Devons nous acheter Tesla Powerwall ?
A few weeks ago, Tesla announced a home battery, the Powerwall. Now that the excitement has subsided, it’s time for us to answer a few questions and take stock.
Why do you want a battery for your house?
This is probably the first and most important question that comes to mind when we think about Tesla Powerwall. To make a long story short, a battery makes it possible to be less dependent on the power grid. Thus, if you generate renewable electricity at home (solar, wind, …), the battery allows you to store this energy to reuse it later, mainly at night when production stops. The battery also reduces the electricity bill and relieves the grid. Indeed, it allows you to charge at night, when prices are lower, and to use the energy stored during the day when demand is high. It’s a win-win situation, you pay less and the electricity grid is less stretched.
Why would the Powerwall be different from other batteries?
We have always had the option of household batteries. The most common way was to use a lead acid battery, like the ones in our cars. It wasn’t that simple, since you had to connect a large number of cells together, and when one cell was discharged, you had to replace it with a charged one. Also, to get enough capacity, you had to spend a lot of money, it wasn’t pretty, it took up a lot of space, and you had to have a minimum amount of knowledge to take care of it.
The Powerwall seems to want to make this technology more “domestic”, in any case more practical and much more esthetic. It is mounted on the wall and you don’t need to intervene on the elements that make up this battery. And to top it all off, the price of a battery is reasonable, since it is between 3000$ and 3500$, but if the power is not enough, it is possible to couple up to 9 cells.
So all you have to do is buy this battery to power your house?
Actually no, at home we have alternating current, whereas a battery only delivers direct current. This means that we will have to equip ourselves with a device, called a DC-AC converter, in order to convert the current from one type to the other. Thus, to power many household appliances, the battery will deliver direct current, which will be converted to alternating current by the converter, to be transformed into direct current by your appliance. This is illogical, but it works like that, as alternating current is easier to transport, this is the solution that has been chosen, but storage is only possible with direct current, so you have to juggle with these two types of current.
In short, this battery, which is already out of stock, is only one element of a system that is quite expensive to set up. The first purchasers should be owners of solar panels or wind turbines, who already own part of the necessary installation, as well as people who regularly have problems with the power supply. For others, the reflection should be a little longer, time to take stock of the advantages and disadvantages.
More info on the official website.
Source : Wired