power or solar photovoltaic) in off-grid installations need to accumulate electricity to supply consumption. Batteries are really necessary and essential, but they are expensive and with a limited duration. Luckily there is a lot of research worldwide that can be give economical solutions for rural residents:

Lead – acid batteries. – These are traditional walled containers of lead and acid in it that acts as the electrolyte. They are efficient and easy to find and manage. But lead is an expensive metal, making it difficult to lower prices, both in time and volume. Lead batteries can hardly help to expand popular renewable energy autonomous since they represent a high cost of the system.

Lithium Ion (Li-ion). – The technology of mobile phones and electric vehicles has forced an extraordinary development of Li-ion batteries, which seeks light weight and compact size. So far I do not see as an alternative to isolated farms, due to its high price, only justifiable if it is on a mobile device or in a car.

Nickel-Cadmium, Zinc Air, Nickel-Metal Hydride (NiMH), carbon nanotubes, etc. - There are a variety of developments in batteries to try to increase their performance and gain less weight and autonomy, but for now they are not going to push down prices as expected.

Sodium batteries

This type of battery is specially recommended for the purpose of this blog: the economic accumulation of renewable electricity in agricultural environments. They are economical because raw materials are abundant (to remove the sodium salt, and water from the glass of the battery). Combine with sulfur or manganese, also abundant.

Sodium batteries are long lasting and hold up to 5,000 cycles of loading and unloading with a notable 85% efficiency. Why aren’t  they more popular if they have all these advantages?.

The main drawback of this type of batteries is that they have to work normally at high temperatures from 270ºC (F 518)  to 400ºC (F 752). This can be a security problem, as that could ignite or explode. Some companies are already researching new developments in molten salt batteries more economical, efficient and secure.

The sodium batteries require space and are not portable, but in an isolated rural building which is looking is to build renewable electricity at the lowest possible cost.

What experience do you have with stationary batteries in your country home? Your opinion counts!